Combined Sewer Overflow Control Plan

	NOTE: This online report DOES NOT contain some photos and maps included in the original. If you would like a hardcopy version, please email Tim.Watkins@mwra.state.ma.us

Combined Sewer Overflow Control Plan
Annual Progress Report 2001
March 2002

1. Introduction

The Massachusetts Water Resources Authority ("MWRA") files this CSO Annual Report for 2001 to comply with reporting requirements in the Federal Court Order in the Boston Harbor Case. The schedule for filing annual reports on MWRA’s CSO plan was changed by the Court in October 2001, when it accepted MWRA’s motion to change the submission date from February to March 15, to coincide with quarterly reporting.

The annual and quarterly CSO reports describe the progress of work to complete MWRA’s long-term CSO control plan, relative to milestones on the court-ordered schedule. The Annual Report for 2001 identifies planning, design and construction progress and accomplishments in 2001 and in the quarterly period December 15, 2001, to March 15, 2002. It also presents issues that may cause delays in completing the projects on schedule and describes efforts to address these issues and move CSO control forward.

MWRA’s long-term CSO control plan was presented in the Final CSO Facilities Plan and Environmental Impact Report ("Facilities Plan/EIR"), which MWRA filed with federal and state regulatory agencies in August 1997. It recommended 25 wastewater system improvement projects (see Figure 1) to bring CSO discharges at 84 outfalls in the metropolitan Boston area into compliance with the federal Clean Water Act and state Water Quality Standards.

The CSO plan proposed elimination of CSO discharges to sensitive use areas (i.e. beaches and shellfish areas), significant reduction or treatment of discharges to less sensitive waters, and means to control floatable materials where CSO discharges will remain. Figure 2 summarizes the schedule and benefits of the plan. The final plan received state and federal regulatory approvals in late 1997 and early 1998, respectively, allowing MWRA to move the projects into design and construction.

Design and construction milestones for all of the projects are included in Schedule Six of the Federal Court Order in the Boston Harbor Case. Overall, Schedule Six calls for the CSO plan to be fully implemented by November 2008.

In 2001, MWRA made considerable design and construction progress on the CSO projects (see Table 1), as described in more detail in Section 5 of this report. Construction of five CSO projects was completed, bringing the total number of completed CSO projects to thirteen. Five additional projects were in construction by the end of 2001. MWRA also filed two Notices of Project Change with the Massachusetts Environmental Policy Act Unit ("MEPA") and conducted extensive public participation programs related to several of its projects.

MWRA also performed a considerable amount of water quality sampling and hydraulic modeling, to respond to site-specific issues and needs. The work focused on key portions of the sewer system and involved updating water quality and sewer system baseline conditions and sewer system performance, primarily to support the reassessment of CSO control plans in certain areas. This work included reassessments relative to the Dorchester Brook Conduit, outfalls MWR018-020 and MWR010, the East Boston Branch Sewer, and Boston Water and Sewer Commission’s ("BWSC’s") South End Facilities Plan. Some of these investigations are summarized below, and all are described in more detail in later sections of this report. MWRA expects to conduct additional reassessments on an as-needed basis, as issues arise during CSO plan implementation.

MWRA continued to update its wastewater system model, by incorporating new information obtained from various investigations and monitoring efforts, as it has done since the model was developed in the early 1990’s. In addition, MWRA commenced work in 2001 to develop a new wastewater system model to replace the 1990’s model and meet its future hydraulic modeling needs. The new model is scheduled to be completed by the end of 2002.

The following progress highlights and key accomplishments are discussed in more detail on the referenced pages of this report.

MWRA reported last year that 21 of the 84 outfalls addressed in the CSO plan had been closed to CSO discharges. While substantial construction progress was made in 2001, no additional CSO outfalls were closed. MWRA has recommended to EPA and DEP that outfall MWR010, the only outfall scheduled to be closed in 2001, remain open to prevent system flooding in extreme storms. MWRA proposes to close a total of 35 CSO outfalls by 2008 (see Figure 3).

