introduction to combined sewer overflow (cso) program

Combined Sewer Overflow Program 47

Introduction to Combined Sewer Overflow (CSO) ProgramDischarges of combined wastewater and stormwater runoff from 63 CSO outfalls in the MWRA system and four ofthe service area community systems (Boston, Cambridge, Chelsea, and Somerville) effect water quality in theCharles, Mystic, and Neponset Rivers and in Boston Harbor. Pursuant to a 1987 stipulation entered in the CleanWater Act case, MWRA has responsibility for developing and implementing a long-term plan for CSO control at alllocations. MWRA first proposed the current long-term plan in its CSO Conceptual Plan and Sewer System MasterPlan in December 1994. The CSO Conceptual Plan incorporated then current information about the volume of CSOflows and water quality impacts, and developed a plan in accordance with EPA’s National CSO Policy.

MWRA completed its Final CSO Facilities Plan and Environmental Impact Report based on the CSO ConceptualPlan in July 1997. The Final CSO Facilities Plan comprises 25 site-specific projects, including such measures assewer separation, interceptor improvements, CSO treatment upgrades and new CSO treatment facilities, and storage.Thirteen of the projects are complete, five are in construction, and the remaining projects are in the planning ordesign stage. The proposed FY04-06 CIP includes $650.7 million for planning, design and construction costs forthese projects. Implementation is planned for a 13-year period which began in 1995, in compliance with more than50 CSO milestones adopted by the Federal District Court in June 1996, as part of the Clean Water Act case. DEPand EPA have approved most of the CSO facilities plan and have made most of the regulatory determinationsnecessary for the facilities plan to comply with state water quality standards, including revising water qualitystandards for certain water bodies. The plan for CSOs affecting the Charles River, Upper Mystic River, and AlewifeBrook areas has received approval through variances from water quality standards, pending the outcome of variousstudies to determine whether additional controls will be cost beneficial. Additional facilities may be required toaddress the CSO objectives outlined by regulatory agencies for these areas.

While most of the projects in the CSO facilities plan are proceeding as scheduled, MWRA has advised the court thatit will not meet a pending milestone relating to the CSO projects for North Dorchester Bay and Reserved Channel inSouth Boston. Due to community opposition to the siting of a proposed CSO pumping and treatment facility,MWRA delayed activity with respect to these projects, and in April 2001, filed a Notice of Project Changerecommending a one-year reassessment of the project and overall CSO control approach for North Dorchester Bayand Reserved Channel. MWRA began the reassessment in September 2001, after receiving regulatory approvals.CSO plans for South Boston will be revised based on the outcome of the reassessment and negotiations withcommunity groups and others.

Anticipated operating cost impacts of the CSO program are summarized below and will be further developed as partof the planning and design phases for individual projects.

Incremental CEB cost

FY06 FY07 FY08 FY09 FY10 FY11 FY12 FY13

$650,750 $0 $394,730 $1,088,294 ($47,392) $50,000 ($50,000) $0Description

The increases in FY06-09 are primarily associated with the start-up and operation of the Union Park DetentionTreatment Facility, the Reserved Channel CSO Facility, and associated remote odor control facilities. Thedecrease in FY10 is associated with the decommissioning of the treatment systems at the Fox Point andCommercial Point CSO facilities following the completion of sewer separation at South Dorchester Bay. Theincreases in FY11 and FY12 reflect maintenance costs associated with the Union Park Detention TreatmentFacility.


North Dorchester Bay Consolidating Conduit, ReservedChannel Consolidation Conduit, Reserved Channel CSOFacility (339)Project Purpose and Benefits

� Contributes to improved public health � Provides environmental benefits� Fulfills a regulatory requirement

This project is intended to eliminate CSO discharges to South Boston beaches and minimize CSO impacts to theReserved Channel. Flows that exceed the proposed storage tunnel’s capacity will be treated at the ReservedChannel CSO Facility prior to discharge to the channel (expected to occur once every 1.5 to 2 years on average).The project is court mandated, is in accordance with MWRA’s approved long-term CSO control plan, and isrequired to meet DEP water quality standards.

Project History and Background

Under MWRA’s original recommended plan for CSO control in South Boston, CSO flows along North DorchesterBay and Reserved Channel would be captured by respective consolidation conduits (tunnels) and stored in the tunnelsystem. Following each storm, the tunnels would be dewatered to the South Boston Interceptor, for transport to theColumbus Park Headworks and Deer Island. In the rare event that flows would surpass the tunnel capacity, excessflows would be discharged to Reserved Channel through a 600 mgd CSO treatment and pumping facility thatMWRA had proposed to construct on vacant land off East First Street (“Site J”). This preferred site lay adjacent tothe former and existing Massachusetts Bay Transportation Authority (MBTA) power plants and the CardinalMedeiros Pier. The plan called for the excess flows to receive fine screening, chlorination, and dechlorination priorto discharge.

Despite MWRA's belief at the time it filed the related 1999 Notice of Project Change that the projects could beimplemented as outlined in that Notice, opposition by elected officials and some residents to siting the ReservedChannel CSO Facility on Site J intensified. In December 1999, elected officials representing South Bostoninformed the MWRA’s Board of Directors that they would block efforts by MWRA to obtain legislation necessaryto build parts of the project on or under designated parkland.

MWRA stopped design work on all elements of the projects in January 2000, and was unable to commenceconstruction by September 2000, as required. MWRA met several times with federal and state officials, SouthBoston elected officials and other interested parties, in an attempt to reach consensus on an approach to moveforward. South Boston elected officials maintained firm opposition to Site J and continued to advocate that MWRAlocate the proposed Reserved Channel facility at a site on Massport's Conley Terminal. When this suggestion wasmade earlier, MWRA rejected it for reasons stated in the 1999 Notice of Project Change, including the higher costof the facility at the relocated site and the uncertainty that a Conley site could be obtained from Massport. Massporthas since indicated that no site on Conley is feasible. Furthermore, siting the facility at Conley Terminal has neverreceived environmental review under the MEPA process, which would be required for MWRA to proceed with theproject at that location.

