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Davisburg Mill Pond Dam Feasibility Report Final Submittal Project number: 60594641 August 7, 2019

Davisburg Mill Pond Dam Feasiblity Report August 7, 2019

Project number: 60594641

AECOM

Prepared for: Oakland County Parks 2800 Watkins Lake Road Waterford, Michigan 48328 Charter Township of Springfield 12000 Davisburg Road Davisburg, Michigan 48350

Prepared by: AECOM 27777 Franklin Road Suite 2000 Southfield, Michigan 48034 aecom.com

Copyright © 2019 by AECOM

All rights reserved. No part of this copyrighted work may be reproduced, distributed, or transmitted in any form or by any means without the prior written permission of AECOM.



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Table of Contents

1. Introduction ......................................................................................................................................... 8 1.1 Feasibility Study Process ......................................................................................................... 9 1.2 Previous Studies ..................................................................................................................... 10

2. Site Assessment ............................................................................................................................... 12 2.1 Existing Condition ................................................................................................................... 12 2.2 Topographical Survey and Base Map ..................................................................................... 13 2.3 Bathymetric Survey ................................................................................................................ 15 2.4 Constraints .............................................................................................................................. 17

3. Dam Disposition Alternatives ............................................................................................................ 17 3.1 Maintain Existing Spillway Alternatives................................................................................... 18 3.2 Replace Existing Spillway Alternatives ................................................................................... 18 3.3 Dam Removal Alternatives ..................................................................................................... 20 3.4 Additional Features ................................................................................................................. 25

4. Hydrologic and Hydraulic Analyses .................................................................................................. 26 4.1 Existing Hydrologic Information .............................................................................................. 26 4.2 Model Setup and Assumptions ............................................................................................... 27 4.3 Hydrologic and Hydraulic Modeling Results ........................................................................... 27

5. Ecological and Environmental Assessment ...................................................................................... 28 5.1 National Environmental Policy Act (NEPA) ............................................................................. 28 5.2 Applicable Regulatory Requirements and Coordination......................................................... 29 5.3 Environmental Consequences of Alternatives ........................................................................ 30

6. Funding Grant Sources ..................................................................................................................... 41 6.1 Dam Modification Funding Sources........................................................................................ 41 6.2 Dam Removal Funding Sources ............................................................................................. 41 6.3 Road Funding ......................................................................................................................... 43

7. Conceptual Construction Cost .......................................................................................................... 43 7.1 Maintenance Costs ................................................................................................................. 45 7.2 Potential Life-Cycle Costs ...................................................................................................... 45

8. Assessment of Alternatives ............................................................................................................... 47 8.1 Non-Monetary Factors ............................................................................................................ 47 8.2 Monetary Factors .................................................................................................................... 48 8.3 Rating Criteria and Decision Matrix ........................................................................................ 48 8.4 Public Engagement Process .................................................................................................. 49 8.5 Conclusions ............................................................................................................................ 49

9. References ........................................................................................................................................ 50

Appendices

Appendix A: Sediment Volume and Sampling Survey (MDEQ)

Appendix B: Survey and Layout (AECOM)

Appendix C: Hydraulic Report (AECOM)

Appendix D: Detailed Cost Estimates (AECOM)



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Figures

Figure 1. Existing Mill Pond Dam Diagram ................................................................................................... 7 Figure 2. Site Overview Map of Davisburg Mill Pond Dam Area. ................................................................. 8 Figure 3. Downstream Discharge and Waterwheel below Dam. .................................................................. 9 Figure 4. Sampling Locations for MDEQ Sediment Sampling Survey. ....................................................... 11 Figure 5. Grouted Riprap on Downstream Embankment. ........................................................................... 13 Figure 6. Wet Area Downstream of Embankment Near Pedestrian Bridge. ............................................... 13 Figure 7. Property Boundaries Map ............................................................................................................ 14 Figure 8. Topography of the Project Site. .................................................................................................... 15 Figure 9. MDEQ Bathymetric Survey Location and Contour Map. ............................................................. 16 Figure 10. MDEQ Estimated Channel and Profile. ..................................................................................... 17 Figure 11. Comparison of Channel Profiles. ............................................................................................... 21 Figure 12. Proposed Channel Plan Form. .................................................................................................. 22 Figure 13. Profiles for Proposed Channels 1 and 2 (With Elevation Constraints). ..................................... 23 Figure 14. Proposed Channel 1 Configuration. .......................................................................................... 23 Figure 15. Proposed Channel 2 Configuration. .......................................................................................... 24 Figure 16. Examples of Step Pools ............................................................................................................. 24 Figure 17. Proposed Channel Cross-Section. ............................................................................................ 28 Figure 18. Wetland Map of Mill Pond Project Area. .................................................................................... 31 Figure 19. Location of Wells near Project Site. (MDEQ Water Well Viewer 1/24/2019). ............................ 33 Figure 20. Map of Areas of High-Ranking MNFI Sites. (Oakland County Planning, 2000). ....................... 37 Figure 21. Shiawassee Park Spaces. (Springfield Township). ................................................................... 40

Tables

Table 1. Flood Discharge and Volume Estimates from MDEQ. .................................................................. 26 Table 2. Low Flow Estimates from MDEQ (cfs). ......................................................................................... 26 Table 3. Wetland Inventory. ......................................................................................................................... 30 Table 4. Conceptual Construction Cost Estimates ...................................................................................... 44 Table 5. 100-year Life-Cycle Cost Estimates .............................................................................................. 46 Table 6. Non-Monetary Factors Rating Criteria........................................................................................... 48 Table 7. Decision matrix completed by Springfield Township Board at Jun 6, 2019 special meeting. ....... 49



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Definitions

Abutment: That part of the valleyside against which the dam is constructed. The left and right abutments of dams are defined with the observer looking downstream from the dam.

Appurtenant Structures: The structures or machinery auxiliary to dams which are built to operate and maintain dams; such as outlet works, spillway, powerhouse, tunnels, etc.

Conduit: A closed channel (round pipe or rectangular box) that conveys water through, around, or under the dam.

Dam: An artificial barrier generally constructed across a watercourse for the purpose of impounding or diverting water.

Drain; Toe (Drain), Foundation (Drain), or Blanket (Drain): A water collection system of sand and gravel and typically pipes along the downstream portion of the dam to collect seepage and convey it to a safe outlet.

Drainage Area (watershed): The geographic area on which rainfall flows into the dam.

Drawdown: The lowering or releasing of the water level in a reservoir over time or the volume lowered or released over a particular period of time.

Embankment: Fill material, usually earth or rock, placed with sloping sides.

Filter: The layers of sand and gravel in a drain that allow seepage through an embankment to discharge into the drain without eroding the embankment soil.

Foundation of Dam: The natural material on which the dam structure is placed.

Freeboard: Vertical distance between a stated water level in the reservoir and the top of dam.

Gate; Slide, Sluice, or Regulating: An operable, watertight valve to manage the discharge of water from the dam.

Hazard Cassification: A system that categorizes dams (high, significant, or low) according to the degree of their potential to create adverse incremental consequences such as loss of life, property damage, or environmental impacts of a failure or misoperation of a dam.

Head: Vertical change in elevation between the head (reservoir) water level and the tailwater (downstream) water level.

Height, Dam: The vertical distance between the lowest point along the top of the dam and the lowest point at the downstream toe, which usually occurs in the bed of the outlet channel. Also referred to as Structural Height.

Hydrograph; Inflow or Outflow: A graphical representation of either the flow rate or flow depth at a specific point above or below the dam over time for a specific flood occurrence.

Inlet Structure: The structure on the upstream side of the dam through which water flows through to enter the conduit.

Piping: The progressive destruction of an embankment or embankment foundation by internal erosion of the soil by seepage flows.

Reservoir/Impoundment: The body of water impounded or potentially impounded by the dam.



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Riprap: A layer of large rock, precast blocks, bags of cement, or other suitable material, generally placed on an embankment or along a watercourse as protection against wave action, erosion, or scour. Can be grouted in place (Grouted Riprap) to provide additional protection against erosion.

Seepage: The natural movement of water through the embankment, foundation, or abutments of the dam.

Spillway; Auxiliary or Emergency: The appurtenant structure that provides the controlled conveyance of excess water through, over, or around the dam.

Spillway Capacity: The maximum discharge the spillway can safely convey with the reservoir at the maximum design elevation.

Spillway Crest: The lowest level (elevation) at which reservoir water can flow into the spillway.

Storage: The retention of water or delay in runoff either by planned operation, as in a reservoir, or by temporarily filling the overflow areas, as in the progression of a flood crest through a natural stream channel.

Tailwater: The body of water immediately downstream of the embankment at a specific point in time.

Toe of Dam: The junction of the upstream or downstream face of an embankment with the ground surface.

Top of Dam: The elevation of an embankment that can safely impound water behind the dam.

Valve: In general, a device fitted to a pipeline or orifice in which the closure member is either rotated or moved transversely or longitudinally in the waterway so as to control or stop the flow.

Weir: A low dam or wall built across a stream to raise the upstream water level or to control overflow. Can be termed a fixed-crested weir when stationary. A structure built across a stream or channel for the purpose of measuring flow, sometimes described as a measuring weir or gauging weir. Types of weirs include broad crested weirs, sharp crested weirs, ogee weirs, and V-notched weirs.



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Figure 1. Existing Mill Pond Dam Diagram

Davisburg Mill Pond Dam Feasiblity Report


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1. Introduction The Mill Pond Dam is located on the upper Shiawassee River in Davisburg, Michigan (Figure 2). The upper Shiawassee River watershed is generally characterized by rolling ground moraines, agricultural land use, and small oak-hickory forests. Upstream of the Mill Pond Dam is a wetland complex and an additional dam that forms the Davisburg Trout Pond (which is scheduled for removal in 2020). Downstream of the Mill Pond Dam is the Shiawassee Basin Preserve, an extensive wetland complex encompassing the downstream Shiawassee River and its path through Davis Lake to Long Lake. Davisburg Road passes over Mill Pond Dam near downtown Davisburg.

Figure 2. Site Overview Map of Davisburg Mill Pond Dam Area.

Rotary Park is owned and managed by Oakland County Parks and Recreation (OCPR), and Mill Pond Park is owned and managed by the Charter Township of Springfield (referred to herein as Springfield Township). The Mill Pond has been jointly managed by both OCPR and Springfield Township, with both entities sharing in invasive species management, and Springfield Township providing public access via Mill Pond Park. The Mill Pond Dam is jointly managed and maintained by OCPRC and Springfield Township via an inter-local agreement signed in 2015. The agreement, based on the 1984 property deed, stipulates that OCPR and Springfield Township will work together to reach a consensus for all work on the dam, including the service, repair, and maintenance of the dam. Per this agreement and based on each party’s proportional share of property frontage on the Mill Pond, OCPRC is responsible for 55% of the financial obligation and Springfield Township is responsible for 45% of the financial obligation.

The Mill Pond Dam was originally constructed in 1835 for the purpose of powering a mill. Mill operations have long since ceased and was demolished in 1948 due to its deteriorating condition, and the remaining dam now creates a recreational impoundment. This impoundment creates fish and wildlife habitat as well as limited opportunities for swimming and boating. Springfield Township developed and maintained a swimming beach for a number of years. However, the functionality and aesthetics of the swimming beach were impacted by the presence of aquatic vegetation and sedimentation that reduced recreational enthusiasm for swimming and wading. The Township previously mechanically and chemically treated the pond to reduce the presence of aquatic vegetation, but this practice was changed to chemical treatment only in 2016 due to the potential to spread starry stonewort, the costs involved, and the limited benefit to beach users.



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The spillway for the Mill Pond Dam was largely reconstructed in 1984. The Mill Pond Dam consists of a 375-foot long earthen embankment and a steel and concrete drop inlet spillway. The structural height of the dam is 16 feet. The dam maintains approximately 14 feet of head, with 2.4 feet of freeboard, and creates a 20-acre impoundment under normal flow conditions. Water discharges through a 4-foot wide drop inlet, into a 36-inch diameter corrugated metal pipe (CMP) outlet, and over a 10-foot long concrete water feature and water wheel before dropping 5 to 6 feet and discharging into the downstream Shiawassee River (Figure 3).

Figure 3. Downstream Discharge and Waterwheel below Dam.

Davisburg Road sits atop the earthen dam embankment. Davisburg Road is a two-lane county road that runs east-west between Independence Township, Springfield Township, and Rose Township. The downstream face of the Mill Pond Dam embankment is comprised of grouted rounded cobbles and boulders that appear to be one to two layers thick.

All elevations within this report refer to the North American Vertical Datum 1988 (NAVD 88).

1.1 Feasibility Study Process The feasibility study process includes engineering and scientific analysis as well as public engagement opportunities. The technical evaluation provides information to decision makers on the expected functionality, risks, maintenance, dimensions, materials, and cost of the proposed solutions (dam repair, modification or removal) and the public engagement process provides input on the public sentiment towards the project. This project held two public information meetings in Springfield Township (March 5, 2019 and May 22, 2019). At both meetings a presentation was given of the feasibility study purpose and progress and time was given for open public comment and questions. Prior to the second meeting the draft feasibility report was made available to the public on the township website. These public information meetings provided the board with feedback from the community prior to the Springfield Township Board special meeting (June 6, 2019) where board members assessed the alternatives presented in this report. In addition, the Oakland County Parks Department and Commission was kept informed on the progress and outcomes of the feasibility study. Presentations were provided to the Oakland County Parks Commission on June 5, 2019 and July 10, 2019.



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1.2 Previous Studies AECOM utilized two previous studies in developing this report. The results of these studies are summarized below.

1.2.1 2011 Preliminary Evaluation Report Mill Pond Dam (SME) The 2011 preliminary dam evaluation conducted by Soil and Materials Engineers, Inc. found several potential issues with the dam’s earthen embankment and spillway:

Erosion and deterioration were noted along the concrete discharge channel. The evaluation suggested removing and replacing the discharge channel.

A deflection or sag within the outflow pipe. The evaluation also noted that the outflow pipe dates back to at least the early 1980s and is likely at the end of its recommended service life.

Inadequate spillway capacity. The evaluation notes that currently the road and grouted riprap slope act as the overflow spillway and will overtop during the 100-year event. Overtopping occurred in 1975, 1981, and possibly 1982.

“Spongy areas” or “springs” in Rotary Park, downstream of the dam embankment.

Cracks and voids in the grouted cobbles and boulders that comprise the downstream slope armoring. Undermining of the grouted cobbles and boulders has occurred along the embankment and at the toe of the slope.

The presence of trees on the upstream slope of the dam.

1.2.2 2018 Sediment Sampling Survey (MDEQ) The Davisburg Mill Pond, Oakland County, Sediment Volume and Sampling Survey, GSS Job #629 was performed by the Department of Environmental Quality (DEQ), Remediation and Redevelopment Division’s (RRD’s), Geological Services Section (GSS) on June 13 and 19, 2018 at the subject site (Figure 4). The DEQ collected 10 sediment samples at 10 locations and analyzed these for heavy metals, polycyclic aromatic hydrocarbons (PAH), and biological oxygen demand (BOD). The sampling locations included areas near the edges as well as throughout the deeper sections of the impoundment. These locations included areas expected to include larger particles (such as the delta) and finer particles such as silts and clays.



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Figure 4. Sampling Locations for MDEQ Sediment Sampling Survey.

NOTE: Yellow points indicate push-probe survey locations for sediment depth, red points indicate locations where a sediment sample was collected for analysis, MDEQ 2018.

Analytical results for the collected samples were compared to applicable Resource Conservation and Recovery Act (RCRA) Region 5 Ecological Screening Levels (ESLs), and MDEQ residential and nonresidential soil criteria and risk-based screening levels (RBSLs) for the select USEPA Methods target analyte list. No criteria exceedances of PAHs were detected in any of the sediment or quality analysis and quality control (QA/QC) samples submitted to the lab. None of the samples exceeded MDEQ residential soil criteria for any of the analytes. Selenium was detected in DMP-1 at 3.0 mg/kg above the aquatic life and wildlife screening levels of 1.9 mg/kg; however, the result was flagged due to Selenium also occurring in the QA/QC blank sample. Selenium is a naturally occurring chemical element. While trace amounts are needed for cellular function in many organisms, selenium is toxic in large amounts. Selenium can leach into waterways and wetlands from agricultural runoff, landfills, coal flue ash, mining and metal smelting, and crude oil processing. Biochemical Oxygen Demand (BOD) was detected above the 250 mg/L value outlined in the WRD Policy for Sediment Testing and Dredging Projects in samples DMP-2, DMP-8, and DMP-10 (MDEQ 2018). BOD is a measure of the amount of dissolved oxygen required by aerobic organisms to break down the organic material present in a given sample. As the organisms consume the organic material they also consume oxygen, if organic material content is high, then dissolved oxygen can be used faster than it is replaced.

No other exceedances of relevant DEQ criteria occurred in the samples collected. Most relevant to this project are the criteria for the Probably Effects Criteria (PEC) for consideration of potential impacts on aquatic organisms and Residential Human Health Criteria for Soil. Also of potential concern are the high BOD levels recorded in 3 samples. Sediments with high BOD can have adverse impacts on oxygen in the water column and aquatic life if large volumes are released downstream in a short period of time.

All sediment quality data is included in Appendix A.



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2. Site Assessment

2.1 Existing Condition AECOM conducted a site inspection of Mill Pond Dam on October 24, 2018. AECOM noted the following deficiencies as part of this inspection:

The outlet pipe is manufactured from corrugated metal pipe. CMP is prone to corrosion. Based on the video inspection completed by the Oakland County Water Resources Commissioner in November 2015, it appears that this outlet pipe is close to the end of its service life. This video notes that the existing outlet pipe has a deformation in the crown of the pipe that reduces the flow area by approximately 30%. This deformation also affects the structural integrity of the outlet pipe. Due to the age and deformation of this outlet pipe, AECOM recommends that this outlet pipe be removed and replaced.

Mill Pond Dam is classified by MDEQ as a “low” hazard dam and, consequently, must be able to pass the 100-year flood to meet MDEQ regulations. The existing spillway system does not have the capacity to pass the 100-year flood. AECOM recommends the capacity of the existing spillway system be expanded to meet MDEQ regulations.

Several wet areas were noted downstream of the dam. These wet areas have been studied and documented as part of other inspection reports. AECOM understands that these wet areas have been present at the dam for many years. AECOM recommends that these wet areas be inspected on a monthly basis and after large precipitation events to ensure that the flow from these wet areas does not change in quantity or turbidity.

There are also several minor maintenance issues that need to be addressed. AECOM noted the presence of rodent holes and woody vegetation on the upstream face of the embankment. AECOM recommends the rodent holes be filled in and the woody vegetation be removed.

AECOM did not operate the existing spillway gate, although the gate appears to be in good condition overall. The existing spillway gate was last inspected by Hubble, Roth, and Clark in 2017. This inspection revealed that the sluice gate seals should be replaced.

AECOM also inspected the drop inlet and the upstream sheetpile wall. Both the drop inlet and upstream sheetpile wall appear to be in fair condition.

Photographs from the AECOM site inspection are presented in Figure 5 and Figure 6.



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Figure 5. Grouted Riprap on Downstream Embankment.

Figure 6. Wet Area Downstream of Embankment Near Pedestrian Bridge.

2.2 Topographical Survey and Base Map AECOM has collected additional survey data needed for the feasibility study. This effort focused on topographical data of the earthen embankment, dam appurtenances (inlet/outlet works, energy dissipation structure, etc.), roadway, toe of the dam and several elevation points around the impoundment. A map of additional survey work can be found in Appendix B. A topographical LiDAR generated map of the project area can be seen in Figure 8. In addition, surveys of critical cross sections along the Shiawassee River were collected. These cross sections are used in the hydraulic analysis. A total of nine cross sections were collected from locations above the impoundment and below the dam.

Additionally, AECOM conducted a deed and title search on the dam site and the properties abutting the impoundment to determine land ownership issues. Specifically, this search included a review of property boundaries and flowage easements. At this time, no flowage easements were found. Figure 7 shows the property boundaries as described in the deeds and titles for properties surrounding the dam site and impoundment.



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Figure 7. Property Boundaries Map



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Figure 8. Topography of the Project Site.

2.3 Bathymetric Survey The Davisburg Mill Pond, Oakland County, Sediment Volume and Sampling Survey, GSS Job #629 was performed by the Department of Environmental Quality (DEQ), Remediation and Redevelopment Division’s (RRD’s), Geological Services Section (GSS) on June 13 and 19, 2018 at the subject site. The survey included 139 push probes on a grid throughout both impoundments (see Figure 9 and Appendix A).

Elevation



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Figure 9. MDEQ Bathymetric Survey Location and Contour Map.

The total volume of soft sediment calculated to be in the impoundment was 84,745.5 cubic yards. The volume of soft sediment above the DEQ estimated channel and floodplain that would be expected to mobilize if the dam were removed was calculated to be 17,094.3 cubic yards (MDEQ, 2018). The MDEQ sediment assessment assumed a 15-foot wide channel with 10 feet of floodplain on either side (20 feet total), at a uniform slope of 0.379% through both segments of the impoundment (Figure 10 and Appendix A).



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Figure 10. MDEQ Estimated Channel and Profile.

2.4 Constraints These analyses are based on the previous studies and data made available by the client and the MDEQ, as well as additional preliminary/precursory data collected for this study. Constraints for alternatives include the upstream and downstream railroad crossing conditions and elevations, conditions of the dam as noted from previous reports and inspections, the type of sediment and sediment contamination levels within the impoundment, and the accuracy of the sediment depth data from the 2018 MDEQ sediment sampling survey. The elevation of parent bed material may dictate the need for grade control structures or additional protection for railroad and road crossings, as well as the volume of sediment to be managed. If elevations were to constrain the proposed channel bed to the upper soft sediment layer, engineered streambed materials and grade control structures may also be required. Additional sediment depth, composition, and contamination data would be needed to advance a rehabilitated channel design. The conceptual channel design seeks to emulate natural functioning conditions in Shiawassee River both upstream and downstream of the dam impoundment, as well as what appears to be the historical alignment of the Shiawassee River prior to the construction of the Mill Pond Dam.

3. Dam Disposition Alternatives Several alternatives are being considered for this project. These alternatives include spillway maintenance, spillway replacement, and dam removal alternatives. These alternatives are described in this section.

The existing spillway outlet pipe needs to be either maintained or replaced due to the age and deformation of this outlet pipe. Both spillway maintenance alternatives (such as lining the existing CMP spillway outlet pipe with a structural liner) and spillway replacement alternatives (such as removing the existing CMP spillway outlet pipe and replacing it with a new outlet pipe) will be presented. Dam removal alternatives will also be presented.



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3.1 Maintain Existing Spillway Alternatives The purpose of maintenance options is to repair the existing spillway to address structural deficiencies within the spillway outlet pipe and extend the service life of the Mill Pond Dam. It is important to note that these alternatives will not address spillway capacity limitations.

Structural deficiencies within spillway outlet pipes are usually rehabilitated utilizing cured-in-place pipe (CIPP) or sliplining methodologies. In the CIPP methodology, a resin-saturated felt pipe is pulled through the host pipe, and steam or ultraviolet light is used to cure the resin, forming a “pipe within a pipe”. In the sliplining methodology, a smaller diameter plastic pipe is pulled through the host pipe, and the annular space between the two pipes is grouted full.

Both CIPP and sliplining rehabilitation methods were ruled out, however, due to the presence of the significant deformation near the downstream end of the pipe where the upper portion of the culvert is compressed. As previously noted, this deformation blocks approximately 30% of the pipe’s cross-sectional area. CIPP lining requires a maximum deformation of approximately 10%. Sliplining would still be possible, but it would lead to a significant decrease in spillway capacity since the pipe inserted through the culvert would necessarily have a much smaller diameter to make it past the deformation.

As a result of these considerations, the alternatives for maintaining the existing spillway were determined to be not feasible.

3.2 Replace Existing Spillway Alternatives Replacing the existing spillway will correct the existing structural deficiencies of the spillway outlet pipe. Five different sub-alternatives to evaluate replacing the existing spillway were developed. In general, each of these sub-alternatives include:

Replacing the spillway outlet pipe with a new pipe or box culvert. The spillway capacity issue may or may not be addressed depending on which sub-alternative is selected.

Replacing or rehabilitating the downstream discharge channel.

Removing woody vegetation on the upstream embankment slope.

Repairing or replacing and maintaining downstream grouted riprap slope.

Continuing Mill Pond vegetation and invasive species management and maintenance.

These sub-alternatives all include the removal and replacement of the existing spillway outlet pipe. Removing and replacing the existing spillway outlet pipe will likely necessitate temporarily closing Davisburg Road to traffic so that the dam embankment can be removed to facilitate outlet pipe replacement. This road will likely be shut down for approximately 1 to 2 months depending on sub-alternative selected and the means and methods of the Contractor.

Each of these sub-alternatives would likely also include bypass management of stream flow, excavation of the road and fill at the stream crossing, and restoration of the road. These sub-alternatives would also require additional geotechnical investigation of the dam embankment area to ensure acceptable materials/support for the structure.

These alternatives, while conceptual, are intended to meet generally accepted dam safety requirements and have a life span of 100 years.

3.2.1 Replacement Alternative A: Replace Existing Spillway with 36” Diameter HDPE Pipe

This alternative would include removing the existing spillway outlet pipe and replacing it with a new 36-inch diameter high-density polyethylene (HDPE) pipe. This alternative would not address the existing spillway capacity issues. That is, the current level of service for the dam will be maintained and Davisburg Road will still be expected to overtop during the 100-year flood event. The existing grouted riprap would have to be



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maintained for this alternative because the dam would be expected to overtop for flood events less than the 100-year flood event.

AECOM recommends that HDPE pipe be used to construct the new spillway outlet instead of CMP. HDPE is a commonly used pipe type in dams due to its resistivity to corrosion and lack of pipe joints. AECOM does not recommend using CMP again due to its susceptibility to corrosion. This material would be pending approval by the Road Commission for Oakland County (RCOC). Most states prohibit the use of CMP as an outlet pipe material.

To minimize seepage potential along the new outlet pipe, AECOM recommends constructing a sand filter along the new outlet pipe. The filter should extend to both sides of the new conduit and key into the existing embankment dam. The filter should be designed to intercept seepage along the embankment/conduit interface as well as prevent internal erosion of the embankment and filter layers.

3.2.2 Replacement Alternative B: Replace Existing Spillway with Four 48” Diameter HDPE Pipes

This alternative would include removing the existing spillway outlet pipe and replacing it with four new 48-inch diameter high-density polyethylene (HDPE) pipes. This alternative would address the existing spillway capacity issues. MDEQ standards would be met because the spillway would be designed to pass the 100-year flood event. The existing grouted riprap would not have to be maintained for this alternative because the dam would not be expected to overtop for flood events less than the 100-year flood event.

This alternative would also require replacement of the drop inlet. It would not be possible to utilize the existing drop inlet structure because the current configuration does not have sufficient lateral space to accommodate four 48-inch diameter culverts.

To minimize seepage potential along the new outlet pipe, AECOM recommends constructing a sand filter along the new outlet pipe. The filter should extend to both sides of the new conduit and key into the existing embankment dam. The filter should be design to intercept seepage along the embankment/conduit interface and prevent internal erosion of the embankment and filter layers.

3.2.3 Replacement Alternative C: Replace Existing Spillway with a 10’ by 4’ Box Culvert

This alternative would include removing the existing spillway outlet pipe and replacing it with a new 10-foot wide by 4-foot tall box culvert. This alternative would address the existing spillway capacity issues. MDEQ standards would be met because the spillway would be designed to pass the 100-year flood event. The existing grouted riprap would not have to be maintained for this alternative because the dam would not be expected to overtop for flood events less than the 100-year flood event.

This alternative would also require replacement of the drop inlet. It would not be possible to utilize the existing drop inlet structure.

To minimize seepage potential along the new box culvert, AECOM recommends constructing a sand filter along the new box culvert. The filter should extend to both sides of the new culvert and key into the existing embankment dam. The filter should be design to intercept seepage along the embankment/culvert interface and prevent internal erosion of the embankment and filter layers.

3.2.4 Replacement Alternative D: New Bridge This alternative would include constructing a new bridge over a new overflow spillway. The existing outlet pipe would be removed and replaced with a new overflow spillway, which would consist of a cast-in-place concrete weir with a stepped chute to allow water to flow into the Shiawassee River. The overflow spillway would have a width of approximately 20 feet.

A bridge would be constructed to allow vehicular traffic to cross over the spillway. The bridge would be comprised of a deck, with a spanning superstructure and a substructure made up of supporting abutments



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and piers. This bridge would be the replacement alternative with the highest initial cost and most complex design requirements. By requirement of the Michigan Department of Transportation, the structure would need to be maintained and inspected as a bridge because the span would likely be greater than 20 feet. As with the above alternatives, a geotechnical investigation of the soils would be needed to ensure proper foundation design and support.

This alternative would require considerable coordination and agreement with the Road Commission for Oakland County as the long-term inspection requirements, maintenance, and repair would likely fall under their jurisdiction.

3.2.5 Replacement Alternative E: Raise Embankment This alternative would include raising the embankment to a height that would impound the 100-year flood to protect the areas downstream. Based on the hydrologic and hydraulic model developed by AECOM, the top of dam elevation would have to be raised by approximately 10 feet to impound the 100-year flood.

Raising the embankment by this amount would induce flooding upstream of the dam. The Mill Pond Park Community Center would suffer flood damage during major flood events for this alternative. Permitting a rise in the flood flow elevation within Mill Pond Dam would require the approval of affected landowners and permit by the MDEQ. This alternative was eliminated from consideration due to these impacts.

3.3 Dam Removal Alternatives Removing the dam would restore the river to a free flowing condition and provide passage for fish and other aquatic species. Dam removal alternatives would eliminate the capital cost for dam repair and the need for regular dam operation, inspections, and maintenance. Dam removal would also alleviate or potentially eliminate concerns over dam safety as well as liability/ownership and maintenance coordination between multiple entities. Dam removal would eliminate current township and county costs for pond maintenance and reduce the risk of invasive plant species moving downstream to Davis Lake and Long Lake. The beach at Mill Pond is now closed.

All dam removal alternatives would include dewatering of the impoundment (Mill Pond), and physically removing the dam including the gated drop inlet, 36-inch CMP outlet, downstream discharge spillway, grouted riprap on the downstream embankment, and a portion of the earthen embankment. Davisburg Road runs on top of the embankment and this functionality would be maintained, so the majority of the embankment would stay in place.

Removal of the dam would require a replacement structure for the stream crossing under Davisburg Road. Alternatives for stream crossing structures presented below include a concrete box culvert, a pre-cast open-bottom culvert, and a bridge.

At the time of completion of this report, OCPRC and Springfield Township have contacted the RCOC to discuss future ownership of alternatives if dam removal was chosen. These alternatives would require review and agreement by the RCOC and could possibly eliminate the need for an inter-local maintenance agreement between OCPRC and Springfield Township if the RCOC took over maintenance of the selected alternative.

Similar to alternatives for replacing the dam outlet pipe, dam removal would require temporary closure of Davisburg Road, bypass management of stream flow, excavation of the road and fill at the stream crossing, replacement of the stream crossing structure, and restoration of the road. For all of the conveyance alternatives, geotechnical investigation of the area under the crossing would be needed to ensure acceptable materials/support for the structure.

All dam removal alternatives would include either active or passive sediment management measures for impounded sediment and formation of a restored river channel and floodplain. Active restoration includes the active construction in-place of a restored channel and floodplain following dam removal, as well as seeding and planting to establish vegetation communities intended to manage erosion and provide habitat and aesthetic value. In contrast, passive restoration allows the river itself to re-establish its own channel,



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pattern, and floodplain. There is typically limited, if any, active restoration work within the channel and minimal management of colonizing vegetation. Consideration must be taken for sediment type and slope stability of the impoundment/floodplain and channel banks, as well as the longitudinal stability of the channel slope and potential for head-cuts. Grade control structures and/or bank stabilization measures may be required.

A more detailed look at the potential channel conditions revealed constraints at the railroad crossing bisecting the impoundment, as well as channel geometry parameters from upstream and downstream reference reaches (Figure 11). A restored channel would also take a sinuous form through the impoundments, increasing the overall proposed channel length compared the MDEQ channel estimate (Figure 12). The estimate for potential sediment mobilization based on the channel plan form and two possible channel profiles shown below ranges between 7,569 and 15,848 cubic yards.

Figure 11. Comparison of Channel Profiles.

Railroad Crossing

Dam



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Figure 12. Proposed Channel Plan Form.

Given the elevation constraints at the upstream and downstream railroad and road crossings, it is likely that a restored channel through the lower part of the Mill Pond impoundment would not reach the parent bed material in all locations. In that case all, or portions, of the restored channel would require engineered materials for the channel bed and additional slope stability considerations. However, this scenario would also mean a smaller sediment volume would need to be removed, mobilized, or otherwise managed.

A range of elevations can be considered for the crossing under Davisburg Road. If the crossing were set at a higher elevation (Proposed Channel 1), then the upstream channel through Mill Pond would be at a milder slope, but give the downstream channel through Rotary Park a steeper slope, as the channel would have a greater drop to meet the downstream channel bed and railroad crossing (See Figure 13). This alignment could necessitate the placement of grade control structures such as a rock ramp or step pool configuration in Rotary Park. Conversely, if the crossing were set at a lower elevation (Proposed Channel 2), then a shallower slope/lesser drop would be provided through Rotary Park, but a slightly steeper slope upstream in Mill Pond. These design details would require more detailed topographical and sediment analysis to settle on an alternative, and have implications for aesthetics and water surface elevations as well as for the costs of channel restoration and sediment management.

Dam removal alternatives may also provide the opportunity for new recreation facilities such as trails. These alternatives may also provide the opportunity to improve pedestrian accessibility and walkability from downtown to the Rotary and Mill Pond Parks.

The two possible channel profiles can be combined with any of the three removal alternatives presented below. It should be noted that as-built plans for the existing railroad bridge located within the Mill Pond should be obtained during detailed engineering efforts to check the foundation elevations of the current bridge and prevent any undermining of the structure if the dam were to be removed. The current channel profiles depicted in Figure 13 show the proposed channels matching the surveyed invert elevation at the railroad bridge crossing. The MDEQ soft sediment appears to be at a higher elevation, but this is likely due to differences and uncertainty in water surface elevations from the MDEQ sediment sampling data.



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3.3.1 Proposed Channel 1 As shown in Figure 13 and described above, Proposed Channel 1 would have a higher invert elevation (944.3’) at the Davisburg Road crossing than Proposed Channel 2. This elevation was chosen as the higher bound of crossing elevations due to the downstream drop in Rotary Park. The downstream railroad crossing culvert is set at 941.14’. If there is approximately 3 feet of drop through Rotary Park, then there is sufficient space to incorporate step-pools or a rock ramp type of control structure at less than 3% slope to allow for fish passage. However, as can be seen in Figure 13, this configuration would require earth moving to form some portions of the channel bed, which would be at a higher elevation than the estimated level of sediment in the impoundment. This alternative would mobilize less sediment downstream, but would also require engineered streambed materials for a large portion of the channel bed (see Figure 14).

Figure 13. Profiles for Proposed Channels 1 and 2 (With Elevation Constraints).

Figure 14. Proposed Channel 1 Configuration.



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3.3.2 Proposed Channel 2 Proposed Channel 2 would have a lower elevation (942.10’) at the Davisburg Road crossing than Proposed Channel 1. This channel alignment represents the lower bound of invert elevations based on meeting the downstream channel elevation in Rotary Park (approximately 942’). This configuration would have a mild slope through Rotary Park, but a steeper upstream slope, particularly in the reach approaching the upstream railroad crossing (see Figure 15). Grade controls such as step-pools or log sills would likely be needed in this higher slope area to stabilize the channel and prevent any negative impacts to the railroad crossing from erosion/channel migration (Figure 16). Similar to Proposed Channel 1, some areas would likely require engineered bed materials where the channel elevation does not reach the hard parent bed material. The downstream parent bed material appears to be at a lower elevation than the stream channel in Rotary Park, which restricts the elevation of the proposed channel in this area (Figure 13).

Figure 15. Proposed Channel 2 Configuration.

