date to: interested parties · 2012. 10. 4. · elm creek interceptor – medina leg environmental...

Date

TO: INTERESTED PARTIES

RE: Elm Creek Interceptor – Medina Leg

Enclosed is the Environmental Assessment Worksheet (EAW) for the Elm Creek Interceptor – MedinaLeg, Hennepin County proposed by Metropolitan Council Environmental Services. The EAW wasprepared by the Minnesota Pollution Control Agency (MPCA) and is being distributed for a 30-dayreview and comment period pursuant to the Environmental Quality Board (EQB) rules. The commentperiod will begin the day the EAW availability notice is published in the EQB Monitor, which will likelyoccur in the April 29, 2002, issue.

Comments received on the EAW will be used by the MPCA in evaluating the potential for significantenvironmental effects from this project and deciding on the need for an Environmental Impact Statement(EIS).

A final decision on the need for an EIS will be made by the MPCA Commissioner after the end of thecomment period. If a request for an EIS is received during the comment period, or if the Commissionerrecommends the preparation of an EIS, the nine-member MPCA Citizens’ Board (Board) will make thefinal decision. The final EIS need decision will also be made by the Board if so requested by the projectproposer, other interested parties or MPCA staff and if this request is agreed to by one or more membersof the Board or the MPCA Commissioner. The Board meets once a month, usually the fourth Tuesday ofeach month, at the MPCA office in St. Paul. Meetings are open to the public and interested persons mayoffer testimony on Board agenda items. A listing of Board members is available on request by calling(651) 296-7306.

Please note that comment letters submitted to the MPCA do become public documents and will be part ofthe official public record for this project.

If you have any questions on the EAW, please contact Eric Kilberg of my staff at (651) 296-8643.

Sincerely,

Beth G. LockwoodSupervisor, Environmental Review UnitOperations and Environmental Review SectionRegional Environmental Management Division

BGL:gs

Enclosure

TDD (for hearing and speech impaired only): (651) 282-5332Printed on recycled paper containing 100% fibers from paper recycled by consumers

ENVIRONMENTAL ASSESSMENT WORKSHEETNote to reviewers: The Environmental Assessment Worksheet (EAW) provides information about a project thatmay have the potential for significant environmental effects. This EAW was prepared by the MinnesotaPollution Control Agency (MPCA), acting as the Responsible Governmental Unit (RGU), to determine whetheran Environmental Impact Statement (EIS) should be prepared. The project proposer supplied reasonablyaccessible data for, but did not complete the final worksheet. Comments on the EAW must be submitted to theMPCA during the 30-day comment period which begins with notice of the availability of the EAW in theMinnesota Environmental Quality Board (EQB) Monitor. Comments on the EAW should address the accuracyand completeness of information, potential impacts that warrant further investigation, and the need for an EIS. Acopy of the EAW may be obtained from the MPCA by calling (651) 296-7398. An electronic version of thecompleted EAW is available at the MPCA Web site http://www.pca.state.mn.us/news/eaw/index.html#open-eaw.

1. Project Title: Elm Creek Interceptor – Medina Leg

2. Proposer: Metropolitan CouncilEnvironmental Services

3. RGU:Minnesota Pollution Control Agency

Contact Person Wayne Rikala Contact Person Eric J. Kilberg

and Title Principal Engineer and Title Planner Principal

Address 230 East 5th Street Address 520 Lafayette Road North

St. Paul, Minnesota 55101 St. Paul, Minnesota 55155

Phone (651) 602-1127 Phone (651) 296-8643

Fax (651) 602-1030 Fax (651) 296-7782

E-mail [email protected] E-mail [email protected]

4. Reason for EAW Preparation:EISScoping

MandatoryEAW X

CitizenPetition

RGUDiscretion

ProposerVolunteered

If EAW or EIS is mandatory give EQB rule category subpart number and name:

4410.4300 subpart 18A Wastewater and Sewage Systems: For expansion, modification, or replacementof a municipal sewage collection system resulting in an increase in design average flow of any part of thatsystem by 1,000,000 gallons per day or more, the MPCA shall be the RGU. The Medina Leg of the ElmCreek Interceptor project is being designed for an average daily flow of four million gallons per day(MGD) and a peak flow of ten MGD.

5. Project Location: County Hennepin City/Twp Maple Grove, Plymouth, Medina

1/4 1/4 Section (see below) Township (see below) Range (see below)

http://www.pca.state.mn.us/news/eaw/index.html#open-eaw

mailto:[email protected]

mailto:[email protected]

Elm Creek Interceptor – Medina Leg Environmental AssessmentMaple Grove, Plymouth, Medina, Minnesota 2 Worksheet

The proposed alignment for the interceptor extends through portions of or along the boundaries of the followingSections:

In Township 119 North, Range 22 West, (the city of Maple Grove) Sections 31 and 32.In Township 118 North, Range 22 West, (the city of Plymouth) Sections 5, 6, and 7.In Township 118 North, Range 23 West, (the city of Medina) Sections 1 and 12.

Attachments to and Figures for the EAW:

Attachments:

Attachment 1 Minnesota Department of Natural Resources (DNR) Natural Heritage and NongameResearch Program response letter, dated November 6, 2001;

Attachment 2 Minnesota Historical Society State Historic Preservation Office (SHPO) response letter,dated November 14, 2001; and

Attachment 3 Minnesota Historical Society SHPO response letter, dated April 5, 2002.

Figures:

Figure 1 Project Location MapFigure 2 USGS Topographic MapFigure 3 Project AlignmentFigure 3A Detailed Project AlignmentFigure 3B Detailed Project AlignmentFigure 3C Detailed Project AlignmentFigure 3D Detailed Project AlignmentFigure 4 Wetlands and Protected WatersFigure 5 Soils Map

6. Description:

a. Provide a project summary of 50 words or less to be published in the EQB Monitor.

The Metropolitan Council Environmental Services Division (MCES) proposes to construct the ElmCreek Interceptor – Medina Leg to convey wastewater from parts of southwest Maple Grove, northwestPlymouth, and Medina, all within the Elm Creek Watershed. The interceptor will replace the existingMetropolitan wastewater pumping station in Medina by providing a gravity outlet.

b. Give a complete description of the proposed project and related new construction. Attach additionalsheets as necessary. Emphasize construction, operation methods and features that will cause physicalmanipulation of the environment or will produce wastes. Include modifications to existing equipment orindustrial processes and significant demolition, removal or remodeling of existing structures. Indicatethe timing and duration of construction activities.

Several alternatives were considered and evaluated for the alignment of the Elm Creek Interceptor –Medina Leg and are discussed in detail in the Elm Creek Interceptor Facility Plan (February 1993). Therecommended plan is the subject of this EAW and consists of the components discussed below. General


construction activities will include excavation, grading, and backfilling, as well as dewatering in someareas. Construction of the Elm Creek Interceptor is proposed to begin in the summer of 2002 and to becomplete by the end of 2003.

The method of construction will be tunneling in the following areas: crossing or parallel to county roads(where needed to avoid tearing up the roads); under one railroad bed (where open cut is prohibited);under a large concrete box culvert for storm water (so as to avoid having to remove and replace theculvert); and under a private residential area near 54th Avenue North and Vagabond Lane (so as tominimize disturbance to the private landscaping and a cul de sac in this area). Figure 3 shows whichportions of the alignment will be tunneled. Horizontal directional drilling does not appear to be feasible,based on insufficient available slopes along most of the alignment. Other tunneling alternatives thathave not been ruled out are jacking and microtunneling. The contractor will choose the method ofconstruction, as long as it achieves the specified product.

The Elm Creek Interceptor – Medina Leg would consist of the construction of approximately 22,700 feetof gravity interceptor pipe (27 and 30-inch diameter), about 2,100 feet of local gravity sewers (8 to 12-inch diameter) and two flow meter stations. It would serve the southwest portion of the city of MapleGrove, the northwest portion of the city of Plymouth, and the entire city of Medina. The alignment, as itis currently proposed, begins in Maple Grove at an existing structure on Garland Lane, near Elm Road.Figure 3 depicts the proposed alignment of the interceptor. Figures 3A through 3D show the alignmentin greater detail.