In April 2001, MWRA filed a Notice of Project Change with MEPA, recommending a one-year reassessment of theproject and overall CSO control approach for North Dorchester Bay and Reserved Channel. The Secretary’sCertificate, issued in June, approved the reassessment as scoped by MWRA, and also required MWRA to include areevaluation of all CSO control alternatives that had previously been considered by MWRA during earlier CSOplanning and environmental review. MWRA began the reassessment in September 2001, under an amendment to itsdesign contract with Metcalf & Eddy. It includes the updating of planning assumptions and water qualityinformation and the evaluation of a full range of CSO control goals and technologies. The reassessment is expectedto be completed by April 2003, longer than originally scheduled, due to low rainfall in the fall of 2001 and 2002 thatdelayed the water quality sampling program.


Scope

Sub-phase ScopeDesign Design, project reevaluation, and engineering services during construction.NDB/RC ConsolidationConduits

Construction of a 13,000-linear feet, 13-foot diameter consolidation, storage andconveyance conduit along North Dorchester Bay to Reserved Channel.Construction of the Reserved Channel consolidation and conveyance conduitrunning approximately 2,700 linear feet, with an inside diameter of 13 feet.

Reserved Channel CSOFacility

Construction of a 600-mgd Reserved Channel CSO facility. Construction of odorcontrol facilities at the upstream end of each conduit.

Early Site Preparation Early site preparation.

TunnelRescue/EmergencyResponse

MOU with the City of Boston for tunnel rescue support and emergency responseduring tunnel construction.

Expenditure Forecast (in $000s)

Total Cost

ProjectedPaymentsthru FY03

RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$224,279 $14,030 $210,249 $513 $1,332 $32,526 $62,353 $62,354 $51,1710

Changes to Project Cost and Schedule

Total Project Cost ($000s) Schedule: Projected Completion Date

FY03 FY04 Change FY03 FY04 Change

$210,204 $224,279 $14,075 Feb 2009 Feb 2009 15 mos.

Explanation of Changes:

� Budget increase is primarily due to adjustment to December 2003 dollars for contracts scheduled for awardafter FY04. In addition, revised costs for project reassessments.

� Schedule revised due to project reassessment. Staff have identified a more manageable set of CSO optionsto be carried forward for more detailed evaluation.

CEB Impact

Included in the CEB impact table at the beginning of the CSO section.


Hydraulic Relief (354)

Project Purpose and Benefits

� Contributes to improved public health � Provides environmental benefits � Fulfills a regulatory requirement

The elimination of hydraulic restrictions between local and MWRA systems at locations in Boston and Cambridgewill improve transport of wet weather flows, thereby reducing CSO discharges into the Mystic and Charles Rivers.The project is court mandated, is in accordance with MWRA’s approved long-term CSO control plan, and isrequired to meet DEP water quality standards.


This project combines two local hydraulic relief projects, one in Cambridge to minimize CSO discharges atCAM005 and one in Charlestown to minimize CSO discharges at BOS017.

In Cambridge, the 24-inch, 40-foot long dry weather connection between the CAM005 regulator and the NorthCharles Metropolitan Sewer, adjacent to Mount Auburn Hospital, was relieved with a new 54-inch connection.

In Charlestown at BOS017, 190 feet of 36-inch pipe were installed in Sullivan Square to divert two local (BWSC)combined sewers to a direct connection with the Cambridge Branch Sewer. In addition, a 10-foot long restrictionbetween the Charlestown and Cambridge Branch Sewers, adjacent to Sullivan Square, was eliminated. Thisimprovement is expected to lower hydraulic grade lines during wet weather, possibly relieving CSO overflowconditions upstream at outfall BOS019.

Scope

Sub-phase ScopeDesign Design, construction services, and resident inspection.

Construction 1 Increase the diameter of the 40-linear feet dry weather connection betweenCAM005 and the North Charles Metropolitan Sewer from 24 to 54 inches.Construct 190 linear feet of 36-inch pipe connecting BOS017 to the CambridgeBranch Sewer. Eliminate the restriction in the Charlestown Branch Sewer.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$2,352 $2,351 $0 $0 $0 $0 $0 $0 $0




$2,352 $2,352 None Aug 2000 Aug 2000 None


East Boston Branch Sewer Relief (347)


� Contributes to improved public health � Provides environmental benefits � Improves system operability and reliability

Upgrading MWRA’s East Boston Branch Sewer will increase hydraulic capacity and provide long-term structuralintegrity through the replacement or rehabilitation of the existing sewers. The project will increase wet weathertransport capacity and reduce CSO discharges along the East Boston shoreline, minimizing CSO impacts to theMystic/Chelsea Confluence and Boston Inner Harbor and facilitating the beneficial uses of these receiving watersegments for most of the year. The project is court mandated, is in accordance with MWRA’s approved long-termCSO control plan, and is required to meet DEP water quality standards.


This project will relieve the interceptor system serving most of East Boston and minimize CSO discharges to BostonHarbor and Chelsea Creek through outfalls BOS003-014. Existing sewers will be replaced, relieved, or rehabilitatedusing a combination of construction methods, including pipe bursting, open cut, micro-tunneling, and pipe repair orrelining.

Scope

Sub-phase ScopeDesign/CS/RI Design, construction services, and resident inspection.East Boston Branch ReliefSewer Construction

Replacement of 13,500 linear feet of new and existing sewers, primarily bymicrotunnelling.