Figure 16. Examples of Step Pools



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3.3.3 Removal Alternative F: Concrete Box Culvert Concrete box culverts come pre-cast in many sizes for ease of installation and have a long service life. There are varying span widths and heights that may be chosen to meet design standards and discharge capacities within the road crossing and elevation constraints. The bottom of the culvert can be buried and have channel bed material placed inside the culvert for a more natural channel bottom and better fish passage conditions. If sized large enough, the box culvert could also include space for the stream bank/margins and provide additional species passage under Davisburg Road.

3.3.4 Removal Alternative G: Pre-Cast Open-Bottom Culvert Pre-cast open-bottom culverts can also come fully engineered, pre-cast, and in sections for quick installation. The three-sided structures provide a natural bottom for environmental and fish passage concerns. As with a box culvert, a wider span structure could incorporate space for other wildlife passage along the stream margins, or potential pedestrian passage. These pre-cast structures offer greater choices for aesthetics such as different façade treatments and arch designs. Open bottom culverts also require a foundation that would need to be designed based on the geotechnical conditions under the road. The potential for scour during high flow events would need to be evaluated and potential scour protection such as cobbles or riprap could be needed.

3.3.5 Removal Alternative H: New Bridge An open-span bridge is another alternative for the crossing at Davisburg Road. A bridge would be comprised of a deck, with a spanning superstructure and a substructure made up of supporting abutments and piers. This bridge would be the removal alternative with the highest initial cost and most complex design requirements. If the resulting span is 20 feet or greater, then the Michigan Department of Transportation classifies it as a bridge and requires it to be maintained and inspected as such. As with the above alternatives, a geotechnical investigation of the soils would be needed to ensure proper foundation design and support. Scour potential at the bridge supports would need to be evaluated and scour protection measures incorporated in the design. A bridge may offer some aesthetic opportunities not available with a culvert (such as constructing a trail to connect both sides of Davisburg Road) and could potentially span the entire width of both the channel and floodplain, providing the least impact to the hydraulics of the Shiawassee River.

This alternative would require considerable coordination and agreement with the Road Commission for Oakland County as the long-term inspection requirements, maintenance, and repair would likely fall under their jurisdiction.

3.4 Additional Features The removal alternatives above all include earthwork and restoration work for the upper impoundment, upstream of the railroad bridge. However, due to site accessibility/easement concerns, and the possible need to maintain the current channel invert elevation at the railroad bridge, we can also consider leaving the upper impoundment to a passive restoration process. Beyond providing grade control at the railroad bridge, this alternative would involve no active work in the upper pond. Given that the channel elevation would be stabilized at the railroad bridge, the channel profile and water surface would not be expected to change significantly, and given the narrowness of the impoundment, options for altering the channel geometry are also limited. A passive restoration approach in this area would be a reasonable consideration. As such, the restoration costs for the upper pond are considered separately in the cost estimates so that each removal alternative can be considered both with and without this component.

Realignment of Davisburg Road is an additional feature that could be incorporated as part of any of the replacement and removal alternatives. Road realignment would have significant cost implications and, similar to the New Bridge replacement and removal alternatives, would require extensive coordination and



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agreement with the Road Commission for Oakland County in order to meet state and local road requirements and provide for a mutually beneficial design.

Widening of Davisburg Road at the Mill Pond Dam location is also an additional feature that could be incorporated as part of any of the replacement and removal alternatives. Based on preliminary discussions with the Road Commission for Oakland County, road widening was indicated as a potential option. The addition of a pedestrian walkway as part of the road widening was also discussed as a possibility. As with the other road related changes (i.e. new bridge, road realignment), considerable coordination with the Road Commission for Oakland County would be required.

These additional features would both have significant cost implications to the project as a whole and could lengthen the amount of time the roadway is closed to traffic, but these additions do also have potential to benefit the community and those who travel Davisburg Road.

Due to the amount of coordination required amongst the various parties, we recommend these features be evaluated once a replacement or removal option is selected.

4. Hydrologic and Hydraulic Analyses

4.1 Existing Hydrologic Information The watershed upstream of the Mill Pond Dam is 7.79 square miles. The flood discharge and volume frequencies (Table 1) estimated by the MDEQ range from 650 cfs (0.2% chance of occurring in a given year, or 500-year recurrence interval) to 200 cfs (10% chance of occurring in a given year, or 10-year recurrence interval), and the low flow (Table 2) at 90% exceedance is approximately 3 cfs. The river channel upstream and downstream of the dam is approximately 12 to 16 feet wide and 1 to 2 feet deep at bankfull flow elevation. Table 1 and Table 2 include flow and volume estimates at various discharge frequencies as reported by the MDEQ. These tables show what the expected highest flows are for various flood events, and what the expected lowest flows are for the river at the dam site. This data provides the range of flows that could be expected through any restored channel and crossing, or through the dam outlet structure.

Table 1. Flood Discharge and Volume Estimates from MDEQ.

Discharge Frequency

(%)

Return Period (years)

0.2%

500

0.5%

200

1%

100

2%

50

10%

10

Discharge (cfs) 650 500 440 360 200

Volume (ac-ft) 700 600

Source: MDEQ 2019

Table 2. Low Flow Estimates from MDEQ (cfs).

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec.

50% 4.3 4.8 7.7 7.8 5.7 4.0 3.2 2.9 2.8 3.3 4.3 4.8

95% 2.8 2.9 4.0 4.7 3.1 2.4 1.9 1.8 1.8 1.8 2.3 2.7

Mean 5.6 6.5 8.8 8.6 6.8 4.8 4.0 3.2 3.5 4.2 4.7 5.5

Source: MDEQ 2019



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4.2 Model Setup and Assumptions As part of the hydrologic and hydraulic analysis of Mill Pond Dam and its vicinity, a Hydraulic Engineering Center River Analysis System (HEC-RAS) computer model was constructed of the existing dam. Developed by the United States Army Corps of Engineers (USACE), HEC-RAS is a model that simulates the topography and water management features of a river system (e.g. culverts, bridges, dams) in order to analyze its behavior for existing conditions as well as proposed conditions. After model setup, hydrologic data describing a flood event, such the peak flow or flood event hydrograph, is entered into the model and the model is run to evaluate the river system’s response. For this analysis, the HEC-RAS model would be described as “steady-state”, meaning the model is only run at the peak flow of each scenario, and that flow simulated within the model does not vary with time.

The base topography used to construct the HEC-RAS model consisted of 1/9th arc-second digital elevation map (DEM) data obtained from the United States Geological Survey (USGS) National Elevation Dataset. This data was combined with bathymetric data of the Mill Pond collected by the Michigan Department of Environmental Quality Remediation and Redevelopment Division’s Geological Services Section on June 13th and June 19th, 2018. This topography was further supplemented in various locations by survey data collected by AECOM on January 10th, 2019 (as discussed in Section 2.2). Data from this survey regarding existing culvert materials, inverts, and locations was also entered into the model.

Lastly, hydrologic data representing peak flows during low flow conditions, the 10-year flood event, and the 100-year flood event was obtained from the Michigan Department of Environmental Quality (MDEQ) flood flow database. The 10-year flood event represents the peak flow that could be expected from a storm that has a 10% (1/10) chance of occurring in any given year, while the 100% flood event represents the peak flow expected from a storm that has a 1% (1/100) chance in any given year.

To assess the HEC-RAS model results qualitatively, the model was run for low flow, 10-year flood event, and existing conditions scenarios. Results were compared against the Mill Pond Dam’s MDEQ Dam Safety report and found to agree approximately with the 100-year flood event scenario.

4.3 Hydrologic and Hydraulic Modeling Results

4.3.1 Maintain Existing Spillway Alternative Results If the dam is maintained at its current level of service, the modeled results indicate that little change is expected to the dam’s hydraulic characteristics. In general, the dam will overtop at a flood event that is greater than the 10-year event, with severe overtopping potentially leading to failure of the dam occurring at the 100-year event.

4.3.2 Replace Existing Spillway Alternative Results If the dam is modified to increase its spillway capacity in accordance with the alternatives discussed in Section 3.2, the results indicate that approximate spillway sizing could consist of either a 10-foot wide by 4-foot tall concrete box culvert, or four 48-inch diameter HDPE or PVC pipe. These sizes represent what is required to pass the 100-year flood event without overtopping Davisburg Road. In either case, the existing intake structure and sluice gate would no longer be large enough to control flow through the proposed spillway, and a new intake structure may be required for installation of a new sluice gate to allow draining of the pond.

Adding some storage in Mill Pond by raising the top of dam elevation of the Mill Pond Dam may alleviate some flooding concerns. However, as mentioned previously in Section 3.2.5, the top of dam elevation would have to be raised by approximately 10 feet to impound the 100-year flood. Raising the embankment by this amount would induce flooding upstream of the dam, including flooding the Mill Pond Park Community Center during major flood events.

It should be noted that these dimensions are calculated to pass the maximum flow, and further hydrologic and hydraulic analysis conducted may refine and lessen the dimensions required.



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4.3.3 Dam Removal Alternative Results The results of the hydrologic and hydraulic analysis were used to approximate the size of the river conveyance features for the various alternatives discussed in Section 4. The proposed channel configurations are based on the MDEQ flood discharge estimate of 80 cfs for a 2-year flood event (commonly referred to as the bankfull event), which we would expect to be the approximate channel-forming event. The MDEQ regional reference curve for the local area was also evaluated and found to be consistent with this bankfull estimate. Additional survey data and channel geometry from reaches downstream and upstream of the dam impoundment were used as additional reference for sizing the proposed channel. The proposed channel ranges from 12 to 20 feet in top width, and 1 to 2 feet in depth, depending on the slope of the channel. The floodplain extends one bankfull width on each side of the channel. Figure 17 shows a typical cross section of the proposed channel.

Figure 17. Proposed Channel Cross-Section.

As noted in the alternatives section above, elevation constraints exist at the downstream and upstream railroad crossings, Davisburg Road crossing, and the downstream channel in Rotary Park (see Figure 13 above). These constraints were used to develop the two longitudinal channel profiles shown in the figure. A hydraulic report describing the various model set ups and results is presented in Appendix C.

5. Ecological and Environmental Assessment

5.1 National Environmental Policy Act (NEPA) The National Environmental Policy Act ([NEPA], 42 United States Code [USC] § 4321-4347) is a federal law that establishes a national environmental policy and provides a framework for planning and decision making by federal agencies. Specifically, NEPA requires that federal agencies integrate an interdisciplinary environmental review process that evaluates a range of alternatives, including the No Action Alternative as part of the decision-making process. This process also establishes a need to include interagency coordination and public participation in the process. In summary, NEPA is intended to promote informed decision making by federal governmental agencies and public participation in the process, as appropriate.

Major actions that have the potential to affect the human environment and that involve federal funding, require a permit, or other authorization from a federal agency are subject to the requirements of the National Environmental Policy Act of 1969 (NEPA; 42 USC 4321 et. seq.). The proposed project is not currently subject to the requirements of NEPA because no federal funding has been allocated to the project at this

0

2

4

6

8

10

12

14

0 20 40 60 80 100 120

Dep

th (f

eet)

Width (feet)

Channel Cross-Section

Bankfull Channel



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time; however, the framework provided by NEPA provides a useful set of guidelines for evaluating projects that have the potential to impact the environment.

5.2 Applicable Regulatory Requirements and Coordination A Joint Permit Application (JPA) to the USACE and MDEQ will be required for work in the floodplain, inland lakes and streams, and wetlands. Coordination between local (CTS, OCPRC), state, and federal entities is a vital component of the process, as well as public involvement.

The primary permitting action that governs dam removal is specified by Part 315 of the Michigan Natural Resources Environmental Protection Act and is administered by the MDEQ. After the permit application is submitted and reviewed, a hydraulic review may be requested as it relates to floodplain hydraulic engineering analyses if deemed necessary by the MDEQ. Additional permitting would be expected in accordance with Soil Erosion and Sedimentation Control (Part 91) in support of the final drawdown/dam removal and associated ecosystem restoration activities if dam removal is selected.

Michigan Department of Environmental Quality

Natural Resources Environmental Protection Act Part 301

Activities in inland lakes and streams, fill placement/stream alteration

Natural Resources Environmental Protection Act Part 303

Dredge/fill activities in wetlands

Federal Clean Water Act 33 CFR 330 Section 401, Section 404

Fill activities in “waters of the State”

Section 402 Land disturbance activities

Michigan State Historic Preservation Office Section 106

Consultation and clearance regarding potential effect to historic properties

U.S. Army Corps of Engineers Federal Clean Water Act 33 CFR 330 Section 404 Permit

Cooperative Consultation with MDEQ on Section 404/401 permitting actions

Oakland County Water Resources Commission

Soil Erosion Control Permit

Construction Projects if within a County Drain

Road Commission for Oakland County

Underground Utility Permit

Paving/Approach Permit

Springfield Charter Township

Applicable Building Permits

U.S. Department of Transportation Federal Highway Administration

Section 4(f) for impacts to Rotary Park

Michigan Natural Features Inventory

Rare Species Review

U.S. Fish and Wildlife Service

Permits as needed for any endangered species in project area



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5.3 Environmental Consequences of Alternatives This section describes the physical, biological, cultural, archaeological, socio-economical, and cumulative impacts of the alternatives.

5.3.1 Physical Environment 5.3.1.1 Hydrology/Hydraulics The alternatives should not adversely affect flooding downstream of the Mill Pond Dam. None of the proposed alternatives raises the elevation of the 100-year flood event downstream of the Mill Pond Dam. The hydrologic and hydraulic consequences are described above in more detail in Section 4.3.

5.3.1.2 Wetland and Riparian Zones Wetlands are present in the areas surrounding Mill Pond (see Figure 18). According to the U.S. Fish and Wildlife Service National Wetlands Inventory, the project area includes the following wetland type:

Table 3. Wetland Inventory.

Classification Type Area (Acres)

PEM1B Freshwater Emergent Wetland 38.46

Source: U.S. Fish and Wildlife Service

This wetland complex exists upstream of the impoundment and surrounding the existing channel.



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Figure 18. Wetland Map of Mill Pond Project Area.

Dam repair or replacement alternatives would leave the impoundment level unchanged and be unlikely to affect overall wetland area and locations. However, the spread of invasive still-water species from the impoundment poses a threat to native wetland plant and animal communities. Any dredging needed to maintain the pond or improve recreation could further degrade the wetlands/prairie fen natural resources of the project area (CTS 2018). AECOM agrees with this assessment as invasive species are known to spread to adjacent areas as well as downstream with the river flow. Dredging activities can further suspend and transport seeds and invasive species and cause turbulence and turbidity which can have negative effects on adjacent sensitive areas.

Another large and biologically diverse wetland complex exists downstream of Rotary Park. Dam repair or replacement alternatives would maintain the existing hydrology and would be unlikely to affect this downstream wetland. Sediment control measures would be needed for any construction activities.

Dam removal alternatives have the potential to affect adjacent wetlands negatively by lowering the water table, potentially draining some wetland areas. Only wetlands immediately adjacent to the existing pond would be likely to be affected, downstream areas such as Shiawassee Basin Preserve and the Long Lake Complex would not likely be affected. However, new wetlands would likely form along the restored channel and in low-lying areas within the newly exposed, former impoundment. In addition, the area is known for its many springs which would likely form additional wetland complexes adjacent to, or near-by the restored channel. To meet criteria for no net wetland loss, additional wetlands can be designed within the former



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impoundment as needed. There are four potential outcomes for wetlands in the project area under dam removal scenarios:

No change – for wetlands which are maintained by springs or groundwater sources other than the impoundment;

Change – for wetlands which may be reduced in some way but not lost, or which may undergo a change of wetland type;

Loss – for open-water or lacustrine type wetlands around the impoundment which could be drained by a drawdown;

Gain – newly exposed areas of the impoundment which could revert back to wetland, wetlands that would develop around exposed springs, wetlands that could be designed or evolve in depressions within the former impoundment.

Under dam removal alternatives, still-water invasive species would be reduced or extirpated from the restored channel, and the likelihood exists for colonization of the restored channel and floodplain by nearby native species

5.3.1.3 Air Resources Air resources will remain unchanged under the feasible alternatives long-term. In the short-term, all feasible alternatives would have similar air impacts due to construction and/or demolition activities for the alternative. Dust and construction equipment exhaust are the primary causes to affect localized air quality during the construction related activities for all feasible alternatives within the construction zone, immediate area, and access roads.

5.3.1.4 Noise and Odor Noise will be a short-term issue during construction and/or demolition of the preferred alternative within the construction area and immediate vicinity. Noise will not be an issue long-term with any alternative. Odor will not be an issue in the long-term with any alternative. For the dam removal alternatives, soils/organic matter exposed from the drawdown may have an odor until it dries out. Some odors will likely persist until the soil dries out, which is expected to occur in a matter of weeks.

5.3.1.5 Soil Resources Soil resources are not expected to be appreciably affected by the alternatives. Some alternatives may require concrete, stone, and/or riprap. These materials would be obtained from commercial sites. Any concrete that would be demolished or removed would be recycled where feasible, or disposed of off-site.

Draw down of the impoundment would affect water table levels and soil saturation in the immediate vicinity of the pond. Draw down of the impoundment will expose new areas which would become soil.

5.3.1.6 Groundwater Resources (Wells and Springs) Local wells were investigated via the Michigan DEQ Wellogic database. There are 32 wells located within the likely hydraulic influence of the Mill Pond impoundment (Figure 19). If the dam were removed and the impoundment drawn down to a restored stream channel level, water levels could be lowered by as much as 16 feet (based on the deepest level to parent bed material from the MDEQ sediment study). Most of the local wells would be unlikely to be impacted by the drawdown since their screening levels are deep. However, there are fewer than 10 shallower wells that could potentially be impacted by a drawdown of 16 feet and could need to be deepened. Some of these wells may need to be deepened, while others may just require well pumps to be lowered. To address this potential issue, should dam removal be selected, the dam removal construction budget should include a contingency amount for any wells that might be negatively impacted and require alterations. An amount of $30,000 has been included in the cost estimate.



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Figure 19. Location of Wells near Project Site. (MDEQ Water Well Viewer 1/24/2019). Note:

Wellogic Wells include household, Type III, irrigation, industrial, test, open loop geothermal, and others.

Type II Wells are non-community wells and serve 25 or more individuals or 15 or more service connections on an average daily basis for 60 or more days per year. Examples include, restaurants, schools, hotels, campgrounds, churches, and day care centers.

The relationship between springs and dam impoundments can be complicated and depend upon the groundwater/surface water exchange regime. Increased groundwater levels can increase spring discharge locally, but reduce the amount available to groundwater in other areas. Fine sedimentation can inhibit the surface water/groundwater exchange, and potentially reduce spring flow or shift it downstream. Increased groundwater levels and pressure from impoundments can also lead to displacement of spring discharge to other areas.

Natural springs pre-dating the impoundment were inundated by the construction of the dam and over time have seen sedimentation from fine material and organics settling in the pond. Under dam removal scenarios some of these springs would likely be exposed, and would be expected to continue flowing, given that their groundwater sources would have been below the impoundment level.

Downstream lakes, such as Davis Lake, receive their water from river flow (which would not be reduced by dam removal), and from the downstream groundwater table. A pond drawdown would only be expected to affect the groundwater table in the immediate vicinity of the pond, and would not be expected to negatively affect groundwater tables as far downstream as Davis Lake and Long Lake. It is helpful to think about the water balance in the impoundment – when the dam was built river flow was obstructed and filled the pond until reaching the outflow level, water flowing into the pond above this level flows out and downstream. The larger pond surface experiences a higher level of water loss from evaporation than the surface of the river. However, this evaporative change is not so much on any given day that removal of the pond would be expected to significantly increase flows during a storm event, though over the course of a year the evaporative loss in the pond would be higher. If the dam were removed the river would flow unobstructed,

Area of Hydraulic Influence



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there would be no storage or evaporative loss in the pond. The same amount of water would flow downstream to feed the river, wetlands, and lakes downstream of the existing dam.

If the dam were to remain in place and maintain a similar water level, local wells and groundwater levels would not be impacted.

5.3.1.7 Septic Fields The performance of septic fields located within the hydraulic influence of Mill Pond Dam could improve. Removing the Mill Pond Dam will lower the groundwater elevation in the vicinity of Mill Pond Dam. Lowering the groundwater elevation could have a positive effect on septic fields in the immediate vicinity of the pond by increasing drainage/infiltration capacity, depending on soil type and existing groundwater elevations.

5.3.2 Biological Environment 5.3.2.1 Aquatic The existing concrete outlet channel with a 5- to 6-foot drop, as well as the 36-inch CMP outlet culvert and drop inlet configuration, act as barriers for fish and aquatic species passage. Dam repair or replacement scenarios would not provide passage given the existing elevation and outlet constraints and drop outlet configuration would be maintained.

Under dam removal scenarios, a restored channel could potentially be designed to meet fish passage requirements utilizing an open-bottom culvert, box culvert, or other culvert/bridge scenario with appropriate slope and natural channel bed materials.

In general, small dams tend to have negative ecological effects on the river system including disruptions in flow regime and sediment transport, reduced aquatic species migration/movement, and reduced cold-water/running water habitat. Water quality also tends to be negatively impacted due to low oxygen conditions, nutrient and sediment build-up, and proliferation of invasive species.

Removing the dam and restoring the river channel would restore more natural flow, oxygen, temperature, and sediment transport regimes, increase running water habitat and fish passage, encourage rehabilitation of native river species populations, and decrease populations of invasive still-water species. Water quality would be expected to improve based on increased dissolved oxygen, decreased temperature, and fewer invasive species.

Under dam repair or replacement scenarios, fish communities would likely stay the same, though they could decrease in the long term with continued sedimentation and invasive plant proliferation. A continued plan for invasive species management and the prevention of invasive species spread would need to be considered for dam repair alternatives. Additionally, an aerator system could be considered to try to improve dissolved oxygen levels and curb invasive plant growth.

Under dam removal scenarios, the fish community would be expected to shift away from warmer water and still-water species to running-water species found elsewhere along this stretch of the Shiawassee River. Under dam removal scenarios an invasive species management plan would need to be developed to control plants which could initially colonize the drawdown area before native plants become established, as well as a plan for preventing the downstream spread of invasive species during the drawdown. Finally, consideration should be given to specific fish species and how they may be handled or relocated during a pond drawdown, and any needs for endangered species management plans for endangered species potentially found in the project area.

Consideration should be given to pre- and post-project monitoring of water quality, fish, and other species.

Fish species currently observed include largemouth bass, bluegill, bullhead, and pumpkinseed sunfish (oakgov.com).

5.3.2.2 Terrestrial Historical land cover type in this area circa 1800 was predominantly black oak barren with patches of mixed conifer swamp (Comer and Albert, 1997). This southern portion of the Shiawassee River watershed consists of better-drained soils than the northern portions, and was mostly deciduous, mixed, and coniferous forest.



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A considerable portion (more than half) of the woody wetlands and forested land in the watershed was cleared and drained for agriculture. Man-made impoundments throughout the watershed have resulted in an increase in open water and emergent herbaceous wetlands, over pre-settlement conditions.

Mill Pond Park and adjacent lands owned by Springfield Township, Oakland County, and MDNR form a portion of the I-75 Woods/Long Lake natural areas. The fen in this area has been identified by the Nature Conservancy as rare within its range and, and globally significant, because of its size and quality (MDNR 2012).

Establishing a natural channel and riparian zone helps to create more diverse habitat for native species. Newly exposed bottomlands would become riparian/wetland areas and remain under public ownership.

5.3.2.3 Plant Communities A 2002 MNFI survey of Davisburg State Wildlife Area just upstream found a State Threatened plant in this area, Small White Lady’s Slipper (Cypripedium candidum). The potential exists for this plant to be found within the project area also. The fen in this area has been identified by the Nature Conservancy as rare within its range and, and globally significant, because of its size and quality (MDNR 2012).

5.3.2.4 Wildlife The Mill Pond area hosts a number of species including wild turkey, white-tailed deer, rabbits, squirrels, raccoons, fox, muskrat, mink, beaver, skunk, opossum, and woodchuck, similar to the adjacent Davisburg State Wildlife Area (MDNR 2012).

Downstream of the Mill Pond Dam area is Springfield Township's Shiawassee Basin Preserve including the recently acquired Hartman Tract along Davis Lake. In 2018, Michigan Natural Features Inventory contracted with Springfield Township to conduct a natural community/species survey on the Hartman Tract. The survey noted the presence of a large and high quality prairie fen habitat including 127 native plant species. Also on the tract is a unique and high quality patch of wet-mesic prairie which the survey noted is of global significance and high state priority. On the north side of Davis Lake two state-threatened species – white ladyslipper and mat muhly are known to grow. Within Shiawassee Basin Preserve lies another pristine prairie fen, home to the endangered Poweshiek Skipperling butterfly. (Penskar and Sanders, 2018).

Several rare animals have also been observed during other studies in nearby areas including Richardson’s sedge (state threatened), Poweshiek Skipperling (state threatened), Blanding’s turtle (state special concern), and Eastern massasauga rattlesnake (state special concern and federal candidate). Other species with a high number of occurrences in Oakland County include tamarack tree cricket (Oecanthus laricis), state threatened insect; and hooded warbler (Wilsonia citrina), state special concern bird. There are also ten great blue heron rookeries throughout the county (MDNR 2012).

Waterfowl use of the area is limited due to the small size of the impoundment and high sediment load in the water which is exacerbated by the dam. The majority of waterfowl are of the dabbling species. Species observed in this area are again similar to species on the upstream Trout Pond including mallards, wood ducks, sandhill cranes, blue wing teal, non-native Mute Swans, and Canada geese (MDNR 2012).

No change would be expected under dam repair or replacement alternatives. Invasive species would remain within the impoundment and continued chemical or dredging treatment would be required. These factors would continue to pose a potential threat to native communities adjacent to the impoundment.

Under dam removal alternatives pond-dependent terrestrial and avian species would be displaced to other nearby habitats in the region. It is likely that with removal of the dam and provision of passage under Davisburg Road, native and sensitive species from nearby areas would be able to colonize the restored channel and floodplain area. The downstream areas noted above have been well preserved as representative habitats that were historically found in the area. Given time and restoration efforts, the impoundment could well become a similar ecosystem/habitat. Areas immediately adjacent to the pond include roads, private dwellings, parks, and a golf course. No significant adverse effects to existing wildlife are expected from dam removal.



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5.3.2.5 Noxious/Invasive Species There is a starry stonewort infestation in Mill Pond. The invasive plant negatively affects the waterway by forming dense mats that inhibit water recreation, by overtaking habitat, and by outcompeting native species thereby reducing diversity, and does not provide functional food or habitat for native animals. Invasive plant species pose a threat to the aforementioned fen habitat. Nuisance geese and non-native Mute Swans occupy the pond and can be aggressive to visitors, while also contributing to higher E. coli levels.

Dam repair or replacement alternatives would not address the invasive species issues. Despite chemical treatment, the starry stonewort remains an ongoing problem and would require continued treatment under dam repair and replacement scenarios. Nuisance geese and non-native swans would be likely to continue inhabiting the pond.

Under dam removal alternatives, the pond would be drawn down and replaced with a restored running-water channel which would be unlikely to sustain starry stonewort given sufficient velocities. Nuisance geese and non-native Mute Swans would no longer find suitable open-water habitat after the pond draw down. In the intermediate term, the newly exposed soil would have the potential for other invasive species colonization and some management would be needed, including seeding of native seed mixes. In the long term, colonization from nearby native species and the existing seed bank would be expected to evolve towards a more native ecosystem similar to those seen on conservation lands downstream.

5.3.3 Cultural Environment The dam has been part of the local landscape since 1836, and the dam and gristmill are a valued part of the town’s history, as are memories of the Mill Pond community beach and swimming lessons. Older residents may remember these cultural landmarks and the community may have a difficult time with a significant landscape change such as dam removal and pond draw down.

A river would offer a different type of recreational and cultural feature as well as recall a history prior to the gristmill and dam construction. The increase in space from reclaimed bottomlands could be used for public recreation. However, the swimming and boating opportunities that some residents remember would no longer be available, and the aesthetic of the pond overlook would be altered as well.

The 2000 Shiawassee and Huron Headwaters Resource Preservation Project identified several ecologically/recreationally important “application areas” within the headwaters. The corridor identified as “Area A” (Figure 20) encompasses the Shiawassee River corridor both upstream and downstream of Mill Pond. The Mill Pond area currently represents the only break in this corridor. Dam removal and channel restoration would offer a unique opportunity to connect these two culturally and environmentally important areas into a continuous segment for preservation and recreation.



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Figure 20. Map of Areas of High-Ranking MNFI Sites. (Oakland County Planning, 2000).

5.3.3.1 Land Use Lands adjacent to the impoundment include public parks, a golf course, and private property. Under dam repair or replacement alternatives, no change in land use would be expected.

Under dam removal alternatives, new bottomlands would be exposed and these areas would remain under public ownership. These lands could be used to increase public recreation space and/or to create trails which could enhance walkability/connectivity between local parks and the downtown area.

Mill Pond



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5.3.3.2 Recreational Resources The Mill Pond Park Committee Report and Initial Recommendations notes that the fishing dock sees “a fair amount” of use. Use for boating and kayaking are limited due to the fact that the impoundment is very shallow and has decades of silt build-up as well as extensive invasive plant growth. Use of the swim beach has declined significantly and the recent decision of the Springfield Township Park Commission has been to close the beach due to lack of use, expense of maintenance, aggressive Mute Swans, and invasive species (CTS 2018).

A flowing stream would provide different recreational opportunities, such as a river walk, river fishing, and bird and wildlife viewing. However, the swimming and open-water boating opportunities that some residents remember would no longer be available. The increase in space from reclaimed bottomlands could be used to increase public recreation opportunities.

5.3.3.3 Visual Resources The Mill Pond Park is located adjacent to the pond and provides views of the pond and waterfowl. The pond itself is considered a focal point of the town and is valued for its nature views. Views from downtown and along Davisburg road are limited, and less than ideal due to the embankment and dam. Water quality is also poor and declining.

Under dam repair and replacement scenarios the visual resources are expected to stay the same in the short term, with potential for continued proliferation of invasive and nuisance species, increased sedimentation, and declining water quality. These issues are typically seen with aging dams and impoundments. The natural action of a dam is to impound sediment and slow the water flow. Over time, sediment accumulates and causes the impoundment to become shallower, water temperature increases, and the lack of flow alters the existing ecosystem and species types toward warmer water and stillwater species. Nutrients also accumulate within the impoundment and the stillwater and high nutrient content allow for proliferation of vegetation and invasive species.

Under dam removal alternatives, the pond would be replaced by a flowing river and floodplain corridor. A flowing stream would be a different resource; however, it would still provide opportunities for viewing and interacting from the park as well as potential connections to Rotary Park and downtown. Restoration of adjacent wetlands and fen could provide aesthetic value and wildlife viewing important to the town’s sense of place. Dam removal would also provide the opportunity to create a fully accessible Township/County park along the Shiawassee River, which is not possible in the rustic areas of the Township's preserves and DNR game area.

The choice of stream crossing structure for the Davisburg Road crossing offers the opportunity to incorporate an aesthetically pleasing alternative which could also provide a different visual resource to the community.

In the short term, dam removal and pond drawdown will expose bottomlands that will take successive seasons to vegetate and may have less aesthetic appeal in the meantime.

5.3.4 Archaeological/Historical and Paleontological Resources There are no known archaeological, paleontological, or registered historic sites on this site.

5.3.5 Socio-Economic Considerations Between 2007 and 2017, the Springfield Township Parks and Recreation Department spent approximately $32,000 to treat the pond (approximately $4,571 per year). This cost does not take into account any funds expended by OCPRC or maintenance staff time. In 2017, the Department spent $6,800 in staff time to maintain the beach area. OCPRC also contributed funds to pond treatments/maintenance as well.

Due to existing structural conditions of the dam, potential repair options have been ruled out.

Dam replacement options would still require ongoing maintenance and repair costs for the life time of the dam. Dam removal would relieve the costs of beach and impoundment maintenance. Initial costs for dam



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removal would exceed the cost of dam replacement; however, long-term dam repair and maintenance may eclipse this cost, and generally more funding is available for dam removal than for replacement of dams which no longer serve an economic purpose. Maintenance for any trails added to the area would need to be considered, as well as general maintenance consisting mostly of debris removal at crossings and grade control structures. Creating a larger and more native natural area could attract more visitors. An Oakland County Parks Baseline Park Analysis for Springfield Oaks estimated over 195,000 people within the drive time service area of the park (Oakland County Parks, 2015). However, township meetings have noted that the current Mill Pond beach and pond see little use. Improved connectivity with other local parks and communities and with the downtown area could increase use of the area by both local residents and visitors.

5.3.5.1 Transportation Traffic impacts would be similar under dam removal and dam rehabilitation alternatives. All alternatives include replacing the stream conveyance/spillway structure under Davisburg Road. This would require temporary closure of Davisburg Road during structure replacement. As previously discussed, Davisburg Road will likely be shut down for approximately 1 to 2 months depending on sub-alternative selected and the means and methods of the Contractor. A shutdown could be longer if road realignment or bridge placement were incorporated into the project.

5.3.5.2 Impacts on Downtown The Springfield Township Master Plan (CWA, 2009) calls for Davisburg to be maintained as an activity center within the township, noting, “…The vision is to create more of a destination for people traveling to other sites within the Township, including cyclists, motorcyclists, and others using the vast natural and recreational attractions the Township has to offer.” Dam removal alternatives could provide for an extension of the local trail system, increase in park space, and connections to other green spaces in the township (Figure 21). Opportunities also exist to increase walkability between the downtown area and Rotary and Mill Pond Parks.



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Figure 21. Shiawassee Park Spaces. (Springfield Township).



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5.3.5.3 Human Health and Safety Short-term effects from dam repair, replacement, or removal alternatives listed above include noise, dust, and odor from construction equipment and processes and road resurfacing. Additional health and safety effects of dam removal are increased safety due to the eliminated risk of dam failure and road overtopping. Water quality would be expected to improve as well, with flowing water and cooler water expected to have lower E.coli counts, lower nutrient levels, and reduced or extirpated invasive species. If the crossing under Davisburg Road were wide enough to allow additional species and/or pedestrian passage, pedestrian safety could be increased by not having to cross the road, and road safety could be positively impacted by reducing wildlife/vehicle interactions.

Dam repair or replacement alternatives could also reduce the risk of overtopping of the road and dam failure. However, the possibility of dam failure or overtopping given a large precipitation event would remain.

Road widening under either dam repair, replacement, or removal alternatives could provide space for pedestrian passage, which could increase pedestrian safety.

6. Funding Grant Sources

6.1 Dam Modification Funding Sources In general, grant funding for dam modification projects is only available for major maintenance work on dams that serve an economic purpose, cause minimal environmental impacts, and present imminent public safety issues.

Michigan Department of Natural Resources Dam Management Grant Program

The objective of this program is to, “…repair or facilitate major maintenance work on dams that serve an economic purpose, cause minimal environmental impacts, and present imminent public safety issues. Please note that the purpose of this grant program is to address failing infrastructure needs. It is not intended to fund general maintenance or to correct deficiencies in the design of otherwise structurally sound dams.” There is no minimum grant request amount and the maximum grant request amount is the amount of funds available in a given year, typically around $350,000. A minimum match of 10% is required.

Given the requirements for this grant, we believe the Mill Pond Dam would likely not qualify for maintenance funding.

Federal Emergency Management Agency Pre-Disaster Mitigation Grant Program (PDM) and Flood Mitigation Assistance (FMA)

Both of these programs provide grant funding to mitigate natural hazards such as floods and to reduce damage to communities and infrastructure. Some funds must be applied for by the state. Local communities must have a FEMA approved local mitigation plan, and mitigation measures must be cost effective. “Modifications must be for increasing risk reduction capabilities of the existing structures and cannot constitute only repairs.”

Given the requirements for this grant, we believe the Mill Pond Dam would likely not qualify for maintenance funding.