The pipe would run south along Garland Lane to Elm Road and then follow the north side of Elm Roadto Lawndale Lane. The pipe would be tunneled under Lawndale Lane and then run south along the westside of Lawndale Lane to the Maple Grove/Plymouth border. The northerly 900 feet of pipe alongLawndale Lane would be tunneled because of the excess depth. This would avoid disruption of trafficon Lawndale Lane. A flow meter station would be located in Plymouth just north of the MapleGrove/Plymouth border.

Approximately 300 feet of the pipe will also be tunneled under County Road 47 and the Theisenproperty located at the NW corner of the intersection of Lawndale Lane and County Road 47. Structureson the Theisen property have been deemed eligible for listing on the National Register of HistoricPlaces. To avoid disturbing the structures (a house and a garage), the pipe will be tunneled.

The pipe would continue south along Lawndale Lane to the large wetland complex associated with ElmCreek. The pipe would follow the west side of the wetland to 54th Avenue at Peony Lane. The reach ofpipe along the wetland will be coordinated with Plymouth’s proposed Northwest Greenway Corridor.

The pipe would continue westerly along 54th Avenue for 700 feet to Ranier Lane and would then enter afarm field. A widened permanent easement (60 feet) would be acquired along the southern end of thefield to allow preservation of the southerly 20 feet of the property as part of the adjacentmaple/basswood forest. Also to protect the forest, the pipe would be routed through the Troy Ridgedevelopment to the west of the farm field. Construction through the development would be acombination of open cut and tunneling to minimize disruption. No construction traffic would be allowedwithin the Troy Ridge Development via their private road (Vagabond Lane) serving that development, asper the construction plans and specifications.


The pipe would leave the Troy Ridge development and head west to Hennepin County State AidHighway (CSAH) 101. Hennepin County is upgrading and realigning CSAH 101 in 2002-2003. TheElm Creek Interceptor – Medina Leg is being coordinated with the Highway 101 alignment andconstruction. The entire 3,100-foot length of pipe along CSAH 101 will be tunneled because of theexcess depth. The pipe would turn south along the east side of CSAH 101 to the intersection withMinnesota Trunk Highway (TH) 55. The pipe will also be tunneled beneath the CSAH 101/TH 55intersection. At this point, the pipe would also be tunneled beneath Elm Creek.

The flow metering station for the city of Medina would be located just southwest of the CSAH 101/TH55/Sioux Drive intersection. The pipe would continue westerly through the parking lots of thebusinesses on the south side of TH 55. The pipe at this point is parallel to Elm Creek, which serves asthe south road ditch for TH 55. The pipe would be tunneled beneath the primary access to thebusinesses to ensure dual direction access to businesses during construction. After leaving the parkinglots the pipe would head south to Hamel Road, crossing under the Canadian Pacific Railway track bymeans of a tunnel. Then the pipe would turn west along Hamel Road to the existing box culvert crossingof Elm Creek. The pipe would be jacked under the culvert, then continue along Hamel Road to theMCES’ Medina Lift Station. The need to operate the Medina Lift Station will be eliminated as a resultof this project, but the station will remain intact for auxiliary use.

Two local sewer segments are to be constructed as part of this project. One consists of 1,450 feet of 12-inch diameter sewer extended west and south of the CSAH 101/TH 55 intersection, across Sioux Driveto the railroad line at the Plymouth/Medina border. The purpose of this pipe is to enable future gravitysewer service to an area of Plymouth south of TH 55. The other segment consists of 650 feet of eight-inch diameter pipe to be constructed in Medina south of Hamel Road on Elm Creek Drive, and westerlynear Elm Creek. This eight-inch sewer would cross Elm Creek by open-cut excavation at two locations.This will improve system reliability by replacing an existing sewer located in the Elm Creek floodplainand by eliminating two private sewer services that cross under the creek. There will also be some short,local sewer segments constructed along Hamel Road to reconnect the existing collection system to thenew interceptor.

c. Explain the project purpose; if the project will be carried out by a governmental unit, explain the needfor the project and identify its beneficiaries.

The proposed Elm Creek Interceptor – Medina Leg is needed to convey wastewater from the southwestportion of Maple Grove, the northwest portion of Plymouth, and the city of Medina to the Elm CreekInterceptor in Maple Grove, and eventually to the Metropolitan Wastewater Treatment Facility (WWTF)in St. Paul. The Metropolitan interceptor system that currently serves the city of Medina will soon lacksufficient capacity to support the growth occurring in Medina. The Medina Leg of the Elm CreekInterceptor will alleviate that immediate deficiency as well as allow for eventual development insouthwest Maple Grove and northwest Plymouth in accordance with the local communities’comprehensive plans.

The beneficiaries of the project are the owners of existing residences, the property owners who will beenabled to develop property, the business interests that will finance and develop those properties, andthe future owners of residences and other properties in the three communities.


d. Are future stages of this development including development on any outlots planned or likely to happen?Yes No

If yes, briefly describe future stages, relationship to present project, timeline and plans for environmentalreview.

Future stages of the Elm Creek Interceptor – Medina Leg are not currently planned. Limited service toLoretto, Corcoran, and Independence might conceivably be considered in the future.

Residential and commercial development, managed by local units of government, is planned to occurwithin the project’s service area. Other than the area near TH 55 where commercial and industrialdevelopment is present, most of the area along the proposed alignment currently consists of residentialdevelopment, agricultural land, undeveloped areas of woodland, wetland and field, and some commercialdevelopment. The ultimate proposed land use for the area is urban residential and commercialdevelopment, with the timing of urbanization varying according to each community’s comprehensive plan.(See Item 27.) Development of the area will be subject to compliance with local storm-water managementplans, comprehensive development plans, and ordinances. Development of adjacent areas is not a part ofthis project and, if required, will be subject to independent environmental review.

The Elm Creek Interceptor – Medina Leg will be coordinated with Hennepin County’s CSAH 101 projectand with Plymouth’s Northwest Greenway Corridor project.

e. Is this project a subsequent stage of an earlier project? Yes NoIf yes, briefly describe the past development, timeline and any past environmental review.

The Elm Creek Interceptor – Medina Leg is a subsequent stage of the MCES’ Elm Creek InterceptorPhases I and II and the city of Maple Grove’s Southwest Trunk Sewer. These projects were all the subjectof EAWs within the past six years.

7. Project Magnitude Data

Total Project Area (acres) 64.8 acres or Length (miles) 4.7 miles (24,800 feet)Number of Residential Units: Unattached NA Attached NA maximum units per building NACommercial/Industrial/Institutional Building Area (gross floor space): total square feet NAIndicate area of specific uses (in square feet):

Office NA Manufacturing NARetail NA Other Industrial NAWarehouse NA Institutional NALight Industrial NA Agricultural NAOther Commercial (specify) NABuilding height NA If over 2 stories, compare to heights of nearby buildings NA


8. Permits and approvals required. List all known local, state and federal permits, approvals and financialassistance for the project. Include modifications of any existing permits, governmental review of plans,and all direct and indirect forms of public financial assistance including bond guarantees, Tax IncrementFinancing and infrastructure.