East Boston Branch SewerRehab Construction

Rehabilitation of 6,000 feet of existing sewer.

Sections 38 & 207Replacement Construction

Replacement of 4,900 feet of existing sewers by pipe bursting.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$59,832 $2,999 $56,832 $6,430 $7,399 $27,588 $15,342 $74 $0




$55,926 $59,832 $3,906 Sep 2006 Mar 2007 6 mos.


� Inflation adjustment to December 2003 dollars based on ENR index for unawarded construction.� Schedule change to allow for evaluation of most cost-effective means to meet project requirements given the

change in project costs for the tunnel phase incorporated as part of the Final FY03 CIP.


Fort Point Channel Consolidation Conduit, CharlestownBOS019 Storage Conduit (348)



To control CSO discharges at outfalls BOS072 and BOS073, and at BOS019, in accordance with MWRA’s approvedlong-term CSO control plan. Outfalls BOS072 and BOS073 discharge to the Fort Point Channel. Outfall BOS019discharges to the Little Mystic Channel in Charlestown. The project is court mandated, is in accordance withMWRA’s approved long-term CSO control plan, and is required to meet DEP water quality standards.


This project combines two CSO storage projects, one at Fort Point Channel in South Boston and one adjacent to theLittle Mystic Channel in Charlestown. At Fort Point Channel, a 10-foot diameter, 1,500-foot long tunnel will beconstructed along A Street in South Boston to capture and store CSO flows from outfalls BOS072 and BOS073 forall but the largest storms in a typical year. The tunnel will provide a storage volume of approximately 0.9 milliongallons. In Charlestown, a 12 feet by 12 feet, 380-foot long box conduit will be constructed adjacent to the TobinBridge to store most CSO flows that now discharge at outfall BOS019. Storage volume in the conduit will beapproximately 0.4 million gallons. The flows stored in the conduits will be pumped back to the Deer Islandtransport system after each storm passes and capacity becomes available.

Scope

Sub-phase ScopeDesign Design, construction services, and resident inspection.Construction 1 Consolidation, storage and conveyance conduit for outfalls BOS072 and

BOS073 at Fort Point Channel.Construction 2 Storage and conveyance conduit for outfall BOS019.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$20,435 $1,125 $19,310 $1,076 $2,701 $9,401 $6,057 $75 $0




$17,653 $20,435 $2,782 Mar 2007 Mar 2007 None.


� Budget increase due to higher than budgeted contract award for design services due in part to addition of anearly reassessment report. Other increases due to inflation adjustment on unawarded construction phases.


Chelsea Trunk Sewer Relief, Chelsea Branch Sewer Relief,CHE008 Outfall Improvements (349)


� Contributes to improved public health � Provides environmental benefits � Fulfills a regulatory requirement� Improves system operability and reliability

To control CSO discharges at outfalls CHE002, CHE003, CHE004, and CHE008 in accordance with MWRA’sapproved long-term CSO control plan. These outfalls discharge to the Mystic River/Chelsea Creek Confluence. Inaddition, the project will relieve the MWRA Chelsea Branch Sewer as well as the lower portion of the RevereExtension Sewer to improve service and control surcharging. The project is court mandated, is in accordance withMWRA’s approved long-term CSO control plan, and is required to meet DEP water quality standards.


This project combines three components recommended in MWRA’s long-term CSO control plan: 1) relief of a Cityof Chelsea-owned trunk sewer to minimize CSO discharges to the Inner Harbor at three outfalls, 2) relief of theMWRA Chelsea Branch Sewer and Revere Extension Sewer to minimize CSO discharges to Chelsea Creek andreduce surcharging in the upstream transport system, and 3) repair of the existing CSO outfall pipe in Chelsea atoutfall CHE008.

Scope

Sub-phase Scope

Design/CS/RI Design, construction services, and resident inspection for the entire project.

Chelsea Trunk Relief The existing Chelsea Trunk Sewer, which varies in diameter from eight to 15inches, was replaced with 2,300 feet of 30-inch diameter pipe, using both opencut and jacked casing methods. Information obtained during design about thephysical conditions of the CHE002, CHE003, and CHE004 outfalls led to adecision to include rehabilitation of sections of the CHE002 and CHE003outfalls in the trunk sewer replacement contract. Underflow baffles were beinstalled at each regulator to provide floatables control.

Chelsea Branch Sewer The MWRA Chelsea Branch and Revere Extension Sewers, which run inparallel along Eastern Avenue in Chelsea, were replaced and/or relieved withapproximately 4,200 feet of 42-inch pipe and 3,500 feet of 66-inch pipe alongor near Cabot Street and along Eastern Avenue in Chelsea. The new pipeswere constructed primarily using microtunneling methods. This phase alsoincluded repairs at outfall CHE008 to reline 540 feet of the 42-inch outfallpipe, replaced 35 feet of the pipe at its downstream end, replaced the headwall,and placed new riprap. One underflow baffle was installed at the soleregulator structure associated with this outfall to provide floatables control.

Rehab/Chelsea Branch/RevereExtension

Cured in place pipe rehabilitation methods were used to line approximately4,200 feet of 36-inch pipe in the Chelsea Branch and 3,000 feet of 54-inchpipe in the Revere Extension Sewer.

Modify Chelsea Screen House Installations of connection points and provision of flow control at the ChelseaScreen House in support of the Chelsea Branch Sewer rehabilitation.



Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$31,000 $30,650 $349 $349 $0 $0 $0 $0 $0




$31,052 $31,000 ($52) Jun 2002 Jun 2002 None.

Explanation of Changes

� Final costs for change order work for additional cleaning of sewer pipe and rehab of sewer manholes were lessthan budgeted.