The overall budget for the CSO program has grown considerably since the CSO plan was recommended in the 1997 Facilities Plan/EIR (see Table 2). Project cost estimates (Table 3) have been affected primarily by site-specific construction requirements and impact mitigation measures identified during early design efforts. New construction cost estimates presented in the preliminary design reports for the East Boston Branch Sewer Relief project and the Union Park Detention/Treatment Facility, both completed last fall, are considerably higher than the cost estimates in the Facilities Plan/EIR. The cost increase for the East Boston project was so great that MWRA is now conducting an investigation into the cost effectiveness of the project. Design work proceeds on schedule pending the results of this investigation.

Preliminary design is complete for most of the projects, but certain cost risks remain. Preliminary designs and associated cost estimates will not be available for the Fort Point Channel and BOS019 Storage Conduits for at least another year; design services are scheduled to commence in July 2002. Furthermore, regulatory decisions on floatables control, regulatory determinations relative to the Charles River and Alewife Brook/Mystic River Variances, and the results of the South Boston CSO reassessment could change the scope and cost of the CSO plan.

The estimated cost of the long-term CSO control plan (design and construction) is $581 million, compared to $441 million in the Facilities Plan/EIR. Together with the costs of past and ongoing CSO planning and support efforts, the current total estimated cost of the CSO control program is $620.7 million.

Note: Actual and projected expenditures are from MWRA’s Proposed FY03-05 CIP. MWRA’s fiscal year (FY) ends on June 30.

MWRA spending on CSO control from 1987 (when MWRA assumed responsibility) through calendar year 2001 has exceeded $160 million. In 2001, the bulk of spending was on construction contracts. Annual spending has increased over the last few years, and will continue to increase as more projects move into construction (Table 4). Spending is expected to peak in FY06, at about $100 million, and end in FY09.

Since late 1997 and early 1998, when EPA and DEP issued water quality standards determinations and CSO plan approvals, the regulatory agencies have requested that MWRA conduct additional planning level investigations to support continuing regulatory review and future regulatory decisions. These investigations fall into the following areas:

Activities related to the Charles River Variance, the Alewife Brook/Upper Mystic River Variance and floatables control are described below. In addition, this section updates the status of efforts by EPA and DEP to modify MWRA’s NPDES permit, to incorporate Phase II CSO requirements. Optimization of project cost/benefit takes place during project design, and any new project recommendations resulting from these investigations are included in the related project report in Section 5.

MWRA has conducted reevaluations of certain project recommendations. Where the results of these evaluations may lead MWRA to recommend plan changes, MWRA works with regulatory agencies to ensure that they are kept informed during the evaluations and have early opportunity for review and input. Such was the case during 2001 for the updated assessment of CSO discharges to the Dorchester Brook Conduit, the reevaluation of CSO discharges and floatables control needed at outfalls MWR018, 019 and 020, and the reevaluation of the feasibility of closing outfall MWR010. These evaluations, all of which led MWRA to recommend plan or schedule changes, are discussed in more detail in Section 5.

The Charles River CSO variance, issued by DEP on October 1, 1998, originally provided a two-year period during which MWRA would implement its 1997 CSO plan for the Charles River and conduct additional water quality and CSO control evaluations, prior to DEP making a final determination on water quality standards and required level of CSO control. Among other conditions in the variance, MWRA must submit a report that reevaluates the cost and benefit of providing additional storage for CSO flows at MWRA’s Cottage Farm CSO facility, using updated water quality information collected during the variance term.

Since the variance was issued, MWRA has participated in Technical Advisory Committee meetings on the United States Geological Survey ("USGS") study of the Charles River Basin, which USGS commenced in January 1999. Most of the stormwater quality monitoring called for in MWRA’s variance conditions falls under the scope of the study, and MWRA has provided $308,000 towards the cost of this USGS work, as well as laboratory services, to meet this variance obligation. In 2000, DEP extended the Charles River CSO Variance and the deadline for MWRA’s report by one year, primarily because the USGS study had experienced schedule delays.

During 2001, MWRA and its CSO planning consultant continued to work with USGS, DEP, EPA and others to coordinate variance-related work. MWRA collected receiving water quality data and USGS collected stormwater related data. This data will be used to recalibrate the receiving water model and will support MWRA’s Cottage Farm storage evaluations. MWRA also continued to participate in meetings of the Technical Advisory Committee.