6.2 Dam Removal Funding Sources In general, more grants are available for dam removal projects than for dam modification projects, which can offset the extra cost to the township/county of the project. Some available grant funding sources are summarized below:



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Michigan Department of Natural Resources Dam Management Grant Program

The objective of this program is to improve aquatic environments and reduce long-term infrastructure costs by removing dams that no longer serve an economic purpose. Removal of Mill Pond dam supports many of the project objectives and seems likely to qualify for funding under this grant. There is no minimum grant request amount and the maximum grant request amount is the amount of funds available in a given year, typically around $350,000. A minimum match of 10% is required. The 10% may be in any of the following forms:

• Applicant’s own cash. • Applicant’s own force account labor, equipment, or materials. • Donations of cash, materials, equipment or services by others – requires letter(s) of commitment from donors at time of application. • Other grants for a complementary scope of work - requires grant award letter(s) at time of application.

Michigan Department of Natural Resources Aquatic Habitat Grant Program

The program goals are to protect intact and rehabilitate degraded aquatic resources. Specifically, this program is meant to, “…rehabilitate inland lakes, Great Lakes, rivers, and streams habitat whose key physical processes that control aquatic habitat and fish production are impaired, where key processes include: hydrology; connectivity; material recruitment and movement; geomorphology; and water quality.” Again, removal of Mill Pond dam and restoration of natural running-water habitat and watershed processes meets many of the grant objectives and criteria. However, increasing self-sustaining fish populations and biomass is a goal that would need to be addressed in final restoration plans to strengthen the application. The minimum grant request amount is $25,000 and the maximum grant request amount is the amount of funds available in a given year, typically around $1.25 million. A minimum match of 10% is required. The 10% may be in any of the following forms:

• Applicant’s own cash. • Applicant’s own force account labor, equipment, or materials. • Donations of cash, materials, equipment or services by others – requires letter(s) of commitment from donors at time of application. • Other grants for a complementary scope of work - requires grant award letter(s) at time of application.

U.S. Fish and Wildlife National Fish Passage Program

The program provides financial and technical assistance for the removal or bypass of artificial barriers which impede fish movement and fragment habitat. Projects that have been funded in the past range from large-scale dam removals to repair or removal of individual culverts. A more recent focus of the program has been in-water fish passage and habitat improvements with an emphasis on small dam removal. Fish passage and habitat reconnection would need to be a focus of the final restoration plans to be likely to receive funding from this program. Project funding has no upper or lower limit. The program notes some flexibility from project to project but aims for a 50% federal OR non-federal match, which can include in-kind contributions.

National Fish and Wildlife Foundation Southeast Michigan Resilience Fund

The fund is a public-private partnership that aims to increase the resilience of southeast Michigan by reducing the impact of stormwater, improving water quality, enhancing habitat, and increasing the accessibility and usability of public green spaces and natural areas. The fund supports projects within St. Clair, Macomb, Oakland, Wayne, Washtenaw, Livingston, and Monroe counties. Individual grants generally range from $50,000 to $300,000, with $1.2 million awarded annually. Habitat projects must have dual design to improve habitat quality and connectivity while also enhancing public access and use-opportunities to natural areas. Removal of the Mill Pond dam, if accompanied by improved recreational access, habitat quality, and engagement would fulfill many of the project goals and lies within the limited geographical boundaries of the grant,



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which would seem to make it likely to receive funding. Projects which can provide 1:1 or greater match funding are most competitive. Match funds may include: cash, in-kind contributions of staff and volunteer time, work performed, materials and services donated, other federal funding sources, or other tangible contributions to the project objectives and outcomes.

National Fish and Wildlife Foundation Resilient Communities Program

The program was established to improve fish and wildlife habitat and enhance community resilience through water, forest health, and coastal projects, with a focus on flood resilience in the mid-west. Proposals should yield measurable and sustainable benefits for natural habitats and for communities. This grant seems less applicable to this project, having a strong emphasis on increasing environmental resilience/preparedness and targeting traditionally underserved populations. Grants range from $200,000 to $500,000, with total funds of about $20 million to be awarded over four years. Projects that meet or exceed a 1:1 match ratio will be more competitive.

National Fish and Wildlife Sustain Our Great Lakes Program

The program is a public-private partnership aimed at improving the ecological health of the Great Lakes basin. Individual grants range from $100,000 to $1,000,000, with approximately $8.2 million to be awarded in 2019. Applicants must provide a minimum of 25% matching funds, but those with a 1:1 ratio or higher will be more competitive. Specific funding priorities include:

Aquatic connectivity (e.g., dam removal, bridge and culvert replacement, installation of fish passage structures);

Riparian and stream habitat (e.g., streambank stabilization, invasive species control, restoration of native vegetation, placement of in-stream structures);

Wetlands (e.g., invasive species control, restoration of native vegetation, hydrological restoration); and

Green stormwater infrastructure (e.g., construction/improvement of urban wetlands, installation of bioswales, pervious surfaces, and rain gardens, and native tree planting).

Each year specific program priorities are selected. The competitiveness of this potential dam removal project would depend on the priorities during the year of application. The project would meet eligibility requirements and fall within one or more funding categories.

6.3 Road Funding Funding for road construction/improvement projects may be made available from the Michigan Department of Transportation, the U.S. Federal Highway Administration, or local road commissions.

7. Conceptual Construction Cost The conceptual construction cost estimates have been developed for each alternative and included in this feasibility study and are considered to be a Class 4 estimate by AACE International. A Class 4 estimate has an expected accuracy range of -30% to +50%. This level of contingency is common at this conceptual evaluation stage. These conceptual costs include estimates for permitting, design engineering, and construction management and oversight. However, these costs are only estimated as a total percent of the total construction cost. Table 4 below summarizes the conceptual cost estimates for each alternative discussed in the report above, except for Alternative E – Raising the Embankment as that alternative has been ruled out of consideration due to flood impacts.

The detailed cost estimates are included in Appendix D.



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Table 4. Conceptual Construction Cost Estimates

Conceptual Construction Cost Estimates for All Alternatives

Alternative A Alternative B Alternative C Alternative D Alternative E Alternative F Alternative G Alternative H

Description Replacement with

36" HDPE Pipe

Replacement with (4) 48"

pipes

Replacement with 10' x 4' Box Culvert

Replacement with New

Bridge

Raise Embankment

Dam Removal with Concrete Box Culvert

Dam Removal with Pre-Cast Open -Bottom Culvert

Dam Removal with New Bridge

Channel Profile 1

Channel Profile 2 Channel Profile 1 Channel Profile 2 Channel Profile 1 Channel Profile 2

Estimated Construction Cost $ 625,932.25 $ 672,484.73 $ 624,397.23 $ 1,226,639.67 $ 1,058,429.12 $ 1,164,358.37 $ 997,791.62 $ 1,097,220.87 $ 1,304,758.62 $ 1,343,257.62

Contingency Cost (40%) $ 250,372.90 $ 268,993.89 $ 249,758.89 $ 490,655.87 $ 423,371.65 $ 465,743.35 $ 399,116.65 $ 438,888.35 $ 521,903.45 $ 537,303.05

Engineering and Permitting (10%) $ 62,593.23 $ 67,248.47 $ 62,439.72 $ 122,663.97 $ 105,842.91 $ 116,435.84 $ 99,779.16 $ 109,722.09 $ 130,475.86 $ 134,325.76

Construction Admin/RPR (10%) $ 62,593.23 $ 67,248.47 $ 62,439.72 $ 122,663.97 $ 105,842.91 $ 116,435.84 $ 99,779.16 $ 109,722.09 $ 130,475.86 $ 134,325.76

Estimated Project TOTAL $ 1,001,491.61 $1,075,975.57 $ 999,035.57 $ 1,962,623.47 $ 1,693,486.59 $ 1,862,973.39 $ 1,596,466.59 $ 1,755,553.39 $ 2,087,613.79 $ 2,149,212.19

Estimated Project TOTAL without Upper Pond Restoration $ 1,571,070.40 $ 1,740,557.20 $ 1,474,050.40 $ 1,633,137.20 $ 1,965,197.60 $ 2,026,796.00



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7.1 Maintenance Costs Annual maintenance costs have also been determined for each alternative (Table 5). For the dam replacement alternatives these maintenance costs include the following:

Regular dam inspections by a Professional Engineer.

Annual treatment of the pond.

Maintenance/repair/replacement of the dam structures that are not expected to last the 100 year design life.

Regular video monitoring of the outlet structure.

To estimate life cycle costs we assumed that over the course of the dams expected design life of 100 years that provisions would be made for replacement of material that will not last for the design life of the structure. Our assumptions for this calculation was that articulated concrete block or grouted riprap for downstream embankment protection would last 50 years, box culverts would last 50 years, HDPE conduit would last 100 years. Replacement or repair costs were assumed to be 75% of initial capital costs to account for the potential reuse of material.

The dam removal alternatives would require the following:

Annual maintenance in the form of invasive species management within the former impoundment.

Regular inspection and maintenance of the culvert or bridge associated with Davisburg Road.

It should be noted that Road Commission for Oakland County would likely take over the maintenance costs associated with the culverts or bridge remaining after dam removal upon approval of a change of ownership agreement. Culvert and bridge clean-out costs are included in the maintenance cost estimate, but inspection costs are not included, as these would fall to the Road Commission for Oakland County.

The annual maintenance costs as presented below are converted to a net present value to allow for a “like for like” comparison. Detailed Maintenance Costs by year are provided in Appendix D.

7.2 Potential Life-Cycle Costs The long-term capital (construction) costs added to the short-term maintenance costs produce the total life-cycle costs. The life-cycle cost is the total cost for constructing and maintaining an alternative. The annual maintenance costs were converted to a net present value so that they can be added to the capital construction costs to allow for a “like for like” comparison. Table 5 provides the total life-cycle costs estimated for each alternative. The life-cycle costs are for a 100-year life. Detailed costs are provided in Appendix D.



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Table 5. 100-year Life-Cycle Cost Estimates

100-year Life Cycle Cost Summary

Alternative A Alternative B Alternative C Alternative D Alternative F Alternative G Alternative H

Description Replacement

with 36" HDPE Pipe

Replacement with (4) 48" pipes

Replacement with 10' x 4' Box

Culvert

Replacement with New Bridge

Dam Removal with Concrete Box Culvert Dam Removal with Pre-Cast Open -Bottom

Culvert Dam Removal with New Bridge

Channel Profile 1 Channel Profile 2 Channel Profile 1 Channel Profile 2 Channel Profile 1 Channel Profile 2

Net Present Value of Annual Maintenance Costs

$321,738.99 $288,840.70 $284,410.56 $315,599.20 $125,072.12 $125,072.12 $125,072.12 $125,072.12 $127,911.15 $127,911.15

Total Project Net Present Value

$1,284,689.90 $1,325,064.33 $1,246,064.20 $2,211,866.67 $1,765,590.99 $1,930,141.28 $1,671,396.81 $1,825,850.02 $2,150,995.09 $2,210,799.36

Total Project Net Present Value without Upper Pond Restoration

$1,284,689.90 $1,325,064.33 $1,246,064.20 $2,211,866.67 $1,646,740.32 $1,811,290.61 $1,552,546.14 $1,706,999.34 $2,032,144.41 $2,091,948.69



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8. Assessment of Alternatives AECOM has developed a decision matrix in order to weigh the relative advantages and disadvantages of each alternative. A decision matrix allows both non-monetary and monetary factors to be considered when evaluating between alternatives.

8.1 Non-Monetary Factors The final list of non-monetary factors evaluated for this study were developed in consultation with the Charter Township of Springfield and Oakland County Parks and Recreation Commission. The non-monetary factors listed below are the factors that were included in the Request for Proposals.

8.1.1 Community Factors Community factors include the following considerations:

Does the alternative support a vibrant and attractive downtown Davisburg?

What is the potential to affect real estate values within the community?

Does the alternative have the potential to affect water wells adversely within the area?

Does the alternative promote safety within the community?

8.1.2 Recreational Benefits Recreational benefits include the following considerations:

Does the alternative maximize the recreational benefit available to the citizens of Davisburg and Oakland County, Michigan?

Does the alternative promote pedestrian connectivity?

8.1.3 Historical Significance Historical significance includes the following considerations:

Does the alternative recognize and respect the historical significance of the Mill Pond Dam?

8.1.4 Ecological and Environmental Considerations Ecological and environmental considerations include the following considerations:

Does the alternative provide for aquatic species passage?

How does the alternative impact water quality?

Does the alternative hinder the growth of invasive plant and animal species?

Will the alternative promote the growth of native plant and animal species?

Does the alternative impact the wetlands and fens in the Shiawassee Basin Preserve?

8.1.5 Dam safety implications Dam safety considerations should include:

Does the principal spillway pass the 100 year flow event?

Does the alternative require dam safety inspections or long term regulation by dam safety agency?



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8.1.6 Permitting Implications Permitting implications include the following considerations:

Can the project be successfully permitted by the State of Michigan and other permitting agencies?

8.2 Monetary Factors Monetary factors include the total lifecycle cost of the project and the potential for outside funding sources such as grants.

8.2.1 Costs Conceptual level cost estimates will be developed for each alternative (see Section 7 above). The life-cycle costs, which incorporate both the long-term capital (construction) costs and the short-term maintenance costs, will be used to evaluate the monetary factors for each alternative.

The cost factor was rated entirely on their conceptual level life-cycle cost estimate. The lowest priced alternative automatically receives 5 points and the highest cost alterative receives 1 point. The remaining alternatives receive points in linear relation between the lowest and highest priced alternative.

8.2.2 Other Funding Sources The potential for other funding sources, such as grants, should be considered while rating each alternative. Factors to consider when evaluating the potential for other funding sources include:

The availability of grant programs to fund the alternative

Examples of similar projects being funded by grants

Magnitude of potential grant sources to offset lifecycle costs

8.3 Rating Criteria and Decision Matrix Each non-monetary factor will be rated on a scale of 1 to 5 based on the criteria described in Table 6 below.

Table 6. Non-Monetary Factors Rating Criteria.

Rating Guidelines Criteria

Outstanding (5 points) The alternative fully addresses all aspects of the criterion. The alternative demonstrates it exceeds the requirements, and offers added value to the Charter Township of Springfield, Oakland County, and the public. The alternative demonstrates no weaknesses.

Acceptable (4 points) The alternative fully addresses all aspects of the criterion. The alternative demonstrates it meets all the requirements, and demonstrates no weaknesses.

Satisfactory (3 points) The alternative fully addresses the criterion and meets most requirements, and demonstrates few weaknesses.

Poor (2 points) The alternative does not fully address all aspects of the criterion but meets some of the requirements. The alternative demonstrates several weaknesses.

Unsatisfactory (1 point) The alternative does not address all aspects of the criterion and does not meet the requirements.

The decision matrix allows for both non-monetary and monetary factors to be evaluated. Each factor is assigned a relative weight based on the importance of the factor to the Charter Township of Springfield, Oakland County, the public, and all other relevant stakeholders. Each non-monetary factor is then rated for



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each alternative based on the rating criteria detailed in Table 6. The monetary factors are scored as described in Section 8.2. The total score for each alternative is the summation of the relative weight multiplied by the rating.

8.4 Public Engagement Process Two public information meetings were held in Springfield Township on March 5, 2019 and May 22, 2019. At both meetings a presentation was given of the feasibility study purpose and progress and time was given for open public comment and questions. Prior to the second meeting the draft feasibility report was made available to the public on the township website and was available for inspection in the township clerk’s office. These public information meetings provided the board with feedback from the community prior to the Springfield Township Board special meeting where board members assessed the alternatives presented in this report.

8.5 Conclusions The Springfield Township Board completed an assessment of the alternatives for Mill Pond Dam at a Special Meeting on Thursday, June 6, 2019. The assessment was based upon the findings of the Feasibility Report, factors outlined in a decision matrix, and taking into consideration public input and future opportunities for the Township.

All board members were present for the meeting. The board discussed each factor and assigned it a weighting factor. After the weighting was assigned and agreed upon, each alternative was assigned a rating between 1 and 5.

The board spent time discussing each alternative and the rating they wanted to assign to it. The board progressed through the alternatives by stating individually their preferred rating and then discussing what ratings would be acceptable to the majority of the board. The board worked through all of the alternatives and factors until all were completed. The final decision matrix is provided (Table 7) which demonstrates Alternative G was preferred by the Township Board.

To expedite the process and allow for the Township Board to focus on their priorities, they collectively decided that Alternative A did not meet the needs of Springfield Township and assigned it a rating of 1 for all factors, effectively eliminating it from consideration. In addition, for Alternatives F, G, and H ratings were only provided for one channel configuration since the final channel configuration will be an engineering consideration. The board based their rating on the higher-cost Channel 2 alternative presented, as the consensus of the board was that Channel 2 was preferred over Channel 1.

The Township Board recommended a course of action to Oakland County, based on the scoring of the decision matrix, that the preferred alternative (Alternative G) would be to remove the dam and restore the river corridor with an arch culvert at the Davisburg Road crossing. The Oakland County Parks & Recreation Commission assessed the alternatives and considered the Township Board’s recommendation at their regularly scheduled Commission Meeting on July 10, 2019. The Commission supported the Township’s recommendation and moved to conceptually approve the preferred alternative.

Table 7. Decision matrix completed by Springfield Township Board at Jun 6, 2019 special meeting.

Factor Weight (%) Alt. A Alt. B Alt. C Alt. D Alt. F Alt. G Alt. H

Community Factors 20.00% 1 2 2 2 3 4 2

Recreational Benefits 10.00% 1 1 1 1 4 4 4

Historical Significance 5.00% 1 2 2 2 2 2 2

Ecological and Environmental 25.00% 1 1 1 1 2 4 4



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Factor Weight (%) Alt. A Alt. B Alt. C Alt. D Alt. F Alt. G Alt. H

Permitting Implications 10.00% 1 3 3 3 4 4 3

Dam Safety Considerations 5.00% 1 4 4 2 4 4 2

Cost 10.00% 4.8 4.7 5 1 2.2 2.6 1

Funding/Grant Sources 15.00% 1 1 1 1 3 4 3

Total Score 100% 1.4 2.0 2.0 1.5 2.9 3.8 2.9

9. References CWA. 2009. Springfield Township Master Plan. Carlisle Wortman Associates, Inc. Amended April 19, 2016.

CTS. 2018. Springfield Charter Township Mill Pond Park Committee. Memo to Township Board and Park Commission: Report and Initial Recommendations. April 5, 2018.

Comer, P., & Albert, D. 1997. Vegetation circa 1800 Maps. Michigan Natural Features Inventory.

Cooper, J. 2001. A Biological Survey of the Shiawassee River and Selected Tributaries in Oakland, Genesee, and Livingston Counties, Michigan, June 12-19, 2000. MDEQ Staff Report #MI/DEQ/SWQ-00/108.

Cooper, J. 2006. A Biological Survey of the Shiawassee River and Selected Tributaries in Oakland, Genesee, Livingston, and Saginaw Counties, Michigan, July 6-27, 2005. MDEQ Staff Report #MI/DEQ/WB-06/014.

Cooper, J. 2011. Biological Survey of the Shiawassee River and Selected Tributaries in Oakland, Genesee, Livingston, and Saginaw Counties, Michigan, June 1-August 31, 2010. MDEQ Staff Report #MI/DEQ/WRD-11/008.

MDEQ. 2019. Flow Discharge Request Process No. 9661. Hydrologic Studies and Dam Safety Unit, Water Resources Division, Department of Environmental Quality. February 12, 2019.

MDEQ. 2018. Davisburg Mill Pond, Oakland County Sediment Volume and Sampling Survey, GSS Job #629. Remediation and Redevelopment Division, Department of Environmental Quality.

MDEQ. 2016. Biological Survey of the Shiawassee River Watershed Midland, Gratiot, Saginaw, Shiawassee, Genessee, and Livingston Counties, Michigan, June-September 2015. MDEQ Staff Report #MI/DEQ/WRD-16/021.

MDNR. 2012. Davisburg State Wildlife Area Master Plan. IC 2039. Revision 6-11-2012. Michigan Department of Natural Resources Wildlife Division.

MDEQ. 2019. Flood Flow Discharge Request No. 168812. Susan Greiner, Hydrologic Studies and Dam Safety Unit, Department of Environmental Quality. Via email February 14, 2019.

Oakland County Parks. 2015. Springfield Oaks Baseline Park Analysis. Updated July 10, 2017.

Oakland County Planning and Economic Development Services, Michigan Natural Features Inventory, Land Information Access Association, and Carlisle Wortman and Associates. 2000. Shiawassee and Huron Headwaters Resource Preservation Project. Pontiac, MI. 230 pp. + appendices

Penskar, M.R. and M.A. Sanders. 2018. Rare Species and Natural Features Assessment of “Hartman Tract” at Shiawassee Basin Preserve, Davisburg, Springfield Township, Oakland County, Michigan. Prepared for Springfield Charter Township. Michigan Natural Features Inventory, Report No. 2018-20, Lansing, MI.



AECOM

Appendix A Sediment Volume and Sampling Survey

STATE OF MICHIGAN

DEPARTMENT OF ENVIRONMENTAL QUALITY LANSING

RICK SNYDER GOVERNOR

C. HEIDI GRETHERDIRECTOR

TO: Julie Oakes, Wildlife Division, Seven Lakes State Park Office Department of Natural Resources

FROM: Brian Eustice, Geologist, Geological Services Section Remediation and Redevelopment Division, Department of Environmental Quality

DATE: November 8, 2018

SUBJECT: Davisburg Mill Pond, Oakland County Sediment Volume and Sampling Survey, GSS Job #629

This memorandum summarizes the methodology and findings from a marine sediment volume and sampling investigation performed by the Department of Environmental Quality (DEQ), Remediation and Redevelopment Division’s (RRD’s), Geological Services Section (GSS) on June 13 and 19, 2018 at the subject site. GSS received the final laboratory results on July 5, 2018.

The purpose of this investigation was to determine the volume of sediment that has accumulated in the impoundment behind the dam as well as the volume of sediment that would potentially mobilize if the dam were removed. In addition, based on the volume of sediment in the impoundment, sediment testing was performed to determine whether the removal of the day would have negative impact on aquatic resources, aquatic life, wildlife or public health.

The Davisburg Mill Pond Dam was originally constructed in 1835 to power a mill that existed at that time. Mill operations have long since been abandoned, and the dam currently creates a recreational impoundment providing fish and wildlife habitat as well as limited boating and swimming opportunities. It consists of a 375-foot long earthen embankment and a steel and concrete drop inlet principal spillway structure. The spillway was largely reconstructed in 1984 and consists of a 4-foot wide gated drop inlet flanked at each side by 10.75-foot wide corrugated steel fixed weir sections. The drop inlet discharges through a 36-inch diameter corrugated metal pipe (CMP) outlet. Outflow from the CMP outlet cascades over a 10-foot long concrete water feature and water wheel to the downstream Shiawassee River. The dam has a structural height of 16 feet, a hydraulic height of 17 feet, and maintains approximately 14 feet of head and 2.4 feet of freeboard, creating a 20-acre impoundment under normal flow conditions.

The GSS utilized a sampling barge system consisting of two 14-feet aluminum v-bottom Sea Nymph boats, coupled together side by side, with a tripod-winch lifting system in the center (Appendix A-Photo 1).

The GSS collected water depth (depth to top of soft sediment) and depth to top of hard sediment (parent bed) measurements at a total of 139 locations along 28 transects throughout the impoundment (Fig 1a). Depth measurements were recorded by pushing a steel rod (push probe) to the bottom of the pond to measure top of soft sediment and then advancing it down by hand until it hit refusal at the top of the parent bed. The locations of the soft and hard sediment boundaries were determined in the field by the geologist performing the push probes. These measurements were then used to determine the thickness of the soft sediment at each location (Table 1).

Depths to top of sediment and top of parent bed measurements were contoured with a 1-foot contour interval and the sediment thickness was contoured with a 0.5-foot contour interval using Surfer 15 contouring software and plotted over aerial images in ArcMap 10.4 (Fig 1b and Fig 1d).

Julie Oakes -2- November 8, 2018 Sediment volume calculations were performed using hydrographic software HYPACK 2016. The push probe easting, northing, and depth data was input into the HYPACK for both the top of soft sediment and top of hard sediment. The software uses these datasets to create triangulated irregular network (TIN) models of each sediment layer and uses the two TIN models to compute the total volume of soft sediment in the impoundment. Next, using estimations based on observations of the river channel above and below the impoundment, a 15-foot wide, by 1-foot deep channel with 10 feet of floodplain on each side was created in the software along the thalweg of the impoundment and given a slope to match the depth to parent bed on each end of the impoundment (4 feet on the upstream end to 8.5 feet on the downstream end near the dam) (Fig 2). Using the TIN models, the software was then used to calculate the amount of soft sediment that would mobilize if the dam were removed and the estimated channel were to form. The total volume of soft sediment calculated to be in the impoundment is 84,745.5 cubic yards. The volume of soft sediment above the 15-foot channel and 20 feet of floodplain that would be expected to mobilize if the dam were removed is calculated to be 17,094.3 cubic yards. The DEQ Water Resources Division’s policy and procedure “Sediment Testing for Dredging Projects” identifies when sediment testing is required for projects where contaminated sediment can mobilize or become exposed, how many samples are required per volume of sediment, what analytes need to be tested for, and screening guidelines for aquatic life and wildlife. Based on the volume of sediment originally estimated to mobilize if the dam were removed, GSS collected ten sediment samples. The GSS collected the ten sediment samples (DMP-01 through DMP-10) using a post pounder and advanced 2-inch diameter, 8-feet long polycarbonate tubes. Staff pieced together clean polycarbonate tubes using custom aluminum couplings and sheet metal screws when depths greater than 8 feet were required. Sediment cores were recovered using a lifting bail secured to the tripod-winch system on the barge. Sediment cores were logged following the Unified Soil Classification System (USCS) and then homogenized and sampled on shore after collection (Appendix B). After completion, sample locations were recorded using a handheld global positioning system (GPS) (Table 2). Sediment samples were submitted under Chain-of-Custody (COC) documentation to Test America in Brighton, Michigan, for heavy metals using USEPA Method 6010B, 60120, and 7471A; Polycyclic Aromatic Hydrocarbon (PAH) analysis using USEPA Method 8270; and Biochemical Oxygen Demand (BOD) using Standard Method 5210B. Analytical results for the sediment samples collected were compared to applicable Resource Conservation and Recovery Act (RCRA) Region 5 Ecological Screening Levels (ESLs), and MDEQ residential and nonresidential soil criteria and risk-based screening levels (RBSLs) for the select USEPA Methods target analyte list (Table 3) (Appendix C). No criteria exceedances of PAHs were detected in any of the sediment or quality analysis and quality control (QA/QC) samples submitted to the lab. Selenium was detected in DMP-1 at 3.0 mg/kg above the aquatic life and wildlife screening levels of 1.9 mg/kg; however, the result was flagged due to Selenium also occurring in the QA/QC blank sample. BOD was detected above the 250 mg/L value outlined in the WRD Policy for Sediment Testing and Dredging Projects in samples DMP-2, DMP-8, and DMP-10. If you have any questions, contact me at 517-242-1170. Attachments cc: Burrell P. Shirey, DEQ

LEGEND1-Ft Contour Lines

0.5-Ft Contour Lines

Survey Points

Sediment Sampling Points

µ

FIGURE 1

GEOLOGIST CREATION DATE

Geological Services Unit

Brian Eustice October 2018

Davisburg Mill Pond

SPRINGFIELD TOWNSHIP, OAKLAND COUNTYT4N R8E SECTION 17

BATHYMETRIC SURVEY LOCATIONAND CONTOUR MAPS

DATUM - NAD83PROJECTION: MICHIGAN GEOREF

AERIAL PHOTO SOURCE: MICHIGAN IMAGERY

Remediation and Redevelopment

Division

1 inch = 449 feet

0 240 480 720 960 Feet

0 0.1 0.2 Miles

1 in = 0.085 miles

DMP-9DMP-8

DMP-7

DMP-6

DMP-5

DMP-4

DMP-3

DMP-2

DMP-1

DMP-10

Depth to Top of Sediment

Depth to Top of Parent Bed Sediment Thickness

Survey Locationsa b

c d

LEGEND0.5-Ft Contour Lines

µ

FIGURE 2

GEOLOGIST CREATION DATE

Geological Services Unit

Brian Eustice October 2018

Davisburg Mill Pond

SPRINGFIELD TOWNSHIP, OAKLAND COUNTYT4N R8E SECTION 17

ESTIMATED CHANNEL AND CROSS SECTION

DATUM - NAD83PROJECTION: MICHIGAN GEOREF

AERIAL PHOTO SOURCE: MICHIGAN IMAGERY

Remediation and Redevelopment

Division

1 inch = 250 feet

0 130 260 390 520 Feet

0 0.055 0.11 Miles

1 in = 0.047 miles

02468

101214161820

0 48 94 137 186 227 276 314 361 402 447 494 530 579 629 676 716 770 823 873 916 967 1,018

1,069

1,112

1,153

1,199

1,246

1,287

1,332

1,379

1,417

1,462

1,504

1,551

1,603

1,659

1,708

1,843

1,889

1,933

1,982

2,031

2,075

2,120

2,163

2,209

2,255

2,301

2,349

2,396

2,444

2,492

2,539

2,592

2,646

2,694

2,739

2,787

2,825

2,871

2,919

2,967

3,014

3,062

3,108

3,154

3,200

3,249

3,298

3,346

3,399

3,451

3,511

Depth

(ft)

Distance (ft)

Soft Sediment Hard Sediment Estimated Channel Series4

Estimated Channel (Red)and Floodplain (Green)

Estimated Soft Sedimentto Mobilize

Depth Measurements Davisburg Mill Pond Dam,Oakland County

Table #1(Page 1 of 5)

Push Probe ID

Easting(feet)

Northing(feet)

Water Depth(feet)

Depth to Parent Bed (feet)

Soft Sedeimnet Thickness (feet)

MP-1A 13345658.7 457372.677 1.75 8.25 6.5MP-1B 13345718.2 457413.635 5 11 6MP-1C 13345790.66 457443.69 11.25 17.75 6.5MP-1D 13345873.26 457478.484 6.75 11 4.25MP-1E 13345927.01 457495.305 2.5 5.5 3MP-2A 13345678.88 457273.393 4 7.5 3.5MP-2B 13345743.71 457315.992 5.75 13.25 7.5MP-2C 13345834.73 457341.25 13 16.25 3.25MP-2D 13345932.3 457370.666 8 10.5 2.5MP-2E 13346009.7 457420.821 1 4 3MP-3A 13345798.52 457192.358 2.5 6.25 3.75MP-3B 13345832.43 457228.487 7 12.25 5.25MP-3C 13345897.37 457271.156 11.75 16.5 4.75MP-3D 13345980.74 457297.925 7 12.5 5.5MP-3E 13346035.28 457336.961 1 3.75 2.75MP-4A 13345846.24 457112.465 3.25 5.75 2.5MP-4B 13345900.23 457159.902 14 17.5 3.5MP-4C 13345989.26 457195.342 15 17 2MP-4D 13346056.31 457224.166 11.75 13 1.25MP-4E 13346104.42 457246.176 1 1.75 0.75MP-5A 13345924.71 457033.32 3 8.5 5.5MP-5B 13345982.84 457059.848 8 12 4MP-5C 13346021.81 457085.138 10.75 15.25 4.5MP-5D 13346081.28 457121.554 8 13 5MP-5E 13346133.38 457160.233 1.25 2 0.75MP-6A 13346045.2 456926.179 1 1.5 0.5MP-6B 13346091.91 456965.506 3.5 5.5 2MP-6C 13346106.69 457026.506 9.5 15.25 5.75MP-6D 13346151.3 457087.882 13.5 16.5 3MP-6E 13346173.56 457135.59 0.5 4.5 4MP-7A 13346175.97 456897.775 0.75 3 2.25MP-7B 13346182.82 456926.542 10 12 2MP-7C 13346198.53 456988.74 12.5 14.5 2MP-7D 13346223.91 457030.434 11 13.25 2.25MP-7E 13346249.38 457086.032 1 2 1MP-8A 13346287.03 456822.982 2 5.25 3.25MP-8B 13346288.77 456871.259 6.25 11 4.75MP-8C 13346291.38 456936.964 9 13.25 4.25MP-8D 13346294.8 456987.06 7.5 10.5 3MP-8E 13346307.34 457037.312 1.5 2.75 1.25MP-9A 13346390.76 456794.38 1.25 5.75 4.5MP-9B 13346405.29 456843.818 5 11.5 6.5MP-9C 13346412.98 456904.823 9.5 12.75 3.25MP-9D 13346413.98 456973.59 6 11 5MP-9E 13346408.58 457041.702 3.4 7.6 4.2MP-10A 13346581.38 456766.47 1 3 2MP-10B 13346551.43 456828.795 7 10.75 3.75MP-10C 13346536.7 456913.817 8.75 12 3.25MP-10D 13346511.56 456987.965 7 11.5 4.5MP-10E 13346469.85 457067.054 1 5 4MP-11A 13346660.65 456871.056 1 3.5 2.5MP-11B 13346642.58 456881.199 4 7.5 3.5MP-11C 13346615.61 456957.25 4.75 10.5 5.75MP-11D 13346597.66 457045.882 5 7.75 2.75MP-11E 13346575.8 457106.104 2.5 4 1.5MP-12A 13346761.05 456933.112 1.1 1.6 0.5MP-12B 13346745.07 456968.902 4.7 10.6 5.9MP-12C 13346723.42 457018.982 5.6 10.3 4.7MP-12D 13346683.46 457069.18 3.7 7.7 4MP-12E 13346661.4 457098.017 1 1.9 0.9MP-13A 13346837.88 457007.181 1.1 3.2 2.1MP-13B 13346823.43 457022.224 1.6 5.8 4.2MP-13C 13346797.67 457064.597 4 8.6 4.6MP-13D 13346780.07 457112.781 4.4 10.7 6.3MP-13E 13346721.79 457139.887 0.5 0.8 0.3MP-14A 13346977.21 457056.408 0.5 6.8 6.3MP-14B 13346935.5 457073.78 2.2 9.1 6.9MP-14C 13346894.16 457112.885 1.4 9.5 8.1MP-14D 13346858.9 457174.087 3.3 10.1 6.8MP-14E 13346822.2 457212.667 0.2 0.6 0.4MP-15A 13347050.456 457205.695 0.4 8.4 8MP-15B 13346998.07 457208.284 2.8 9.7 6.9MP-15C 13346929.35 457216.415 3.2 11.9 8.7MP-15D 13346889.78 457225.944 2.6 7.7 5.1MP-15E 13346833.24 457219.369 0.8 1.7 0.9MP-16A 13346997.08 457356.571 3 7.7 4.7MP-16B 13346964.37 457332.059 3 8.8 5.8MP-16C 13346920.48 457306.918 1.6 6.2 4.6MP-16D 13346877.85 457293.521 1.2 6 4.8MP-16E 13346843.61 457286.655 0.9 2.9 2MP-17A 13346968.82 457398.812 3 5.9 2.9MP-17B 13346862.18 457391.042 1.3 4.7 3.4MP-17C 13346798.78 457382.761 4.4 8 3.6MP-17D 13346696.76 457373.481 6.1 9 2.9MP-17E 13346570.57 457350.877 1 2.3 1.3

Depth Measurements Davisburg Mill Pond Dam,Oakland County


Push Probe ID

Easting(feet)

Northing(feet)

Water Depth(feet)

Depth to Parent Bed (feet)

Soft Sedeimnet Thickness (feet)

MP-18A 13346977.24 457584.795 0.5 1.8 1.3MP-18B 13346923.46 457587.333 1.7 6.8 5.1MP-18C 13346878.83 457586.352 0.8 6.2 5.4MP-18D 13346822.49 457591.495 4.4 10 5.6MP-18E 13346753.628 457585.192 1.2 3.2 2MP-19A 13346988.86 457603.215 0.7 2.3 1.6MP-19B 13346980.05 457621.167 1.4 7.5 6.1MP-19C 13346971.3 457641.922 1.9 6.3 4.4MP-19D 13346960.81 457665.118 1.8 8 6.2MP-19E 13346945.77 457688.323 0.8 2.1 1.3MP-20A 13347068.06 457648.878 0.9 2.8 1.9MP-20B 13347050.86 457670.091 0.8 4.9 4.1MP-20C 13347040.28 457688.337 1.1 5.7 4.6MP-20D 13347031.67 457708.679 1.2 6.6 5.4MP-20E 13347016.99 457729.389 0.6 1.9 1.3MP-21A 13347135.62 457745.042 0.4 4.2 3.8MP-21B 13347126.95 457754.477 2.5 5.7 3.2MP-21C 13347120.11 457763.595 1.2 6 4.8MP-21D 13347111.31 457772.676 1.2 4.4 3.2MP-21E 13347082.435 457770.587 0.4 2 1.6MP-22A 13347218.29 457851.771 0.8 2.1 1.3MP-22B 13347212.35 457861.551 2.2 4.6 2.4MP-22C 13347203.16 457867.094 2 6.9 4.9MP-22D 13347191.74 457875.468 1.8 5.4 3.6MP-23A 13347260.64 457894.975 1.1 4.6 3.5MP-23B 13347254.12 457907.401 0.9 5.9 5MP-23C 13347244.85 457915.096 1.5 5.3 3.8MP-23D 13347235.24 457929.029 1.2 4.6 3.4MP-23E 13347224 457937.286 0.8 3.8 3MP-25A 13347384.53 457922.808 0.3 4.1 3.8MP-25B 13347391.63 457957.374 0.8 6.1 5.3MP-25C 13347398.09 457993.903 1.6 6.8 5.2MP-25D 13347405.14 458031.653 1.4 7.6 6.2MP-25E 13347411.36 458057.358 2.9 7 4.1MP-27A 13347567.25 457861.063 0.3 4.5 4.2MP-27B 13347584.29 457913.684 1.5 7.2 5.7MP-27C 13347594.15 457951.683 1.7 3.8 2.1MP-27D 13347609.61 457987.211 2.2 5.8 3.6MP-27E 13347637.62 458026.972 0.7 10 9.3MP-29A 13347718.62 457828.146 0.3 2.4 2.1MP-29B 13347735.98 457842.046 1.5 3.7 2.2MP-29C 13347747.74 457853.499 2 4.6 2.6MP-29D 13347759.53 457861.925 1.6 4.3 2.7MP-29E 13347771.63 457871.359 1.1 2.6 1.5MP-31B 13347790.13 457634.539 1.4 4.5 3.1MP-31C 13347821.52 457657.865 1.9 5.9 4MP-31D 13347862.91 457668.513 1.8 2.8 1MP-33A 13347951.16 457459.091 1.2 10.8 9.6MP-33B 13347966.48 457482.61 1.6 5.1 3.5MP-33C 13347985.46 457509.764 1.6 5.5 3.9MP-33D 13348206.757 457481.915 1.4 6.3 4.9MP-35A 13348207.61 457391.833 1.7 5.5 3.8MP-35B 13348203.489 457423.067 1.1 8.3 7.2MP-35C 13348205.123 457452.491 1.45 11.2 9.75

GPS Data Davisburg Mill Pond,Oakland County


Sample Location

Latitude1

(°)Longitude1

(°)Northing2

(feet)Easting2

(feet)

DMP-1 42.7522427 -83.5384611 457444.609 13345787.93DMP-2 42.7517321 -83.53801 457259.751 13345910.89DMP-3 42.7512508 -83.537157 457086.615 13346141.7DMP-4 42.7509087 -83.535386 456966.615 13346618.58DMP-5 42.7514411 -83.5345226 457162.947 13346848.53DMP-6 42.7519045 -83.5340961 457332.951 13346961.39DMP-7 42.7528917 -83.5339367 457693.108 13347000.64DMP-8 42.7535076 -83.53303 457919.945 13347241.93DMP-9 42.753228 -83.5310608 457823.325 13347771.76

DMP-10 42.7527731 -83.5307926 457658.26 13347845.43

'1 = Latitude and Longitude coordinates measured using WGS84 datum.'2 = Northing and Easting coordinates measured using NAD83 datum and projected in Michigan State Plane South.