Unit of Government Type of Application StatusU.S. Army Corps of Engineers Minnesota Local/State /Federal Application

for Public Transportation and Linear UtilityProjects – Application for Department of theArmy Permit (GP/LOP-98-MN – Section404 Activities); Requested LOP-A

Submitted 1/21/02

MPCA Approval of Facility Plan and ConstructionPlans and Specifications (for MinnesotaPublic Facilities Authority fundingeligibility)

To be submitted

MPCA National Pollutant Discharge EliminationSystem (NPDES) General Permit fordischarge of storm water during constructionactivities

To be submitted

Application for Sewer Extension Permit To be submitted

Minnesota Department of NaturalResources (DNR)

Application for General Permit 97-0005 forTemporary Water Appropriations

To be submitted byConstructionContractor if morethan 10,000 gallonsper day of water isappropriated

Application for License to Cross PublicLands and Waters (License # 144-65-5310)

Submitted 1/21/02

Minnesota Department of Health(MDH)

Application for Water Well Permits To be submitted (ifwells required)

Minnesota Department ofTransportation (MnDOT)

Application for Utility Permit on TrunkHighway Right of Way (Form #TP-02525-03)

To be submitted

Elm Creek WatershedManagement Commission

Approval of Grading Plan, Sediment andErosion Control Plan, and FloodplainImpacts

To be submitted

Hennepin County TransportationDepartment

Permit Application for Utility Construction(for work in road right-of-way and roadcrossings) (Form #HC5136)

To be submitted

City of Maple Grove Application for Minnesota WetlandConservation Act (WCA) Certificate of NoLoss or Exemption

Submitted 1/21/02


Unit of Government Type of Application StatusCity of Plymouth Sewer and Water Permit Application To be submitted

Application for Minnesota WCA Certificateof No Loss or Exemption

Submitted 1/21/02

City of Medina Application for Minnesota WCA Certificateof No Loss or Exemption

Submitted 1/21/02

9. Land use. Describe current and recent past land use and development on the site and on adjacent lands.Discuss project compatibility with adjacent and nearby land uses. Indicate whether any potential conflictsinvolve environmental matters. Identify any potential environmental hazards due to past site uses, such assoil contamination or abandoned storage tanks, or proximity to nearby hazardous liquid or gas pipelines.

Land UseIn general, the area of the interceptor corridor is primarily undeveloped or agricultural, with scatteredresidences and farms for most of the corridor. The project is located in the valley of Elm Creek, and thereare some rather extensive wetlands and some remnants of the Bigwoods Forest that characterizedpresettlememt vegetation. Toward the southern portion of the alignment, particularly near TrunkHighway 55, and the village of Hamel, there is fairly dense residential, commercial and industrialdevelopment. Most of the corridor traverses an area with rapidly expanding growth, and can be describedas in a state of transition from primarily agricultural land to primarily urban land. The proposed project iscompatible with current and planned land use for the area and is intended to support future growth.

Known Contamination/Chemical UseIn order to determine whether construction of the project would involve any contaminated properties, agovernment records search inventory was conducted for the interceptor corridor. Chemical use andrelease sites were identified and plotted in relation to the corridor location.

Numerous sites were identified within one-half mile of the corridor. These sites included: 10 LeakingUnderground Storage Tank (LUST) sites, 8 underground storage tank sites, 22 Small Quantity HazardousWaste Generator (SQG) sites, 2 Large Quantity Hazardous Waste Generator (LQG) sites, 3 abovegroundstorage tank sites, 2 Spill sites, and one agricultural chemical spill (AGSPILL) site. Of the 10 LUST sitesidentified, 9 have been issued closure by the MPCA. The MPCA issues closure to sites it determines nolonger present a threat to human health or the environment. The LUST site that remains open appears tobe a gas station located near the intersection of Trunk Highway 55 and County Road 116, located one-quarter mile northwest of the nearest point on the proposed corridor.

One of the spill sites identified appears to be located near the intersection of County Road 47 andLawndale Lane, and the other near the intersection of Hamel Road and Tower Drive. Both spillsoccurred in the early 1990s and do not appear to have been significant. The AGSPILL site is alsoidentified near the intersection of Hamel Road and Tower Drive, which is approximately one-third milewest of the project site. It appears to have been to an area covered with asphalt. Other informationregarding the spill was not provided.

Contamination is not known to be associated with the hazardous waste generator sites identified in thecorridor vicinity. However, 6 violations were reported at one LQG site located near the intersection ofTrunk Highway 55 and County Road 116, during a 1992 Compliance Evaluation Inspection (CEI).Compliance was reportedly achieved three months later. County Road 116 is not located within the


project corridor. One violation was reported at an additional SQG site located near the intersection ofHamel Road and Tower Drive, during a CEI in 1996. Compliance was reportedly achieved by thisfacility two months later.

All but one of the sites identified are located near TH 55. Because of the commercial/industrial nature ofthis area, a contingency plan will be developed for use in the event that contamination is encounteredduring construction of the interceptor in this area. If contaminated soils are encountered, they will be setaside and the State Duty Officer will be notified.

10. Cover Types. Estimate the acreage of the site with each of the following cover types before and afterdevelopment:

Before After Before AfterTypes 1-8 wetlands 9.6 ac 9.6 ac Lawn/landscaping 5.4 ac 5.4 acWooded/forest 1.7 ac 0.0 ac Impervious Surfaces 2.5 ac 2.5 acBrush/grassland 15.8 ac 17.5 ac Other (describe) 4.5 ac 4.5 acCropland 25.3 ac 25.3 ac (tunneled area)

TOTAL 64.8 ac 64.8 ac

11. Fish, Wildlife, and Ecologically Sensitive Resources.

a. Identify fish and wildlife resources and habitats on or near the site and describe how they would beaffected by the project. Describe any measures to be taken to minimize or avoid impacts.

Wildlife inhabitants of the area vary as a function of the habitat, which in turn is determined byland use. Along the route of the proposed interceptor and in the area that will eventually be servedby it, land use varies but is primarily agricultural, low-density residential, or open land, with someforested areas and many wetlands. Most of the interceptor route in Medina is in the old village ofHamel, where land use is a mix of residential, commercial, and light industrial. Land use – andconsequently wildlife habitat – in the area is in transition from rural and agricultural to urban.Wildlife presently found in the area consists of mammals typically of agricultural, wetland, andwoodland areas, such as deer, raccoon, coyote, fox, raccoons, squirrels, muskrats, mice, and voles.Avian species include game birds, raptors, and songbirds. Amphibians include frogs, toads, andsalamanders, and reptiles include snakes, turtles, and lizards. In the wetlands, intermittent streams,and Elm Creek, wetland fauna species include marsh birds, frogs, turtles, snakes, and typicalwetland invertebrates. A variety of fish, mostly minnows, rough fish, and some game fish arepresent in Elm Creek.

Unique natural communities are found adjacent to the project route: In the north one-half ofSection 7 of Plymouth (North of the Wayzata High School, South of 54th Avenue North, West ofPeony Lane), lies a contiguous forest parcel that is largely undisturbed since presettlement. Threedistinct natural communities are represented: A Maple-Basswood Forest, an Oak Forest – MesicSubtype and a Lowland Hardwood Forest. These communities are listed on the Hennepin CountyBiological Survey Map. Wildlife populations here are expected to be more diverse, since these areasare essentially undisturbed. It seems likely, however, that species within this area are to somedegree adversely impacted by fragmentation of habitat.

Short-term impacts on wildlife include the disruptive effects of construction, including excavation,stockpiling of soils and materiel, noise, potentially erosion and sedimentation, and vehiclemovement. Habitat and individual animals will be destroyed by the actual excavation or placementof stockpiled earth or bedding. Surviving small species may be forced to leave their territories andcompete with established individuals in other areas. Larger species may be forced to relocate to


portions of their territories that are not impacted. Seasonal activities such as nesting may bedisrupted or curtailed, depending upon the season of construction.

Permits requiring mitigation measures include: The NPDES General Permit for discharge ofstorm water during construction activities, the Elm Creek Watershed Management District GradingPlan, Sediment and Erosion Control Plan, and the Certificates of Wetland Exemption issued by therespective cities. These and the other permits listed in Item 8 of this EAW will include specificmitigation measures to be provided for erosion and sedimentation control and runoff, as well asmitigation of wetland impacts. These measures include erosion control best management practices,such as erosion control blankets and rapid re-establishment of vegetation. The contractspecifications will also escrow payments to the contractor to enable prompt correction of erosioncontrol failure until final cover is applied. Even with effective erosion controls, water clarity may betemporarily affected by suspended solids carried in drainage ditches along the construction corridor.After construction, these effects may remain for a short time, before water clarity returns to normal.During construction through wetland areas, a minimum of one foot of bottom sediments will besalvaged and re-spread over the disturbed area to replace the native seedbed. After construction, thewetlands will be restored to their original contours. Therefore, pre-construction drainage patternswill not be altered by the project.