In June, 2001, USGS completed two draft reports as part of the Lower Charles River Study: Streamflow, Water Quality and Contaminant Loads to the Lower Charles River Basin, MA, 1999-2000: An Ultra Urban Drainage Basin and A Rainfall-Runoff Model to Simulate Stormwater Runoff to the Lower Charles River Basin, MA, October 1999-October 2000. MWRA and other parties provided comments on these draft documents. USGS is now completing work to identify potential pollution reductions from implementation of stormwater Best Management Practices (BMPs). Once these efforts are completed, MWRA will incorporate this information into the receiving water model to assess the potential for water quality improvement associated with different levels of reduction of stormwater bacteria loading. MWRA met with the regulatory agencies in January 2002, to discuss in greater detail the receiving water model and its intended use.

In October of 2001, DEP issued a second one-year extension to the Charles River variance, to October 2002. The variance extension included a corresponding one-year deferral of the deadline for MWRA’s report on the Cottage Farm CSO Facility, now July 1, 2002. This extension was intended to provide both MWRA and USGS additional time to complete certain tasks related to the variance conditions, most notably USGS’s report on stormwater BMPs and MWRA’s collection of water quality data on the raw influent and treated effluent flows at the Cottage Farm facility during several storm events. Sampling of Cottage Farm flows were hindered in 2001 by a lack of significant rainfall events. Sampling efforts were suspended for the winter season, but will resume soon. In the meantime, MWRA’s evaluation of the feasibility, cost and benefit of additional storage at Cottage Farm is now underway.

The Alewife Brook/Upper Mystic River CSO Variance, issued by DEP on March 5, 1999, covers a three-year period during which MWRA was to implement its 1997 CSO plan and conduct additional water quality and CSO control evaluations, prior to DEP making a final determination on water quality standards and the required level of CSO control for these receiving waters. Variance conditions require MWRA, Cambridge and Somerville to perform stormwater monitoring and also require MWRA to conduct receiving water sampling and prepare a reassessment report on the potential benefits of higher levels of CSO control, using the new water quality data.

During 2001, MWRA continued the activities required by the variance conditions. On April 2, 2001, MWRA submitted two required reports related to Alewife Brook and Mystic River water quality: the Summary Data Report on the results of sampling conducted by MWRA and others during 2000 and the Proposed 2001 Sampling Plan. MWRA understands that DEP has since reviewed these reports and generally concurs with the level of information and the recommendations contained therein.

Due to the lack of adequate storm events in 2001, MWRA was only able to sample two of three intended sampling events. MWRA is now preparing one data report on the two events that occurred in September and October, which it expects to submit soon. MWRA plans to conduct additional storm drain sampling during two storms in the spring of 2002 and one in the fall. During the sampling period, MWRA installs and operates meters to measure storm drain flows. MWRA recently reinstalled the flow meters and expects to start up the spring sampling program by the end of March.

Early in the year, MWRA completed the required data report on receiving water sampling conducted in 2000 on the Alewife Brook and Mystic River and submitted the sampling plan which detailed the proposed 2001 sampling program. MWRA also participated as a sponsoring organization in the internship program of the Tufts University River Institute. This effort was an outgrowth of a collaboration between Tufts University and the Mystic River Watershed Association. MWRA, in cooperation with the Tufts University River Institute, compiled much of the historical water quality information available for Alewife Brook and Mystic River from a range of sources, including municipalities, the Metropolitan District Commission and non-profit organizations. This information will support preparation of MWRA’s final reassessment report, the schedule of which is part of a proposed extension to the term of the variance.

In December 2001, MWRA submitted a letter to DEP requesting an 18-month extension of the Alewife Brook/Upper Mystic River variance, to September 2003. The extension is necessary to allow MWRA to complete stormwater sampling and analysis needed to prepare the final assessment report required by the variance, as well as to allow time to complete the MEPA process so that a final plan for Alewife Brook can be approved. The final report will summarize and assess the information gathered during the variance process and reevaluate the recommended level of CSO control for Alewife Brook and Mystic River. Once the report is complete and the plan is finalized, DEP can make its water quality standards determinations. The work necessary to complete the MEPA process and finalize the CSO plan is described in the "Cambridge/Alewife Brook Sewer Separation" report in Section 5.