Table #3(Page 4 of 5)Job ID:

Report Date:Client:Attention:Project Name:Project Number:

190-16632-1 190-16632-3 190-16632-5 190-16632-7 190-16632-9DMP-1 DMP-2 DMP-3 DMP-4 DMP-5

6/19/2018 6/19/2018 6/19/2018 6/19/2018 6/19/20186/20/2018 6/20/2018 6/20/2018 6/20/2018 6/20/2018

Analyte Units Method

Arsenic mg/kg 6020 5,800 4,600 4,600 NLV 7,600 33 28 20 7.2 4 3.9Barium mg/kg 6010B 75,000 1.E+06 (G) NLV 4.E+07 46 59 63 38 140Cadmium mg/kg 6010B 1,200 6,000 (G,X) NLV 6.E+05 4.98 0.31 0.17 0.16 0.23 0.14Chromium mg/kg 6010B 18,000 1.0E+9 (D) (G,X) NLV 8.E+08 111 7.7 8.2 7.6 13 22Copper mg/kg 6020 32,000 6.E+06 (G) NLV 2.E+07 149 10 5.6 5.6 14 15Lead mg/kg 6020 21,000 7.E+05 (G,X) NLV 4.E+05 128 4.2 7 3.2 7.9 8.9Mercury mg/kg 7471A 130 1,700 50 (M); 1.2 48,000 2.E+05 1.06 <0.096 <0.079 0.035 (J) <0.047 0.036 (J)Selenium mg/kg 6020 410 4,000 400 NLV 3.E+06 1.90 3 (B) 0.82 (B) 0.76 (B) 0.51 (B) 0.38 (B)Silver mg/kg 6020 1,000 4,500 100 (M); 27 NLV 3.E+06 <0.19 <0.14 0.036 (J) 0.055 (J) 0.046 (J)Zinc mg/kg 6010B 47,000 2.E+06 (G) NLV 2.E+08 459 40 25 18 42 36

Anthracene ug/kg 8270 NA 3.E+05 8,700 2.E+08 4.E+07 845 <630 7.1 (J) <510 <340 <350Benz[a]anthracene ug/kg 8270 NA NLL NLL NLV 2.E+04 1,050 <630 36 (J) <510 <340 <350Benzo[a]pyrene ug/kg 8270 NA NLL NLL NLV 2,000 1,450 <630 41 (J) <510 <340 <350Chrysene ug/kg 8270 NA NLL NLL ID 2.E+06 1,290 <630 43 (J) <510 <340 <350Fluoranthene ug/kg 8270 NA 7.E+05 5,500 1.0E+9 (D) 5.E+07 2,230 <630 86 (J) <510 5.3 (J) <350Fluorene ug/kg 8270 NA 4.E+05 5,300 6.E+08 3.E+07 536 <630 <510 <510 <340 <350Naphthalene ug/kg 8270 NA 4.E+04 730 3.E+05 2.E+07 561 <630 <510 <510 <340 <350Phenanthrene ug/kg 8270 NA 6.E+04 2,100 3.E+06 2.E+06 1,170 <630 42 (J) <510 <340 <350Pyrene ug/kg 8270 NA 5.E+05 ID 1.0E+9 (D) 3.E+07 1,520 <630 68 (J) <510 <340 <350

Biochemical Oxygen Demand mg/L 5210B 250 150 2,300 200 170 150% Total Solids % 2540 B NA NA NA NA NA 41.7 51.2 51.6 75.9 73.9

“G” refers to Footnote G of the Criteria/RBSLs tables. The GSI criteria must be calculated.

"J" flag after value means that contaminant was found at less than the reporting limit but greater than the method detection limit and concentration is an appoximate value.

Metals

PAHs

General Chemistry

"B" flag after value means that contaminant was found in blank sample.

“ID” means insufficient data to develop criterion.“NA” means a criterion or value is not available or, in the case of background, not applicable.“NLL” means hazardous substance is not likely to leach under most soil conditions.“NLV” means hazardous substance is not likely to volatilize under most conditions.

Letters in criteria columns refer to Footnotes of the Criteria/RBSLs tables.

Orange indicates contaminant exceeds one or more criteria; SVIIC and/or DCC.Red indicates value exceeds Aquatic Life and Wildlife Screening Levels.

Grey indicates contaminant was detected.Yellow indicates contaminant exceeds DWPC.Blue indicates contaminant exceeds GSIPC.Green indicates contaminant exceeds both DWPC and GSIPC.

Test America Analytical Report

Sample Number Statewide Default

Background Level

(SDBL)

Drinking Water

Protection Criteria (DWPC)

Groundwater Surface Water

Protection Criteria (GSIPC)

Sample IDSample DepthDate CollectedDate Received

Aquatic Life and Wildlife

Screening Levels

190-16632-17/5/2018DNRJulie OakesDavisburg Mill PondDam ID 244

Soil Volatilization to

Indoor Air Inhalation

Criteria (SVIIC)

Direct Contact Criteria (DCC)

Table #3(Page 5 of 5)Job ID:

Report Date:Client:Attention:Project Name:Project Number:

Analyte Units Method

Arsenic mg/kg 6020 5,800 4,600 4,600 NLV 7,600 33Barium mg/kg 6010B 75,000 1.E+06 (G) NLV 4.E+07 Cadmium mg/kg 6010B 1,200 6,000 (G,X) NLV 6.E+05 4.98Chromium mg/kg 6010B 18,000 1.0E+9 (D) (G,X) NLV 8.E+08 111Copper mg/kg 6020 32,000 6.E+06 (G) NLV 2.E+07 149Lead mg/kg 6020 21,000 7.E+05 (G,X) NLV 4.E+05 128Mercury mg/kg 7471A 130 1,700 50 (M); 1.2 48,000 2.E+05 1.06Selenium mg/kg 6020 410 4,000 400 NLV 3.E+06 1.90Silver mg/kg 6020 1,000 4,500 100 (M); 27 NLV 3.E+06Zinc mg/kg 6010B 47,000 2.E+06 (G) NLV 2.E+08 459

Anthracene ug/kg 8270 NA 3.E+05 8,700 2.E+08 4.E+07 845Benz[a]anthracene ug/kg 8270 NA NLL NLL NLV 2.E+04 1,050Benzo[a]pyrene ug/kg 8270 NA NLL NLL NLV 2,000 1,450Chrysene ug/kg 8270 NA NLL NLL ID 2.E+06 1,290Fluoranthene ug/kg 8270 NA 7.E+05 5,500 1.0E+9 (D) 5.E+07 2,230Fluorene ug/kg 8270 NA 4.E+05 5,300 6.E+08 3.E+07 536Naphthalene ug/kg 8270 NA 4.E+04 730 3.E+05 2.E+07 561Phenanthrene ug/kg 8270 NA 6.E+04 2,100 3.E+06 2.E+06 1,170Pyrene ug/kg 8270 NA 5.E+05 ID 1.0E+9 (D) 3.E+07 1,520

Biochemical Oxygen Demand mg/L 5210B 250% Total Solids % 2540 B NA NA NA NA NA

“G” refers to Footnote G of the Criteria/RBSLs tables. The GSI criteria must be calculated.

"J" flag after value means that contaminant was found at less than the reporting limit but greater than the method detection limit and concentration is an appoximate value.

Metals

PAHs

General Chemistry

"B" flag after value means that contaminant was found in blank sample.

“ID” means insufficient data to develop criterion.“NA” means a criterion or value is not available or, in the case of background, not applicable.“NLL” means hazardous substance is not likely to leach under most soil conditions.“NLV” means hazardous substance is not likely to volatilize under most conditions.

Letters in criteria columns refer to Footnotes of the Criteria/RBSLs tables.

Orange indicates contaminant exceeds one or more criteria; SVIIC and/or DCC.Red indicates value exceeds Aquatic Life and Wildlife Screening Levels.

Grey indicates contaminant was detected.Yellow indicates contaminant exceeds DWPC.Blue indicates contaminant exceeds GSIPC.Green indicates contaminant exceeds both DWPC and GSIPC.

Test America Analytical Report

Sample Number Statewide Default

Background Level

(SDBL)

Drinking Water

Protection Criteria (DWPC)

Groundwater Surface Water

Protection Criteria (GSIPC)

Sample IDSample DepthDate CollectedDate Received

Aquatic Life and Wildlife

Screening Levels

190-16632-17/5/2018DNRJulie OakesDavisburg Mill PondDam ID 244

Soil Volatilization to

Indoor Air Inhalation

Criteria (SVIIC)

Direct Contact Criteria (DCC)

190-16632-11 190-16632-13 190-16632-15 190-16632-17 190-16632-19DMP-6 DMP-7 DMP-8 DMP-9 DMP-10

6/19/2018 6/19/2018 6/19/2018 6/19/2018 6/19/20186/20/2018 6/20/2018 6/20/2018 6/20/2018 6/20/2018

9.9 14 31 8 1567 37 210 100 64

0.21 0.18 0.27 0.089 (J) 0.097 (J)8 6.6 9.4 4.1 5.3

5.7 7.3 9.2 3.9 3.73.1 4.7 4.7 2.4 3.7

<0.092 <0.057 0.051 (J) <0.077 <0.0740.38 (B) 0.38 (B) 1.3 (B) 0.39 (B) <0.25<0.14 <0.11 <0.017 <0.12 <0.12

20 18 36 14 20

<600 <390 <640 <450 <470<600 <390 19 (J) <450 9.3 (J)<600 <390 19 (J) <450 9.9 (J)<600 <390 23 (J) <450 11 (J)10 (J) <390 46 (J) <450 23 (J)<600 <390 <640 <450 <470<600 <390 <640 <450 <470<600 <390 20 (J) <450 13 (J)

7.7 (J) <390 37 (J) <450 20 (J)

150 220 640 120 32043.6 67.6 40.5 58 55.1

APPENDIX A

Davisburg Mill Pond, Oakland County

DEQ Photo Log

Photo 1: Advancing sediment core from barge

Photo 2: Pulling sediment core at location

Photo 3: Sediment core processing area

Photo 4: Logging sediment core

APPENDIX B


DEQ Sediment Core Logs

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:

SECTION:LOCATION DESCRIPTION:

DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:

TOTAL DEPTH:ERNIE ID#

VERTICAL DATUM:GRD. ELEVATION:

T.O.C.:S.W.L.:

CASING:SCREEN:

WELL DEPTH:COMPLETION NOTES:

LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

10

SAM

PLE

ID

SAM

PLE

TYPE

NOTES

Davisburg Mill Pond DamDMP-1

Oakland

Springfield

4N

8E

17Mill Pond Dam Impoundment

6/19/2018

B. Eustice

B. Lower

Post Pounder

20.5' in 9.25' of water

River Bottom

FINESDark brown - black, fines with organics, very soft.

PEAT and FINESDark brown, organic rich peat, gray silt streaks from 5.3-5.6ft, moist to wet.

SILTGray, wet, firm.

SANDDark gray, fine grain, some silt, well sorted.

No recovery

E.O.B.

DMP-1

1 100ppbPID

42.7522427

-83.5384611

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder

5.8' in 0.8' of water

River Bottom

FINESDark gray - black, very soft.

SANDY GRAVELSmall to large gravel, poorly sorted.

No recovery

E.O.B.

DMP-10

1 100ppbPID

42.7527731

-83.5307926

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder

17.5' in 13.5' of water

River Bottom

FINESDark gray - black, very soft.

SANDDark brown - gray, trace gravel, poorly sorted, soft to firm, wet.

ORGANICSDark brown organic rich layer.

SANDY GRAVELCoarse grain sand, large rounded gravel.

No recovery

E.O.B.

DMP-2

1 100ppbPID

42.7517321

-83.53801

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

10

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder

19.5' in 10.5' of water

River Bottom

FINESDark brown - black, fines with organics, very soft.

PEATPeaty material with some sand lenses.

SANDY GRAVELSand with small, well rounded gravel.

SANDY CLAYGray, fine grain sand, trace gravel, cohesive, moist.

No recovery

E.O.B.

DMP-3

1 100ppbPID

42.7512508

-83.537157

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

10

15

20

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder


River Bottom

FINESDark brown - black, very soft.

SANDY GRAVELBrown, small to large gravel, poorly sorted.

SAND and CLAYGray, medium to coarse grain, slightly plastic, thickly layered.

No recovery

E.O.B.

DMP-4

1 100ppbPID

42.7509087

-83.535386

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder


River Bottom

CLAYGray, trace organics (wood debris), firm to stiff, moist.

No recovery

E.O.B.

DMP-5

1 100ppbPID

42.7514411

-83.5345226

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder

9.5' in 2' of water

River Bottom


PEATPeat layer, wood debris.

SANDBrown - dark gray, coarse grain.

No recovery

E.O.B.

DMP-6

1 100ppbPID

42.7519045

-83.5340961

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

10

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder

11.75' in 1.3' of water

River Bottom


SANDY GRAVELAngular and rounded gravel, well sorted.

SILTY SANDDark gray, fine to medium grain, wet.

SANDY SILTGray - brown, fine grain, trace gravel and shell fragments.

No recovery

E.O.B.

DMP-7

1 100ppbPID

42.7528917

-83.5339367

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder

6' in 1.3' of water

River Bottom


PEATDark brown, wood debris.

SAND and GRAVELDark gray, small to large, well rounded gravel.

No recovery

E.O.B.

DMP-8

1 100ppbPID

42.7535076

-83.53303

SITE: BORING/WELL:

COUNTY:

TOWNSHIP:

TOWN:

RANGE:


DATE:

DRILLER:

GEOLOGIST:

DRILL METHOD:



T.O.C.:S.W.L.:

CASING:SCREEN:


LATITUDE:

LONGITUDE:

PROJECTION:

NORTHING:

EASTING:

BOREHOLE LOG

WELLCONSTRUCTION

LITH

OLO

GIC

LOG

DESCRIPTION

DEP

TH

0

5

SAM

PLE

ID

SAM

PLE

TYPE

NOTES


Oakland

Springfield

4N

8E


6/19/2018

B. Eustice

B. Lower

Post Pounder


River Bottom


GRAVEL and SANDSmall to medium gravel, well rounded.

SANDY SILTGray to light brown, fine grain, trace gravel, vertical roots throughout.

No recovery

E.O.B.

DMP-9

1 100ppbPID

42.753228

-83.5310608

APPENDIX C


Test America Laboratory Results

ANALYTICAL REPORTTestAmerica Laboratories, Inc.TestAmerica Michigan10448 Citation DriveSuite 200Brighton, MI 48116Tel: (810)229-2763

TestAmerica Job ID: 190-16632-1Client Project/Site: Davisburg Mill Pond

For:Michigan Dept. of Environmental Quality8100 GrangeHall RoadHolly, Michigan 48442

Attn: Julie Oak

Authorized for release by:7/5/2018 10:58:17 AMPatrick O'Meara, Manager of Project Management(330)[email protected] forKris Brooks, Project Manager II(330)[email protected]

This report has been electronically signed and authorized by the signatory. Electronic signature isintended to be the legally binding equivalent of a traditionally handwritten signature.

Results relate only to the items tested and the sample(s) as received by the laboratory.

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https://secure.testamericainc.com/TotalAccess/login.aspx

http://www.testamericainc.com/AskTheExpert/Expert_index.htm

http://www.testamericainc.com

mailto:[email protected]

mailto:[email protected]

Table of Contents

Client: Michigan Dept. of Environmental QualityProject/Site: Davisburg Mill Pond

TestAmerica Job ID: 190-16632-1

Page 2 of 28TestAmerica Michigan

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Cover Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Sample Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Case Narrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Client Sample Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6QC Sample Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Definitions/Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Chain of Custody . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

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Sample SummaryTestAmerica Job ID: 190-16632-1Client: Michigan Dept. of Environmental Quality

Project/Site: Davisburg Mill Pond

Lab Sample ID Client Sample ID ReceivedCollectedMatrix190-16632-1 DMP-1 Water Water 06/19/18 16:35 06/20/18 09:26190-16632-2 DMP-1 Solid Solid 06/19/18 16:35 06/20/18 09:26190-16632-3 DMP-2 Water Water 06/19/18 16:50 06/20/18 09:26190-16632-4 DMP-2 Solid Solid 06/19/18 16:50 06/20/18 09:26190-16632-5 DMP-3 Water Water 06/19/18 17:05 06/20/18 09:26190-16632-6 DMP-3 Solid Solid 06/19/18 17:05 06/20/18 09:26190-16632-7 DMP-4 Water Water 06/19/18 17:15 06/20/18 09:26190-16632-8 DMP-4 Solid Solid 06/19/18 17:15 06/20/18 09:26190-16632-9 DMP-5 Water Water 06/19/18 17:25 06/20/18 09:26190-16632-10 DMP-5 Solid Solid 06/19/18 17:25 06/20/18 09:26190-16632-11 DMP-6 Water Water 06/19/18 17:35 06/20/18 09:26190-16632-12 DMP-6 Solid Solid 06/19/18 17:35 06/20/18 09:26190-16632-13 DMP-7 Water Water 06/19/18 17:45 06/20/18 09:26190-16632-14 DMP-7 Solid Solid 06/19/18 17:45 06/20/18 09:26190-16632-15 DMP-8 Water Water 06/19/18 17:50 06/20/18 09:26190-16632-16 DMP-8 Solid Solid 06/19/18 17:50 06/20/18 09:26190-16632-17 DMP-9 Water Water 06/19/18 17:55 06/20/18 09:26190-16632-18 DMP-9 Solid Solid 06/19/18 17:55 06/20/18 09:26190-16632-19 DMP-10 Water Water 06/19/18 18:05 06/20/18 09:26190-16632-20 DMP-10 Solid Solid 06/19/18 18:05 06/20/18 09:26

TestAmerica Michigan

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Case NarrativeClient: Michigan Dept. of Environmental Quality TestAmerica Job ID: 190-16632-1Project/Site: Davisburg Mill Pond

Job ID: 190-16632-1Laboratory: TestAmerica Michigan

Narrative

CASE NARRATIVE

Client: Michigan Dept. of Environmental Quality

Project: Davisburg Mill Pond

Report Number: 190-16632-1

With the exceptions noted as flags or footnotes, standard analytical protocols were followed in the analysis of the samples and no problems were encountered or anomalies observed. In addition all laboratory quality control samples were within established control limits, with any exceptions noted below. Each sample was analyzed to achieve the lowest possible reporting limit within the constraints of the method. In some cases, due to interference or analytes present at high concentrations, samples were diluted. For diluted samples, the reporting limits are adjusted relative to the dilution required.

TestAmerica Canton attests to the validity of the laboratory data generated by TestAmerica facilities reported herein. All analyses performed by TestAmerica facilities were done using established laboratory SOPs that incorporate QA/QC procedures described in the application methods. TestAmerica’s operations groups have reviewed the data for compliance with the laboratory QA/QC plan, and data have been found to be compliant with laboratory protocols unless otherwise noted below.

The 5210B Biochemical Oxygen Demand analysis was performed at the TestAmerica Michigan laboratory.

The test results in this report meet all NELAP requirements for parameters for which accreditation is required or available. Any exceptions to NELAP requirements are noted in this report. Pursuant to NELAP, this report may not be reproduced, except in full, without the written approval of the laboratory.

Calculations are performed before rounding to avoid round-off errors in calculated results.

All holding times were met and proper preservation noted for the methods performed on these samples, unless otherwise detailed in the individual sections below.

This laboratory report is confidential and is intended for the sole use of TestAmerica and its client.

RECEIPTThe samples were received on 6/20/2018 9:26 AM; the samples arrived in good condition, properly preserved and, where required, on ice. The temperature of the cooler at receipt was 11.0º C.

SEMIVOLATILE ORGANIC COMPOUNDS (GCMS)Samples DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20) were analyzed for semivolatile organic compounds (GCMS) in accordance with EPA SW-846 Method 8270C. The samples were prepared on 06/22/2018 and 06/28/2018 and analyzed on 06/25/2018, 06/27/2018 and 07/02/2018.

Surrogates are added during the extraction process prior to dilution. When the sample is diluted, surrogate recoveries are diluted out and no corrective action is required.

No additional analytical or quality issues were noted, other than those described above or in the Definitions/Glossary page.

TOTAL METALS (ICP)Samples DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20) were analyzed for total metals (ICP) in accordance with EPA SW-846 Method 6010B. The samples

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Case NarrativeClient: Michigan Dept. of Environmental Quality TestAmerica Job ID: 190-16632-1Project/Site: Davisburg Mill Pond

Job ID: 190-16632-1 (Continued)Laboratory: TestAmerica Michigan (Continued)were prepared on 06/22/2018 and analyzed on 06/27/2018.

Sample DMP-8 Solid (190-16632-16)[2X] required dilution prior to analysis. The reporting limits have been adjusted accordingly.

Some requested practical quantitation limits (PQLs) on the following samples fall below the laboratory's verified standard quantitation limit: DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20). The continuing calibration blanks and method blanks may not support the lower PQL.


TOTAL METALS (ICPMS)Samples DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20) were analyzed for total metals (ICPMS) in accordance with EPA SW-846 Method 6020. The samples were prepared on 06/22/2018 and analyzed on 06/23/2018 and 06/24/2018.

Selenium was detected in method blank MB 240-332943/1-A at a level exceeding the reporting limit. If the associated sample reported a result above the MDL and/or RL, the result has been flagged.

Some requested practical quantitation limits (PQLs) on the following samples fall below the laboratory's verified standard quantitation limit: DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20)The continuing calibration blanks and method blanks may not support the lower PQL.


TOTAL MERCURYSamples DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20) were analyzed for total mercury in accordance with EPA SW-846 Method 7471A. The samples were prepared on 06/22/2018 and analyzed on 06/26/2018.

No analytical or quality issues were noted, other than those described above or in the Definitions/Glossary page.

BIOCHEMICAL OXYGEN DEMANDSamples DMP-1 Water (190-16632-1), DMP-2 Water (190-16632-3), DMP-3 Water (190-16632-5), DMP-4 Water (190-16632-7), DMP-5 Water (190-16632-9), DMP-6 Water (190-16632-11), DMP-7 Water (190-16632-13), DMP-8 Water (190-16632-15), DMP-9 Water (190-16632-17) and DMP-10 Water (190-16632-19) were analyzed for Biochemical oxygen demand in accordance with SM 5210B. The samples were analyzed on 06/20/2018.

Biochemical Oxygen Demand was detected in method blank SCB 190-8818/2 at a level exceeding the reporting limit.


PERCENT SOLIDSSamples DMP-1 Solid (190-16632-2), DMP-2 Solid (190-16632-4), DMP-3 Solid (190-16632-6), DMP-4 Solid (190-16632-8), DMP-5 Solid (190-16632-10), DMP-6 Solid (190-16632-12), DMP-7 Solid (190-16632-14), DMP-8 Solid (190-16632-16), DMP-9 Solid (190-16632-18) and DMP-10 Solid (190-16632-20) were analyzed for percent solids in accordance with ASTM Method D2216-80. The samples were analyzed on 06/25/2018.

No analytical or quality issues were noted, other than those described above or in the Definitions/Glossary page.

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Client Sample ResultsTestAmerica Job ID: 190-16632-1Client: Michigan Dept. of Environmental Quality


Lab Sample ID: 190-16632-1Client Sample ID: DMP-1 WaterMatrix: WaterDate Collected: 06/19/18 16:35

Date Received: 06/20/18 09:26

General ChemistryRL MDL

Biochemical Oxygen Demand 150 60 15 ppm 06/20/18 16:28 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

Lab Sample ID: 190-16632-2Client Sample ID: DMP-1 SolidMatrix: SolidDate Collected: 06/19/18 16:35

Percent Solids: 41.7Date Received: 06/20/18 09:26

Method: 8270C - Semivolatile Organic Compounds (GC/MS)RL MDL

Benzo[a]anthracene <630 630 1.5 ug/Kg ☼ 06/22/18 08:29 06/25/18 18:09 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

630 1.5 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Benzo[a]pyrene <630630 1.4 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Benzo[b]fluoranthene <630630 0.84 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Benzo[g,h,i]perylene <630630 1.6 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Benzo[k]fluoranthene <630630 1.9 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Anthracene <630630 2.6 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Chrysene <630630 1.6 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Dibenz(a,h)anthracene <630630 1.3 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Fluoranthene <630630 1.3 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Fluorene <630630 0.84 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Indeno[1,2,3-cd]pyrene <630630 1.7 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Phenanthrene <630630 1.1 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Pyrene <630630 1.8 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Acenaphthene <630630 0.84 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Acenaphthylene <630630 2.0 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼Naphthalene <630630 1.2 ug/Kg 06/22/18 08:29 06/25/18 18:09 1☼2-Methylnaphthalene <630

2-Fluorobiphenyl (Surr) 80 32 - 120 06/22/18 08:29 06/25/18 18:09 1

Surrogate Dil FacAnalyzedPreparedQualifier Limits%Recovery

2-Fluorophenol (Surr) 79 06/22/18 08:29 06/25/18 18:09 129 - 120

2,4,6-Tribromophenol (Surr) 64 06/22/18 08:29 06/25/18 18:09 110 - 120

Nitrobenzene-d5 (Surr) 71 06/22/18 08:29 06/25/18 18:09 130 - 120

Phenol-d5 (Surr) 83 06/22/18 08:29 06/25/18 18:09 129 - 120

Terphenyl-d14 (Surr) 88 06/22/18 08:29 06/25/18 18:09 141 - 120

Method: 6010B - Metals (ICP)RL MDL

Barium 46 1.9 0.86 mg/Kg ☼ 06/22/18 15:00 06/27/18 01:01 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

0.19 0.11 mg/Kg 06/22/18 15:00 06/27/18 01:01 1☼Cadmium 0.311.9 0.36 mg/Kg 06/22/18 15:00 06/27/18 01:01 1☼Chromium 7.74.7 3.2 mg/Kg 06/22/18 15:00 06/27/18 01:01 1☼Zinc 40

Method: 6020 - Metals (ICP/MS)RL MDL

Arsenic 28 0.19 0.14 mg/Kg ☼ 06/22/18 15:00 06/23/18 23:15 2Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

0.95 0.54 mg/Kg 06/22/18 15:00 06/23/18 23:15 2☼Copper 100.47 0.15 mg/Kg 06/22/18 15:00 06/23/18 23:15 2☼Lead 4.20.38 0.28 mg/Kg 06/22/18 15:00 06/23/18 23:15 2☼Selenium 3.0 B0.19 0.052 mg/Kg 06/22/18 15:00 06/23/18 23:15 2☼Silver <0.19


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Method: 7471A - Mercury (CVAA)RL MDL

Mercury <0.096 0.096 0.043 mg/Kg ☼ 06/22/18 16:00 06/26/18 17:03 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier


Percent Solids 41.7 0.1 0.1 % 06/25/18 15:57 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

0.1 0.1 % 06/25/18 15:57 1Percent Moisture 58.3








Benzo[a]anthracene 36 J 510 1.2 ug/Kg ☼ 06/22/18 08:29 06/25/18 15:29 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

510 1.2 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Benzo[a]pyrene 41 J510 1.1 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Benzo[b]fluoranthene 66 J510 0.68 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Benzo[g,h,i]perylene 21 J510 1.3 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Benzo[k]fluoranthene 29 J510 1.5 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Anthracene 7.1 J510 2.1 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Chrysene 43 J510 1.3 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Dibenz(a,h)anthracene <510510 1.1 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Fluoranthene 86 J510 1.0 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Fluorene <510510 0.68 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Indeno[1,2,3-cd]pyrene 22 J510 1.4 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Phenanthrene 42 J510 0.85 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Pyrene 68 J510 1.5 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Acenaphthene <510510 0.68 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Acenaphthylene <510510 1.6 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼Naphthalene <510510 0.97 ug/Kg 06/22/18 08:29 06/25/18 15:29 1☼2-Methylnaphthalene <510






Phenol-d5 (Surr) 64 06/22/18 08:29 06/25/18 15:29 129 - 120

Terphenyl-d14 (Surr) 75 06/22/18 08:29 06/25/18 15:29 141 - 120



0.14 0.082 mg/Kg 06/22/18 15:00 06/27/18 01:06 1☼Cadmium 0.17


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Method: 6010B - Metals (ICP) (Continued)RL MDL

Chromium 8.2 1.4 0.26 mg/Kg ☼ 06/22/18 15:00 06/27/18 01:06 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

3.4 2.3 mg/Kg 06/22/18 15:00 06/27/18 01:06 1☼Zinc 25



0.68 0.39 mg/Kg 06/22/18 15:00 06/23/18 23:37 2☼Copper 5.60.34 0.11 mg/Kg 06/22/18 15:00 06/23/18 23:37 2☼Lead 7.00.27 0.21 mg/Kg 06/22/18 15:00 06/23/18 23:37 2☼Selenium 0.82 B0.14 0.038 mg/Kg 06/22/18 15:00 06/23/18 23:37 2☼Silver <0.14
















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Phenol-d5 (Surr) 60 06/22/18 08:29 06/27/18 14:46 129 - 120

Terphenyl-d14 (Surr) 62 06/22/18 08:29 06/27/18 14:46 141 - 120





Arsenic 7.5 0.11 0.081 mg/Kg ☼ 06/22/18 15:00 06/23/18 23:42 2Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

0.54 0.31 mg/Kg 06/22/18 15:00 06/23/18 23:42 2☼Copper 5.60.27 0.084 mg/Kg 06/22/18 15:00 06/23/18 23:42 2☼Lead 3.20.22 0.16 mg/Kg 06/22/18 15:00 06/23/18 23:42 2☼Selenium 0.76 B0.11 0.030 mg/Kg 06/22/18 15:00 06/23/18 23:42 2☼Silver 0.036 J


Mercury 0.035 J 0.079 0.035 mg/Kg ☼ 06/22/18 16:00 06/26/18 17:07 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier












340 0.83 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Benzo[a]pyrene <340340 0.76 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Benzo[b]fluoranthene <340340 0.45 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Benzo[g,h,i]perylene <340340 0.88 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Benzo[k]fluoranthene <340340 1.0 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Anthracene <340340 1.4 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Chrysene <340340 0.86 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Dibenz(a,h)anthracene <340340 0.71 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Fluoranthene 5.3 J340 0.69 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Fluorene <340340 0.45 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Indeno[1,2,3-cd]pyrene <340


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Method: 8270C - Semivolatile Organic Compounds (GC/MS) (Continued)RL MDL

Phenanthrene <340 340 0.95 ug/Kg ☼ 06/28/18 08:59 07/02/18 14:52 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

340 0.57 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Pyrene <340340 0.99 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Acenaphthene <340340 0.45 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Acenaphthylene <340340 1.1 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼Naphthalene <340340 0.65 ug/Kg 06/28/18 08:59 07/02/18 14:52 1☼2-Methylnaphthalene <340






Phenol-d5 (Surr) 69 06/28/18 08:59 07/02/18 14:52 129 - 120

Terphenyl-d14 (Surr) 77 06/28/18 08:59 07/02/18 14:52 141 - 120



0.084 0.050 mg/Kg 06/22/18 15:00 06/27/18 01:17 1☼Cadmium 0.230.84 0.16 mg/Kg 06/22/18 15:00 06/27/18 01:17 1☼Chromium 13

2.1 1.4 mg/Kg 06/22/18 15:00 06/27/18 01:17 1☼Zinc 42



0.42 0.24 mg/Kg 06/22/18 15:00 06/23/18 23:55 2☼Copper 140.21 0.065 mg/Kg 06/22/18 15:00 06/23/18 23:55 2☼Lead 7.90.17 0.13 mg/Kg 06/22/18 15:00 06/23/18 23:55 2☼Selenium 0.51 B

0.084 0.023 mg/Kg 06/22/18 15:00 06/23/18 23:55 2☼Silver 0.055 J











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Phenol-d5 (Surr) 54 06/22/18 08:29 06/27/18 15:12 129 - 120

Terphenyl-d14 (Surr) 68 06/22/18 08:29 06/27/18 15:12 141 - 120



0.085 0.051 mg/Kg 06/22/18 15:00 06/27/18 01:22 1☼Cadmium 0.140.85 0.16 mg/Kg 06/22/18 15:00 06/27/18 01:22 1☼Chromium 22

2.1 1.4 mg/Kg 06/22/18 15:00 06/27/18 01:22 1☼Zinc 36



0.42 0.24 mg/Kg 06/22/18 15:00 06/24/18 00:00 2☼Copper 150.21 0.066 mg/Kg 06/22/18 15:00 06/24/18 00:00 2☼Lead 8.90.17 0.13 mg/Kg 06/22/18 15:00 06/24/18 00:00 2☼Selenium 0.38 B