Union Park Detention Treatment Facility (350)



To reduce the frequency and impacts of CSO discharges from the BWSC Union Park Pumping Station (CSO outfallBOS070). Outfall BOS070 discharges into the Fort Point Channel. This project is court mandated, is inaccordance with MWRA’s approved long-term CSO control plan, and is required to meet DEP water qualitystandards.


This project will improve water quality in the Fort Point Channel by providing for the treatment of CSO dischargesthrough BWSC’s Union Park Pumping Station. The existing pumping station, constructed in 1976, provides floodcontrol for the South End neighborhood of Boston. The Final EIR calls for the detention/treatment facility to beconstructed adjacent to the existing pumping station, on property now owned by BWSC at the intersections ofAlbany, Malden, and Union Park Streets in the South End. Flows will pass through the new treatment facilitybefore entering the pumping station wet well.

The recommended plan calls for adding fine screens, chlorination with sodium hypochlorite, dechlorination withsodium bisulfite, and below-ground, rapid-settling detention tanks measuring approximately 90 feet by 140 feet and20 feet deep. The buried tanks, which will have a combined storage capacity of 2.2 million gallons, will facilitate areduction in the number of pumping station discharges to the Fort Point Channel. While most of the new facilitywill be below ground, the plan includes an addition to the above ground structure of the existing pumping station.

While some layout changes within the existing pumping station are planned to optimize use of available space andminimize aboveground construction, the treatment facility will be constructed as an add-on to the pumping station.No changes to the pumps, the wet well, or the current operation of the pumps for flood control are proposed as partof this project. The pumping station will remain in service and be fully operational during construction of thetreatment facility. However, MWRA and BWSC agree that it is technically necessary that operations of the newtreatment facility and the existing pumping station be integrated. MWRA will continue to work with BWSC duringthe course of design to develop an agreement for the future operation of the integrated facilities.

In 1999, BWSC initiated a South End Facilities Plan to address the causes of serious flooding during extreme stormsover the last few years. The South End Facilities Plan, including BWSC’s long-term recommendations, was issuedin 2001. The information and recommendations from BWSC’s study may affect design of MWRA’s treatmentfacility. The agencies have exchanged technical information as BWSC implements its facilities plan and MWRAcompletes design.

A neighborhood playground recently completed by the Boston Parks Department covers approximately half of theproposed treatment facility site. As discussed at public meetings during facilities planning and as stipulated in alease agreement signed by Boston Parks, BWSC, and MWRA in 1997, MWRA will remove the playground duringconstruction. A replacement playground will be constructed at a nearby site owned by the Boston Parks Departmentand a passive park is proposed to be built over the CSO facility detention basin following construction. MWRA hasbeen coordinating these efforts with the Boston Parks Department and the neighborhood.

Scope

Sub-phase ScopeDesign and Construction Design and construction of the Union Park Detention Facility including storage

tanks with a capacity of 2.2 mg, and a 90 feet by 140 feet by 20 feet highaddition to the existing pump station.

BWSC Construction* Portions of the construction project will directly support BWSC. Tocoordinate construction activities, the project will be bid jointly and BWSCwill pay for its portions of the contract.


Construction – Park Replacement Playground to be constructed early in construction of the treatmentfacility.

*Change in Project Scope


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$38,612 $4,547 $34,065 $18,848 $15,049 $168 $0 $0 $0




$40,461 $38,612 ($1,849) Mar 2005 Mar 2005 None


� Budget decrease based on revised 100% design submittal and reduced reserves.


Upgrade Existing CSO Facilities and MWRA FloatablesControl (353)


� Contributes to improved public health � Provides environmental benefits � Fulfills a regulatory requirement� Extends current asset life

To minimize CSO impacts to the Lower Charles River, Upper Inner Harbor, Mystic/Chelsea Confluence, and SouthDorchester Bay receiving waters by upgrading five MWRA CSO treatment facilities (Fox Point, Commercial Point,Cottage Farm, Prison Point, and Somerville Marginal), closing outfall MWR010, and providing floatables controlat all MWRA CSO outfalls not associated with treatment facilities (located along the Charles River). These projectsare court mandated, are in accordance with MWRA’s approved long-term CSO control plan, and are required tomeet DEP water quality standards.


Five of the six existing CSO facilities (Commercial Point, Cottage Farm, Fox Point, Prison Point, and SomervilleMarginal) were upgraded to improve treatment performance and meet new residual chlorine discharge limits. Thework generally included replacement and upgrade of the existing chlorine disinfection systems and construction ofdechlorination systems, as well as other process control and safety improvements. At the Cottage Farm and PrisonPoint facilities, the upgrade work took place entirely within the existing facility site bounds. The Commercial Pointupgrade called for a remote 36-foot by 36-foot dechlorination building to be constructed nearly one-half miledownstream of the facility on Massachusetts Highway Department (MHD) property adjacent to the SoutheastExpressway. The Fox Point upgrade included construction of a new chlorination and dechlorination building next tothe existing facility and a 2,700-foot force main from the new building to the dechlorination point, where a 12-footby 12-foot process control and sampling building was constructed adjacent to Morrissey Boulevard. The plan forSomerville Marginal was similar to that for Fox Point. A new chlorination and dechlorination building wasconstructed adjacent to the existing facility under the elevated portion of Route 93. A force main was installed tothe dechlorination point 1,800 feet downstream of the facility, where a 12 feet by 12 feet process control andsampling building was constructed on the Assembly Square Mall property.