Long-term impacts associated with development in the areas served by the interceptor areanticipated. With suburban development of these areas, indigenous wildlife populations will bereplaced by wildlife populations more typical of residential areas. Adherence to comprehensiveplans and storm water ordinances adopted by the Elm Creek Watershed Management Commissionand local municipalities will mitigate storm-water impacts resulting from development.

b. Are any state (endangered or threatened) species, rare plant communities or other sensitive ecologicalresources such as native prairie habitat, colonial waterbird nesting colonies or regionally rare plantcommunities on or near the site? Yes NoIf yes, describe the resource and how it would be affected by the project. Indicate if a site survey ofthe resources has been conducted and describe the results. If the DNR Natural Heritage and NongameResearch program has been contacted give the correspondence reference number. ERDB 20020390Describe measures to minimize or avoid adverse impacts.

The DNR Natural Heritage and Nongame Research Program was contacted regarding the potentialpresence of threatened or endangered species, as well as other rare or sensitive biological resourcesin the vicinity of the project. According to the response received (see Attachment 1), there are 12known occurrences of rare species or natural communities in the vicinity of the project. A list of theoccurrences and a map of biological communities in the vicinity was provided. After review of thisinformation and discussion with DNR staff, it appears that only 2 of the 12 occurrences have thepotential to be impacted by the project. These are the Blandings turtle and a natural forestcommunity.

Blanding’s Turtle: Although the DNR does not feel that the interceptor corridor includes primehabitat for Blanding’s turtle (Emydoidea blandingii), the potential exists for the turtle to be present.Due to the limited amount of wetland impacted by construction, direct impact on the species isunlikely. Storm water and erosion and sedimentation control strategies required by the variouspermits listed in Item 8 should assure that these impacts do not occur from the construction. Inaddition, areas disturbed during construction of the interceptor will be restored to their originalcontours after construction.

Although long-term impacts to the Blanding’s turtle will not result directly from construction of thisproject, per se, long-term impacts will result from the development enabled by the interceptor.


These turtles typically overwinter in lakes, spend spring and summer in shallower wetlands, and laytheir eggs in sandy soil. They may travel a considerable distance to the nesting areas. Proliferationof residential development will not occur in lakes, but some impacts from this development couldoccur in wetland areas, subject to the requirements of the Wetland Conservation Act. While it isunlikely that there will be much impact on primary habitat (wetlands and lakes) of the species, itseems quite likely that upland areas suitable for turtle nesting will be developed as residential landuse, which will likely destroy nesting habitat. Construction of housing, fences and roadways mayalso interdict natural migration of the species. Increased road traffic and road development resultingfrom this project could result in more road kills of the turtle. As a result, if there is a population ofBlanding’s Turtle in the area, it is likely to decline as development proceeds.

Maple-Basswood Forest, Oak Forest – Mesic Subtype/Lowland Hardwood Forest: The naturalcommunity in question is a forested area located south of Peony Lane and 54th Avenue in the city ofPlymouth. It includes areas designated on the Hennepin County Biological Survey Map as Maple-Basswood Forest, Oak Forest – Mesic Subtype, and Lowland Hardwood Forest. A hayfield and alow-density housing development borders the forested area to the north. The Interceptor is proposedto extend through the hayfield, north of the forested area. A 60-foot wide permanent easement isproposed in this area, with the extra 20 feet of the easement to be set aside as a buffer to protect theforested area. There are small diameter regrowth trees that extend into the hayfield and some ofthese will be removed during construction of the project. However, tree loss will be minimal andwill not extend into the undisturbed forest proper.

The natural community is not legally protected in a formal sense. However, the city of Plymouthhas purchased approximately 55 acres of land containing most of this natural community and zonedit as Open Space to effectively preserve it. Also, the Wayzata School District owns land adjoiningthe southern edge of the city property and has adopted a stewardship role towards the naturalcommunity.

12. Physical Impacts on Water Resources. Will the project involve the physical or hydrologic alteration(dredging, filling, stream diversion, outfall structure, diking, and impoundment) of any surface waters suchas a lake, pond, wetland, stream or drainage ditch? Yes NoIf yes, identify water resource affected. Describe alternatives considered and proposed mitigationmeasures to minimize impacts. Give the DNR Protected Waters Inventory (PWI) number(s) if the waterresources affected are on the PWI.

According to analysis of the National Wetlands Inventory Map, 15 wetlands have the potential to beimpacted by the interceptor project. During field verification and wetland delineation activities, two ofthese basins were found to be non-wetlands. In all, approximately 9.6 acres of wetland will betemporarily impacted by construction of the interceptor, along the alignment currently proposed (seeFigure 4). One of the wetlands to be temporarily impacted is DNR Protected Wetland 456W, a largewetland in the floodplain of Elm Creek. In addition, the interceptor will cross a DNR ProtectedWatercourse, Elm Creek, in four locations in the southern portion of the alignment (see Figure 4).

To minimize impact to the wetland areas, a trench box will be used during the construction process. Insituations where a trench box is used, water will either be pumped out of or diverted around theconstruction trench. Dewatering discharge will be directed to sediment traps or vegetative buffer strips ifthe discharge is laden with sediment. A filter sock may also be used to trap the sediment and filter thewater prior to discharge. Clean discharge from well point dewatering will be dissipated and spread outover the adjacent wetland area located beyond the construction limits. During construction throughwetland areas, a minimum of one foot of bottom sediments will be salvaged and re-spread over thedisturbed area to replace the native seedbed. After construction, the wetlands will be restored to theiroriginal contours. Therefore, pre-construction drainage patterns will not be altered by the project.


A NPDES General Storm Water Construction Activity Permit will be obtained, as required, from theMPCA. As required by the permit, a soil erosion and control plan will be prepared and implementedduring construction.

The sediment and erosion control plan will provide more detail as to the specific measures to beimplemented and will also address: the phasing of construction; vehicle tracking of sediment; inspectionof erosion control measures; and the time frames in which the erosion control measures will beimplemented.

Along the area between the Troy Ridge development and CSAH 101, the project alignment lies close andparallel to a ditched and straightened tributary of Elm Creek. The Plans and Specifications includeseveral extensive requirements for the control of erosion and sedimentation, both during and subsequentto construction. These measures include the machine sliced installation of velocity fences and high-flowsilt fence. Installation of wattles (alone and in combination with rip rap) erosion control blanket, turfreinforcement mat, and rip rap in two configurations to attenuate erosive energy will allow the promptestablishment of a vegetated soil stabilization system. (A wattle is an assembled “log” or “roll” madefrom a variety of harvested materials, such as flax, straw, rice, wheat, wood fibers and/or coconut fiberused to limit runoff flow velocity and to remove sediment from runoff.)

Minn. R. 8420.0122, subp. 6a provides an exemption from wetland replacement for utilities/public worksprojects, such as this sanitary sewer interceptor project. However, development enabled by theinterceptor project will be subject to the Wetland Conservation Act rules. Potential wetland or othersurface water impacts associated with future developments in the area will be addressed during theplanning and permitting processes of the city in which the development is proposed (Maple Grove,Plymouth, or Medina).

13. Water Use. Will the project involve installation or abandonment of any water wells, connection to orchanges in any public water supply or appropriation of any ground or surface water (includingdewatering)? Yes NoIf yes, as applicable, give location and purpose of any new wells; public supply affected, changes to bemade, and water quantities to be used; the source, duration, quantity and purpose of any appropriations;and unique well numbers and DNR appropriation permit numbers, if known. Identify any existing and newwells on the site map. If there are no wells known on site, explain methodology used to determine.

Additional water supply wells will not be needed for the project. One existing residential water well isproposed to be abandoned as part of the project. The interceptor will be too close to this well to affordthe required separation distance between the existing well and the new interceptor. The well is on theDouglas W. Theis property located approximately one-half mile north of TH 55 on CSAH 101. The wellwould be replaced by extending about 300 feet of eight-inch watermain and a one-inch copper servicepipe to the residence.

Ground water may be encountered in some areas during placement of the pipe. Trench dams will beinstalled to prevent migration of ground water along the pipe. The soil borings taken for this projectindicate that wetted soils near the pipe grade are distributed intermittently. Therefore trench dams will betargeted at wet locations. The spacing of trench dams will depend on observed ground water conditions.Based on the geotechnical information for an area containing such wetted soils, it is anticipated thattrench dams placed at 1,000 feet apart will provide the necessary control.