0.085 0.023 mg/Kg 06/22/18 15:00 06/24/18 00:00 2☼Silver 0.046 J







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600 1.4 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Benzo[a]pyrene <600600 1.3 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Benzo[b]fluoranthene <600600 0.79 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Benzo[g,h,i]perylene <600600 1.5 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Benzo[k]fluoranthene <600600 1.8 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Anthracene <600600 2.5 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Chrysene <600600 1.5 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Dibenz(a,h)anthracene <600600 1.2 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Fluoranthene 10 J600 1.2 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Fluorene <600600 0.79 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Indeno[1,2,3-cd]pyrene <600600 1.6 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Phenanthrene <600600 0.99 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Pyrene 7.7 J600 1.7 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Acenaphthene <600600 0.79 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Acenaphthylene <600600 1.9 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼Naphthalene <600600 1.1 ug/Kg 06/22/18 08:29 06/25/18 15:56 1☼2-Methylnaphthalene <600






Phenol-d5 (Surr) 71 06/22/18 08:29 06/25/18 15:56 129 - 120

Terphenyl-d14 (Surr) 77 06/22/18 08:29 06/25/18 15:56 141 - 120








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Phenol-d5 (Surr) 73 06/22/18 08:29 06/25/18 16:23 129 - 120

Terphenyl-d14 (Surr) 82 06/22/18 08:29 06/25/18 16:23 141 - 120



0.11 0.068 mg/Kg 06/22/18 15:00 06/27/18 01:32 1☼Cadmium 0.18


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Method: 6010B - Metals (ICP) (Continued)RL MDL

Chromium 6.6 1.1 0.21 mg/Kg ☼ 06/22/18 15:00 06/27/18 01:32 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

2.8 1.9 mg/Kg 06/22/18 15:00 06/27/18 01:32 1☼Zinc 18
















Benzo[a]anthracene 19 J 640 1.5 ug/Kg ☼ 06/22/18 08:29 06/25/18 17:16 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

640 1.6 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Benzo[a]pyrene 19 J640 1.4 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Benzo[b]fluoranthene 28 J640 0.85 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Benzo[g,h,i]perylene <640640 1.7 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Benzo[k]fluoranthene 11 J640 1.9 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Anthracene <640640 2.7 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Chrysene 23 J640 1.6 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Dibenz(a,h)anthracene <640640 1.3 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Fluoranthene 46 J640 1.3 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Fluorene <640640 0.85 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Indeno[1,2,3-cd]pyrene <640640 1.8 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Phenanthrene 20 J640 1.1 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Pyrene 37 J640 1.9 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Acenaphthene <640640 0.85 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Acenaphthylene <640640 2.0 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼Naphthalene <640640 1.2 ug/Kg 06/22/18 08:29 06/25/18 17:16 1☼2-Methylnaphthalene <640


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Phenol-d5 (Surr) 69 06/22/18 08:29 06/25/18 17:16 129 - 120

Terphenyl-d14 (Surr) 73 06/22/18 08:29 06/25/18 17:16 141 - 120




















450 1.1 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Benzo[a]pyrene <450450 1.0 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Benzo[b]fluoranthene <450450 0.59 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Benzo[g,h,i]perylene <450450 1.2 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Benzo[k]fluoranthene <450450 1.3 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Anthracene <450450 1.9 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Chrysene <450450 1.1 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Dibenz(a,h)anthracene <450450 0.93 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Fluoranthene <450450 0.90 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Fluorene <450450 0.59 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Indeno[1,2,3-cd]pyrene <450


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Method: 8270C - Semivolatile Organic Compounds (GC/MS) (Continued)RL MDL

Phenanthrene <450 450 1.2 ug/Kg ☼ 06/22/18 08:29 06/25/18 17:42 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

450 0.75 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Pyrene <450450 1.3 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Acenaphthene <450450 0.59 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Acenaphthylene <450450 1.4 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼Naphthalene <450450 0.85 ug/Kg 06/22/18 08:29 06/25/18 17:42 1☼2-Methylnaphthalene <450






Phenol-d5 (Surr) 66 06/22/18 08:29 06/25/18 17:42 129 - 120

Terphenyl-d14 (Surr) 70 06/22/18 08:29 06/25/18 17:42 141 - 120



0.12 0.070 mg/Kg 06/22/18 15:00 06/27/18 16:08 1☼Cadmium 0.089 J1.2 0.22 mg/Kg 06/22/18 15:00 06/27/18 16:08 1☼Chromium 4.12.9 2.0 mg/Kg 06/22/18 15:00 06/27/18 16:08 1☼Zinc 14














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Benzo[a]anthracene 9.3 J 470 1.1 ug/Kg ☼ 06/22/18 08:29 06/25/18 16:49 1Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

470 1.1 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Benzo[a]pyrene 9.9 J470 1.1 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Benzo[b]fluoranthene 14 J470 0.63 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Benzo[g,h,i]perylene <470470 1.2 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Benzo[k]fluoranthene 7.4 J470 1.4 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Anthracene <470470 2.0 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Chrysene 11 J470 1.2 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Dibenz(a,h)anthracene <470470 0.99 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Fluoranthene 23 J470 0.95 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Fluorene <470470 0.63 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Indeno[1,2,3-cd]pyrene <470470 1.3 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Phenanthrene 13 J470 0.79 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Pyrene 20 J470 1.4 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Acenaphthene <470470 0.63 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Acenaphthylene <470470 1.5 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼Naphthalene <470470 0.90 ug/Kg 06/22/18 08:29 06/25/18 16:49 1☼2-Methylnaphthalene <470






Phenol-d5 (Surr) 71 06/22/18 08:29 06/25/18 16:49 129 - 120

Terphenyl-d14 (Surr) 72 06/22/18 08:29 06/25/18 16:49 141 - 120



0.12 0.074 mg/Kg 06/22/18 15:00 06/27/18 16:13 1☼Cadmium 0.097 J1.2 0.23 mg/Kg 06/22/18 15:00 06/27/18 16:13 1☼Chromium 5.33.1 2.1 mg/Kg 06/22/18 15:00 06/27/18 16:13 1☼Zinc 20



0.62 0.35 mg/Kg 06/22/18 15:00 06/24/18 00:22 2☼Copper 3.70.31 0.096 mg/Kg 06/22/18 15:00 06/24/18 00:22 2☼Lead 3.70.25 0.18 mg/Kg 06/22/18 15:00 06/24/18 00:22 2☼Selenium <0.250.12 0.034 mg/Kg 06/22/18 15:00 06/24/18 00:22 2☼Silver <0.12







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QC Sample ResultsTestAmerica Job ID: 190-16632-1Client: Michigan Dept. of Environmental Quality


Method: 8270C - Semivolatile Organic Compounds (GC/MS)

Client Sample ID: Method BlankLab Sample ID: MB 240-332885/18-AMatrix: Solid Prep Type: Total/NAAnalysis Batch: 333218 Prep Batch: 332885

RL MDLBenzo[a]anthracene <260 260 0.63 ug/Kg 06/22/18 08:29 06/25/18 09:17 1

MB MBAnalyte Dil FacAnalyzedPreparedDUnitResult Qualifier

<260 0.64260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Benzo[a]pyrene<260 0.59260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Benzo[b]fluoranthene<260 0.35260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Benzo[g,h,i]perylene<260 0.68260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Benzo[k]fluoranthene<260 0.78260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Anthracene<260 1.1260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Chrysene<260 0.66260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Dibenz(a,h)anthracene<260 0.55260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Fluoranthene<260 0.53260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Fluorene<260 0.35260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Indeno[1,2,3-cd]pyrene<260 0.73260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Phenanthrene<260 0.44260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Pyrene<260 0.76260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Acenaphthene<260 0.35260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Acenaphthylene<260 0.82260 ug/Kg 06/22/18 08:29 06/25/18 09:17 1Naphthalene<260 0.50260 ug/Kg 06/22/18 08:29 06/25/18 09:17 12-Methylnaphthalene

2-Fluorobiphenyl (Surr) 68 32 - 120 06/25/18 09:17 1

MB MB

Surrogate

06/22/18 08:29

Dil FacPrepared AnalyzedQualifier Limits%Recovery

66 06/22/18 08:29 06/25/18 09:17 12-Fluorophenol (Surr) 29 - 120

55 06/22/18 08:29 06/25/18 09:17 12,4,6-Tribromophenol (Surr) 10 - 120

58 06/22/18 08:29 06/25/18 09:17 1Nitrobenzene-d5 (Surr) 30 - 120

68 06/22/18 08:29 06/25/18 09:17 1Phenol-d5 (Surr) 29 - 120

81 06/22/18 08:29 06/25/18 09:17 1Terphenyl-d14 (Surr) 41 - 120

Client Sample ID: Lab Control SampleLab Sample ID: LCS 240-332885/19-AMatrix: Solid Prep Type: Total/NAAnalysis Batch: 333218 Prep Batch: 332885

Benzo[a]anthracene 667 392 ug/Kg 59 53 - 120Analyte

LCS LCSDUnitResult Qualifier %Rec

SpikeAdded

%Rec.Limits

Benzo[a]pyrene 667 412 ug/Kg 62 50 - 120Benzo[b]fluoranthene 667 413 ug/Kg 62 48 - 120Benzo[g,h,i]perylene 667 424 ug/Kg 64 50 - 120Benzo[k]fluoranthene 667 407 ug/Kg 61 51 - 120Anthracene 667 398 ug/Kg 60 51 - 120Chrysene 667 395 ug/Kg 59 54 - 120Dibenz(a,h)anthracene 667 438 ug/Kg 66 48 - 120Fluoranthene 667 411 ug/Kg 62 53 - 120Fluorene 667 365 ug/Kg 55 50 - 120Indeno[1,2,3-cd]pyrene 667 435 ug/Kg 65 49 - 120Phenanthrene 667 395 ug/Kg 59 52 - 120Pyrene 667 417 ug/Kg 62 55 - 120Acenaphthene 667 373 ug/Kg 56 48 - 120Acenaphthylene 667 366 ug/Kg 55 46 - 120Naphthalene 667 359 ug/Kg 54 48 - 1202-Methylnaphthalene 667 366 ug/Kg 55 49 - 120


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2-Fluorobiphenyl (Surr) 32 - 120

Surrogate

60

LCS LCS

Qualifier Limits%Recovery

582-Fluorophenol (Surr) 29 - 120

532,4,6-Tribromophenol (Surr) 10 - 120

55Nitrobenzene-d5 (Surr) 30 - 120

61Phenol-d5 (Surr) 29 - 120

66Terphenyl-d14 (Surr) 41 - 120


RL MDLBenzo[a]anthracene <260 260 0.63 ug/Kg 06/28/18 10:10 07/02/18 12:50 1


<260 0.64260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Benzo[a]pyrene<260 0.59260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Benzo[b]fluoranthene<260 0.35260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Benzo[g,h,i]perylene<260 0.68260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Benzo[k]fluoranthene<260 0.78260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Anthracene<260 1.1260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Chrysene<260 0.66260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Dibenz(a,h)anthracene<260 0.55260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Fluoranthene<260 0.53260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Fluorene<260 0.35260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Indeno[1,2,3-cd]pyrene<260 0.73260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Phenanthrene<260 0.44260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Pyrene<260 0.76260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Acenaphthene<260 0.35260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Acenaphthylene<260 0.82260 ug/Kg 06/28/18 10:10 07/02/18 12:50 1Naphthalene<260 0.50260 ug/Kg 06/28/18 10:10 07/02/18 12:50 12-Methylnaphthalene

2-Fluorobiphenyl (Surr) 65 32 - 120 07/02/18 12:50 1

MB MB

Surrogate

06/28/18 10:10

Dil FacPrepared AnalyzedQualifier Limits%Recovery

70 06/28/18 10:10 07/02/18 12:50 12-Fluorophenol (Surr) 29 - 120

39 06/28/18 10:10 07/02/18 12:50 12,4,6-Tribromophenol (Surr) 10 - 120

65 06/28/18 10:10 07/02/18 12:50 1Nitrobenzene-d5 (Surr) 30 - 120

70 06/28/18 10:10 07/02/18 12:50 1Phenol-d5 (Surr) 29 - 120

78 06/28/18 10:10 07/02/18 12:50 1Terphenyl-d14 (Surr) 41 - 120


Benzo[a]anthracene 667 512 ug/Kg 77 53 - 120Analyte


SpikeAdded

%Rec.Limits

Benzo[a]pyrene 667 547 ug/Kg 82 50 - 120Benzo[b]fluoranthene 667 507 ug/Kg 76 48 - 120Benzo[g,h,i]perylene 667 590 ug/Kg 89 50 - 120Benzo[k]fluoranthene 667 502 ug/Kg 75 51 - 120Anthracene 667 510 ug/Kg 76 51 - 120Chrysene 667 495 ug/Kg 74 54 - 120Dibenz(a,h)anthracene 667 585 ug/Kg 88 48 - 120Fluoranthene 667 486 ug/Kg 73 53 - 120Fluorene 667 511 ug/Kg 77 50 - 120


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Method: 8270C - Semivolatile Organic Compounds (GC/MS) (Continued)Client Sample ID: Lab Control SampleLab Sample ID: LCS 240-333905/24-A

Matrix: Solid Prep Type: Total/NAAnalysis Batch: 334341 Prep Batch: 333905

Indeno[1,2,3-cd]pyrene 667 590 ug/Kg 89 49 - 120Analyte


SpikeAdded

%Rec.Limits

Phenanthrene 667 481 ug/Kg 72 52 - 120Pyrene 667 526 ug/Kg 79 55 - 120Acenaphthene 667 477 ug/Kg 72 48 - 120Acenaphthylene 667 482 ug/Kg 72 46 - 120Naphthalene 667 438 ug/Kg 66 48 - 1202-Methylnaphthalene 667 460 ug/Kg 69 49 - 120

2-Fluorobiphenyl (Surr) 32 - 120

Surrogate

61

LCS LCS

Qualifier Limits%Recovery

652-Fluorophenol (Surr) 29 - 120

422,4,6-Tribromophenol (Surr) 10 - 120

64Nitrobenzene-d5 (Surr) 30 - 120

66Phenol-d5 (Surr) 29 - 120

74Terphenyl-d14 (Surr) 41 - 120

Method: 6010B - Metals (ICP)


RL MDLBarium <0.80 0.80 0.36 mg/Kg 06/22/18 15:00 06/27/18 15:40 1


<0.080 0.0480.080 mg/Kg 06/22/18 15:00 06/27/18 15:40 1Cadmium<0.80 0.150.80 mg/Kg 06/22/18 15:00 06/27/18 15:40 1Chromium

<2.0 1.42.0 mg/Kg 06/22/18 15:00 06/27/18 15:40 1Zinc


Barium 200 189 mg/Kg 95 80 - 120Analyte


SpikeAdded

%Rec.Limits

Cadmium 5.00 4.87 mg/Kg 97 80 - 120Chromium 20.0 19.6 mg/Kg 98 80 - 120Zinc 50.0 48.7 mg/Kg 97 80 - 120

Method: 6020 - Metals (ICP/MS)

Client Sample ID: Method BlankLab Sample ID: MB 240-332943/1-A ^2Matrix: Solid Prep Type: Total/NAAnalysis Batch: 333143 Prep Batch: 332943

RL MDLArsenic <0.080 0.080 0.060 mg/Kg 06/22/18 15:00 06/23/18 23:06 2


<0.40 0.230.40 mg/Kg 06/22/18 15:00 06/23/18 23:06 2Copper<0.20 0.0620.20 mg/Kg 06/22/18 15:00 06/23/18 23:06 2Lead


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Method: 6020 - Metals (ICP/MS) (Continued)Client Sample ID: Method BlankLab Sample ID: MB 240-332943/1-A ^2

Matrix: Solid Prep Type: Total/NAAnalysis Batch: 333143 Prep Batch: 332943

RL MDLSelenium 0.281 0.16 0.12 mg/Kg 06/22/18 15:00 06/23/18 23:06 2


<0.080 0.0220.080 mg/Kg 06/22/18 15:00 06/23/18 23:06 2Silver

Client Sample ID: Lab Control SampleLab Sample ID: LCS 240-332943/3-A ^2Matrix: Solid Prep Type: Total/NAAnalysis Batch: 333143 Prep Batch: 332943

Arsenic 100 87.8 mg/Kg 88 80 - 120Analyte


SpikeAdded

%Rec.Limits

Copper 100 104 mg/Kg 104 80 - 120Lead 100 98.0 mg/Kg 98 80 - 120Selenium 100 102 mg/Kg 102 80 - 120Silver 10.0 9.68 mg/Kg 97 80 - 120

Client Sample ID: DMP-1 SolidLab Sample ID: 190-16632-2 MSMatrix: Solid Prep Type: Total/NAAnalysis Batch: 333143 Prep Batch: 332943

Arsenic 28 216 216 mg/Kg 87 75 - 125☼Analyte

MS MSDUnitResult Qualifier %Rec

SpikeAdded

SampleResult

SampleQualifier

%Rec.Limits

Copper 10 216 216 mg/Kg 95 75 - 125☼

Lead 4.2 216 206 mg/Kg 93 75 - 125☼

Selenium 3.0 B 216 215 mg/Kg 98 75 - 125☼

Silver <0.19 21.6 20.7 mg/Kg 96 75 - 125☼

Client Sample ID: DMP-1 SolidLab Sample ID: 190-16632-2 MSDMatrix: Solid Prep Type: Total/NAAnalysis Batch: 333143 Prep Batch: 332943

Arsenic 28 216 226 mg/Kg 92 75 - 125 5 20☼Analyte

MSD MSDDUnitResult Qualifier %Rec

SpikeAdded

SampleResult

SampleQualifier

%Rec.Limits LimitRPD

RPD

Copper 10 216 226 mg/Kg 100 75 - 125 5 20☼

Lead 4.2 216 211 mg/Kg 96 75 - 125 2 20☼

Selenium 3.0 B 216 221 mg/Kg 101 75 - 125 3 20☼

Silver <0.19 21.6 21.0 mg/Kg 97 75 - 125 2 20☼

Method: 7471A - Mercury (CVAA)


RL MDLMercury <0.040 0.040 0.018 mg/Kg 06/22/18 16:00 06/26/18 16:52 1



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Method: 7471A - Mercury (CVAA) (Continued)


Mercury 0.833 0.810 mg/Kg 97 80 - 120Analyte


SpikeAdded

%Rec.Limits

Method: Moisture - Percent Moisture

Client Sample ID: DMP-7 SolidLab Sample ID: 190-16632-14 DUMatrix: Solid Prep Type: Total/NAAnalysis Batch: 333295

Percent Solids 67.6 66.9 % 1 20Analyte

DU DUDUnitResult Qualifier

SampleResult

SampleQualifier LimitRPD

RPD

Percent Moisture 32.4 33.1 % 2 20

Method: SM 5210B - BOD, 5-Day

Client Sample ID: Method BlankLab Sample ID: SCB 190-8818/2Matrix: Water Prep Type: Total/NAAnalysis Batch: 8818

RL MDLBiochemical Oxygen Demand 1.15 1.0 0.25 ppm 06/20/18 16:28 1

SCB SCBAnalyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: Method BlankLab Sample ID: USB 190-8818/1Matrix: Water Prep Type: Total/NAAnalysis Batch: 8818

RL MDLBiochemical Oxygen Demand <1.0 1.0 0.25 ppm 06/20/18 16:28 1

USB USBAnalyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: Lab Control SampleLab Sample ID: LCS 190-8818/3Matrix: Water Prep Type: Total/NAAnalysis Batch: 8818

Biochemical Oxygen Demand 198 190 ppm 96 85 - 115Analyte


SpikeAdded

%Rec.Limits

Client Sample ID: DMP-1 WaterLab Sample ID: 190-16632-1 DUMatrix: Water Prep Type: Total/NAAnalysis Batch: 8818

Biochemical Oxygen Demand 150 171 ppm 11 20Analyte

DU DUDUnitResult Qualifier

SampleResult

SampleQualifier LimitRPD

RPD


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Definitions/GlossaryTestAmerica Job ID: 190-16632-1Client: Michigan Dept. of Environmental Quality


QualifiersGC/MS Semi VOA

Qualifier DescriptionJ Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.Qualifier

MetalsQualifier Description

B Compound was found in the blank and sample.Qualifier

J Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.

GlossaryThese commonly used abbreviations may or may not be present in this report.

¤ Listed under the "D" column to designate that the result is reported on a dry weight basisAbbreviation

%R Percent RecoveryCFL Contains Free LiquidCNF Contains No Free LiquidDER Duplicate Error Ratio (normalized absolute difference)Dil Fac Dilution FactorDL Detection Limit (DoD/DOE)DL, RA, RE, IN Indicates a Dilution, Re-analysis, Re-extraction, or additional Initial metals/anion analysis of the sampleDLC Decision Level Concentration (Radiochemistry)EDL Estimated Detection Limit (Dioxin)LOD Limit of Detection (DoD/DOE)LOQ Limit of Quantitation (DoD/DOE)MDA Minimum Detectable Activity (Radiochemistry)MDC Minimum Detectable Concentration (Radiochemistry)MDL Method Detection LimitML Minimum Level (Dioxin)NC Not CalculatedND Not Detected at the reporting limit (or MDL or EDL if shown)PQL Practical Quantitation LimitQC Quality ControlRER Relative Error Ratio (Radiochemistry)RL Reporting Limit or Requested Limit (Radiochemistry)RPD Relative Percent Difference, a measure of the relative difference between two pointsTEF Toxicity Equivalent Factor (Dioxin)TEQ Toxicity Equivalent Quotient (Dioxin)


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AECOM

Appendix B Survey and Layout



AECOM

Appendix C Hydraulic Report

AECOM 10850 Traverse Highway, Suite 3365 Traverse City, Michigan 49684 04/15/2019

Hydraulic Report Mill Pond Dam Feasibility Study Davisburg, Michigan

April 2019

Prepared By: Drew Browning, PE AECOM (216) 622-2484 [email protected]

Reviewed By : Janeen McDermott, PE

AECOM (248) 204-4136 [email protected]

AECOM Mill Pond Dam Feasibility Study Table of Contents i

April 2019

1 Introduction ................................................................................................................................................................. 1-1 2 Method of Analysis ...................................................................................................................................................... 2-1

2.1 Existing Model ....................................................................................................................................................... 2-1 2.2 Proposed Model – Dam Replacement Scenarios .................................................................................................... 2-1

2.2.1 Dam Replacement Scenario A ...................................................................................................................... 2-1 2.2.2 Dam Replacement Scenario B ...................................................................................................................... 2-1 2.2.3 Dam Replacement Scenario C ...................................................................................................................... 2-2 2.2.4 Dam Replacement Scenario D ...................................................................................................................... 2-2 2.2.5 Dam Replacement Scenario E ...................................................................................................................... 2-2

2.3 Proposed Model – Dam Removal Scenarios........................................................................................................... 2-2

2.3.1 Proposed Channel 1 ..................................................................................................................................... 2-3 2.3.2 Proposed Channel 2 ..................................................................................................................................... 2-3 2.3.3 Other Dam Removal Alternatives (F, G, and H) .............................................................................................. 2-3

3 Upstream and Downstream Modeling Boundaries ..................................................................................................... 3-1 4 Variables, Coefficients, and Modeling Strategies ....................................................................................................... 4-1

4.1 Contraction and Expansion Coefficients ................................................................................................................. 4-1 4.2 Manning’s N Values............................................................................................................................................... 4-1 4.3 Ineffective Flow Areas ........................................................................................................................................... 4-1

5 Discussion ................................................................................................................................................................... 5-1 6 Conclusions................................................................................................................................................................. 6-1 7 References ................................................................................................................................................................... 7-1

List of Appendices Appendix A. HEC-RAS Modeling Results Appendix B. HydroCAD Modeling Results

Table of Contents

AECOM Mill Pond Dam Feasibility Study Introduction 1-1

April 2019

The goal of the Feasibility Study is to assess rehabilitation and removal options for the Davisburg Mill Pond Dam. To assess the hydraulic characteristics of each option, proposed geometries were created as necessary to represent the characteristics of each dam rehabilitation or removal option. The hydraulic performance of each geometry was then simulated in a steady-state Hydraulic Engineering Center River Analysis System (HEC-RAS) model to determine the viability of different methods of replacement or removal. In addition to HEC-RAS, HydroCAD hydraulic modeling software was also used to assess those aspects of the project that required analysis of unsteady flow and complex compound outlet structures. This Draft Hydraulic Report summarizes the HEC-RAS and HydroCAD hydraulic modeling completed for the Feasibility Study. The purpose of this Hydraulic Report is to describe the setup and development of the HEC-RAS and HydroCAD models, as well as to describe how each dam replacement and removal alternative was modeled and present results of that modeling effort.

As described in the Feasibility Study report, the Mill Pond Dam is located on the upper Shiawassee River in Davisburg, Michigan. It was originally constructed in 1835 for the purpose of powering a mill. Mill operations have long since ceased, and the dam now creates a recreational impoundment. Upstream of the Mill Pond Dam is a wetland complex and an additional dam owned by the Michigan Department of Natural Resources (MDNR) that forms the Davisburg Trout Pond (which is scheduled for removal in 2020). Downstream of the Mill Pond Dam is the Shiawassee Basin Preserve, an extensive wetland complex encompassing the downstream Shiawassee River and its path through Davis Lake to Long Lake. A two-lane county road named Davisburg Road passes over Mill Pond Dam near downtown Davisburg.

The spillway for the Mill Pond Dam was largely reconstructed in 1984. The Mill Pond Dam consists of a 375-foot long earthen embankment with a steel and concrete drop inlet spillway. The structural height of the dam is 16 feet. The dam maintains approximately 14 feet of head, with 2.4 feet of freeboard, and creates a 20-acre impoundment under normal flow conditions. The 4-foot wide gated drop inlet is flanked on either side by 10.75-foot wide corrugated steel fixed weir sections. Water discharges through a 4-foot wide drop inlet, into a 36-inch diameter corrugated metal pipe (CMP) outlet, and over a 10-foot long concrete water feature and water wheel before dropping 5 to 6 feet and discharging into the downstream Shiawassee River. The downstream face of the Mill Pond Dam embankment is comprised of grouted rounded cobbles and boulders that appear to be one to two layers thick.

1 Introduction

AECOM Mill Pond Dam Feasibility Study Method of Analysis 2-1

April 2019

A one-dimensional, steady-state Hydraulic Engineering Center River Analysis System (HEC-RAS) model (version 5.0.3; USACE, 2016) was developed to understand hydraulic characteristics of the river under existing and proposed conditions. A simple HydroCAD model was also created to represent the dam and spillway system in order to calculate items that require unsteady flow analysis.

2.1 Existing Model

The base topography used to construct the HEC-RAS and HydroCAD models consisted of 1/9th arc-second digital elevation map (DEM) data obtained from the United States Geological Survey (USGS) National Elevation Dataset. This data was combined with bathymetric data of the Mill Pond collected by the Michigan Department of Environmental Quality Remediation and Redevelopment Division’s Geological Services Section on June 13th and June 19th, 2018. This topography was further supplemented in various locations by survey data collected by AECOM on January 10th, 2019, and March 15, 2019. Data from this survey regarding existing culvert materials, inverts, and locations was also entered into the model. Hydrologic data representing peak flows during low flow conditions, the 10-year flood event, and the 100-year flood event was obtained from the Michigan Department of Environmental Quality (MDEQ) flood flow database.

The existing conduit for the dam was entered into the models as a 36” CMP pipe, with an assumed inlet elevation of 950.0’ and an outlet elevation of 948.32’. A blocked depth of 0.25 feet was entered to approximately simulate the deformation of the crown of the conduit. The existing inlet weir was modeled as a sharp-crested weir approximately 4 feet wide, with an elevation of 957.25. Lastly, the grate above the inlet structure was entered into the model as a 4-foot by 12-foot orifice in the horizontal plane, with an invert elevation of 958.50. These elevations and all elevations that follow are provided in reference to the North American Vertical Datum of 1988 (NAVD 88).

This information was entered into HydroCAD, and a rating curve was developed for the 100-year event to simulate the outlet structure’s response. The resulting rating curve was entered into HEC-RAS, and the model was run for the 100-year existing conditions scenario. To assess the HEC-RAS model results qualitatively, the model was run for the 100-year existing conditions scenario. Results were compared against the Mill Pond Dam’s MDEQ Dam Safety report and found to agree approximately with the 100-year flood event scenario. The HydoCAD model output used to develop the rating curve for the existing scenario is provided within Appendix B.

2.2 Proposed Model – Dam Replacement Scenarios

The following changes to existing conditions were modeled to represent proposed conditions for each scenario.

2.2.1 Dam Replacement Scenario A This alternative would include removing the existing spillway outlet pipe and replacing it with a new 36-inch diameter high-density polyethylene (HDPE) pipe. This alternative would not address the existing spillway capacity issues (i.e., the current level of service for the dam will be maintained and Davisburg Road will still be expected to overtop during the 100-year flood event). To model this scenario, the blocked depth was removed from the 36” conduit, simulating replacement of the existing deformed culvert with a new one. The culvert Manning’s n value was changed from 0.024 to 0.012 to simulate the smoother surface of an HDPE conduit. As in the existing geometry, the invert of the pipe was assumed to be elevation 950.0’ and kept at the same slope as the existing pipe. The existing outlet structure and pipe combination was modeled in HydroCAD and entered into the inline structure within HEC-RAS as a rating curve. The HydoCAD model output used to develop the rating curve for this scenario is provided within Appendix B. The peak water surface elevation for the Mill Pond is provided within Section 6 below.

2.2.2 Dam Replacement Scenario B This alternative would include removing the existing spillway outlet pipe and replacing it with four new 48-inch diameter HDPE pipes. This alternative would address the existing spillway capacity issues. MDEQ standards would be met because the

2 Method of Analysis


April 2019

spillway would be designed to pass the 100-year flood event. To model this scenario, the 36” conduit was replaced with four 48” conduits. The Manning’s n value was changed from 0.024 to 0.012 to simulate the smoother surface of an HDPE conduit. The invert of each pipe was modeled as elevation 950.0’ and pipe slopes were kept the same as the existing pipe.

Using four 48-inch diameter pipes would require construction of a new overflow structure with a weir to keep the pond at normal levels while allowing for installation of a lake drain. The lake drain is envisioned as a sluice gate, and would allow lowering of the lake for maintenance of the overflow structure or in emergencies. The overflow structure was conceptually sized as requiring a 50-foot long weir length using HydroCAD. The proposed outlet structure and pipe combination was modeled in HydroCAD and entered into the inline structure within HEC-RAS as a rating curve. The HydoCAD model output used to develop the rating curve for this scenario is provided within Appendix B

2.2.3 Dam Replacement Scenario C This alternative would include removing the existing spillway outlet pipe and replacing it with a new 10-foot wide by 4-foot tall precast box culvert. This alternative would address the existing spillway capacity issues. MDEQ standards would be met because the spillway would be designed to pass the 100-year flood event.

Similar to Replacement Scenario B, an overflow structure with a weir was modeled in HydroCAD to convey flow to the box culvert. This structure was conceptually sized using HydroCAD, and the proposed outlet structure and pipe combination was modeled in HydroCAD and entered into the inline structure within HEC-RAS as a rating curve. The HydoCAD model output used to develop the rating curve for this scenario is provided within Appendix B. A 50-foot long weir length would be required to allow the culvert to pass the 100-year flood event, while maintaining normal water levels. As with Scenario C, construction of an overflow structure would allow for the installation of a lake drain.

2.2.4 Dam Replacement Scenario D This alternative would include constructing a new bridge over a new cast-in-place concrete overflow spillway. The existing outlet pipe would be removed and replaced with a new overflow spillway, which would consist of a cast-in-place concrete weir with a stepped chute to allow water to flow into the Shiawassee River. A Manning’s n value of 0.012 was entered for this structure. The overflow spillway would have a width of approximately 20 feet, with a slope of 3%. A rating curve was not necessary for this scenario due to the relatively simple configuration of the spillway.

2.2.5 Dam Replacement Scenario E This alternative would include raising the embankment to a height that would impound the 100-year flood to protect the areas downstream. To model this scenario, a HydroCAD model was created of the Mill Pond. A catchment node was created given the contributing upstream drainage area (6.8 square miles). The curve number and time of concentration were iteratively adjusted for the catchment to simulate the characteristics of the 1% recurrence interval flood volume (600 acre-feet) and peak flow (440 cfs) provided by the Michigan Department of Environmental Quality (MDEQ).

The HydroCAD model included approximate storage contours developed from the same topography source as the HEC-RAS model. This model assumed the replacement in-kind of the existing 36” outlet culvert, similar to Dam Replacement Scenario A. The dam was modeled with a 36” primary spillway outlet, and the embankment crest was modeled as a secondary broad-crested weir outlet. Based on the topography of the vicinity of the dam, the embankment crest of the dam would have to be raised 10 feet to contain the 100-year flood without overtopping. HydroCAD results for this scenario are presented in Appendix B.

2.3 Proposed Model – Dam Removal Scenarios

Two proposed channel alternatives were evaluated in conjunction with Dam Removal Scenarios F, G, and H. Both channel alternatives have identical slopes and channel/floodplain widths upstream of the railroad crossing above the Mill Pond. However, the first option, Proposed Channel 1, has varying slopes from the railroad crossing to the river’s passage under Davisburg Rd. These slopes would result in less required excavation of sediment, but more sediment would be able to mobilize and travel downstream, and engineered streambed materials may be required to prevent this mobilization.

In contrast, the slope from the railroad crossing to Davisburg Rd is steeper in Proposed Channel 2, which would require more sediment excavation and disposal than Proposed Channel 1, but less long-term stabilization due to its foundation on harder native streambed materials.


April 2019

2.3.1 Proposed Channel 1 To model the Channel 1 scenario, proposed topography was developed for the new channel and floodplain. Proposed Channel 1 consists of a 1 to 2-foot deep trapezoidal channel, 12 feet to 20 feet in top width, with varying slopes along its profile. The upstream slope is relatively flat to avoid undermining the foundation of the existing railroad bridge. The downstream channel varies in slope from 0.5% to 0.1%. To model this proposed topography in HEC-RAS, a proposed channel surface was developed in AutoCAD Civil 3D, merged with the existing topography, and imported into the model.

2.3.2 Proposed Channel 2 Similar to Channel 1, Proposed Channel 2 consists of a 1 to 2-foot deep trapezoidal channel, 12 feet to 20 feet in top width, with varying slopes of 0.1% to 1.8% along its profile. This configuration would have a steeper slope from Davisburg Rd to the railroad crossing than Channel 1, particularly in the reach approaching the upstream railroad crossing. The slope upstream of the railroad crossing is relatively flat (and identical to Channel 1) to avoid undermining the foundation of the existing railroad bridge.

As with the Channel 1 scenario, proposed topography was developed for the new channel and floodplain, and combined with existing topography to simulate a final condition. A proposed channel surface was developed in AutoCAD Civil 3D, merged with the existing topography, and imported into the HEC-RAS model.

2.3.3 Other Dam Removal Alternatives (F, G, and H) Alternative F consists of installation of a concrete box culvert, sized at a minimum of 10 feet wide by 4 feet tall to pass the 100-year event, but potentially larger. Alternative G considered installation of a precast open-bottom culvert. Finally, Alternative H includes construction of a new bridge for the crossing at Davisburg Road.

These alternatives were substantially similar to Dam Replacement Scenario C; as such, they were not modeled in detail; however, conceptual results with a 20-foot wide arched open-bottom culvert per Alternative G using both Channel 1 and Channel 2 are presented below in Section 6 and in Appendix A. This conduit size was selected so that the channel would be able to maintain its full width without being restricted by the road crossing.

It should also be noted that Alternatives F, G, and H can be constructed in combination with either Proposed Channel 1 or Proposed Channel 2 profiles. These alternatives will meet MDEQ flood discharge requirements and pass the 100-year storm event.

AECOM Mill Pond Dam Feasibility Study Upstream and Downstream Modeling Boundaries

3-1

April 2019

The upstream boundary condition applied was based on the flow developed by MDEQ for the various storm events as calculated at the Trout Pond Dam. Upstream boundary conditions were applied at cross section 11235.08. The downstream boundary condition for the baseflow to 500-yr floods was set as normal depth with a friction slope of 0.001 due to the model’s termination in Kirby Lake. Discharges routed through the model included all of the flood quantiles estimated by the MDEQ (Table 1).