MWRA obtained separate MHD permits to construct the Commercial Point dechlorination building on MHDproperty, to install the Fox Point sodium bisulfite force main beneath the Southeast Expressway, and to construct theon-site chemical storage building and portions of the bisulfite force main under I-93 at Somerville Marginal. Eachpermit must be renewed annually. A Use and Occupancy Agreement between MDC and MWRA related to FoxPoint was necessary to allow temporary use of MDC lands for CSO-related purposes and includes the alignment ofthe Fox Point bisulfite force main beneath Savin Hill/Malibu Beach and the location of the proposed 12-foot by 12-foot sampling building near the Savin Hill Yacht Club, as well as associated piping beneath Morrissey Boulevard.

A contract for design, construction administration, and resident inspection services for all construction contracts wasexecuted in June 1996. Unforeseen extensive deterioration of existing concrete floors in the Cottage Farm facility,discovered during construction of the upgrades, led MWRA to develop an interim plan for operating the newdisinfection and dechlorination equipment at Cottage Farm while the floors were reconstructed. This plan allowedthe upgraded facility to become operational by March 1999 (in compliance with Schedule Six), utilizing interim,flow-based controls for enhanced chlorination and dechlorination. By January 2000, the concrete floor was repairedand the permanent control systems were installed.

Construction of the Cottage Farm upgrade commenced in March 1998 and reached substantial completion inJanuary 2000. Late in 1999, while testing treatment system components, MWRA discovered several problems withthe new flow meters and electrical equipment interfaces. These problems were corrected and full systemperformance testing began in January 2000. At this time, MWRA is continuing to test wet-weather performance,adjust equipment, and train operators. In 2001, MWRA commenced systems optimization as part of the start-upperiod referenced in Schedule Six. Funds for programming process control systems at Cottage Farm were added tothe CIP during FY01. Work began in October 2000.

MWRA has recommended not closing outfall MWR010. This recommendation awaits acceptance by DEP andEPA.


Scope

Sub-phase ScopeDesign Design/CS/RI of upgrade for five CSO facilities.

Design – MWR010* Design of the closure of Outfall MWR010.

Cottage Farm CSO Facility Replacement/upgrade of the existing disinfection system and theconstruction of a dechlorination system.

Cottage Farm Programming Program final process control systems.Prison Point CSO Facility Replacement/upgrade of the existing disinfection system and the

construction of a dechlorination system.

Commercial Point, Fox Point,Somerville Marginal

Upgrades including the replacement/upgrade of the existing disinfectionsystems. A 36 feet by 36 feet dechlorination facility was constructedapproximately 0.5 miles downstream of the Commercial Point facility.New chlorination/dechlorination facilities were constructed next to theexisting Fox Point and Somerville Marginal facilities. Force mains, 2,700and 1,800 feet respectively, connect each facility to 12 feet by 12 feetprocess control/sampling buildings.

Non-Treated Floatables (Beacon) MWRA non-treated CSO floatables control. Bulkhead and close MWR021and MWR022 CSO outfalls (completed by MWRA). Construct underflowbaffles at four regulators tributary to outfalls MWR019 and MWR020.

Non-Treated Floatables(Other)*

Construction of underflow baffles at seven regulators tributary tooutfall MWR018.

Closure of Outfall MWR010* Close CSO Outfall MWR010.

*Eliminated Project Subphases in Bold.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

Beyond FY08

$22,384 $22,384 $0 $0 $0 $0 $0 $0 $0

Changes to Total Project Cost and Schedule



$23,014 $22,384 ($630) Oct 2003 Dec 2001 (22 mos.)


� Budget increase is primarily due to the actual amendment for construction services and start-up services for allfive CSO Facilities. This was partially offset by final adjustments to the construction contracts.

� Schedule reduced due to the change in scope that resulted in the elimination of multiple subphases.


South Dorchester Bay Sewer Separation (Fox Point) (340)



This project, together with sewer separation at Commercial Point, will eliminate CSO discharges to SouthDorchester Bay by separating combined sewer systems in Dorchester. The project is court mandated, is inaccordance with MWRA’s approved long-term CSO control plan, and is required to meet DEP water qualitystandards.


This project involves the construction of new storm drains and appurtenant structures, relocation of storm runoffconnections from the existing combined sewers to the new storm drains, and rehabilitation of existing combinedsewers for use as sanitary sewers. The plan calls for construction of approximately 64,000 feet of new storm drains.BWSC is implementing the project with MWRA funds.

A contract for design services was executed by BWSC in June 1996, and a preliminary design report was submittedin December 1997. BWSC executed a separate contract for construction management services in December 1998.

The first construction contracts, which commenced in April 1999, involved work in the downstream portions of theproject area, including Savin Hill. Work on a paving replacement contract began in August 1999. BWSC hasscheduled a total of seven construction contracts under this project.

Scope

Sub-phase ScopeDesign Design services for construction contracts to be bid, awarded, and managed by

BWSC.Construction Construction of 64,000 feet of new storm drains and appurtenant structures.

Relocation of storm runoff connections from the existing combined sewers to thenew storm drains. Rehabilitation of the existing combined sewers for use assanitary sewers.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$56,150 $27,042 $29,108 $8,973 $8,506 $7,546 $2,511 $933 $639




$52,057 $56,150 $4,093 Nov 2006 Nov 2006 None


� Budget increase is due to revised cost estimates for construction including increases to Contracts 3, 4,police details and sediment removal which were partially offset by a decrease in paving. Design decreaseddue to inflation and contingency being removed, and amendments moved to Commercial Point unawardeddesign. Inflation adjustment and awarded construction also account for the increase.