Due to the shallow depth of ground water in some areas of the proposed project, temporary dewateringwells may be needed in order to place the interceptor pipe at the required depths. The dewatering wellswill be sited by the construction contractor based on the evaluation of dewatering needed. It is not yetknown if the volumes of water will be such that a DNR Temporary Water Appropriation Permit will berequired. The threshold for the DNR Water Appropriation Permit is 10,000 gallons per day, or 1 milliongallons per year. The Medina Leg project may need a temporary permit – the Department of NaturalResources General Permit 97-0005 for Temporary Water Appropriations. The threshold for this permit isalso 10,000 gallons per day. Total gallons pumped cannot exceed 50 million gallons, and waterappropriations must be completed within one year from the start of pumping. Where dewatering isrequired, the discharge of dewatering water will be managed as discussed in Item 12 of this EAW.

The depth to ground water along the proposed alignment varies, with the shallowest occurrences near ElmCreek, wetland areas, and drainage ditches. After dewatering is completed, the dewatering wells will beproperly abandoned in accordance with MDH Water Well Code. It is anticipated that in some areas,dewatering the trench with a centrifugal sump pump will be sufficient to control water levels.

14. Water-related land use management districts. Does any part of the project involve a shoreland zoningdistrict, a delineated 100-year flood plain, or a state or federally designated wild or scenic river land usedistrict? Yes NoIf yes, identify the district and discuss project compatibility with district land use restrictions.

The project is located within the Elm Creek Watershed. Several segments of the project pass through theElm Creek 100-year flood plain. The project, because of its sub-grade construction, is compatible withflood plain restrictions and with the Elm Creek Watershed Management Commission’s requirements. Allstructures (e.g., manholes) will be located outside or above the 100-year flood plain. Developmentenabled by the project will also be subject to restrictions and will be reviewed for compatibility by therespective municipalities on a project specific basis.

15. Water Surface Use. Will the project change the number or type of watercraft on any water body? Yes No

If yes, indicate the current and projected watercraft usage and discuss any potential overcrowding orconflicts with other uses.

The proposed project will not result in an increase in the number of watercraft on any water body in thearea.

16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to beMoved: 64.8 acres; 580,000 cubic yards. Describe any steep slopes or highly erodable soilsAnd identify them on the site map. Describe any erosion and sedimentation control measures to be usedduring and after project construction.

Two of the soils identified in the project vicinity by the Soil Survey of Hennepin County have slopesgreater than 12 percent - Erin loam, 12 to 18 percent slopes, and Hayden clay loam, 12 to 18 percentslopes, eroded. They are designated on Figure 5 by the map units EnD and HcD2. The Erin loam soil islocated in the southern portion of the corridor, along the north side of Trunk Highway 55. The Haydenclay loam soil is located in the northern portion of the alignment, near the intersection of Lawndale Laneand County Road 47. The Hayden clay loam soil is also identified as being eroded, as are two other slopeclasses of Hayden clay loam – 2 to 6 percent slopes (HcB2) and 6 to 12 percent slopes (HcC2). Thesesoils are also located in the northern portion of the alignment, with an additional area located in thesouthern portion of the alignment, along the south side of TH 55.


Where potential erosion due to soil slopes or current conditions is an issue, erosion control measures willbe used to minimize the potential. Specific information will be incorporated into the erosion control plan,as required by the general storm-water permit. In general, high flow areas will be protected by turfreinforcement mats. Any potential high flows from off site will be mitigated as they enter theconstruction site; this may involve the use of some or all of the following: high-flow silt fence,checkdams, biologs, and/or stilling basins. Areas with steeper slopes (such as those near Elm Road andLawndale Lane) will be seeded and stabilized as soon as possible after construction. A fiber blanketand/or hydraulic seed stabilizer may be utilized.

The majority of excavated soil will be returned to the construction trench after placement of the pipe.Any excess soil will be disposed of in upland areas where sediment will not impact water resources orother sensitive areas. Soil erosion control practices will be implemented to minimize impacts to wetlandsand other surface waters in the vicinity of the project. Best management practices protocols will beobserved. A sediment and erosion control plan must be prepared in accordance with the MPCA NPDESGeneral Storm Water Construction Activity Permit. Erosion control measures will be implemented priorto the start of any construction activities. Soil erosion control measures will include:

� Use of silt fencing and sedimentation basins in those areas where surface water runoff may exitthe site;

� Use of check dams consisting of high-flow silt fence, washed aggregate, or a combination ofboth;

� Use of construction management practices that limit the duration of exposed soils to wind andrain;

� Escrow funds to promote prompt re-establishment of vegetative ground cover in the event ofunanticipated emergencies; and

� Development, approval, and adherence to an erosion control plan, as required by the MPCA.

17. Water Quality – Surface Water Runoff.

a. Compare the quantity and quality of site runoff before and after the project. Describe permanentcontrols to manage or treat runoff. Describe any storm water pollution prevention plans.

Because the interceptor will be buried, the quantity and quality of runoff before and after the projectwill not change significantly. Discharge from dewatering activities during excavation is discussed inItem 12 and will be conducted as stipulated in applicable permits and approvals (see 8, 12 and 16)

b. Identify routes and receiving water bodies for runoff from the site; include major downstream waterbodies as well as the immediate receiving waters. Estimate impact runoff on the quality of receivingwaters.

Receiving water bodies in the vicinity of the proposed project include wetlands, Elm Creek, andultimately the Mississippi River. Elm Creek begins in Medina and flows northeasterly throughPlymouth, Maple Grove, Dayton, and Champlin to the Mississippi River. As discussed in Items 12and 16, appropriate erosion control measures will be implemented during construction, and runofffrom the site will be minimized. Because the interceptor will be placed below grade, and becausethe disturbance caused by construction of the project will be temporary, significant impacts toreceiving water bodies are not anticipated.


Vegetation will be restored as soon as possible after construction. Fiber blankets and/or hydraulicseeding will be used where necessary to ensure prompt re-vegetation. The NPDES General Permitfor Discharge of Storm Water during Construction Activities will outline specific timelineprovisions for re-vegetation. The contractor will comply with these timelines. In the event ofunanticipated incidents of erosion, escrowed funds will be available to finance emergencystabilization of erosional areas.

18. Water Quality – Wastewater.

a. Describe sources, composition and quantities of all sanitary, municipal and industrial wastewaterproduced or treated at the site.

The Medina Leg of the Elm Creek Interceptor will serve portions of Maple Grove, Plymouth, andMedina and will convey sanitary wastewater to the Metropolitan WWTF in St. Paul. Thewastewater will be within the range of normal strength domestic wastewater.

b. Describe waste treatment methods or pollution prevention efforts and give estimates of compositionafter treatment. Identify receiving waters, including major downstream water bodies, and estimate thedischarge impact on the quality of receiving waters. If the project involves on-site sewage systems,discuss the suitability of site conditions for such systems.

The project service areas within Maple Grove and Plymouth are currently outside the MetropolitanUrban Service Area, and therefore have no centralized wastewater treatment and collection. As onewould expect, an area relying on on-site wastewater treatment systems is not likely to be the locationfor high-strength wastewater generators. There are no permitees registered in the MCES IndustrialWaste Permit program in these areas, nor are any otherwise known to exist.

The project area in Medina includes the town of Hamel, which does have centralized wastewatercollection. A search was performed of the MCES Industrial Waste Permit database. No permiteeswere found in Hamel or Medina who were subject to pretreatment requirements. There is oneindustrial waste permit in an unsewered part of rural Medina: The Woodlake (Hamel) Landfill.Leachate from this facility is collected and then hauled to the MCES’ Third Street and CommercialStreet discharge site near the Metropolitan WWTF, whence it flows for treatment.

c. If wastes will be discharged into a publicly owned treatment facility, identify the facility, describe anypretreatment provisions and discuss the facility’s ability to handle the volume and composition ofwastes, identifying any improvements necessary.