Table 1 – Shiawassee River Discharges

Recurrence Interval

Discharge At Trout

Pond Dam (cfs)

Discharge at Mill Pond

Dam (cfs)

Baseflow 5 5

10yr 180 200

50yr 310 360

100yr 370 440

200yr 450 500

500yr 550 650

3 Upstream and Downstream Modeling Boundaries

AECOM Union Street Dam FishPass Variables, Coefficients, and Modeling Strategies

4-1

April 2019

4.1 Contraction and Expansion Coefficients

The Existing and Proposed HEC-RAS steady state models contain seven bridges/culverts within the vicinity of the Mill Pond Dam on the Shiawassee River. From upstream to downstream, these bridges/culverts are as follows:

36" culvert under railroad embankment upstream of Trout Pond Dam 60" culvert at Dilley Rd crossing Bridge for railroad embankment upstream of Mill Pond Dam 72" culvert under railroad downstream of Davisburg Rd 72" culvert at Eaton Rd crossing These crossings and structures were modeled using Standard Step Energy Computation Methods for both low flow and high flow conditions. The contraction and expansion coefficients for the HEC-RAS cross sections upstream and downstream of the bridges were set to 0.3 and 0.5 as recommended by the HEC-RAS Version 5.0 User’s Manual (USACE, 2016).

4.2 Manning’s N Values

Roughness values for the existing conditions model were estimated based on ground cover shown in aerial mapping of the site. Roughness coefficients for the design conditions model within the project limits were determined based on the materials proposed for lining the designed channel bottom and banks.

River HEC-RAS Model Values

Channel "n" Overbank "n" Shiawassee 0.03 – 0.035 0.035 – 0.05

These Manning’s Roughness values were chosen to represent varying conditions observed throughout the reach including grass (n=0.03), light brush (n=0.04), thicker brush (n=0.05). It was assumed that the final condition in the removal scenario will include grass cover.

4.3 Ineffective Flow Areas

Ineffective flows were set at all bridges and culvert crossings to represent the areas that do not pass flow in the upstream and downstream areas near these crossings. These crossings have ineffective flow areas that store floodwater, but do not convey flow. The ineffective flow areas for these crossings were applied as recommended by the HEC-RAS Version 5.0 User’s Manual (USACE, 2016). The ineffective flow area elevations are set by the height of the crossings and are applied only outside of the bridge or culvert openings. The ineffective flow areas are used in the modeling to analyze how the approaches to the bridges block flow from passing under the bridges. In addition, the downstream ineffective flow areas are set as a function of the flow downstream of the bridge abutments that do not convey flow, but store floodwater.

In addition to the ineffective flow areas applied at the bridge and culvert crossings, there are a few cross sections through the Trout Pond which also have ineffective flow areas specified where flood waters inundate areas that do not convey flow. The proposed conditions model used the same ineffective flow areas as the existing conditions model.

4 Variables, Coefficients, and Modeling Strategies

AECOM Union Street Dam FishPass Discussion 5-1

April 2019

5 Discussion Due to the options presented, the hydraulic performance of the existing dam will be improved in all replacement scenarios. Removal scenarios also result in lowered flood levels upstream of the dam and reduce the overtopping threat to the roadway. Overall, the modeled results of these scenarios indicate that any flooding upstream of the Mill Pond resulting from the 100-year storm event will be reduced to a degree depending on the capacity of the alternative. Since the model is steady-state, modeled flows are constant across all cross sections and do not change with time or attenuate due to storage in the floodplain. Future modeling efforts may require development of an unsteady-state model to evaluate downstream impacts on Eaton Road flooding.

AECOM Mill Pond Dam Feasibility Study Conclusions 6-1

April 2019

Upon comparison of the water surface elevation outputs from the existing and proposed conditions model, no rise in flood water surface elevation at the Mill Pond is shown. The water surface elevation outputs are presented In Table 5.

Table 5 – Existing and Proposed Conditions WSE Comparison, 100-year Storm Event

Scenario Name

Existing Scenario

Replacement Option A

Replacement Option B

Replacement Option C

Replacement Option D

Proposed Ch. 1

Proposed Ch. 2

Maximum WSE in

Mill Pond (or

restored river)

959.33 959.32 958.79 958.85 958.01 953.58 953.58

Does Davisburg Road (El.

959.0) Overtop?

Yes Yes No No No No No

6 Conclusions

AECOM Mill Pond Dam Feasibility Study References 7-1

April 2019

7 References

FEMA, 2009. Flood Insurance Study, Oakland County, Michigan (All Jurisdictions).

Michigan Department of Environment Quality (MDEQ), 2013. Hydraulic Report Guidelines. Revised February.

USACE, 2016. HEC-RAS River Analysis System User’s Manual. Version 5.0. February.

AECOM Mill Pond Dam Feasibility Study Appendices A-1

April 2019

Appendix A.HEC-RAS Modeling Results

0 200 400 600 800 1000 1200 1400940

950

960

970

980

Davisburg Plan: Existing RC 4/24/2019 RS = 2608 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Existing Scenario - Cross Section at Davisburg Rd.(100-year Results)

0 200 400 600 800 1000 1200 1400940

950

960

970

980

Davisburg Plan: Opt A RC 4/24/2019 RS = 2608 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Option A Scenario - 36" Culvert ReplacementCross Section at Davisburg Rd. (100-year Results)

0 200 400 600 800 1000 1200 1400940

950

960

970

980

Davisburg Plan: Opt B RC 4/24/2019 RS = 2608 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Option B Scenario - 4 48" CulvertsCross Section at Davisburg Rd. (100-year Results)

0 200 400 600 800 1000 1200 1400940

950

960

970

980

Davisburg Plan: Opt C RC 4/24/2019 RS = 2608 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Option C Scenario - 10'x4' Box CulvertCross Section at Davisburg Rd. (100-year Results)

0 200 400 600 800 1000 1200 1400940

950

960

970

980

Davisburg Plan: Steady100_Rep_Alt_D 4/24/2019 RS = 2608 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Option D Scenario - Overflow SpillwayCross Section at Davisburg Rd. (100-year Results)

0 200 400 600 800 1000 1200 1400940

945

950

955

960

965

970

975

980

Davisburg Plan: Steady 100-yr Removal Ch1 4/24/2019 RS = 2610.351 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Option G Scenario - Precast Open-Bottom Culvert with Channel 1Cross Section at Davisburg Rd. (100-year Results)

0 200 400 600 800 1000 1200 1400940

945

950

955

960

965

970

975

980

Davisburg Plan: Steady 100-yr Removal Ch 2 4/24/2019 RS = 2610.351 IS

Station (ft)

Ele

vatio

n (ft

)

Legend

EG PF 1

WS PF 1

Ground

Ineff

Bank Sta

.04 .03 .04

Option G Scenario - Precast Open-Bottom Culvert with Channel 2Cross Section at Davisburg Rd. (100-year Results)

AECOM Mill Pond Dam Feasibility Study Appendices A-2

April 2019

Appendix B.HydroCAD Modeling Results

2S

100-yr Davisburg Dam Contributing Area 6.85 mi2 400 cfs 600 ac-ft

1P

Mill Pond Dam (w/Raised

Embankment)

Routing Diagram for Davisburg Embankment Raise Estimate (for report)Prepared by AECOM, Printed 4/19/2019

HydroCAD® 10.00 s/n 01723 © 2013 HydroCAD Software Solutions LLC

Subcat Reach Pond Link

Replacement Alt. E - Raise Dam EmbankmentType II 24-hr 24-hr 100-yr Rainfall=5.45"Davisburg Embankment Raise Estimate (for report)

Printed 4/19/2019Prepared by AECOMPage 2HydroCAD® 10.00 s/n 01723 © 2013 HydroCAD Software Solutions LLC

Summary for Subcatchment 2S: 100-yr Davisburg Dam Contributing Area 6.85 mi2 400 cfs 600 ac-ft

Runoff = 440.38 cfs @ 24.99 hrs, Volume= 590.817 af, Depth> 1.62"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrsType II 24-hr 24-hr 100-yr Rainfall=5.45"

Area (ac) CN Description* 4,384.000 61 >75% Grass cover, Good, HSG A

4,384.000 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)900.0 Direct Entry, Estimate

Subcatchment 2S: 100-yr Davisburg Dam Contributing Area 6.85 mi2 400 cfs 600 ac-ft

Runoff

Hydrograph

Time (hours)454035302520151050

Flow

(cf

s)

450400350300250200150100

500

Type II 24-hr24-hr 100-yr Rainfall=5.45"Runoff Area=4,384.000 acRunoff Volume=590.817 afRunoff Depth>1.62"Tc=900.0 minCN=61

440.38 cfs



Hydrograph for Subcatchment 2S: 100-yr Davisburg Dam Contributing Area 6.85 mi2 400 cfs 600 ac-ft

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

0.00 0.00 0.00 0.000.50 0.03 0.00 0.001.00 0.06 0.00 0.001.50 0.09 0.00 0.002.00 0.12 0.00 0.002.50 0.15 0.00 0.003.00 0.19 0.00 0.003.50 0.22 0.00 0.004.00 0.26 0.00 0.004.50 0.30 0.00 0.005.00 0.34 0.00 0.005.50 0.39 0.00 0.006.00 0.44 0.00 0.006.50 0.49 0.00 0.007.00 0.54 0.00 0.007.50 0.60 0.00 0.008.00 0.65 0.00 0.008.50 0.72 0.00 0.009.00 0.80 0.00 0.009.50 0.89 0.00 0.00

10.00 0.99 0.00 0.0010.50 1.11 0.00 0.0011.00 1.28 0.00 0.0011.50 1.54 0.01 0.0012.00 3.61 0.62 0.0412.50 4.01 0.82 3.1013.00 4.21 0.92 6.2613.50 4.35 1.00 13.4414.00 4.47 1.06 20.7314.50 4.57 1.12 32.1615.00 4.65 1.16 43.7115.50 4.73 1.21 61.1216.00 4.80 1.25 78.6816.50 4.86 1.28 102.5917.00 4.91 1.32 126.6617.50 4.97 1.35 157.0718.00 5.02 1.38 187.5918.50 5.07 1.41 219.1419.00 5.11 1.44 250.7019.50 5.15 1.46 281.0920.00 5.19 1.48 311.4020.50 5.22 1.51 336.6821.00 5.26 1.53 361.8121.50 5.29 1.55 380.5822.00 5.32 1.57 399.2022.50 5.36 1.59 412.9723.00 5.39 1.61 426.5823.50 5.42 1.63 431.7924.00 5.45 1.65 436.8524.50 5.45 1.65 438.6625.00 5.45 1.65 440.3625.50 5.45 1.65 436.3726.00 5.45 1.65 432.24

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

26.50 5.45 1.65 424.0327.00 5.45 1.65 415.7027.50 5.45 1.65 402.0328.00 5.45 1.65 388.2828.50 5.45 1.65 373.6829.00 5.45 1.65 359.0529.50 5.45 1.65 343.5430.00 5.45 1.65 328.0230.50 5.45 1.65 312.7031.00 5.45 1.65 297.4031.50 5.45 1.65 282.2532.00 5.45 1.65 267.1232.50 5.45 1.65 252.9133.00 5.45 1.65 238.7033.50 5.45 1.65 224.7034.00 5.45 1.65 210.7134.50 5.45 1.65 197.6135.00 5.45 1.65 184.5235.50 5.45 1.65 172.2336.00 5.45 1.65 159.9736.50 5.45 1.65 148.8637.00 5.45 1.65 137.7837.50 5.45 1.65 127.7838.00 5.45 1.65 117.8238.50 5.45 1.65 109.0339.00 5.45 1.65 100.2639.50 5.45 1.65 92.4540.00 5.45 1.65 84.6740.50 5.45 1.65 78.1741.00 5.45 1.65 71.7141.50 5.45 1.65 66.1742.00 5.45 1.65 60.6642.50 5.45 1.65 56.1843.00 5.45 1.65 51.7243.50 5.45 1.65 47.7544.00 5.45 1.65 43.8144.50 5.45 1.65 40.5845.00 5.45 1.65 37.3645.50 5.45 1.65 34.5446.00 5.45 1.65 31.7346.50 5.45 1.65 29.3947.00 5.45 1.65 27.0647.50 5.45 1.65 24.9748.00 5.45 1.65 22.89



Summary for Pond 1P: Mill Pond Dam (w/Raised Embankment)

Inflow Area = 4,384.000 ac, 0.00% Impervious, Inflow Depth > 1.62" for 24-hr 100-yr eventInflow = 440.38 cfs @ 24.99 hrs, Volume= 590.817 afOutflow = 135.46 cfs @ 37.12 hrs, Volume= 309.719 af, Atten= 69%, Lag= 727.7 minPrimary = 135.46 cfs @ 37.12 hrs, Volume= 309.719 afSecondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrsStarting Elev= 955.00' Surf.Area= 431,133 sf Storage= 2,013,566 cfPeak Elev= 967.34' @ 37.12 hrs Surf.Area= 3,951,026 sf Storage= 17,036,703 cf (15,023,137 cf above start)

Plug-Flow detention time= 869.7 min calculated for 263.219 af (45% of inflow)Center-of-Mass det. time= 387.5 min ( 2,037.5 - 1,650.1 )

Volume Invert Avail.Storage Storage Description#1 947.00' 30,030,336 cf Custom Stage Data (Irregular) Listed below (Recalc)

Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area(feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft)

947.00 92,551 1,787.0 0 0 92,551948.00 129,294 2,411.0 110,412 110,412 301,019954.00 391,642 5,308.0 1,491,925 1,602,337 2,080,676955.00 431,133 5,073.0 411,229 2,013,566 2,274,878956.00 451,422 4,732.0 441,239 2,454,805 2,540,991957.00 514,120 5,626.0 482,431 2,937,236 3,277,900958.00 599,996 6,308.0 556,506 3,493,742 3,925,608959.00 667,010 6,084.0 633,207 4,126,949 4,146,587963.00 955,357 6,245.0 3,227,514 7,354,463 4,306,458964.00 1,027,979 6,397.0 991,446 8,345,910 4,459,504966.00 3,123,394 16,054.0 3,962,159 12,308,069 21,712,655970.00 5,882,053 30,355.0 17,722,267 30,030,336 74,527,915

Device Routing Invert Outlet Devices#1 Primary 950.00' 36.0" Round Culvert

L= 30.0' Box, headwall w/3 square edges, Ke= 0.500Inlet / Outlet Invert= 950.00' / 949.70' S= 0.0100 '/' Cc= 0.900n= 0.024, Flow Area= 7.07 sf

#2 Device 1 957.25' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s)6.0' Crest Height

#3 Device 1 958.50' 48.0" x 144.0" Horiz. Orifice/Grate C= 0.600Limited to weir flow at low heads

#4 Secondary 968.00' 430.0' long x 24.0' breadth Broad-Crested Rectangular WeirHead (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63



Primary OutFlow Max=135.46 cfs @ 37.12 hrs HW=967.34' (Free Discharge)1=Culvert (Inlet Controls 135.46 cfs @ 19.16 fps)

2=Sharp-Crested Rectangular Weir (Passes < 252.73 cfs potential flow)3=Orifice/Grate (Passes < 687.16 cfs potential flow)

Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=955.00' (Free Discharge)4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

Pond 1P: Mill Pond Dam (w/Raised Embankment)

InflowOutflowPrimarySecondary

Hydrograph

Time (hours)454035302520151050

Flow

(cf

s)

450400350300250200150100

500

Inflow Area=4,384.000 acPeak Elev=967.34'Storage=17,036,703 cf

440.38 cfs

135.46 cfs135.46 cfs

0.00 cfs



Hydrograph for Pond 1P: Mill Pond Dam (w/Raised Embankment)

Time(hours)

Inflow(cfs)

Storage(cubic-feet)

Elevation(feet)

Outflow(cfs)

Primary(cfs)

Secondary(cfs)

0.00 0.00 2,013,566 955.00 0.00 0.00 0.001.00 0.00 2,013,566 955.00 0.00 0.00 0.002.00 0.00 2,013,566 955.00 0.00 0.00 0.003.00 0.00 2,013,566 955.00 0.00 0.00 0.004.00 0.00 2,013,566 955.00 0.00 0.00 0.005.00 0.00 2,013,566 955.00 0.00 0.00 0.006.00 0.00 2,013,566 955.00 0.00 0.00 0.007.00 0.00 2,013,566 955.00 0.00 0.00 0.008.00 0.00 2,013,566 955.00 0.00 0.00 0.009.00 0.00 2,013,566 955.00 0.00 0.00 0.00

10.00 0.00 2,013,566 955.00 0.00 0.00 0.0011.00 0.00 2,013,566 955.00 0.00 0.00 0.0012.00 0.04 2,013,570 955.00 0.00 0.00 0.0013.00 6.26 2,024,745 955.03 0.00 0.00 0.0014.00 20.73 2,073,146 955.14 0.00 0.00 0.0015.00 43.71 2,188,932 955.40 0.00 0.00 0.0016.00 78.68 2,408,971 955.90 0.00 0.00 0.0017.00 126.66 2,778,296 956.68 0.00 0.00 0.0018.00 187.59 3,340,876 957.74 4.49 4.49 0.0019.00 250.70 4,062,364 958.90 53.71 53.71 0.0020.00 311.40 4,751,765 959.90 98.62 98.62 0.0021.00 361.81 5,597,484 961.00 104.91 104.91 0.0022.00 399.20 6,578,628 962.16 111.12 111.12 0.0023.00 426.58 7,654,646 963.31 116.97 116.97 0.0024.00 436.85 8,778,327 964.36 122.07 122.07 0.0025.00 440.36 9,911,820 965.05 125.29 125.29 0.0026.00 432.24 11,027,394 965.54 127.55 127.55 0.0027.00 415.70 12,091,463 965.93 129.28 129.28 0.0028.00 388.28 13,070,778 966.24 130.66 130.66 0.0029.00 359.05 13,943,498 966.50 131.81 131.81 0.0030.00 328.02 14,703,935 966.72 132.77 132.77 0.0031.00 297.40 15,350,256 966.90 133.54 133.54 0.0032.00 267.12 15,884,435 967.04 134.17 134.17 0.0033.00 238.70 16,310,984 967.15 134.65 134.65 0.0034.00 210.71 16,634,470 967.24 135.02 135.02 0.0035.00 184.52 16,859,326 967.29 135.26 135.26 0.0036.00 159.97 16,992,150 967.33 135.40 135.40 0.0037.00 137.78 17,040,475 967.34 135.46 135.46 0.0038.00 117.82 17,012,883 967.33 135.43 135.43 0.0039.00 100.26 16,918,009 967.31 135.32 135.32 0.0040.00 84.67 16,763,946 967.27 135.16 135.16 0.0041.00 71.71 16,559,187 967.22 134.93 134.93 0.0042.00 60.66 16,312,141 967.15 134.65 134.65 0.0043.00 51.72 16,030,202 967.08 134.33 134.33 0.0044.00 43.81 15,719,134 967.00 133.98 133.98 0.0045.00 37.36 15,383,588 966.90 133.58 133.58 0.0046.00 31.73 15,027,792 966.81 133.16 133.16 0.0047.00 27.06 14,655,031 966.70 132.71 132.71 0.0048.00 22.89 14,268,041 966.59 132.23 132.23 0.00



Stage-Area-Storage for Pond 1P: Mill Pond Dam (w/Raised Embankment)

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

947.00 92,551 0947.25 101,162 24,206947.50 110,157 50,613947.75 119,534 79,316948.00 129,294 110,412948.25 137,395 143,743948.50 145,742 179,130948.75 154,335 216,634949.00 163,174 256,318949.25 172,259 298,242949.50 181,590 342,468949.75 191,168 389,057950.00 200,992 438,072950.25 211,061 489,574950.50 221,377 543,623950.75 231,939 600,283951.00 242,747 659,613951.25 253,802 721,677951.50 265,102 786,535951.75 276,648 854,248952.00 288,441 924,879952.25 300,480 998,489952.50 312,764 1,075,140952.75 325,295 1,154,892953.00 338,072 1,237,808953.25 351,096 1,323,949953.50 364,365 1,413,376953.75 377,880 1,506,152954.00 391,642 1,602,337954.25 401,337 1,701,457954.50 411,150 1,803,015954.75 421,082 1,907,042955.00 431,133 2,013,566955.25 436,162 2,121,978955.50 441,219 2,231,650955.75 446,306 2,342,590956.00 451,422 2,454,805956.25 466,714 2,569,567956.50 482,262 2,688,184956.75 498,063 2,810,719957.00 514,120 2,937,236957.25 534,968 3,068,364957.50 556,229 3,204,755957.75 577,906 3,346,513958.00 599,996 3,493,742958.25 616,417 3,645,789958.50 633,060 3,801,969958.75 649,924 3,962,337959.00 667,010 4,126,949959.25 683,518 4,295,761959.50 700,228 4,468,725959.75 717,140 4,645,892960.00 734,254 4,827,312

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

960.25 751,569 5,013,036960.50 769,086 5,203,114960.75 786,805 5,397,596961.00 804,726 5,596,533961.25 822,849 5,799,976961.50 841,173 6,007,974961.75 859,699 6,220,579962.00 878,427 6,437,840962.25 897,357 6,659,809962.50 916,488 6,886,536962.75 935,822 7,118,070963.00 955,357 7,354,463963.25 973,263 7,595,538963.50 991,335 7,841,109963.75 1,009,574 8,091,219964.00 1,027,979 8,345,910964.25 1,227,820 8,627,515964.50 1,445,400 8,961,298964.75 1,680,719 9,351,693965.00 1,933,776 9,803,136965.25 2,204,572 10,320,060965.50 2,493,108 10,906,900965.75 2,799,381 11,568,092966.00 3,123,394 12,308,069966.25 3,270,443 13,107,228966.50 3,420,874 13,943,572966.75 3,574,687 14,817,947967.00 3,731,882 15,731,198967.25 3,892,460 16,684,170967.50 4,056,421 17,677,710967.75 4,223,763 18,712,662968.00 4,394,488 19,789,873968.25 4,568,596 20,910,188968.50 4,746,086 22,074,453968.75 4,926,958 23,283,513969.00 5,111,212 24,538,214969.25 5,298,849 25,839,401969.50 5,489,868 27,187,920969.75 5,684,269 28,584,617970.00 5,882,053 30,030,336

2S

100-yr Davisburg Dam Contributing Area 6.85

400 cfs 600 af

13S


400 cfs 600 af

16S


400 cfs 600 af

17S


400 cfs 600 af

10P

Mill Pond Dam (Replacement Option

B)

11P


A)

14P

Mill Pond Dam (Existing)

15P


C)

Routing Diagram for Davisburg Rating Curve Development (working copy)Prepared by AECOM, Printed 4/24/2019

HydroCAD® 10.00 s/n 01723 © 2013 HydroCAD Software Solutions LLC

Subcat Reach Pond Link

Replacement Alternatives - Rating Curve DevelopmentType II 24-hr 24-hr 100-yr Rainfall=5.45"Davisburg Rating Curve Development (working copy


Summary for Subcatchment 2S: 100-yr Davisburg Dam Contributing Area 6.85 400 cfs 600 af




4,384.000 100.00% Pervious Area


Subcatchment 2S: 100-yr Davisburg Dam Contributing Area 6.85 400 cfs 600 af

Runoff

Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500

Type II 24-hr24-hr 100-yr Rainfall=5.45"Runoff Area=4,384.000 ac

Runoff Volume=601.689 afRunoff Depth>1.65"

Tc=900.0 minCN=61

440.38 cfs



Hydrograph for Subcatchment 2S: 100-yr Davisburg Dam Contributing Area 6.85 400 cfs 600 af

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

0.00 0.00 0.00 0.001.00 0.06 0.00 0.002.00 0.12 0.00 0.003.00 0.19 0.00 0.004.00 0.26 0.00 0.005.00 0.34 0.00 0.006.00 0.44 0.00 0.007.00 0.54 0.00 0.008.00 0.65 0.00 0.009.00 0.80 0.00 0.00

10.00 0.99 0.00 0.0011.00 1.28 0.00 0.0012.00 3.61 0.62 0.0413.00 4.21 0.92 6.2614.00 4.47 1.06 20.7315.00 4.65 1.16 43.7116.00 4.80 1.25 78.6817.00 4.91 1.32 126.6618.00 5.02 1.38 187.5919.00 5.11 1.44 250.7020.00 5.19 1.48 311.4021.00 5.26 1.53 361.8122.00 5.32 1.57 399.2023.00 5.39 1.61 426.5824.00 5.45 1.65 436.8525.00 5.45 1.65 440.3626.00 5.45 1.65 432.2427.00 5.45 1.65 415.7028.00 5.45 1.65 388.2829.00 5.45 1.65 359.0530.00 5.45 1.65 328.0231.00 5.45 1.65 297.4032.00 5.45 1.65 267.1233.00 5.45 1.65 238.7034.00 5.45 1.65 210.7135.00 5.45 1.65 184.5236.00 5.45 1.65 159.9737.00 5.45 1.65 137.7838.00 5.45 1.65 117.8239.00 5.45 1.65 100.2640.00 5.45 1.65 84.6741.00 5.45 1.65 71.7142.00 5.45 1.65 60.6643.00 5.45 1.65 51.7244.00 5.45 1.65 43.8145.00 5.45 1.65 37.3646.00 5.45 1.65 31.7347.00 5.45 1.65 27.0648.00 5.45 1.65 22.8949.00 5.45 1.65 19.5950.00 5.45 1.65 16.5151.00 5.45 1.65 14.1552.00 5.45 1.65 11.93

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

53.00 5.45 1.65 10.1554.00 5.45 1.65 8.6455.00 5.45 1.65 7.3756.00 5.45 1.65 6.3157.00 5.45 1.65 5.3758.00 5.45 1.65 4.5359.00 5.45 1.65 3.7760.00 5.45 1.65 3.0661.00 5.45 1.65 2.4062.00 5.45 1.65 1.7763.00 5.45 1.65 1.3864.00 5.45 1.65 1.0265.00 5.45 1.65 0.7966.00 5.45 1.65 0.6067.00 5.45 1.65 0.4768.00 5.45 1.65 0.3469.00 5.45 1.65 0.2570.00 5.45 1.65 0.1671.00 5.45 1.65 0.1172.00 5.45 1.65 0.05







4,384.000 100.00% Pervious Area



Runoff

Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500



Tc=900.0 minCN=61

440.38 cfs




Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

0.00 0.00 0.00 0.001.00 0.06 0.00 0.002.00 0.12 0.00 0.003.00 0.19 0.00 0.004.00 0.26 0.00 0.005.00 0.34 0.00 0.006.00 0.44 0.00 0.007.00 0.54 0.00 0.008.00 0.65 0.00 0.009.00 0.80 0.00 0.00

10.00 0.99 0.00 0.0011.00 1.28 0.00 0.0012.00 3.61 0.62 0.0413.00 4.21 0.92 6.2614.00 4.47 1.06 20.7315.00 4.65 1.16 43.7116.00 4.80 1.25 78.6817.00 4.91 1.32 126.6618.00 5.02 1.38 187.5919.00 5.11 1.44 250.7020.00 5.19 1.48 311.4021.00 5.26 1.53 361.8122.00 5.32 1.57 399.2023.00 5.39 1.61 426.5824.00 5.45 1.65 436.8525.00 5.45 1.65 440.3626.00 5.45 1.65 432.2427.00 5.45 1.65 415.7028.00 5.45 1.65 388.2829.00 5.45 1.65 359.0530.00 5.45 1.65 328.0231.00 5.45 1.65 297.4032.00 5.45 1.65 267.1233.00 5.45 1.65 238.7034.00 5.45 1.65 210.7135.00 5.45 1.65 184.5236.00 5.45 1.65 159.9737.00 5.45 1.65 137.7838.00 5.45 1.65 117.8239.00 5.45 1.65 100.2640.00 5.45 1.65 84.6741.00 5.45 1.65 71.7142.00 5.45 1.65 60.6643.00 5.45 1.65 51.7244.00 5.45 1.65 43.8145.00 5.45 1.65 37.3646.00 5.45 1.65 31.7347.00 5.45 1.65 27.0648.00 5.45 1.65 22.8949.00 5.45 1.65 19.5950.00 5.45 1.65 16.5151.00 5.45 1.65 14.1552.00 5.45 1.65 11.93

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

53.00 5.45 1.65 10.1554.00 5.45 1.65 8.6455.00 5.45 1.65 7.3756.00 5.45 1.65 6.3157.00 5.45 1.65 5.3758.00 5.45 1.65 4.5359.00 5.45 1.65 3.7760.00 5.45 1.65 3.0661.00 5.45 1.65 2.4062.00 5.45 1.65 1.7763.00 5.45 1.65 1.3864.00 5.45 1.65 1.0265.00 5.45 1.65 0.7966.00 5.45 1.65 0.6067.00 5.45 1.65 0.4768.00 5.45 1.65 0.3469.00 5.45 1.65 0.2570.00 5.45 1.65 0.1671.00 5.45 1.65 0.1172.00 5.45 1.65 0.05







4,384.000 100.00% Pervious Area



Runoff

Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500



Tc=900.0 minCN=61

440.38 cfs




Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

0.00 0.00 0.00 0.001.00 0.06 0.00 0.002.00 0.12 0.00 0.003.00 0.19 0.00 0.004.00 0.26 0.00 0.005.00 0.34 0.00 0.006.00 0.44 0.00 0.007.00 0.54 0.00 0.008.00 0.65 0.00 0.009.00 0.80 0.00 0.00

10.00 0.99 0.00 0.0011.00 1.28 0.00 0.0012.00 3.61 0.62 0.0413.00 4.21 0.92 6.2614.00 4.47 1.06 20.7315.00 4.65 1.16 43.7116.00 4.80 1.25 78.6817.00 4.91 1.32 126.6618.00 5.02 1.38 187.5919.00 5.11 1.44 250.7020.00 5.19 1.48 311.4021.00 5.26 1.53 361.8122.00 5.32 1.57 399.2023.00 5.39 1.61 426.5824.00 5.45 1.65 436.8525.00 5.45 1.65 440.3626.00 5.45 1.65 432.2427.00 5.45 1.65 415.7028.00 5.45 1.65 388.2829.00 5.45 1.65 359.0530.00 5.45 1.65 328.0231.00 5.45 1.65 297.4032.00 5.45 1.65 267.1233.00 5.45 1.65 238.7034.00 5.45 1.65 210.7135.00 5.45 1.65 184.5236.00 5.45 1.65 159.9737.00 5.45 1.65 137.7838.00 5.45 1.65 117.8239.00 5.45 1.65 100.2640.00 5.45 1.65 84.6741.00 5.45 1.65 71.7142.00 5.45 1.65 60.6643.00 5.45 1.65 51.7244.00 5.45 1.65 43.8145.00 5.45 1.65 37.3646.00 5.45 1.65 31.7347.00 5.45 1.65 27.0648.00 5.45 1.65 22.8949.00 5.45 1.65 19.5950.00 5.45 1.65 16.5151.00 5.45 1.65 14.1552.00 5.45 1.65 11.93

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

53.00 5.45 1.65 10.1554.00 5.45 1.65 8.6455.00 5.45 1.65 7.3756.00 5.45 1.65 6.3157.00 5.45 1.65 5.3758.00 5.45 1.65 4.5359.00 5.45 1.65 3.7760.00 5.45 1.65 3.0661.00 5.45 1.65 2.4062.00 5.45 1.65 1.7763.00 5.45 1.65 1.3864.00 5.45 1.65 1.0265.00 5.45 1.65 0.7966.00 5.45 1.65 0.6067.00 5.45 1.65 0.4768.00 5.45 1.65 0.3469.00 5.45 1.65 0.2570.00 5.45 1.65 0.1671.00 5.45 1.65 0.1172.00 5.45 1.65 0.05







4,384.000 100.00% Pervious Area



Runoff

Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500



Tc=900.0 minCN=61

440.38 cfs




Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

0.00 0.00 0.00 0.001.00 0.06 0.00 0.002.00 0.12 0.00 0.003.00 0.19 0.00 0.004.00 0.26 0.00 0.005.00 0.34 0.00 0.006.00 0.44 0.00 0.007.00 0.54 0.00 0.008.00 0.65 0.00 0.009.00 0.80 0.00 0.00

10.00 0.99 0.00 0.0011.00 1.28 0.00 0.0012.00 3.61 0.62 0.0413.00 4.21 0.92 6.2614.00 4.47 1.06 20.7315.00 4.65 1.16 43.7116.00 4.80 1.25 78.6817.00 4.91 1.32 126.6618.00 5.02 1.38 187.5919.00 5.11 1.44 250.7020.00 5.19 1.48 311.4021.00 5.26 1.53 361.8122.00 5.32 1.57 399.2023.00 5.39 1.61 426.5824.00 5.45 1.65 436.8525.00 5.45 1.65 440.3626.00 5.45 1.65 432.2427.00 5.45 1.65 415.7028.00 5.45 1.65 388.2829.00 5.45 1.65 359.0530.00 5.45 1.65 328.0231.00 5.45 1.65 297.4032.00 5.45 1.65 267.1233.00 5.45 1.65 238.7034.00 5.45 1.65 210.7135.00 5.45 1.65 184.5236.00 5.45 1.65 159.9737.00 5.45 1.65 137.7838.00 5.45 1.65 117.8239.00 5.45 1.65 100.2640.00 5.45 1.65 84.6741.00 5.45 1.65 71.7142.00 5.45 1.65 60.6643.00 5.45 1.65 51.7244.00 5.45 1.65 43.8145.00 5.45 1.65 37.3646.00 5.45 1.65 31.7347.00 5.45 1.65 27.0648.00 5.45 1.65 22.8949.00 5.45 1.65 19.5950.00 5.45 1.65 16.5151.00 5.45 1.65 14.1552.00 5.45 1.65 11.93

Time(hours)

Precip.(inches)

Excess(inches)

Runoff(cfs)

53.00 5.45 1.65 10.1554.00 5.45 1.65 8.6455.00 5.45 1.65 7.3756.00 5.45 1.65 6.3157.00 5.45 1.65 5.3758.00 5.45 1.65 4.5359.00 5.45 1.65 3.7760.00 5.45 1.65 3.0661.00 5.45 1.65 2.4062.00 5.45 1.65 1.7763.00 5.45 1.65 1.3864.00 5.45 1.65 1.0265.00 5.45 1.65 0.7966.00 5.45 1.65 0.6067.00 5.45 1.65 0.4768.00 5.45 1.65 0.3469.00 5.45 1.65 0.2570.00 5.45 1.65 0.1671.00 5.45 1.65 0.1172.00 5.45 1.65 0.05



Summary for Pond 10P: Mill Pond Dam (Replacement Option B)

Inflow Area = 4,384.000 ac, 0.00% Impervious, Inflow Depth > 1.74" for 24-hr 100-yr eventInflow = 445.88 cfs @ 24.99 hrs, Volume= 634.439 af, Incl. 5.50 cfs Base FlowOutflow = 443.89 cfs @ 25.25 hrs, Volume= 633.229 af, Atten= 0%, Lag= 15.9 minPrimary = 443.89 cfs @ 25.25 hrs, Volume= 633.229 afSecondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrsStarting Elev= 957.00' Surf.Area= 514,120 sf Storage= 2,937,236 cfPeak Elev= 958.91' @ 25.25 hrs Surf.Area= 661,002 sf Storage= 4,068,827 cf (1,131,590 cf above start)




947.00 92,551 1,787.0 0 0 92,551948.00 129,294 2,411.0 110,412 110,412 301,019954.00 391,642 5,308.0 1,491,925 1,602,337 2,080,676955.00 431,133 5,073.0 411,229 2,013,566 2,274,878956.00 451,422 4,732.0 441,239 2,454,805 2,540,991957.00 514,120 5,626.0 482,431 2,937,236 3,277,900958.00 599,996 6,308.0 556,506 3,493,742 3,925,608959.00 667,010 6,084.0 633,207 4,126,949 4,146,587963.00 955,357 6,245.0 3,227,514 7,354,463 4,306,458964.00 1,027,979 6,397.0 991,446 8,345,910 4,459,504966.00 3,123,394 16,054.0 3,962,159 12,308,069 21,712,655970.00 5,882,053 30,355.0 17,722,267 30,030,336 74,527,915