South Dorchester Bay Sewer Separation (Commercial Point)(341) Project Purpose and Benefits � Contributes to improved public health � Provides environmental benefits � Fulfills a regulatory requirement

This project, together with sewer separation at Fox Point, will eliminate CSO discharges to South Dorchester Bayby separating combined sewer systems in Dorchester. The project is court mandated, is in accordance withMWRA’s approved long-term CSO control plan, and is required to meet DEP water quality standards. Project History and Background This project involves the construction of new storm drains and appurtenant structures, relocation of storm runoffconnections from the existing combined sewers to the new storm drains, and rehabilitation of the existing combinedsewers for use as sanitary sewers. The plan calls for construction of approximately 72,000 feet of new storm drains.BWSC is implementing the project with MWRA funds. A contract for design services was executed by BWSC in June 1996, and a preliminary design report was submittedin December 1997. BWSC executed a separate contract for construction management services in December 1998. The first construction contract, which commenced in April 1999, involved work in the downstream portions of theproject area along South Dorchester Bay. Scope

Sub-phase

Scope

Design Design services for construction contracts to be bid, awarded, and managed byBWSC.

Construction Construction of 72,000 feet of new storm drains and appurtenant structures.Relocation of storm runoff connections from the existing combined sewers to thenew storm drains. Rehabilitation of the existing combined sewers for use assanitary sewers.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$62,301

$15,562

$46,739

$7,127

$10,854

$10,267

$5,964

$7,510

$5,018


Total Project Cost ($000s)

Schedule: Projected Completion Date

FY03

FY04

Change

FY03

FY04

Change

$62,301

$62,607

$306

Nov 2007

Nov 2007

None


� Budget increase is due to revised cost estimates including increases to Design, inflation adjustments andunawarded to awarded increases offset by contingency and unawarded decreases. Also, revised net costsfor construction contracts including sediment cleaning, Dorchester Interceptor, police, police paving, anddisconnect contract.


Stony Brook Sewer Separation (344) Project Purpose and Benefits


To minimize CSO discharges to Stony Brook Conduit and the Back Bay Fens, both of which drain to the CharlesRiver, by separating combined sewer systems in parts of Roxbury and Jamaica Plain. Implementation of therecommended sewer separation plan will reduce the number of overflows to the Stony Brook Conduit from as manyas 22 to zero in a typical year. This project is court mandated, is in accordance with MWRA’s approved long-termCSO control plan, and is required to meet DEP water quality standards. Project History and Background This project, which involves constructing approximately 75,000 feet of new storm drains, is being managed byBWSC with MWRA funds and oversight. The CIP reflects the FEIR recommendation for sewer separation. BWSChas agreed to complete the project and fund any costs in excess of $45 million plus appropriate inflationadjustments. The Preliminary Design Report recommends construction of 75,435 feet of new storm drains, ranging from 12inches to 48 inches in diameter. While BWSC will convert some of the existing combined sewers to storm drains,BWSC will convert the majority to sanitary sewers. In addition, BWSC plans to rehabilitate some of the existingsewers to ensure structural integrity through the planning period. The plan also calls for installing 2,975 feet of newsanitary sewers ranging in size from 8 inches to 36 inches and disconnecting thousands of privately owned roofdrainage systems. BWSC has scheduled a total of seven construction contracts under this project. Initialconstruction commenced in July 2000. Scope

Sub-phase

Scope

Design Design services.

Construction Construction of 75,000 feet of new storm drains. This work will be managed byBWSC.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$43,428

$18,575

$24,853

$9,226

$8,502

$6,295

$830

$0

$0




FY03

FY04

Change

FY03

FY04

Change

$38,278

$43,428

$5,150

Sep 2006

Sep 2006

None


� Budget increase is due to revised cost estimates for contracts 2, 3, and downspouts. Separation workincreased due to the need to install increased length of sanitary sewer lines. Also, increases for inflationadjustment due to new ENR index. Increases were partially offset by decreases in Design due to decrease incontingency and force account reductions.


Neponset River Sewer Separation (342) Project Purpose and Benefits


This project will eliminate CSO discharges to the Neponset River and protect water quality at downstreamswimming areas in South Dorchester (primarily Tenean Beach) by separating combined sewer systems in theNeponset section of Dorchester and by permanently closing CSO regulators associated with outfalls BOS093 andBOS095. The project is court mandated, is in accordance with MWRA’s approved long-term CSO control plan, andis required to meet DEP water quality standards. Project History and Background This project involves construction of approximately 10,000 feet of new storm drains, and is being managed byBWSC with MWRA funds and oversight. Scope

Sub-phase

Scope

Design

Design services.

Construction

Three contracts for the construction of 10,000 feet of new storm drains.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$2,681

$2,623

$58

$58

$0

$0

$0

$0

$0




FY03

FY04

Change

FY03

FY04

Change

$2,985

$2,681

($304)

Oct 2002

Oct 2002

None.

Explanation of Changes: � Budget decrease is due to transfer of non-residential inflow contract to Fox Point contract.� Schedule shifted due to additional nonresidential inflow removal added to the project.


Constitution Beach Sewer Separation (343)



This project will eliminate CSO discharges at the Constitution Beach CSO facility by separating combined sewersystems in parts of East Boston. The project is court mandated, is in accordance with MWRA’s approved long-termCSO control plan, and is required to meet DEP water quality standards.


The separation work involves construction of approximately 14,000 feet of new storm drains. The project is beingmanaged by BWSC with MWRA funds and oversight.

Scope

Sub-phase Scope


Construction Construction of 14,000 feet of new storm drains.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$3,769 $3,769 $0 $0 $0 $0 $0 $0 $0




$3,774 $3,769 ($5) Apr 2002 Apr 2002 None.


� Budget decrease is due to revised cost for awarded construction.


Cambridge CAM002-004 Sewer Separation (346)



To minimize CSO discharges to Alewife Brook by separating combined sewer systems in parts of Cambridge. Thisproject is court mandated, is in accordance with MWRA’s approved long-term CSO control plan, and is required tomeet DEP water quality standards.