Sanitary sewer waste will be conveyed by the Medina Leg of the Elm Creek Interceptor to theMetropolitan WWTF in St. Paul. The treatment facility has ample capacity to handle the additionalaverage daily flow of 4 MGD. The Metropolitan WWTF has a capacity of approximately 250 MGDand is currently treating approximately 200 MGD.

d. If the project requires disposal of liquid animal manure, describe disposal technique and location anddiscuss capacity to handle the volume and composition of manure. Identify any improvementsnecessary. Describe any required setbacks for land disposal systems.

Not applicable.


19. Geologic hazards and soil conditions.

a. Approximate depth (in feet) to Ground water: 7 ft. Minimum; 7–68 ft (range) average.Bedrock: 151 ft Minimum; 151-300 ft (range) average.

Describe any of the following geologic site hazards to ground water and also identify them on the sitemap: sinkholes, shallow limestone formations or karst conditions. Describe measures to avoid orminimize environmental problems due to any of these hazards.

Geologic hazards are not known to exist in the project area. Ground water depth informationpresented above was obtained from soil borings completed along the alignment. Bedrock andsurficial geology information was obtained from the Minnesota Geological Survey Geologic Atlas ofHennepin County (1989).

According to the Geologic Atlas of Hennepin County, most of Hennepin County is underlain bysediments deposited during the Quaternary Period. This period began approximately two millionyears ago and extends to the present. The Surficial Geology map in the geologic atlas indicates thatthe majority of the alignment proceeds through areas of glacial till deposits of loamy till. Soiltextures are mainly loam. A few beds and lenses of stratified sediment are present, as are smallareas of thick, fine loamy colluvium. The mid-section of the alignment (near 54th Avenue North andRanier Lane) proceeds through an area of lacustrine clay and silt. These surficial deposits consist oflayers of laminated clay to silt, generally less than ten feet thick. Also in this area, and alongportions of County Road 101, the alignment proceeds through clayey till deposits. Soil textures inthese areas range from loam to clay loam, with small areas of silt loam. Small areas of organicdeposits, consisting of peat and organic-rich sediment, are also present along the alignment.

According to the Bedrock Geology map included in the geologic atlas, the uppermost bedrock unitsunder the proposed alignment are mainly the St. Peter Sandstone and the Jordan Sandstone. For asmall portion of the alignment (near 54th Avenue and Ranier Lane), the uppermost bedrock unit isindicated by the map to be the St. Lawrence and Franconia Formations.

b. Describe the soils on the site, giving SCS classifications, if known. Discuss soil granularity andpotential for groundwater contamination from wastes or chemicals spread or spilled onto the soils.Discuss any mitigation measures to prevent such contamination.

Soil Types

Symbol Soil Name Special SignificanceBo Borrow landCo Cordova silty clay loam Hydric, prime farmland (where drained)Cu Cut and fill landDIB Dalbo silt loam, 2 to 6 percent slopes Prime farmlandDu Dundas silt loam Hydric, prime farmland (where drained)EnB Erin loam, 2 to 6 percent slopes Prime farmlandEnC Erin loam, 6 to 12 percent slopes Farmland soil of statewide importanceEnD Erin loam, 12 to 18 percent slopes Steep slopeGc Glencoe silty clay loam Hydric, prime farmland (where drained)Ha Hamel loam Hydric, prime farmland (where drained)HbB Hayden loam, 2 to 6 percent slopes Prime farmlandHbC Hayden loam, 6 to 12 percent slopes Farmland soil of statewide importanceHcB2 Hayden clay loam, 2 to 6 percent

slopes, erodedEroded, prime farmland


Symbol Soil Name Special SignificanceHcC2 Hayden clay loam, 6 to 12 percent

slopes, erodedEroded, farmland soil of statewideimportance

HcD2 Hayden clay loam, 12 to 18 percentslopes, eroded

Eroded, steep slope

LtB Le Sueur loam, 1 to 4 percent slopes Prime farmlandMa Marsh Hydric*Mt Minnetonka silty clay loam Hydric, prime farmland (where drained)Pa Peaty muck Hydric*Pm Peaty muck over loam Hydric*

Hydric soils were identified using the Hydric Soils of Minnesota list, revised January 1992. Soilsmarked as Hydric* are those soils where, though they are not included on the Hydric Soils ofMinnesota list, they are generally located in areas with hydric conditions (e.g., wetland areas).Prime farmland soils and farmland soils of statewide importance were identified using lists from theUnited States Department of Agriculture Natural Resource Conservation Service, provided by theHennepin Conservation District.

Due to the nature of the project, the potential for impacts to ground water is minimal. Mitigationmeasures for potential contaminant sources are discussed below in Item 20, parts b and c.

20. Solid Wastes, Hazardous Wastes, Storage Tanks.

a. Describe types, amounts and compositions of solid or hazardous wastes, including solid animalmanure, sludge and ash, produced during construction and operation. Identify method and location ofdisposal. For projects generating municipal solid waste, indicate if there is a source separation plan;describe how the project will be modified for recycling. If hazardous waste is generated, indicate ifthere is a hazardous waste minimization plan and routine hazardous waste reduction assessments.

Not applicable.

b. Identify any toxic or hazardous materials to be used or present at the site and identify measures to beused to prevent them from contaminating groundwater. If the use of toxic or hazardous materials willlead to a regulated waste, discharge or emission, discuss any alternatives considered to minimize oreliminate the waste, discharge or emission.

During construction, equipment and vehicles utilizing gasoline, diesel fuel, antifreeze, and oil willbe used at the project site. Portable storage tanks of fuel may be temporarily located at the siteduring construction. Fueling of vehicles and equipment will be conducted away from sensitiveareas.

c. Indicate the number, location, size and use of any above or below ground tanks to store petroleumproducts or other materials, except water. Describe any emergency response containment plans.

As discussed above, portable storage tanks of fuel may be temporarily located at the site duringconstruction.


21. Traffic. Parking spaces added: 0 Existing spaces (if project involves expansion): 0Estimated total average daily traffic generated: < 1 trip Estimated maximum peak hour trafficgenerated (if known) and its timing: NA Provide an estimate of the impact on trafficcongestion affected roads and describe any traffic improvements necessary. If the project is within theTwin Cities metropolitan area, discuss its impact on the regional transportation system.

A noticeable permanent increase in traffic will not occur directly due to construction of the project per se.The only increase in traffic resulting directly from the project will be additional trips to the two meterstations for routine maintenance. These trips are estimated to total two trips per week and as such, willnot impact traffic congestion or require traffic improvements.

During the construction process, construction vehicles will be utilizing local roads. Construction trafficwill be precluded from entering the Troy Ridge Development. A note on the plan set states: “Noconstruction traffic allowed on this private road system at any time.”

Portions of local roads may be closed for up to two days at a time, during open cutting and placement ofthe pipe. Detours for local roads will be coordinated with the applicable city. Detours will be limited,and will not involve collector streets. Major impacts on traffic are not anticipated, as any roadspotentially involved in detours have average daily traffic (ADT) counts of less than 500. Tunneled areas(see Figure 3) will experience minimal traffic disruption.

In the future, traffic in the vicinity of the project will increase with urbanized development. Residential,commercial, and other types of development will be enabled as a result of the project. It is the purpose ofthe project to provide wastewater collection and conveyance for the project service area. The projectservice area includes portions of Maple Grove, Plymouth, and Medina. As a result of increaseddevelopment of these areas in the future, vehicular traffic will increase. It will be necessary for MNDOT,Hennepin County, Medina, Plymouth, and Maple Grove to plan for and provide appropriate roadwayimprovements and measures to mitigate traffic congestion. Each of the three cities involved in the projecthas a City Transportation Plan that provides the basis for dealing with increased traffic due to populationgrowth.

22. Vehicle-related Air Emissions. Estimate the effect of the project’s traffic generation on air quality,including carbon monoxide levels. Discuss the effect of traffic improvements or other mitigation measureson air quality impacts. Note: If the project involves 500 or more parking spaces, consult EAW Guidelinesabout whether a detailed air quality analysis is needed.