Device Routing Invert Outlet Devices#1 Primary 950.00' 48.0" Round 4 48" Culverts X 4.00




Primary OutFlow Max=443.45 cfs @ 25.25 hrs HW=958.91' (Free Discharge)1=4 48" Culverts (Passes 443.45 cfs of 636.33 cfs potential flow)

2=Sharp-Crested Rectangular Weir (Weir Controls 443.45 cfs @ 4.67 fps)




Pond 10P: Mill Pond Dam (Replacement Option B)


Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500

Inflow Area=4,384.000 acPeak Elev=958.91'

Storage=4,068,827 cf

445.88 cfs443.89 cfs443.89 cfs

0.00 cfs



Hydrograph for Pond 10P: Mill Pond Dam (Replacement Option B)

Time(hours)

Inflow(cfs)

Storage(cubic-feet)

Elevation(feet)

Outflow(cfs)

Primary(cfs)

Secondary(cfs)

0.00 5.50 2,937,727 957.00 0.05 0.05 0.002.50 5.50 2,968,926 957.06 3.46 3.46 0.005.00 5.50 2,980,593 957.08 4.74 4.74 0.007.50 5.50 2,984,957 957.09 5.22 5.22 0.00

10.00 5.50 2,986,588 957.10 5.39 5.39 0.0012.50 8.60 2,989,821 957.10 5.75 5.75 0.0015.00 49.21 3,093,916 957.30 27.73 27.73 0.0017.50 162.57 3,383,704 957.81 121.44 121.44 0.0020.00 316.90 3,746,806 958.41 280.16 280.16 0.0022.50 418.47 3,988,156 958.79 401.13 401.13 0.0025.00 445.86 4,068,035 958.91 443.32 443.32 0.0027.50 407.53 4,022,823 958.84 419.44 419.44 0.0030.00 333.52 3,889,159 958.64 350.31 350.31 0.0032.50 258.41 3,736,629 958.40 275.32 275.32 0.0035.00 190.02 3,587,055 958.15 206.50 206.50 0.0037.50 133.28 3,448,972 957.92 147.69 147.69 0.0040.00 90.17 3,331,213 957.72 102.34 102.34 0.0042.50 61.68 3,240,716 957.56 70.10 70.10 0.0045.00 42.86 3,172,449 957.44 49.30 49.30 0.0047.50 30.47 3,124,833 957.35 34.79 34.79 0.0050.00 22.01 3,086,389 957.28 26.06 26.06 0.0052.50 16.54 3,056,085 957.23 19.34 19.34 0.0055.00 12.87 3,035,335 957.19 14.74 14.74 0.0057.50 10.45 3,021,638 957.16 11.71 11.71 0.0060.00 8.56 3,011,791 957.14 9.53 9.53 0.0062.50 7.08 3,003,985 957.13 7.80 7.80 0.0065.00 6.29 2,998,959 957.12 6.75 6.75 0.0067.50 5.90 2,994,972 957.11 6.31 6.31 0.0070.00 5.66 2,991,790 957.11 5.96 5.96 0.00



Stage-Discharge for Pond 10P: Mill Pond Dam (Replacement Option B)

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

947.00 0.00 0.00 0.00947.25 0.00 0.00 0.00947.50 0.00 0.00 0.00947.75 0.00 0.00 0.00948.00 0.00 0.00 0.00948.25 0.00 0.00 0.00948.50 0.00 0.00 0.00948.75 0.00 0.00 0.00949.00 0.00 0.00 0.00949.25 0.00 0.00 0.00949.50 0.00 0.00 0.00949.75 0.00 0.00 0.00950.00 0.00 0.00 0.00950.25 0.00 0.00 0.00950.50 0.00 0.00 0.00950.75 0.00 0.00 0.00951.00 0.00 0.00 0.00951.25 0.00 0.00 0.00951.50 0.00 0.00 0.00951.75 0.00 0.00 0.00952.00 0.00 0.00 0.00952.25 0.00 0.00 0.00952.50 0.00 0.00 0.00952.75 0.00 0.00 0.00953.00 0.00 0.00 0.00953.25 0.00 0.00 0.00953.50 0.00 0.00 0.00953.75 0.00 0.00 0.00954.00 0.00 0.00 0.00954.25 0.00 0.00 0.00954.50 0.00 0.00 0.00954.75 0.00 0.00 0.00955.00 0.00 0.00 0.00955.25 0.00 0.00 0.00955.50 0.00 0.00 0.00955.75 0.00 0.00 0.00956.00 0.00 0.00 0.00956.25 0.00 0.00 0.00956.50 0.00 0.00 0.00956.75 0.00 0.00 0.00957.00 0.00 0.00 0.00957.25 20.51 20.51 0.00957.50 58.19 58.19 0.00957.75 107.27 107.27 0.00958.00 165.69 165.69 0.00958.25 232.32 232.32 0.00958.50 306.39 306.39 0.00958.75 387.35 387.35 0.00959.00 474.78 474.78 0.00959.25 712.67 568.35 144.32959.50 1,073.29 662.82 410.48959.75 1,415.30 673.77 741.52960.00 1,815.46 684.56 1,130.90

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

960.25 2,281.66 695.17 1,586.49960.50 2,787.17 705.62 2,081.55960.75 3,334.00 715.93 2,618.07961.00 3,924.75 726.08 3,198.67961.25 4,552.88 736.10 3,816.79961.50 5,216.25 745.98 4,470.27961.75 5,913.04 755.73 5,157.31962.00 6,641.69 765.36 5,876.33962.25 7,400.83 774.86 6,625.97962.50 8,189.28 784.26 7,405.02962.75 9,005.96 793.54 8,212.42963.00 9,849.91 802.71 9,047.20963.25 10,720.28 811.78 9,908.49963.50 11,616.26 820.75 10,795.51963.75 12,537.14 829.63 11,707.51964.00 13,482.25 838.41 12,643.85964.25 14,450.99 847.09 13,603.89964.50 15,442.77 855.70 14,587.08964.75 16,457.08 864.21 15,592.87965.00 17,493.41 872.64 16,620.77965.25 18,551.30 880.99 17,670.31965.50 19,630.33 889.26 18,741.06965.75 20,730.07 897.46 19,832.61966.00 21,850.14 905.58 20,944.56966.25 22,990.18 913.63 22,076.55966.50 24,149.84 921.61 23,228.23966.75 25,328.79 929.52 24,399.27967.00 26,526.71 937.37 25,589.35967.25 27,743.32 945.15 26,798.17967.50 28,978.31 952.86 28,025.45967.75 30,231.43 960.52 29,270.91968.00 31,502.41 968.11 30,534.30968.25 32,791.00 975.64 31,815.36968.50 34,096.96 983.12 33,113.85968.75 35,420.07 990.54 34,429.53969.00 36,760.10 997.90 35,762.20969.25 38,116.84 1,005.21 37,111.63969.50 39,490.09 1,012.47 38,477.62969.75 40,879.64 1,019.68 39,859.96970.00 42,285.31 1,026.83 41,258.48



Stage-Area-Storage for Pond 10P: Mill Pond Dam (Replacement Option B)

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

947.00 92,551 0947.25 101,162 24,206947.50 110,157 50,613947.75 119,534 79,316948.00 129,294 110,412948.25 137,395 143,743948.50 145,742 179,130948.75 154,335 216,634949.00 163,174 256,318949.25 172,259 298,242949.50 181,590 342,468949.75 191,168 389,057950.00 200,992 438,072950.25 211,061 489,574950.50 221,377 543,623950.75 231,939 600,283951.00 242,747 659,613951.25 253,802 721,677951.50 265,102 786,535951.75 276,648 854,248952.00 288,441 924,879952.25 300,480 998,489952.50 312,764 1,075,140952.75 325,295 1,154,892953.00 338,072 1,237,808953.25 351,096 1,323,949953.50 364,365 1,413,376953.75 377,880 1,506,152954.00 391,642 1,602,337954.25 401,337 1,701,457954.50 411,150 1,803,015954.75 421,082 1,907,042955.00 431,133 2,013,566955.25 436,162 2,121,978955.50 441,219 2,231,650955.75 446,306 2,342,590956.00 451,422 2,454,805956.25 466,714 2,569,567956.50 482,262 2,688,184956.75 498,063 2,810,719957.00 514,120 2,937,236957.25 534,968 3,068,364957.50 556,229 3,204,755957.75 577,906 3,346,513958.00 599,996 3,493,742958.25 616,417 3,645,789958.50 633,060 3,801,969958.75 649,924 3,962,337959.00 667,010 4,126,949959.25 683,518 4,295,761959.50 700,228 4,468,725959.75 717,140 4,645,892960.00 734,254 4,827,312

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

960.25 751,569 5,013,036960.50 769,086 5,203,114960.75 786,805 5,397,596961.00 804,726 5,596,533961.25 822,849 5,799,976961.50 841,173 6,007,974961.75 859,699 6,220,579962.00 878,427 6,437,840962.25 897,357 6,659,809962.50 916,488 6,886,536962.75 935,822 7,118,070963.00 955,357 7,354,463963.25 973,263 7,595,538963.50 991,335 7,841,109963.75 1,009,574 8,091,219964.00 1,027,979 8,345,910964.25 1,227,820 8,627,515964.50 1,445,400 8,961,298964.75 1,680,719 9,351,693965.00 1,933,776 9,803,136965.25 2,204,572 10,320,060965.50 2,493,108 10,906,900965.75 2,799,381 11,568,092966.00 3,123,394 12,308,069966.25 3,270,443 13,107,228966.50 3,420,874 13,943,572966.75 3,574,687 14,817,947967.00 3,731,882 15,731,198967.25 3,892,460 16,684,170967.50 4,056,421 17,677,710967.75 4,223,763 18,712,662968.00 4,394,488 19,789,873968.25 4,568,596 20,910,188968.50 4,746,086 22,074,453968.75 4,926,958 23,283,513969.00 5,111,212 24,538,214969.25 5,298,849 25,839,401969.50 5,489,868 27,187,920969.75 5,684,269 28,584,617970.00 5,882,053 30,030,336



Summary for Pond 11P: Mill Pond Dam (Replacement Option A)






947.00 92,551 1,787.0 0 0 92,551948.00 129,294 2,411.0 110,412 110,412 301,019954.00 391,642 5,308.0 1,491,925 1,602,337 2,080,676955.00 431,133 5,073.0 411,229 2,013,566 2,274,878956.00 451,422 4,732.0 441,239 2,454,805 2,540,991957.00 514,120 5,626.0 482,431 2,937,236 3,277,900958.00 599,996 6,308.0 556,506 3,493,742 3,925,608959.00 667,010 6,084.0 633,207 4,126,949 4,146,587963.00 955,357 6,245.0 3,227,514 7,354,463 4,306,458964.00 1,027,979 6,397.0 991,446 8,345,910 4,459,504966.00 3,123,394 16,054.0 3,962,159 12,308,069 21,712,655970.00 5,882,053 30,355.0 17,722,267 30,030,336 74,527,915

Device Routing Invert Outlet Devices#1 Primary 950.00' 36.0" Round 36" Replacement Culvert







Primary OutFlow Max=95.94 cfs @ 25.06 hrs HW=959.45' (Free Discharge)1=36" Replacement Culvert (Inlet Controls 95.94 cfs @ 13.57 fps)


Secondary OutFlow Max=346.57 cfs @ 25.06 hrs HW=959.45' (Free Discharge)4=Broad-Crested Rectangular Weir (Weir Controls 346.57 cfs @ 1.80 fps)

Pond 11P: Mill Pond Dam (Replacement Option A)


Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500



445.88 cfs445.47 cfs

95.94 cfs

349.52 cfs



Hydrograph for Pond 11P: Mill Pond Dam (Replacement Option A)

Time(hours)

Inflow(cfs)

Storage(cubic-feet)

Elevation(feet)

Outflow(cfs)

Primary(cfs)

Secondary(cfs)

0.00 5.50 3,068,858 957.25 0.00 0.00 0.002.50 5.50 3,116,660 957.34 0.37 0.37 0.005.00 5.50 3,160,028 957.42 1.02 1.02 0.007.50 5.50 3,197,585 957.49 1.62 1.62 0.00

10.00 5.50 3,230,089 957.54 2.14 2.14 0.0012.50 8.60 3,260,905 957.60 2.71 2.71 0.0015.00 49.21 3,445,534 957.92 7.05 7.05 0.0017.50 162.57 4,136,505 959.01 74.80 67.67 7.1320.00 316.90 4,337,298 959.31 305.00 94.52 210.4722.50 418.47 4,413,698 959.42 413.19 95.79 317.4025.00 445.86 4,431,607 959.45 445.38 95.94 349.4327.50 407.53 4,412,871 959.42 411.73 95.78 315.9430.00 333.52 4,361,813 959.35 339.62 94.93 244.6932.50 258.41 4,308,282 959.27 264.02 94.04 169.9835.00 190.02 4,259,525 959.20 195.17 93.23 101.9437.50 133.28 4,203,458 959.11 139.17 82.08 57.0840.00 90.17 4,157,181 959.04 94.68 72.12 22.5642.50 61.68 4,125,428 959.00 65.31 65.31 0.0045.00 42.86 4,055,070 958.89 52.44 52.44 0.0047.50 30.47 3,974,679 958.77 38.42 38.42 0.0050.00 22.01 3,908,205 958.67 29.42 29.42 0.0052.50 16.54 3,847,254 958.57 22.62 22.62 0.0055.00 12.87 3,799,827 958.50 17.51 17.51 0.0057.50 10.45 3,753,117 958.42 16.04 16.04 0.0060.00 8.56 3,701,306 958.34 14.41 14.41 0.0062.50 7.08 3,648,872 958.25 12.78 12.78 0.0065.00 6.29 3,600,069 958.17 11.36 11.36 0.0067.50 5.90 3,558,195 958.11 10.14 10.14 0.0070.00 5.66 3,523,575 958.05 9.13 9.13 0.00



Stage-Discharge for Pond 11P: Mill Pond Dam (Replacement Option A)

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

947.00 0.00 0.00 0.00947.25 0.00 0.00 0.00947.50 0.00 0.00 0.00947.75 0.00 0.00 0.00948.00 0.00 0.00 0.00948.25 0.00 0.00 0.00948.50 0.00 0.00 0.00948.75 0.00 0.00 0.00949.00 0.00 0.00 0.00949.25 0.00 0.00 0.00949.50 0.00 0.00 0.00949.75 0.00 0.00 0.00950.00 0.00 0.00 0.00950.25 0.00 0.00 0.00950.50 0.00 0.00 0.00950.75 0.00 0.00 0.00951.00 0.00 0.00 0.00951.25 0.00 0.00 0.00951.50 0.00 0.00 0.00951.75 0.00 0.00 0.00952.00 0.00 0.00 0.00952.25 0.00 0.00 0.00952.50 0.00 0.00 0.00952.75 0.00 0.00 0.00953.00 0.00 0.00 0.00953.25 0.00 0.00 0.00953.50 0.00 0.00 0.00953.75 0.00 0.00 0.00954.00 0.00 0.00 0.00954.25 0.00 0.00 0.00954.50 0.00 0.00 0.00954.75 0.00 0.00 0.00955.00 0.00 0.00 0.00955.25 0.00 0.00 0.00955.50 0.00 0.00 0.00955.75 0.00 0.00 0.00956.00 0.00 0.00 0.00956.25 0.00 0.00 0.00956.50 0.00 0.00 0.00956.75 0.00 0.00 0.00957.00 0.00 0.00 0.00957.25 0.00 0.00 0.00957.50 1.62 1.62 0.00957.75 4.55 4.55 0.00958.00 8.30 8.30 0.00958.25 12.68 12.68 0.00958.50 17.57 17.57 0.00958.75 35.99 35.99 0.00959.00 65.61 65.61 0.00959.25 239.07 94.75 144.32959.50 506.74 96.27 410.48959.75 839.28 97.76 741.52960.00 1,230.13 99.23 1,130.90

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

960.25 1,687.17 100.68 1,586.49960.50 2,183.65 102.11 2,081.55960.75 2,721.58 103.51 2,618.07961.00 3,303.57 104.90 3,198.67961.25 3,923.06 106.27 3,816.79961.50 4,577.90 107.63 4,470.27961.75 5,266.28 108.97 5,157.31962.00 5,986.61 110.29 5,876.33962.25 6,737.56 111.59 6,625.97962.50 7,517.90 112.88 7,405.02962.75 8,326.58 114.16 8,212.42963.00 9,162.62 115.42 9,047.20963.25 10,025.16 116.67 9,908.49963.50 10,913.41 117.90 10,795.51963.75 11,826.63 119.12 11,707.51964.00 12,764.18 120.33 12,643.85964.25 13,725.42 121.53 13,603.89964.50 14,709.79 122.72 14,587.08964.75 15,716.76 123.89 15,592.87965.00 16,745.82 125.05 16,620.77965.25 17,796.52 126.21 17,670.31965.50 18,868.41 127.35 18,741.06965.75 19,961.09 128.48 19,832.61966.00 21,074.16 129.60 20,944.56966.25 22,207.26 130.71 22,076.55966.50 23,360.05 131.82 23,228.23966.75 24,532.18 132.91 24,399.27967.00 25,723.34 134.00 25,589.35967.25 26,933.24 135.07 26,798.17967.50 28,161.59 136.14 28,025.45967.75 29,408.11 137.20 29,270.91968.00 30,672.55 138.25 30,534.30968.25 31,954.65 139.29 31,815.36968.50 33,254.18 140.33 33,113.85968.75 34,570.89 141.36 34,429.53969.00 35,904.58 142.38 35,762.20969.25 37,255.02 143.39 37,111.63969.50 38,622.01 144.40 38,477.62969.75 40,005.36 145.40 39,859.96970.00 41,404.87 146.39 41,258.48



Stage-Area-Storage for Pond 11P: Mill Pond Dam (Replacement Option A)

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

947.00 92,551 0947.25 101,162 24,206947.50 110,157 50,613947.75 119,534 79,316948.00 129,294 110,412948.25 137,395 143,743948.50 145,742 179,130948.75 154,335 216,634949.00 163,174 256,318949.25 172,259 298,242949.50 181,590 342,468949.75 191,168 389,057950.00 200,992 438,072950.25 211,061 489,574950.50 221,377 543,623950.75 231,939 600,283951.00 242,747 659,613951.25 253,802 721,677951.50 265,102 786,535951.75 276,648 854,248952.00 288,441 924,879952.25 300,480 998,489952.50 312,764 1,075,140952.75 325,295 1,154,892953.00 338,072 1,237,808953.25 351,096 1,323,949953.50 364,365 1,413,376953.75 377,880 1,506,152954.00 391,642 1,602,337954.25 401,337 1,701,457954.50 411,150 1,803,015954.75 421,082 1,907,042955.00 431,133 2,013,566955.25 436,162 2,121,978955.50 441,219 2,231,650955.75 446,306 2,342,590956.00 451,422 2,454,805956.25 466,714 2,569,567956.50 482,262 2,688,184956.75 498,063 2,810,719957.00 514,120 2,937,236957.25 534,968 3,068,364957.50 556,229 3,204,755957.75 577,906 3,346,513958.00 599,996 3,493,742958.25 616,417 3,645,789958.50 633,060 3,801,969958.75 649,924 3,962,337959.00 667,010 4,126,949959.25 683,518 4,295,761959.50 700,228 4,468,725959.75 717,140 4,645,892960.00 734,254 4,827,312

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

960.25 751,569 5,013,036960.50 769,086 5,203,114960.75 786,805 5,397,596961.00 804,726 5,596,533961.25 822,849 5,799,976961.50 841,173 6,007,974961.75 859,699 6,220,579962.00 878,427 6,437,840962.25 897,357 6,659,809962.50 916,488 6,886,536962.75 935,822 7,118,070963.00 955,357 7,354,463963.25 973,263 7,595,538963.50 991,335 7,841,109963.75 1,009,574 8,091,219964.00 1,027,979 8,345,910964.25 1,227,820 8,627,515964.50 1,445,400 8,961,298964.75 1,680,719 9,351,693965.00 1,933,776 9,803,136965.25 2,204,572 10,320,060965.50 2,493,108 10,906,900965.75 2,799,381 11,568,092966.00 3,123,394 12,308,069966.25 3,270,443 13,107,228966.50 3,420,874 13,943,572966.75 3,574,687 14,817,947967.00 3,731,882 15,731,198967.25 3,892,460 16,684,170967.50 4,056,421 17,677,710967.75 4,223,763 18,712,662968.00 4,394,488 19,789,873968.25 4,568,596 20,910,188968.50 4,746,086 22,074,453968.75 4,926,958 23,283,513969.00 5,111,212 24,538,214969.25 5,298,849 25,839,401969.50 5,489,868 27,187,920969.75 5,684,269 28,584,617970.00 5,882,053 30,030,336



Summary for Pond 14P: Mill Pond Dam (Existing)






947.00 92,551 1,787.0 0 0 92,551948.00 129,294 2,411.0 110,412 110,412 301,019954.00 391,642 5,308.0 1,491,925 1,602,337 2,080,676955.00 431,133 5,073.0 411,229 2,013,566 2,274,878956.00 451,422 4,732.0 441,239 2,454,805 2,540,991957.00 514,120 5,626.0 482,431 2,937,236 3,277,900958.00 599,996 6,308.0 556,506 3,493,742 3,925,608959.00 667,010 6,084.0 633,207 4,126,949 4,146,587963.00 955,357 6,245.0 3,227,514 7,354,463 4,306,458964.00 1,027,979 6,397.0 991,446 8,345,910 4,459,504966.00 3,123,394 16,054.0 3,962,159 12,308,069 21,712,655970.00 5,882,053 30,355.0 17,722,267 30,030,336 74,527,915

Device Routing Invert Outlet Devices#1 Primary 950.25' 36.0" Round 36" Culvert w/ 3.0" inside fill







Primary OutFlow Max=91.73 cfs @ 25.06 hrs HW=959.45' (Free Discharge)1=36" Culvert (Inlet Controls 91.73 cfs @ 13.51 fps)


Secondary OutFlow Max=350.49 cfs @ 25.06 hrs HW=959.45' (Free Discharge)4=Broad-Crested Rectangular Weir (Weir Controls 350.49 cfs @ 1.81 fps)

Pond 14P: Mill Pond Dam (Existing)


Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500



445.88 cfs445.47 cfs

91.72 cfs

353.74 cfs



Hydrograph for Pond 14P: Mill Pond Dam (Existing)

Time(hours)

Inflow(cfs)

Storage(cubic-feet)

Elevation(feet)

Outflow(cfs)

Primary(cfs)

Secondary(cfs)

0.00 5.50 3,068,858 957.25 0.00 0.00 0.002.50 5.50 3,116,660 957.34 0.37 0.37 0.005.00 5.50 3,160,028 957.42 1.02 1.02 0.007.50 5.50 3,197,585 957.49 1.62 1.62 0.00

10.00 5.50 3,230,089 957.54 2.14 2.14 0.0012.50 8.60 3,260,905 957.60 2.71 2.71 0.0015.00 49.21 3,445,534 957.92 7.05 7.05 0.0017.50 162.57 4,136,523 959.01 74.60 67.45 7.1420.00 316.90 4,339,828 959.31 304.93 90.92 214.0122.50 418.47 4,416,368 959.42 413.76 91.58 322.1825.00 445.86 4,433,966 959.45 445.38 91.72 353.6527.50 407.53 4,415,229 959.42 411.71 91.57 320.1430.00 333.52 4,364,558 959.35 339.65 91.14 248.5232.50 258.41 4,310,718 959.27 264.06 90.67 173.3835.00 190.02 4,261,678 959.20 195.20 90.25 104.9437.50 133.28 4,205,502 959.12 139.32 80.71 58.6140.00 90.17 4,158,046 959.05 94.79 71.59 23.2042.50 61.68 4,125,498 959.00 65.32 65.32 0.0045.00 42.86 4,055,083 958.89 52.44 52.44 0.0047.50 30.47 3,974,682 958.77 38.42 38.42 0.0050.00 22.01 3,908,206 958.67 29.42 29.42 0.0052.50 16.54 3,847,254 958.57 22.62 22.62 0.0055.00 12.87 3,799,827 958.50 17.51 17.51 0.0057.50 10.45 3,753,117 958.42 16.04 16.04 0.0060.00 8.56 3,701,306 958.34 14.41 14.41 0.0062.50 7.08 3,648,872 958.25 12.78 12.78 0.0065.00 6.29 3,600,069 958.17 11.36 11.36 0.0067.50 5.90 3,558,195 958.11 10.14 10.14 0.0070.00 5.66 3,523,575 958.05 9.13 9.13 0.00



Stage-Discharge for Pond 14P: Mill Pond Dam (Existing)

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

947.00 0.00 0.00 0.00947.25 0.00 0.00 0.00947.50 0.00 0.00 0.00947.75 0.00 0.00 0.00948.00 0.00 0.00 0.00948.25 0.00 0.00 0.00948.50 0.00 0.00 0.00948.75 0.00 0.00 0.00949.00 0.00 0.00 0.00949.25 0.00 0.00 0.00949.50 0.00 0.00 0.00949.75 0.00 0.00 0.00950.00 0.00 0.00 0.00950.25 0.00 0.00 0.00950.50 0.00 0.00 0.00950.75 0.00 0.00 0.00951.00 0.00 0.00 0.00951.25 0.00 0.00 0.00951.50 0.00 0.00 0.00951.75 0.00 0.00 0.00952.00 0.00 0.00 0.00952.25 0.00 0.00 0.00952.50 0.00 0.00 0.00952.75 0.00 0.00 0.00953.00 0.00 0.00 0.00953.25 0.00 0.00 0.00953.50 0.00 0.00 0.00953.75 0.00 0.00 0.00954.00 0.00 0.00 0.00954.25 0.00 0.00 0.00954.50 0.00 0.00 0.00954.75 0.00 0.00 0.00955.00 0.00 0.00 0.00955.25 0.00 0.00 0.00955.50 0.00 0.00 0.00955.75 0.00 0.00 0.00956.00 0.00 0.00 0.00956.25 0.00 0.00 0.00956.50 0.00 0.00 0.00956.75 0.00 0.00 0.00957.00 0.00 0.00 0.00957.25 0.00 0.00 0.00957.50 1.62 1.62 0.00957.75 4.55 4.55 0.00958.00 8.30 8.30 0.00958.25 12.68 12.68 0.00958.50 17.57 17.57 0.00958.75 35.99 35.99 0.00959.00 65.61 65.61 0.00959.25 234.87 90.55 144.32959.50 502.49 92.02 410.48959.75 834.98 93.46 741.52960.00 1,225.78 94.88 1,130.90

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

960.25 1,682.77 96.28 1,586.49960.50 2,179.20 97.66 2,081.55960.75 2,717.09 99.02 2,618.07961.00 3,299.03 100.36 3,198.67961.25 3,918.47 101.68 3,816.79961.50 4,573.26 102.99 4,470.27961.75 5,261.59 104.28 5,157.31962.00 5,981.88 105.55 5,876.33962.25 6,732.78 106.81 6,625.97962.50 7,513.08 108.05 7,405.02962.75 8,321.70 109.28 8,212.42963.00 9,157.70 110.50 9,047.20963.25 10,020.20 111.70 9,908.49963.50 10,908.40 112.89 10,795.51963.75 11,821.58 114.07 11,707.51964.00 12,759.08 115.24 12,643.85964.25 13,720.28 116.39 13,603.89964.50 14,704.61 117.53 14,587.08964.75 15,711.53 118.66 15,592.87965.00 16,740.55 119.78 16,620.77965.25 17,791.21 120.89 17,670.31965.50 18,863.06 121.99 18,741.06965.75 19,955.69 123.08 19,832.61966.00 21,068.73 124.16 20,944.56966.25 22,201.79 125.24 22,076.55966.50 23,354.53 126.30 23,228.23966.75 24,526.62 127.35 24,399.27967.00 25,717.74 128.40 25,589.35967.25 26,927.60 129.43 26,798.17967.50 28,155.91 130.46 28,025.45967.75 29,402.39 131.48 29,270.91968.00 30,666.79 132.49 30,534.30968.25 31,948.85 133.50 31,815.36968.50 33,248.34 134.49 33,113.85968.75 34,565.01 135.48 34,429.53969.00 35,898.66 136.46 35,762.20969.25 37,249.07 137.44 37,111.63969.50 38,616.02 138.41 38,477.62969.75 39,999.33 139.37 39,859.96970.00 41,398.81 140.32 41,258.48



Stage-Area-Storage for Pond 14P: Mill Pond Dam (Existing)

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

947.00 92,551 0947.25 101,162 24,206947.50 110,157 50,613947.75 119,534 79,316948.00 129,294 110,412948.25 137,395 143,743948.50 145,742 179,130948.75 154,335 216,634949.00 163,174 256,318949.25 172,259 298,242949.50 181,590 342,468949.75 191,168 389,057950.00 200,992 438,072950.25 211,061 489,574950.50 221,377 543,623950.75 231,939 600,283951.00 242,747 659,613951.25 253,802 721,677951.50 265,102 786,535951.75 276,648 854,248952.00 288,441 924,879952.25 300,480 998,489952.50 312,764 1,075,140952.75 325,295 1,154,892953.00 338,072 1,237,808953.25 351,096 1,323,949953.50 364,365 1,413,376953.75 377,880 1,506,152954.00 391,642 1,602,337954.25 401,337 1,701,457954.50 411,150 1,803,015954.75 421,082 1,907,042955.00 431,133 2,013,566955.25 436,162 2,121,978955.50 441,219 2,231,650955.75 446,306 2,342,590956.00 451,422 2,454,805956.25 466,714 2,569,567956.50 482,262 2,688,184956.75 498,063 2,810,719957.00 514,120 2,937,236957.25 534,968 3,068,364957.50 556,229 3,204,755957.75 577,906 3,346,513958.00 599,996 3,493,742958.25 616,417 3,645,789958.50 633,060 3,801,969958.75 649,924 3,962,337959.00 667,010 4,126,949959.25 683,518 4,295,761959.50 700,228 4,468,725959.75 717,140 4,645,892960.00 734,254 4,827,312

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

960.25 751,569 5,013,036960.50 769,086 5,203,114960.75 786,805 5,397,596961.00 804,726 5,596,533961.25 822,849 5,799,976961.50 841,173 6,007,974961.75 859,699 6,220,579962.00 878,427 6,437,840962.25 897,357 6,659,809962.50 916,488 6,886,536962.75 935,822 7,118,070963.00 955,357 7,354,463963.25 973,263 7,595,538963.50 991,335 7,841,109963.75 1,009,574 8,091,219964.00 1,027,979 8,345,910964.25 1,227,820 8,627,515964.50 1,445,400 8,961,298964.75 1,680,719 9,351,693965.00 1,933,776 9,803,136965.25 2,204,572 10,320,060965.50 2,493,108 10,906,900965.75 2,799,381 11,568,092966.00 3,123,394 12,308,069966.25 3,270,443 13,107,228966.50 3,420,874 13,943,572966.75 3,574,687 14,817,947967.00 3,731,882 15,731,198967.25 3,892,460 16,684,170967.50 4,056,421 17,677,710967.75 4,223,763 18,712,662968.00 4,394,488 19,789,873968.25 4,568,596 20,910,188968.50 4,746,086 22,074,453968.75 4,926,958 23,283,513969.00 5,111,212 24,538,214969.25 5,298,849 25,839,401969.50 5,489,868 27,187,920969.75 5,684,269 28,584,617970.00 5,882,053 30,030,336



Summary for Pond 15P: Mill Pond Dam (Replacement Option C)






947.00 92,551 1,787.0 0 0 92,551948.00 129,294 2,411.0 110,412 110,412 301,019954.00 391,642 5,308.0 1,491,925 1,602,337 2,080,676955.00 431,133 5,073.0 411,229 2,013,566 2,274,878956.00 451,422 4,732.0 441,239 2,454,805 2,540,991957.00 514,120 5,626.0 482,431 2,937,236 3,277,900958.00 599,996 6,308.0 556,506 3,493,742 3,925,608959.00 667,010 6,084.0 633,207 4,126,949 4,146,587963.00 955,357 6,245.0 3,227,514 7,354,463 4,306,458964.00 1,027,979 6,397.0 991,446 8,345,910 4,459,504966.00 3,123,394 16,054.0 3,962,159 12,308,069 21,712,655970.00 5,882,053 30,355.0 17,722,267 30,030,336 74,527,915

Device Routing Invert Outlet Devices#1 Primary 950.00' 120.0" W x 48.0" H Box Culvert




Primary OutFlow Max=443.45 cfs @ 25.25 hrs HW=958.91' (Free Discharge)1=Culvert (Passes 443.45 cfs of 504.58 cfs potential flow)

2=Sharp-Crested Rectangular Weir (Weir Controls 443.45 cfs @ 4.67 fps)




Pond 15P: Mill Pond Dam (Replacement Option C)


Hydrograph

Time (hours)7065605550454035302520151050

Flow

(cf

s)

450400350300250200150100

500



445.88 cfs443.89 cfs443.89 cfs

0.00 cfs



Hydrograph for Pond 15P: Mill Pond Dam (Replacement Option C)

Time(hours)

Inflow(cfs)

Storage(cubic-feet)

Elevation(feet)

Outflow(cfs)

Primary(cfs)

Secondary(cfs)

0.00 5.50 2,937,727 957.00 0.05 0.05 0.002.50 5.50 2,968,926 957.06 3.46 3.46 0.005.00 5.50 2,980,593 957.08 4.74 4.74 0.007.50 5.50 2,984,957 957.09 5.22 5.22 0.00

10.00 5.50 2,986,588 957.10 5.39 5.39 0.0012.50 8.60 2,989,821 957.10 5.75 5.75 0.0015.00 49.21 3,093,916 957.30 27.73 27.73 0.0017.50 162.57 3,383,704 957.81 121.44 121.44 0.0020.00 316.90 3,746,806 958.41 280.16 280.16 0.0022.50 418.47 3,988,156 958.79 401.13 401.13 0.0025.00 445.86 4,068,035 958.91 443.32 443.32 0.0027.50 407.53 4,022,823 958.84 419.44 419.44 0.0030.00 333.52 3,889,159 958.64 350.31 350.31 0.0032.50 258.41 3,736,629 958.40 275.32 275.32 0.0035.00 190.02 3,587,055 958.15 206.50 206.50 0.0037.50 133.28 3,448,972 957.92 147.69 147.69 0.0040.00 90.17 3,331,213 957.72 102.34 102.34 0.0042.50 61.68 3,240,716 957.56 70.10 70.10 0.0045.00 42.86 3,172,449 957.44 49.30 49.30 0.0047.50 30.47 3,124,833 957.35 34.79 34.79 0.0050.00 22.01 3,086,389 957.28 26.06 26.06 0.0052.50 16.54 3,056,085 957.23 19.34 19.34 0.0055.00 12.87 3,035,335 957.19 14.74 14.74 0.0057.50 10.45 3,021,638 957.16 11.71 11.71 0.0060.00 8.56 3,011,791 957.14 9.53 9.53 0.0062.50 7.08 3,003,985 957.13 7.80 7.80 0.0065.00 6.29 2,998,959 957.12 6.75 6.75 0.0067.50 5.90 2,994,972 957.11 6.31 6.31 0.0070.00 5.66 2,991,790 957.11 5.96 5.96 0.00



Stage-Discharge for Pond 15P: Mill Pond Dam (Replacement Option C)