The City of Cambridge is managing the separation work with MWRA funds and oversight.

As reported to the court in 1999, information gathered by the City of Cambridge during the design phase of thisproject indicated that the physical configurations of the Cambridge sewer and storm drain systems, including thedegree to which these systems are interconnected, are significantly different from conditions shown on the city’sbase plans and older design plans. Both sets of plans were used by MWRA to develop the conceptual plan for theproject. As a result, extensive additional work to separate sewers is required to meet CSO control goals. Whileconstruction began in 1998 on schedule, completion of construction has been delayed.

MWRA responded to the significant increase in estimated project costs by instructing Cambridge to suspendremaining final design efforts and award of any construction contracts not yet approved, until MWRA andCambridge could complete a thorough reassessment of project costs and alternatives. At that time, Cambridge hadreceived approval from MWRA to commence four of the ten proposed construction contracts that comprised theoriginal scope.

Based upon an evaluation conducted by MWRA and Cambridge of alternatives that considered cost, performance,and non-monetary factors, the revised recommended plan for controlling CSO discharges to Alewife Brook, like theoriginal plan, is a partial sewer separation alternative that includes the following components:

� Completion of sewer separation in the CAM004 tributary area (similar to the original CSO control plan, butwith expanded scope).

� Separation of the CAM400 tributary area (new).� Relief of dry weather flow connections at CAM002, CAM401B, and SOM01A (new).� Relief of an existing siphon and installation of a flow control gate at MWR003 (new).� No further sewer separation in the CAM002 tributary area. (Although this work was included in the

original plan and a small, related construction contract was completed by Cambridge in 1999, the revisedplan recommends not completing separation in this area.)

� No additional CSO control recommended for the recently discovered outfall at CAM401B.� Floatables control at remaining CSO outfalls.

On May 24, 2000, the Board of Directors approved a revised CSO Control Plan for Alewife Brook. This budgetreflects MWRA’s estimate of the cost and MWRA share of the revised plan. The federal court schedule milestonefor completion of construction of sewer separation was January 2000. MWRA previously informed the court andcourt parties that MWRA would be unable to meet this milestone due to the increased scope of the project. MWRAhas begun negotiations with the court parties regarding proposed revisions to the schedule. Finalizing proposedchanges to the court schedule may have to be deferred until the public review process has been completed, in partthrough public review of a Notice of Project Change filed in April 2001.

The City of Cambridge executed a contract for design services in January 1997. The first three constructioncontracts were completed in 1999.


Scope

Sub-phase Scope


Construction Four construction contracts for sewer separation work have been awarded Theremaining scope of work for this project, outlined above, is still being reviewed byMWRA.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$38,928 $16,463 $22,465 $2,253 $2,093 $5,100 $5,447 $378 $7,194




$37,512 $38,928 $1,416 Dec 2009 Mar 2010 3 mos.


� Budget increase is due to revised construction estimates including contracts 8 and 9 as a result of surfacework being completed ahead of separation work, which will have to be restored after separation work iscompleted. Also, increase is due to inflation adjustment due to new ENR index. These increases werepartially offset by design decreases due to program management being deleted and net design cost changes.

� The court milestone for completion of this project was January 2000. The project was re-evaluated in April2001 and is currently in the MEPA process. Revised court milestones need to be negotiated with the courtparties. The revised project schedule is based upon receiving the Secretary's certificate in October 2002.Construction schedule is based upon City of Cambridge coordination with other on-going/proposedconstruction contracts within the City.

Combined Sewer Overflow Program

66

BWSC Floatables Control (351) Project Purpose and Benefits � Contributes to improved public health � Provides environmental benefits � Fulfills a regulatory requirement

This project will limit the discharge of floatables materials from eight BWSC combined sewer outfalls and reducethe number of beach closings following wet weather events. The project is court mandated, is in accordance withMWRA’s approved long-term CSO control plan, and is required to meet DEP water quality standards. Project History and Background Floatables control at the ten BWSC outfalls included in this project involves the installation of underflow baffles inexisting CSO regulator structures. The work is being managed by BWSC with MWRA funds and oversight. Design began in December 1998, following completion of an MWRA study on the performance of underflowbaffles and a preliminary design report, which was completed in November 1999. Scope

Sub-phase

Scope

Design Design services. Construction Installation of underflow baffles at ten BWCS combined sewer outfalls.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$933

$933

$0

$0

$0

$0

$0

$0

$0




FY03

FY04

Change

FY03

FY04

Change

$933

$933

$0

Mar 2002

Mar 2002

None.

Explanation of Changes: � The project was completed in March 2002. The MOU/FAA with BWSC is scheduled to be amended in July in

order to transfer the remaining funds to BWSC. Labor relations issues prevented project from being completedin May 2001 (court milestone).


67

Cambridge Floatables Control (352) Project Purpose and Benefits


This project will limit the discharge of floatables materials from nine Cambridge CSO outfalls. This project is courtmandated, is in accordance with MWRA’s approved long-term CSO control plan, and is required to meet DEPwater quality standards. Project History and Background Floatables control devices to be installed at each outfall in this project include combing screens, continuousdeflective separation devices, brush screens, and underflow baffles. The City of Cambridge is managing the workwith MWRA funds and oversight Scope

Sub-phase

Scope

Design Design for the City of Cambridge construction contract. Construction Installation of floatables control devices at nine combined sewer outfalls.


Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$2,520

$1,055

$1,465

$1,048

$417

$0

$0

$0

$0




FY03

FY04

Change

FY03

FY04

Change

$2,561

$2,520

($41)

June 2005

June 2005

None.