Vehicle emissions associated with the facility per se will not have a significant effect on air quality.However, residential and other development enabled by the construction of wastewater conveyancecapacity may result in measurable but not significant impacts. If traffic increases result locally in futuredeterioration in levels of service and/or air quality violations, mitigative measures are available. Theseinclude roadway improvements, signal installation, and provision of alternative transportation choices.

23. Stationary Source Air Emissions. Describe the type, sources, quantities and compositions of anyemissions from stationary sources of air emissions such as boilers, exhaust stacks or fugitive dustsources. Include any hazardous air pollutants (consult EAW Guidelines for a listing), any greenhousegases (such as carbon dioxide, methane, and nitrous oxides), and ozone-depleting chemicals(chlorofluorocarbons, hydrofluorocarbons, perfluorocarbons or sulfur hexafluoride). Also describe anyproposed pollution prevention techniques and proposed air pollution control devices. Describe theimpacts on air quality.

Not applicable.


24. Odors, noise and dust. Will the project generate odors, noise or dust during construction or duringoperation? Yes NoIf yes, describe sources, characteristics, duration, quantities or intensity and any proposed measures tomitigate adverse impacts. Also identify locations of nearby sensitive receptors and estimate impacts onthem. Discuss potential impacts on human health or quality of life. (Note: fugitive dust generated byoperations may be discussed at item 23 instead of here.)

Dust and noise will be generated by equipment during construction. Odors may also be generated fromconstruction equipment exhaust. Equipment will include trucks, backhoes, loaders, cranes, andcompressors. Dust will most likely be controlled by daily cleanup of the construction site; water will beused to wet the soil and reduce the airborne dust when necessary. Noise and odors from constructionequipment will be controlled by restricting hours of operation to daylight hours, or those permitted bylocal ordinances.

The nearest receptors are some townhomes along Hamel Road located approximately 40 feet from thearea of disturbance. Other residential homes are located near Hamel Road and Elm Creek Drive(approximately 80 feet from the area of disturbance), near Evergreen Lane and County Road 101(approximately 150-200 feet from the area of disturbance), and along Lawndale Lane, near County Road47 (approximately 100 feet from the area of disturbance). Average exposure times for residents areestimated to be approximately four weeks in any one area, and will not exceed eight weeks.

As in any sanitary sewer system, there is the potential for the formation of odors during operation of theElm Creek Interceptor. Hydrogen sulfide has the potential to form in sewage material under anaerobicconditions, and can produce a rotten-egg odor, particularly where flow turbulence releases gas fromsolution in the wastewater. The addition of chemicals to the sanitary sewer system to suppress growth ofthe odor-causing bacteria is one option if hydrogen sulfide odor becomes a problem in the future.Filtering air ventilated from the sewer system through a biofilter is another method of controlling odors.A biofilter consists of a media such as wood chips, laid on a bed in the ground, through which ventilatedair is blown by means of a fan and air piping. Water, as from a conventional lawn irrigation system, issometimes used to keep the filter bed moist.

Although odor problems are not expected, there are two locations where odor control may becomenecessary in the future. These areas are the two flow meter stations, planned at the Maple Grove/Plymouthborder on the west side of Lawndale Lane, and at the Plymouth/Medina border, south of TH 55 at CSAH101. Although meter stations generally produce only minor flow turbulence, sufficient easements will beacquired in the locations of the flow meter stations to allow future installation of biofilters.

This project is similar to many of the mid-size trunk sanitary sewer projects throughout the metropolitanarea. It is a gravity system, where slopes are generally mild, and turbulence is not expected to be aproblem. The meter stations are not expected to generate odors objectionable to neighboring properties,based on the MCES’ previous experience at similar sites. The easement areas around the meter stationsare believed to provide sufficient buffer, because the potential for odors is minimal. The easements arebeing acquired, as a precaution in the event that biofilters do become necessary at the meter stations. It isvery unlikely that biofilters would fail to mitigate a minor odor source such as these. Packaged carbonfiltration systems are another option for odor control.


25. Nearby resources. Are any of the following resources on or in proximity to the site?

a. Archaeological, historical, or architectural resources? Yes Nob. Prime or unique farmlands or land within an agricultural preserve? Yes Noc. Designated parks, recreation areas, or trails? Yes Nod. Scenic views and vistas? Yes Noe. Other unique resources? Yes No

If yes, describe the resource and identify any project-related impacts on the resources. Describe anymeasures to minimize or avoid adverse impacts.

Archaeological, Historical, or Architectural ResourcesThe State Historic Preservation Office (SHPO) was contacted regarding the presence of known orsuspected cultural resources in the vicinity of the proposed project. According to the initial responsereceived from SHPO, there was a good probability that unreported archaeological properties might bepresent in the project area. Therefore, SHPO had recommended that a survey of the area be completed(see November 14, 2001 letter Attachment 2).

A Phase I cultural resources survey has been completed and the archaeologist’s report (dated February2002) submitted to the SHPO on March 8, 2002. The archaeological survey identified two historicbuilding clusters along Lawndale Lane. They are included in the Minnesota Inventory for Historic/Architecture, but neither has been evaluated for the National Register. The first is on the U.S. HomeCorporation property located at the southwest corner of the intersection of 63rd Avenue North andLawndale Lane. The pipe is located well away from these structures and will have no impact on thehistoric property. The second is a former schoolhouse, converted to a residence, located at the northwestcorner of Lawndale Lane and County Road 47. Here the pipe is being jacked to avoid any disturbance tothe house or garage on the property. The William Baer farm cluster of structures was identified in aprevious survey on file with the SHPO. The pipe is located well away from all of these structures andwill have no impact on them. Other significant resources were not identified by the archaeologist’s reportto be present in the project corridor. In a letter dated April 5, 2002, the SHPO stated that “Based on theresults of this survey, we feel that the probability of any unreported properties being located in the area ofpotential effect is low” (see Attachment 3).

Prime or Unique Farmlands, Agricultural Preserve LandsAccording to information from the Hennepin Conservation District, several of the soil types in thevicinity of the proposed corridor are classified as prime farmland soils. Specific soils include: Cordovasilty clay loam (where drained); Dalbo silt loam, 2 to 6 percent slopes; Dundas silt loam (where drained);Erin loam, 2 to 6 percent slopes; Glencoe silty clay loam (where drained); Hamel loam (where drained);Hayden loam, 2 to 6 percent slopes; Hayden clay loam, 2 to 6 percent slopes, eroded; Le Sueur loam, 1 to4 percent slopes; and Minnetonka silty clay loam (where drained). Three additional soils are identified asfarmland soils of statewide importance: Erin loam, 6 to 12 percent slopes; Hayden loam, 6 to 12 percentslopes; and Hayden clay loam, 6 to 12 percent slopes, eroded.

The service area intended to be served by the Medina Leg of the Elm Creek Interceptor is planned forurban development so areas of prime farmland soil currently in crop production will be taken out ofproduction. While development in the areas served by the interceptor project will be subject to theComprehensive Plans and Zoning Regulations of the respective cities, over time, there is nothing in anyof these processes that will prevent the total conversion of agricultural to residential land use. Thisconversion is an unavoidable consequence of population growth and our existing economic system.


Designated Parks, Recreation Areas, or TrailsDue to the sub-grade nature of the project, existing and future parks and recreation areas will not bepermanently impacted by the project. However, some of these areas may be temporarily affected duringconstruction of the project. A Maple Grove park near Elm Road will be temporarily disturbed duringconstruction. The interceptor pipe and easement will be coordinated with Plymouth’s NorthwestGreenway Corridor project.

Scenic Views or VistasDue to the sub-grade nature of the project, scenic views and vistas will not be impacted once constructionis completed.

Other Unique ResourcesThe project alignment follows the alignment of Elm Creek in some areas. Permanent impacts to the creekare not expected to result directly from the project. As discussed under previous items, erosion controlmeasures will be implemented during and after construction to minimize erosion and sedimentation. Inaddition, necessary permits (see Item 8.) will be obtained and adhered to during construction of theproject.

Potential impacts to Elm Creek due to future development enabled by the interceptor project will bereviewed by the respective municipality as each development is proposed.