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

947.00 0.00 0.00 0.00947.25 0.00 0.00 0.00947.50 0.00 0.00 0.00947.75 0.00 0.00 0.00948.00 0.00 0.00 0.00948.25 0.00 0.00 0.00948.50 0.00 0.00 0.00948.75 0.00 0.00 0.00949.00 0.00 0.00 0.00949.25 0.00 0.00 0.00949.50 0.00 0.00 0.00949.75 0.00 0.00 0.00950.00 0.00 0.00 0.00950.25 0.00 0.00 0.00950.50 0.00 0.00 0.00950.75 0.00 0.00 0.00951.00 0.00 0.00 0.00951.25 0.00 0.00 0.00951.50 0.00 0.00 0.00951.75 0.00 0.00 0.00952.00 0.00 0.00 0.00952.25 0.00 0.00 0.00952.50 0.00 0.00 0.00952.75 0.00 0.00 0.00953.00 0.00 0.00 0.00953.25 0.00 0.00 0.00953.50 0.00 0.00 0.00953.75 0.00 0.00 0.00954.00 0.00 0.00 0.00954.25 0.00 0.00 0.00954.50 0.00 0.00 0.00954.75 0.00 0.00 0.00955.00 0.00 0.00 0.00955.25 0.00 0.00 0.00955.50 0.00 0.00 0.00955.75 0.00 0.00 0.00956.00 0.00 0.00 0.00956.25 0.00 0.00 0.00956.50 0.00 0.00 0.00956.75 0.00 0.00 0.00957.00 0.00 0.00 0.00957.25 20.51 20.51 0.00957.50 58.19 58.19 0.00957.75 107.27 107.27 0.00958.00 165.69 165.69 0.00958.25 232.32 232.32 0.00958.50 306.39 306.39 0.00958.75 387.35 387.35 0.00959.00 474.78 474.78 0.00959.25 661.24 516.92 144.32959.50 936.35 525.87 410.48959.75 1,276.19 534.67 741.52960.00 1,674.22 543.32 1,130.90

Elevation(feet)

Discharge(cfs)

Primary(cfs)

Secondary(cfs)

960.25 2,138.32 551.83 1,586.49960.50 2,641.75 560.21 2,081.55960.75 3,186.53 568.46 2,618.07961.00 3,775.27 576.60 3,198.67961.25 4,401.40 584.62 3,816.79961.50 5,062.80 592.52 4,470.27961.75 5,757.64 600.33 5,157.31962.00 6,484.36 608.03 5,876.33962.25 7,241.60 615.63 6,625.97962.50 8,028.16 623.14 7,405.02962.75 8,842.98 630.56 8,212.42963.00 9,685.09 637.89 9,047.20963.25 10,553.63 645.14 9,908.49963.50 11,447.81 652.31 10,795.51963.75 12,366.91 659.39 11,707.51964.00 13,310.25 666.41 12,643.85964.25 14,277.24 673.34 13,603.89964.50 15,267.29 680.21 14,587.08964.75 16,279.87 687.01 15,592.87965.00 17,314.51 693.74 16,620.77965.25 18,370.72 700.40 17,670.31965.50 19,448.07 707.00 18,741.06965.75 20,546.15 713.54 19,832.61966.00 21,664.59 720.02 20,944.56966.25 22,803.00 726.45 22,076.55966.50 23,961.04 732.81 23,228.23966.75 25,138.39 739.12 24,399.27967.00 26,334.72 745.38 25,589.35967.25 27,549.75 751.58 26,798.17967.50 28,783.19 757.74 28,025.45967.75 30,034.75 763.84 29,270.91968.00 31,304.19 769.89 30,534.30968.25 32,591.26 775.90 31,815.36968.50 33,895.71 781.86 33,113.85968.75 35,217.31 787.78 34,429.53969.00 36,555.85 793.65 35,762.20969.25 37,911.10 799.47 37,111.63969.50 39,282.88 805.26 38,477.62969.75 40,670.97 811.00 39,859.96970.00 42,075.19 816.71 41,258.48



Stage-Area-Storage for Pond 15P: Mill Pond Dam (Replacement Option C)

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

947.00 92,551 0947.25 101,162 24,206947.50 110,157 50,613947.75 119,534 79,316948.00 129,294 110,412948.25 137,395 143,743948.50 145,742 179,130948.75 154,335 216,634949.00 163,174 256,318949.25 172,259 298,242949.50 181,590 342,468949.75 191,168 389,057950.00 200,992 438,072950.25 211,061 489,574950.50 221,377 543,623950.75 231,939 600,283951.00 242,747 659,613951.25 253,802 721,677951.50 265,102 786,535951.75 276,648 854,248952.00 288,441 924,879952.25 300,480 998,489952.50 312,764 1,075,140952.75 325,295 1,154,892953.00 338,072 1,237,808953.25 351,096 1,323,949953.50 364,365 1,413,376953.75 377,880 1,506,152954.00 391,642 1,602,337954.25 401,337 1,701,457954.50 411,150 1,803,015954.75 421,082 1,907,042955.00 431,133 2,013,566955.25 436,162 2,121,978955.50 441,219 2,231,650955.75 446,306 2,342,590956.00 451,422 2,454,805956.25 466,714 2,569,567956.50 482,262 2,688,184956.75 498,063 2,810,719957.00 514,120 2,937,236957.25 534,968 3,068,364957.50 556,229 3,204,755957.75 577,906 3,346,513958.00 599,996 3,493,742958.25 616,417 3,645,789958.50 633,060 3,801,969958.75 649,924 3,962,337959.00 667,010 4,126,949959.25 683,518 4,295,761959.50 700,228 4,468,725959.75 717,140 4,645,892960.00 734,254 4,827,312

Elevation(feet)

Surface(sq-ft)

Storage(cubic-feet)

960.25 751,569 5,013,036960.50 769,086 5,203,114960.75 786,805 5,397,596961.00 804,726 5,596,533961.25 822,849 5,799,976961.50 841,173 6,007,974961.75 859,699 6,220,579962.00 878,427 6,437,840962.25 897,357 6,659,809962.50 916,488 6,886,536962.75 935,822 7,118,070963.00 955,357 7,354,463963.25 973,263 7,595,538963.50 991,335 7,841,109963.75 1,009,574 8,091,219964.00 1,027,979 8,345,910964.25 1,227,820 8,627,515964.50 1,445,400 8,961,298964.75 1,680,719 9,351,693965.00 1,933,776 9,803,136965.25 2,204,572 10,320,060965.50 2,493,108 10,906,900965.75 2,799,381 11,568,092966.00 3,123,394 12,308,069966.25 3,270,443 13,107,228966.50 3,420,874 13,943,572966.75 3,574,687 14,817,947967.00 3,731,882 15,731,198967.25 3,892,460 16,684,170967.50 4,056,421 17,677,710967.75 4,223,763 18,712,662968.00 4,394,488 19,789,873968.25 4,568,596 20,910,188968.50 4,746,086 22,074,453968.75 4,926,958 23,283,513969.00 5,111,212 24,538,214969.25 5,298,849 25,839,401969.50 5,489,868 27,187,920969.75 5,684,269 28,584,617970.00 5,882,053 30,030,336

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10850 Traverse Highway, Suite 3365Traverse City, Michigan 49684231-932-7592

Davisburg Mill Pond Dam Feasiblity Report Project number: 60594641

AECOM

Appendix D Detailed Cost Estimates

Feasibility Report - Replacement Alternative Detailed Cost Estimates

Overall Unit PriceSite Preparation A B CMobilization/Demobilization Lsum 150,000.00$ 1 150,000.00$ 1 150,000.00$ 1 150,000.00$Site Clearing Acre 4,000.00$ 1 4,000.00$ 1 4,000.00$ 1 4,000.00$Erosion Control LSum 12,000.00$ 1 12,000.00$ 1 12,000.00$ 1 12,000.00$

Dam RemovalConcrete demolition CYD 20.00$ 0 -$ 55 1,100.00$ 55 1,100.00$Dam material disposal Ton 10.00$ 0 -$ 112 1,116.50$ 112 1,116.50$Embankment Excavation CYD 14.00$ 163 2,282.00$ 434 6,076.00$ 300 4,200.00$Flow Diversion Lsum 20,000.00$ 1 20,000.00$ 1 20,000.00$ 1 20,000.00$Pavement Removal SYD 4.00$ 72 288.00$ 122 488.00$ 95 380.00$Guardrail Removal Ft 2.00$ 100 200.00$ 100 200.00$ 100 200.00$Traffic Management Lsum 20,000.00$ 1 20,000.00$ 1 20,000.00$ 1 20,000.00$

Road Crossing Replacement36" HDPE Culvert Ft 243.00$ 43 10,449.00$ 0 -$ 0 -$Precast Stilling Basin for 36" HDPE Culvert CYD 750.00$ 16 12,000.00$ 0 -$ 0 -$48" HDPE Culvert Ft 400.00$ 0 -$ 172 68,800.00$ 0 -$10'x4' Precast Box Culvert Ft 1,898.00$ 0 -$ 0 -$ 43 81,614.00$Culvert Bedding CYD 50.00$ 17 850.00$ 445 22,250.00$ 32 1,600.00$Backfill Structure CIP CYD 25.00$ 2997 74,925.00$ 4141 103,525.00$ 2685 67,125.00$Road Subbase, Class II CYD 25.00$ 48 1,200.00$ 81 2,033.33$ 63 1,583.33$Aggregate CYD 60.00$ 48 2,880.00$ 81 4,880.00$ 63 3,800.00$Pavement, Replace CYD 75.00$ 12 900.00$ 20 1,525.00$ 16 1,187.50$Guardrail Replace Ft 25.00$ 100 2,500.00$ 100 2,500.00$ 100 2,500.00$Bridge Cost SF 450.00$ 0 -$ 0 -$ 0 -$Approach Pavement SYD 175.00$ 0 -$ 0 -$ 0 -$Guardrail Anchorage to Bridge EA 1,500.00$ 0 -$ 0 -$ 0 -$Guardrail Replace (Bridge) Ft 22.00$ 0 -$ 0 -$ 0 -$Guardrail Terminal EA 2,200.00$ 0 -$ 0 -$ 0 -$Cast-in-place concrete for inlet structure CYD 1,000.00$ 0 -$ 214 214,097.96$ 214 214,097.96$

Replace w/36" HDPE Replace w/4 48" HDPE Replace w/10'x4' Box

Culvert

1 05/01/2019


Overall Unit PriceSite Preparation A B C

Replace w/36" HDPE Replace w/4 48" HDPE Replace w/10'x4' Box

Culvert

Cast-in-place concrete for spillway CYD 1,000.00$ 0 -$ 0 -$ 0 -$Spillway Bedding CYD 50.00$ 0 -$ 0 -$ 0 -$Site RestorationArticulated Conc. Block (ACB) Protection LSum 250,000.00$ 1 250,000.00$ 0 -$ 0 -$Riprap Bank Protection CYD 101.00$ 100 10,100.00$ 0 -$ 0 -$Grout for Riprap Bank Protection CYD 404.00$ 33 13,465.32$ 0 -$ 0 -$Topsoil 6" SYD 26.40$ 375 9,902.93$ 375 9,902.93$ 375 9,902.93$

Seeding Acre 5,980.00$ 0.5 2,990.00$ 0.5 2,990.00$ 0.5 2,990.00$Site Restoration LSum 10,000.00$ 1 10,000.00$ 1 10,000.00$ 1 10,000.00$Pedestrian Bridge and Trail Replacement LSum 15,000.00$ 1 15,000.00$ 1 15,000.00$ 1 15,000.00$Estimated Construction Cost 625,932.25$ 672,484.73$ 624,397.23$Contingency Cost (40%) 250,372.90$ 268,993.89$ 249,758.89$Engineering and Permitting (10%) 62,593.23$ 67,248.47$ 62,439.72$Construction Admin/RPR (10%) 62,593.23$ 67,248.47$ 62,439.72$Estimated Project TOTAL 1,001,491.61$ 1,075,975.57$ 999,035.57$

Operation and Maintenance Cost in $1,284,689.90 $1,325,064.33 $1,246,064.20Present Value for 100 year Lifecycle

2 05/01/2019


Site PreparationMobilization/DemobilizationSite ClearingErosion Control

Dam RemovalConcrete demolitionDam material disposalEmbankment ExcavationFlow DiversionPavement RemovalGuardrail RemovalTraffic Management

Road Crossing Replacement36" HDPE CulvertPrecast Stilling Basin for 36" HDPE Culvert48" HDPE Culvert10'x4' Precast Box CulvertCulvert BeddingBackfill Structure CIPRoad Subbase, Class IIAggregatePavement, ReplaceGuardrail ReplaceBridge CostApproach PavementGuardrail Anchorage to BridgeGuardrail Replace (Bridge)Guardrail TerminalCast-in-place concrete for inlet structure

D1 150,000.00$1 4,000.00$1 12,000.00$

55 1,100.00$112 1,116.50$

1221 17,094.00$1 20,000.00$

256 1,024.00$200 400.00$

1 20,000.00$

0 -$0 -$0 -$0 -$0 -$0 -$0 -$0 -$0 -$0 -$

1360 612,000.00$40 7,000.00$4 6,000.00$

80 1,760.00$4 8,800.00$0 -$

New Bridge

3 05/01/2019


Site PreparationCast-in-place concrete for spillwaySpillway BeddingSite RestorationArticulated Conc. Block (ACB) ProtectionRiprap Bank ProtectionGrout for Riprap Bank ProtectionTopsoil 6"

SeedingSite RestorationPedestrian Bridge and Trail ReplacementEstimated Construction CostContingency Cost (40%)Engineering and Permitting (10%)Construction Admin/RPR (10%)Estimated Project TOTAL

Operation and Maintenance Cost inPresent Value for 100 year Lifecycle

DNew Bridge

321 321,481.48$103 5,155.56$

0 -$0 -$0 -$

368 9,718.13$

0.5 2,990.00$1 10,000.00$1 15,000.00$

1,226,639.67$490,655.87$122,663.97$122,663.97$

1,962,623.47$

$2,211,866.67

4 05/01/2019

Feasibility Study - Dam Removal Detailed Life-Cycle Costs

Year Option A B C D Notes0 1,001,492$ 1,075,976$ 999,036$ 1,962,623$1 $5,000 $5,000 $5,000 $5,000 Just invasive species control2 $5,000 $5,000 $5,000 $5,000 Just invasive species control3 $5,000 $5,000 $5,000 $5,000 Just invasive species control4 $5,000 $5,000 $5,000 $5,000 Just invasive species control5 $9,108 $9,882 $9,108 $9,175 Inspection/Concrete Repair6 $5,000 $5,000 $5,000 $5,0007 $5,000 $5,000 $5,000 $5,0008 $5,000 $5,000 $5,000 $5,0009 $5,000 $5,000 $5,000 $5,000

10 $9,108 $9,882 $9,108 $9,17511 $5,000 $5,000 $5,000 $5,00012 $5,000 $5,000 $5,000 $5,00013 $5,000 $5,000 $5,000 $5,00014 $5,000 $5,000 $5,000 $5,00015 $9,108 $9,882 $9,108 $9,17516 $5,000 $5,000 $5,000 $5,00017 $5,000 $5,000 $5,000 $5,00018 $5,000 $5,000 $5,000 $5,00019 $5,000 $5,000 $5,000 $5,00020 $9,108 $9,882 $9,108 $9,17521 $5,000 $5,000 $5,000 $5,00022 $5,000 $5,000 $5,000 $5,00023 $5,000 $5,000 $5,000 $5,00024 $5,000 $5,000 $5,000 $5,00025 $9,108 $9,882 $9,108 $9,17526 $5,000 $5,000 $5,000 $5,00027 $5,000 $5,000 $5,000 $5,00028 $5,000 $5,000 $5,000 $5,00029 $5,000 $5,000 $5,000 $5,00030 $9,108 $9,882 $9,108 $9,17531 $5,000 $5,000 $5,000 $5,000

Alternatives

1 05/01/2019


Year Option A B C D NotesAlternatives

32 $5,000 $5,000 $5,000 $5,00033 $5,000 $5,000 $5,000 $5,00034 $5,000 $5,000 $5,000 $5,00035 $9,108 $9,882 $9,108 $9,17536 $5,000 $5,000 $5,000 $5,00037 $5,000 $5,000 $5,000 $5,00038 $5,000 $5,000 $5,000 $5,00039 $5,000 $5,000 $5,000 $5,00040 $9,108 $9,882 $9,108 $9,17541 $5,000 $5,000 $5,000 $5,00042 $5,000 $5,000 $5,000 $5,00043 $5,000 $5,000 $5,000 $5,00044 $5,000 $5,000 $5,000 $5,00045 $9,108 $9,882 $9,108 $9,17546 $5,000 $5,000 $5,000 $5,00047 $5,000 $5,000 $5,000 $5,00048 $5,000 $5,000 $5,000 $5,00049 $5,000 $5,000 $5,000 $5,00050 $619,762 $456,118 $456,118 $591,164 Replace/rehab concrete elements of alternative51 $5,000 $5,000 $5,000 $5,00052 $5,000 $5,000 $5,000 $5,00053 $5,000 $5,000 $5,000 $5,00054 $5,000 $5,000 $5,000 $5,00055 $9,108 $9,882 $9,108 $9,17556 $5,000 $5,000 $5,000 $5,00057 $5,000 $5,000 $5,000 $5,00058 $5,000 $5,000 $5,000 $5,00059 $5,000 $5,000 $5,000 $5,00060 $9,108 $9,882 $9,108 $9,17561 $5,000 $5,000 $5,000 $5,00062 $5,000 $5,000 $5,000 $5,00063 $5,000 $5,000 $5,000 $5,000

2 05/01/2019



64 $5,000 $5,000 $5,000 $5,00065 $9,108 $9,882 $9,108 $9,17566 $5,000 $5,000 $5,000 $5,00067 $5,000 $5,000 $5,000 $5,00068 $5,000 $5,000 $5,000 $5,00069 $5,000 $5,000 $5,000 $5,00070 $9,108 $9,882 $9,108 $9,17571 $5,000 $5,000 $5,000 $5,00072 $5,000 $5,000 $5,000 $5,00073 $5,000 $5,000 $5,000 $5,00074 $5,000 $5,000 $5,000 $5,00075 $9,108 $9,882 $9,108 $9,17576 $5,000 $5,000 $5,000 $5,00077 $5,000 $5,000 $5,000 $5,00078 $5,000 $5,000 $5,000 $5,00079 $5,000 $5,000 $5,000 $5,00080 $9,108 $9,882 $9,108 $9,17581 $5,000 $5,000 $5,000 $5,00082 $5,000 $5,000 $5,000 $5,00083 $5,000 $5,000 $5,000 $5,00084 $5,000 $5,000 $5,000 $5,00085 $9,108 $9,882 $9,108 $9,17586 $5,000 $5,000 $5,000 $5,00087 $5,000 $5,000 $5,000 $5,00088 $5,000 $5,000 $5,000 $5,00089 $5,000 $5,000 $5,000 $5,00090 $9,108 $9,882 $9,108 $9,17591 $5,000 $5,000 $5,000 $5,00092 $5,000 $5,000 $5,000 $5,00093 $5,000 $5,000 $5,000 $5,00094 $5,000 $5,000 $5,000 $5,00095 $9,108 $9,882 $9,108 $9,175

3 05/01/2019



96 $5,000 $5,000 $5,000 $5,00097 $5,000 $5,000 $5,000 $5,00098 $5,000 $5,000 $5,000 $5,00099 $5,000 $5,000 $5,000 $5,000

100 $9,108 $9,882 $9,108 $9,175NPV Maintenanceonly $321,738.99 $288,840.70 $284,410.56 $315,599.20NPV Life-Cycle $1,284,689.90 $1,325,064.33 $1,246,064.20 $2,211,866.67

4 05/01/2019

Feasibility Report ‐ Removal Alternative Detailed Cost Estimates

shallower cut deeper cut shallower cutbox culvert box culvert open bottom

Alternatives Unit Price 1F 2F 1GSite PreparationMobilization/Demobilization Lsum 150,000.00$ 1 150,000.00$ 1 150,000.00$ 1 150,000.00$ Site Clearing Acre 4,000.00$ 3 12,000.00$ 3 12,000.00$ 3 12,000.00$ Erosion Control/Sediment Traps/Erosion Control Blanket LSum 25,000.00$ 1 25,000.00$ 1 25,000.00$ 1 25,000.00$

Dam RemovalConcrete demolition CYD 20.00$ 55 1,100.00$ 55 1,100.00$ 55 1,100.00$ Dam material disposal Ton 10.00$ 111.65 1,116.50$ 111.65 1,116.50$ 111.65 1,116.50$ Embankment Excavation CYD 14.00$ 3708 51,912.00$ 4861 68,054.00$ 3708 51,912.00$ Flow Diversion Lsum 20,000.00$ 1 20,000.00$ 1 20,000.00$ 1 20,000.00$ Pavement Removal SYD 4.00$ 347 1,388.00$ 347 1,388.00$ 347 1,388.00$ Guardrail Removal Ft 2.00$ 200 400.00$ 200 400.00$ 200 400.00$ Traffic Management Lsum 20,000.00$ 1 20,000.00$ 1 20,000.00$ 1 20,000.00$ Contingency Fund for Well Adjustments Lsum 30,000.00$ 1 30,000.00$ 1 30,000.00$ 1 30,000.00$

Road Crossing ReplacementConcrete Box Culvert Ft 2,500.00$ 117 292,500.00$ 130 325,000.00$ 0 ‐$ Precast Three‐Sided Culvert Ft 2,000.00$ 0 ‐$ 0 ‐$ 117 234,000.00$ Bridge Structure SFT 450.00$ 0 ‐$ 0 ‐$ 0 ‐$ Culvert Bedding CYD 50.00$ 104 5,200.00$ 104 5,200.00$ 0 ‐$ Backfill Structure CIP CYD 25.00$ 3413 85,312.50$ 4854 121,343.75$ 3535 88,375.00$ Road Subbase, Class II CYD 25.00$ 96 2,400.00$ 96 2,400.00$ 96 2,400.00$ Aggregate CYD 60.00$ 64 3,840.00$ 64 3,840.00$ 64 3,840.00$ Pavement, Replace CYD 75.00$ 32 2,400.00$ 32 2,400.00$ 32 2,400.00$ Guardrail Replace Ft 25.00$ 200 5,000.00$ 200 5,000.00$ 200 5,000.00$ Bridge Riprap Protection SYD 160.00$ 0 ‐$ 0 ‐$ 0 ‐$ Approach Pavement SYD 175.00$ 0 ‐$ 0 ‐$ 0 ‐$ Guardrail Anchorage to Bridge EA 1,500.00$ 0 ‐$ 0 ‐$ 0 ‐$ Guardrail FT 22.00$ 0 ‐$ 0 ‐$ 0 ‐$ Guardrail Terminal EA 2,200.00$ 0 ‐$ 0 ‐$ 0 ‐$

River Restoration and Sediment ManagementImpound Excavation CYD 10.00$ 2365 23,650.00$ 6895 68,950.00$ 2365 23,650.00$ Engineered Riffle SYD 80.00$ 476 38,080.00$ 450 36,000.00$ 476 38,080.00$ Riprap Bank Protection CYD 101.00$ 240 24,240.00$ 180 18,180.00$ 240 24,240.00$ Channel Bed Materials Ton 71.00$ 308 21,868.00$ 84 5,964.00$ 308 21,868.00$ Habitat Boulders Ea 125.00$ 50 6,250.00$ 50 6,250.00$ 50 6,250.00$ Topsoil 6" SYD 2.70$ 24000 64,800.00$ 24000 64,800.00$ 24000 64,800.00$ Live Stakes Ea 5.02$ 475 2,384.50$ 475 2,384.50$ 475 2,384.50$ Plants (Bare Root Stock) Ea 25.11$ 250 6,277.50$ 250 6,277.50$ 250 6,277.50$ Seeding Acre 5,980.00$ 10 59,800.00$ 10 59,800.00$ 10 59,800.00$

1 05/01/2019


shallower cut deeper cut shallower cutbox culvert box culvert open bottom

Alternatives Unit Price 1F 2F 1GSite Restoration LSum 10,000.00$ 1 10,000.00$ 1 10,000.00$ 1 10,000.00$ Pedestrian Bridge and Trail Replacement (Rotary Park) LSum 15,000.00$ 1 15,000.00$ 1 15,000.00$ 1 15,000.00$ Estimated Construction Cost 981,919.00$ 1,087,848.25$ 921,281.50$ Contingency Cost (40%) 392,767.60$ 435,139.30$ 368,512.60$ Engineering and Permitting (10%) 98,191.90$ 108,784.83$ 92,128.15$ Construction Admin/RPR (10%) 98,191.90$ 108,784.83$ 92,128.15$ Estimated Project TOTAL without Upper Pond Restoration 1,571,070.40$ 1,740,557.20$ 1,474,050.40$

Upper Pond River Restoration and Sediment ManagementImpound Excavation CYD 10.00$ 1740 17,400.00$ 1740 17,400.00$ 1740 17,400.00$ Engineered Riffle SYD 80.00$ 267 21,360.00$ 267 21,360.00$ 267 21,360.00$ Riprap Bank Protection CYD 101.00$ 0 ‐$ 0 ‐$ 0 ‐$ Channel Bed Materials Ton 71.00$ 0 ‐$ 0 ‐$ 0 ‐$ Habitat Boulders Ea 125.00$ 36 4,500.00$ 36 4,500.00$ 36 4,500.00$ Topsoil 6" SYD 2.70$ 5000 13,500.00$ 5000 13,500.00$ 5000 13,500.00$ Live Stakes Ea 5.02$ 456 2,289.12$ 456 2,289.12$ 456 2,289.12$ Plants (Bare Root Stock) Ea 25.11$ 100 2,511.00$ 100 2,511.00$ 100 2,511.00$ Seeding Acre 5,980.00$ 2.5 14,950.00$ 2.5 14,950.00$ 2.5 14,950.00$ Estimated Construction Cost 76,510.12$ 76,510.12$ 76,510.12$ Contingency Cost (40%) 30,604.05$ 30,604.05$ 30,604.05$ Engineering and Permitting (10%) 7,651.01$ 7,651.01$ 7,651.01$ Construction Admin/RPR (10%) 7,651.01$ 7,651.01$ 7,651.01$ Estimated Upper Pond TOTAL 122,416.19$ 122,416.19$ 122,416.19$

Estimated Project TOTAL with Upper Pond Restoration 1,693,486.59$ 1,862,973.39$ 1,596,466.59$

Operation and Maintenance Cost in Present Value for 100year Lifecycle $125,072.12 $125,072.12 $125,072.12

2 05/01/2019


Alternatives Unit PriceSite PreparationMobilization/Demobilization Lsum 150,000.00$ Site Clearing Acre 4,000.00$ Erosion Control/Sediment Traps/Erosion Control Blanket LSum 25,000.00$

Dam RemovalConcrete demolition CYD 20.00$ Dam material disposal Ton 10.00$ Embankment Excavation CYD 14.00$ Flow Diversion Lsum 20,000.00$ Pavement Removal SYD 4.00$ Guardrail Removal Ft 2.00$ Traffic Management Lsum 20,000.00$ Contingency Fund for Well Adjustments Lsum 30,000.00$

Road Crossing ReplacementConcrete Box Culvert Ft 2,500.00$ Precast Three‐Sided Culvert Ft 2,000.00$ Bridge Structure SFT 450.00$ Culvert Bedding CYD 50.00$ Backfill Structure CIP CYD 25.00$ Road Subbase, Class II CYD 25.00$ Aggregate CYD 60.00$ Pavement, Replace CYD 75.00$ Guardrail Replace Ft 25.00$ Bridge Riprap Protection SYD 160.00$ Approach Pavement SYD 175.00$ Guardrail Anchorage to Bridge EA 1,500.00$ Guardrail FT 22.00$ Guardrail Terminal EA 2,200.00$

River Restoration and Sediment ManagementImpound Excavation CYD 10.00$ Engineered Riffle SYD 80.00$ Riprap Bank Protection CYD 101.00$ Channel Bed Materials Ton 71.00$ Habitat Boulders Ea 125.00$ Topsoil 6" SYD 2.70$ Live Stakes Ea 5.02$ Plants (Bare Root Stock) Ea 25.11$ Seeding Acre 5,980.00$

deeper cut shallower cut deeper cutopen bottom bridge bridge

2G 1H 2H

1 150,000.00$ 1 150,000.00$ 1 150,000.00$ 3 12,000.00$ 3 12,000.00$ 3 12,000.00$ 1 25,000.00$ 1 25,000.00$ 1 25,000.00$

55 1,100.00$ 55 1,100.00$ 55 1,100.00$ 111.65 1,116.50$ 111.65 1,116.50$ 111.65 1,116.50$ 4861 68,054.00$ 3708 51,912.00$ 4861 68,054.00$ 1 20,000.00$ 1 20,000.00$ 1 20,000.00$

347 1,388.00$ 347 1,388.00$ 347 1,388.00$ 200 400.00$ 0 ‐$ 0 ‐$1 20,000.00$ 1 20,000.00$ 1 20,000.00$ 1 30,000.00$ 1 30,000.00$ 1 30,000.00$

0 ‐$ 0 ‐$ 0 ‐$ 130 260,000.00$ 0 ‐$ 0 ‐$ 0 ‐$ 1360 612,000.00$ 1360 612,000.00$ 0 ‐$ 0 ‐$ 0 ‐$

4976 124,406.25$ 270 6,750.00$ 310 7,750.00$ 96 2,400.00$ 0 ‐$ 0 ‐$ 64 3,840.00$ 0 ‐$ 0 ‐$ 32 2,400.00$ 0 ‐$ 0 ‐$ 200 5,000.00$ 0 ‐$ 0 ‐$ 0 ‐$ 37 5,920.00$ 37 5,920.00$ 0 ‐$ 40 7,000.00$ 40 7,000.00$ 0 ‐$ 4 6,000.00$ 4 6,000.00$ 0 ‐$ 80 1,760.00$ 80 1,760.00$ 0 ‐$ 4 8,800.00$ 4 8,800.00$

6895 68,950.00$ 2365 23,650.00$ 6895 68,950.00$ 450 36,000.00$ 476 38,080.00$ 450 36,000.00$ 180 18,180.00$ 192 19,392.00$ 133 13,433.00$ 84 5,964.00$ 308 21,868.00$ 84 5,964.00$ 50 6,250.00$ 50 6,250.00$ 50 6,250.00$

24000 64,800.00$ 24000 64,800.00$ 24000 64,800.00$ 475 2,384.50$ 475 2,384.50$ 475 2,384.50$ 250 6,277.50$ 250 6,277.50$ 250 6,277.50$ 10 59,800.00$ 10 59,800.00$ 10 59,800.00$

3 05/01/2019


Alternatives Unit PriceSite Restoration LSum 10,000.00$ Pedestrian Bridge and Trail Replacement (Rotary Park) LSum 15,000.00$ Estimated Construction CostContingency Cost (40%)Engineering and Permitting (10%)Construction Admin/RPR (10%)Estimated Project TOTAL without Upper Pond Restoration

Upper Pond River Restoration and Sediment ManagementImpound Excavation CYD 10.00$ Engineered Riffle SYD 80.00$ Riprap Bank Protection CYD 101.00$ Channel Bed Materials Ton 71.00$ Habitat Boulders Ea 125.00$ Topsoil 6" SYD 2.70$ Live Stakes Ea 5.02$ Plants (Bare Root Stock) Ea 25.11$ Seeding Acre 5,980.00$ Estimated Construction CostContingency Cost (40%)Engineering and Permitting (10%)Construction Admin/RPR (10%)Estimated Upper Pond TOTAL

Estimated Project TOTAL with Upper Pond Restoration

Operation and Maintenance Cost in Present Value for 100year Lifecycle

deeper cut shallower cut deeper cutopen bottom bridge bridge

2G 1H 2H1 10,000.00$ 1 10,000.00$ 1 10,000.00$ 1 15,000.00$ 1 15,000.00$ 1 15,000.00$

1,020,710.75$ 1,228,248.50$ 1,266,747.50$ 408,284.30$ 491,299.40$ 506,699.00$ 102,071.08$ 122,824.85$ 126,674.75$ 102,071.08$ 122,824.85$ 126,674.75$

1,633,137.20$ 1,965,197.60$ 2,026,796.00$

1740 17,400.00$ 1740 17,400.00$ 1740 17,400.00$ 267 21,360.00$ 267 21,360.00$ 267 21,360.00$

0 ‐$ 0 ‐$ 0 ‐$0 ‐$ 0 ‐$ 0 ‐$

36 4,500.00$ 36 4,500.00$ 36 4,500.00$ 5000 13,500.00$ 5000 13,500.00$ 5000 13,500.00$ 456 2,289.12$ 456 2,289.12$ 456 2,289.12$ 100 2,511.00$ 100 2,511.00$ 100 2,511.00$ 2.5 14,950.00$ 2.5 14,950.00$ 2.5 14,950.00$

76,510.12$ 76,510.12$ 76,510.12$ 30,604.05$ 30,604.05$ 30,604.05$ 7,651.01$ 7,651.01$ 7,651.01$ 7,651.01$ 7,651.01$ 7,651.01$

122,416.19$ 122,416.19$ 122,416.19$

1,755,553.39$ 2,087,613.79$ 2,149,212.19$

$125,072.12 $127,911.15 $127,911.15

4 05/01/2019


4.23.2019Inputs:

Lifecycle Cost Item Unit Price Unit F (1) F (2) G (1) G (2) H (1) H (2)Invasive Species Control 750 $/acre $9,000.00 $9,000.00 $9,000.00 $9,000.00 $9,000.00 $9,000.00Crossing Clean out 200 LSUM $200.00 $200.00 $200.00 $200.00Crossing Maintenance 500 LSUM $500.00 $500.00 $500.00 $500.00 $500.00 $500.00Annual park maintenance $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00Total cost every 5 years - $12,700.00 $12,700.00 $12,700.00 $12,700.00 $12,500.00 $12,500.00Total cost every 5 years without Invasive Species Control $700.00 $700.00 $700.00 $700.00 $500.00 $500.00

1 05/01/2019


Year Option F (1) F (2) G (1) G (2) H (1) H (2) Notes

0 1,571,070.40$ 1,740,557.20$ 1,474,050.40$ 1,633,137.20$ 1,965,197.60$ 2,026,796.00$Initial Construction Cost WITHOUT UpperPond Restoration

0 1,693,486.59$ 1,862,973.39$ 1,596,466.59$ 1,755,553.39$ 2,087,613.79$ 2,149,212.19$ Initial Construction Cost

1 $12,000.00 $12,000.00 $12,000.00 $12,000.00 $12,000.00 $12,000.00Just invasive species control and parkmaintenance



4 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 Just annual park maintenance

5 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.00Annual Park Maintenance,Crossing cleanout and maintenance

6 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.007 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.008 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.009 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00

10 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0011 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0012 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0013 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0014 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0015 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $8,000.00 $8,000.0016 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0017 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0018 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0019 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0020 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0021 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0022 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0023 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0024 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0025 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0026 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0027 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0028 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0029 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0030 $4,700.00 $4,700.00 $4,700.00 $4,700.00 $3,500.00 $3,500.0031 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0032 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0033 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0034 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00

Alternatives

2 05/01/2019


Year Option F (1) F (2) G (1) G (2) H (1) H (2) NotesAlternatives

35 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,700.0036 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0037 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0038 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0039 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0040 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0041 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0042 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0043 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0044 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0045 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $8,000.00 $8,000.0046 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0047 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0048 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0049 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0050 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0051 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0052 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0053 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0054 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0055 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0056 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0057 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0058 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0059 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0060 $4,700.00 $4,700.00 $4,700.00 $4,700.00 $3,500.00 $3,500.0061 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0062 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0063 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0064 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0065 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,700.0066 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0067 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0068 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0069 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0070 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0071 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0072 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0073 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0074 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0075 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $8,000.00 $8,000.00

3 05/01/2019


Year Option F (1) F (2) G (1) G (2) H (1) H (2) NotesAlternatives

76 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0077 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0078 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0079 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0080 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0081 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0082 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0083 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0084 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0085 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.0086 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0087 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0088 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0089 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0090 $4,700.00 $4,700.00 $4,700.00 $4,700.00 $3,500.00 $3,500.0091 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0092 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0093 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0094 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0095 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,700.0096 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0097 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0098 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.0099 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00 $3,000.00

100 $3,700.00 $3,700.00 $3,700.00 $3,700.00 $3,500.00 $3,500.00NPV Maintenance only $125,072.12 $125,072.12 $125,072.12 $125,072.12 $127,911.15 $127,911.15NPV Life-Cycle Total $1,765,590.99 $1,930,141.28 $1,671,396.81 $1,825,850.02 $2,150,995.09 $2,210,799.36NPV Life-Cycle Total WITHOUTUpper Pond Restoration $1,646,740.32 $1,811,290.61 $1,552,546.14 $1,706,999.34 $2,032,144.41 $2,091,948.69

4 05/01/2019

Davisburg Mill Pond Dam Feasiblity Report Project number: 60594641

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