� The court milestone for completion of this project was May 2001. Portions of this project are currently inthe MEPA process. Revised court milestones need to be negotiated with the court parties. The revisedproject schedule is based upon receiving the Secretary's certificate in October 2002.


68

CSO Planning and Support (324) Project Purpose and Benefits


The goals of the CSO Program are to minimize CSO discharges, reduce beach closings following wet weatherevents, and maximize the beneficial use of CSO receiving waters. This project includes CSO conceptual planning,system master planning, and facilities planning/environmental review. It also includes directly related watershedplanning activities, short term CSO control measures (known as “SOPs”), various as-needed technical supportactivities, and acquisition of land and easements required for CSO control plan implementation. Project History and Background MWRA CSO planning work began in 1986. A revised Final Conceptual Plan and System Master Plan wascompleted in 1994, and a Final CSO Facilities Plan and EIR was filed with MEPA in August 1997. A MEPAcertificate was issued in October 1997. In December 1997, DEP issued water quality determinations that werenecessary for final CSO plan approval by DEP and EPA. DEP issued a two-year variance for the Charles River inOctober 1998. DEP has extended the Charles River variance twice, to October 2002 and has issued a tentativedetermination proposing an additional one-year extension to October 2003.. A three-year variance for Upper MysticRiver and Alewife Brook CSOs was issued in March 1999. In 2002, DEP extended the term of this variance toSeptember 2003. Under Master Planning, consultant services include assisting MWRA in satisfying varianceconditions. As part of CSO Planning and Support, MWRA provided financial and technical assistance to the Charles RiverWatershed Association in its watershed planning efforts for the Charles River, known as the IM3 Study. Alsoincluded was funding for a portion of the costs of a USGS water quality study of the Charles River Basin. Results ofthese studies will provide additional technical information to support the reassessment of the appropriateness of therecommended Charles River controls in the CSO plan. To comply with its requirements under the Charles RiverCSO variance, in 1999 MWRA began funding USGS efforts to collect updated information on Charles River waterquality. Final payments to the Charles River Watershed Association and USGS were made in the fall of 1998 andthe fall of 2001, respectively. Schedule Six of the federal court order in the Boston Harbor Case required MWRA to develop, by June 1993, a planfor optimizing the existing combined sewer systems to maximize transport and in-system storage capacities, therebyminimizing CSO discharges prior to developing and implementing a long-term control plan. In June 1993, MWRAcompleted a report entitled System Optimization Plans for CSO Control which recommended more than 100relatively low cost and easily implemented projects to optimize operation of existing systems. The projects weredesigned and constructed primarily by the CSO communities, pursuant to SOP financial assistance agreementsexecuted between MWRA and each CSO community. Under the agreements, MWRA reimbursed the communitiesfor design and construction costs. The SOP projects also include two projects that are part of the long-term plan:Somerville Baffle Manhole Separation and Somerville Floatables Control. Short-term plans for CSO SOPs werecompleted in 1997 and MWRA obtained regulatory approvals for its long-term plan in 1997 and 1998. The performance of the sewerage system is constantly improving as CSO and non-CSO projects are completed andas maintenance efforts continue to increase the system’s capacity. Updated assessments of the systems hydraulicperformance and estimates of CSO discharges based on actual field data are essential to verify the predicted benefitsof various CSO-related improvements, to recalibrate the system hydraulic model to reflect updated conditions, andto provide up-to-date information to support CSO planning and design efforts. This project provides for temporaryflow metering and other efforts to gather and evaluate new performance data. Various CSO plan reevaluations and systems assessments have been performed under amendments to the MasterPlanning contract (5716), including: reevaluation of Alewife Brook sewer separation plan; reevaluation of the needfor the Dorchester Brook In-line Storage Project (not included in the CSO Plan or the CIP); reevaluation of thefeasibility of closing MWR010; reassessment of CSO discharges from the Boston Marginal Conduit to reevaluatethe need for floatables control; and reevaluation of the cost-effectiveness of the East Boston Branch Sewer Reliefproject in light of cost increases.


69

Also added to Contract 5716 by amendment, were system modeling services to estimate and report actual CSOdischarges on an annual basis, in compliance with new provisions in MWRA’s NPDES permit. Scope

Sub-phase

Scope

Technical Assistance Preliminary planning services prior to and in support of the 1988-90 FacilitiesPlanning/EIR efforts.

Planning/EIR Facilities planning and environmental review of CSO control alternatives (1990Recommended CSO Control Plan).

Master Planning System inspections, flow monitoring, water quality monitoring, and performanceassessments to improve MWRA’s understanding of the combined sewer andregional wastewater systems, optimize the performance of the existing systems, andreassess CSO control needs in the context of evolving EPA policy and a systemmaster plan. Revisions to Facilities Plan/EIR.

Watershed Planning External watershed planning efforts that may affect CSO control needs, includingthe Charles River Watershed Association IM3 Study and ongoing USGS waterquality studies.

Modeling Receiving water quality modeling support to the Master Planning efforts. SOP Program Develop and fund implementation of System Optimization Plans for short term CSO

control. Implemented by CSO communities. System Assessment Temporary flow metering and other efforts to gather and evaluate new data on

system performance. Expenditure Forecast (in $000s)

Total Cost


RemainingBalance

FY04

FY05

FY06

FY07

FY08

BeyondFY08

$40,791

$37,458

$3,333

$935

$1,081

$801

$351

$81

$85




FY03

FY04

Change

FY03

FY04

Change

$40,689

$40,791

$102

Dec 2009

Dec 2009

None


� Budget increase is due to an amendment to the Master Planning subphase to complete the MEPA process,and assist with permitting of Alewife Brook, Cottage Farm report, and modeling efforts.

introduction to combined sewer overflow (cso) program

Documents