26. Visual impacts. Will the project create adverse visual impacts during construction or operation? Such asglare from intense lights, lights visible in wilderness areas and large visible plumes from cooling towers orexhaust stacks? Yes NoIf yes, explain.

No such impacts are anticipated.

27. Compatibility with plans and land use regulations. Is the project subject to an adopted localcomprehensive plan, land use plan or regulation, or other applicable land use, water, or resourcemanagement plan of a local, regional, state or federal agency? Yes NoIf yes, describe the plan, discuss its compatibility with the project and explain how any conflicts will beresolved. If no, explain.

The 1976 Metropolitan Land Planning Act requires local governments to prepare comprehensive plansand submit them to the Metropolitan Council to determine their consistency with metropolitan systemplans. All cities in the Metropolitan Area were recently required to submit updated ComprehensivePlans. The Metropolitan Council reviews and comments on these plans. The local comprehensive planincludes a sewer element covering the collection and disposal of wastewater generated by the community.

Similarly, under the Metropolitan Act, local governments are required to submit a Comprehensive SewerPolicy Plan (CSPP) describing service needs from the MCES to the Metropolitan Council for itsapproval. The CSPP is broader in scope than the sewer element of the local comprehensive plan andprovides detailed sewer system engineering information. The CSPPs for Maple Grove, Plymouth, andMedina outline potential alignments and sizing for city trunk sewers, as well as connection points to themetropolitan interceptor.

The Metropolitan Council has consulted with the cities of Maple Grove, Plymouth and Medina regardingthe detailed design of the Medina Interceptor. The interceptor design is compatible with the three cities’Comprehensive Plans and the CSPPs. The planning process that will regulate land use changes within theservice area of the Medina Interceptor varies by community.


The area of Maple Grove tributary to the Medina Interceptor lies completely within the city’s and MetroCouncil approved 2010 Metropolitan Urban Service Area (MUSA). The city has adopted its own stagingplan for the timing of extension of urban services within the MUSA. The Metropolitan Council’s policyis that a city can urbanize anywhere within the 2010 MUSA, subject only to approval of a SewerExtension Permit from the MPCA for each sewer project. Metropolitan Council also reviews each SewerExtension Permit and provides comment to the MPCA as to whether the sewer connection is consistentwith local comprehensive plans. The city would then be responsible to regulate changes in land usethrough a development process in accordance with its Comprehensive Plan and local zoning ordinances.

The city of Plymouth’s Comprehensive Plan, on the other hand, currently designates the service areatributary to the Medina Interceptor as rural residential until 2020. This means that no centralizedwastewater collection system may be constructed until 2020, or until such time as a Comprehensive Planis amended and the Metropolitan Council formally acknowledges the new plan. Once the ComprehensivePlan designates an area for urban services, the city must obtain the Sewer Extension Permits, and regulateland use in accordance with its Comprehensive Plan and local zoning ordinances as outlined in theparagraph above.

The city of Medina’s Comprehensive Plan defines 2010 MUSA staging within a 2020 MUSA, and UrbanReserve Areas. Urban Reserves are lands designated only for widely dispersed development that will notimpair eventual urbanized land use beyond a 20 year planning horizon (currently defined as 2020). Thusthe city may urbanize within the 2010 MUSA similar to the process described for Maple Grove above.But were the city to desire to urbanize any area within the 2020 MUSA or the Urban Reserve area, itwould first need to submit a Comprehensive Plan amendment to the Metropolitan Council similar to theprocess described above for Plymouth.

28. Impact on infrastructure and public services. Will new or expanded utilities, roads, other infrastructureor public services be required to serve the project? Yes NoIf yes, describe the new or additional infrastructure or services needed. (Note: any infrastructure that is aconnected action with respect to the project must be assessed in the EAW; see EAW Guidelines fordetails.)

Although construction of the Medina Leg of the Elm Creek Interceptor will not require additionalinfrastructure, the development planned for the interceptor service area will. As development of the areaprogresses, other utilities and infrastructure, such as roadways, collector streets, collector sewers, potablewater distribution systems, storm-water collection and treatment systems, schools, police and fireprotection, and other urban services will be needed to service the area.

29. Cumulative impacts. Minn. R. 4410.1700, subp. 7, item B requires that the RGU consider the“cumulative potential effects of related or anticipated future projects” when determining the need for anenvironmental impact statement. Identify any past, present or reasonably foreseeable future projects thatmay interact with the project described in this EAW in such a way as to cause cumulative impacts.Describe the nature of the cumulative impacts and summarize any other available information relevant todetermining whether there is potential for significant environmental effects due to cumulative impacts (ordiscuss each cumulative impact under appropriate item(s) elsewhere on this form).

Future residential and commercial development of the service area has been considered in the planning ofthis project. The interceptor has been sized to accommodate long-range wastewater flows afterdevelopment of the area. The interceptor line will be placed in locations that best meet the long-termgoals of the community. The potential environmental impacts from future planned development will be


mitigated through enforcement of local, state, and federal ordinances and regulations. Individualdevelopment projects may be subject to environmental review and the preparation of project-specificEAWs or an Alternative Urban Areawide Review. Any sanitary sewer extensions require a permit fromthe MPCA.

30. Other Potential Environmental Impacts. If the project may cause any adverse environmental impactsnot addressed by items 1 to 28, identify and discuss them here, along with any proposed mitigation.

Environmental impacts other than those already discussed in this EAW are not anticipated as a result ofthe project.

31. Summary of issues. List any impacts and issues identified above that may require further investigationbefore the project is begun. Discuss any alternatives or mitigative measures that have been or may beconsidered for these impacts and issues, including those that have been or may be ordered as permitconditions.

Wetlands/Water ResourcesApproximately 9.6 acres of wetland will be temporarily impacted by construction activities. Mitigationof these construction activities will be performed by segregation of bottom sediments excavated andreplacement of these sediments to serve as seedbed for re-vegetation of the wetland area impacted. Inaddition, the alignment crosses Elm Creek, a DNR Protected Watercourse, in four locations. Impacts willbe minimized at the crossing locations, as well as in wetland areas, with the use of a trench box.

Storm-Water Runoff/Erosion and Sedimentation ControlAs with any extensive construction project, storm-water runoff poses potential for temporary surfacewater impacts. Mitigation measures to be taken to minimize these potential impacts include preparationand implementation of construction erosion and sedimentation control plans, which will be required bythe MPCA.

The future development planned for the service area will likely result in increased storm-water runoff.The runoff could entrain sediments and nutrients with resulting impacts on water quality. Thecomprehensive plans, storm-water ordinances, and other requirements of the cities of Maple Grove,Plymouth, and Medina and the Elm Creek Watershed District will be sufficient to protect water quality byrequiring appropriate mitigation with each development as it is proposed and reviewed.

Cumulative ImpactsThis project is intended to provide sewer service to areas not presently served. Secondary developmentof residential, commercial, and industrial properties must be appropriately regulated by the involvedmunicipalities, the MPCA and the Elm Creek Watershed Management Commission to assure thedevelopment does not adversely impact the environment. Statutory authority has been provided to theseentities.


RGU CERTIFICATION.

I hereby certify that:� The information contained in this document is accurate and complete to the best of my knowledge.� The EAW describes the complete project; there are no other projects, stages or components other than those

described in this document, which are related to the project as connected actions or phased actions, asdefined at Minn. R. 4410.0200, subps. 9b and 60, respectively.

� Copies of this EAW are being sent to the entire EQB distribution list.

Name and Title of Signer:Beth G. Lockwood, Supervisor, Environmental Review UnitOperations and Environmental Review SectionRegional Environmental Management Division

Date:

The format of the Environmental Assessment Worksheet was prepared by the staff of the EnvironmentalQuality Board at Minnesota Planning. For additional information, worksheets or for EAW Guidelines, contact:Environmental Quality Board, 658 Cedar St., St. Paul, MN 55155, 651-296-8253, or at their Web sitehttp://ww.mnplan.state.mn.us

http://ww.mnplan.state.mn.us

date to: interested parties · 2012. 10. 4. · elm creek interceptor – medina leg environmental...

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