DEP issued a public notice on the proposed variance extension in late December. The public comment period on this proposal closed on February 22, 2002. In response to numerous public questions and concerns on the proposed variance extension, DEP conducted an informational public meeting in early February. MWRA expects that DEP will make a final decision on the variance extension soon.

In the Facilities Plan/EIR, MWRA recommended extensive use of underflow baffles to meet federal and state requirements for CSO floatables control. To address federal and state regulatory concerns that the performance of underflow baffles had not been tested, or proven in the field, MWRA conducted a laboratory physical model study in 1996 and a field verification program, in part using prototype baffle installations, from 1997 through 1999.

Although the field study did not yield the data necessary to support a quantitative evaluation of underflow baffle performance, MWRA concluded in a final report submitted in February 2000 that underflow baffles are effective in controlling floatables in CSO discharges, based on ect evidence from the 1996 laboratory studies and the field observations at prototype baffle installations, at outfalls BOS012 and BOS078. During a meeting in July 2000, EPA and DEP requested more information comparing the capture efficiency of underflow baffles to other, more widely-used technologies, such as screens and nets. MWRA submitted this information in October 2000.

No additional discussions on this subject have since occurred, and no regulatory decisions have been issued. In 2001, MWRA and the CSO communities continued to design and construct floatables controls using underflow baffles and conducted investigations to reevaluate floatables controls in certain areas. This work is described in the "Region-wide Floatables Control and Outfall Closing Projects" report in Section 5.

In 2001, MWRA, EPA and DEP continued discussions regarding modifications to MWRA’s NPDES permit, to incorporate Phase II CSO requirements. The new permit generally includes Phase I provisions only, which call for the implementation of the long-term CSO control plan and require MWRA to estimate CSO discharges for every rainfall event, but generally do not set CSO discharge limitations that reflect long-term plan conditions. The primary objective of Phase II provisions is to require and verify that the implementation of the CSO controls in the long-term control plan will meet Clean Water Act requirements, including Water Quality Standards.

Several key issues with the Phase II modifications were resolved in 2001, and MWRA expects the draft permit modification to be released soon, for public review. In June 2001, MWRA submitted a draft report on CSO discharge estimates for calendar year 2000 and held discussions with EPA and DEP on its modeling and metering approaches for developing these estimates in future years. MWRA’s CSO consultant recently has been developing the estimates for storms in year 2001, and MWRA plans to submit a report with these estimates to EPA and DEP by the end of March 2002.

This section presents the scope and schedule for each of the projects recommended in the long-term CSO control plan, along with progress made in 2001, project changes, if any, and key issues that may affect future progress. Many of the CSO projects recommended in the final plan have been combined into design and construction packages, as presented below.

NORTH DORCHESTER BAY AND RESERVED CHANNEL
CONSOLIDATION CONDUITS AND RESERVED CHANNEL CSO FACILITY

Because MWRA was unable to implement the plan recommended in the Facilities Plan/EIR, efforts in 2001 focused on a reassessment of CSO control alternatives for the South Boston beaches and the Reserved Channel. Below is a brief review of the project history leading to the reassessment, followed by a description of the activities MWRA undertook in 2001.

MWRA’s original plan for CSO control in South Boston proposed 13-foot diameter consolidation conduits (constructed as tunnels) along the South Boston beaches and Reserved Channel. The tunnels would store CSO discharges in most storms, for later pumping to Deer Island. During large storms when CSO flows exceed the storage capacity of the tunnels, the excess flows would be conveyed away from the beaches, treated, and pumped into the Reserved Channel. Treatment and pumping was to be provided by a 600 mgd facility that was to include fine screens, disinfection and dechlorination systems. MWRA proposed that this facility be located on vacant land off East First Street, designated "Site J."

Design of the tunnels and facility began in 1997. As design progressed, opposition by elected officials and some residents to siting the CSO facility on Site J intensified. In December 1999, elected officials representing South Boston informed the MWRA’s Board of ectors that they would block efforts by MWRA to obtain Article 97 legislation necessary to build the facility on Site J, which through earlier legislation had been designated as parkland, although no plans for a park have ever been proposed.

In January 2000, MWRA stopped design work on all elements of the project. MWRA then met several times with federal and state regulatory officials, South Boston elected officials and other interested parties, in an attempt to reach consensus on an approach to move forward. South Boston elected officials maintained firm opposition to Site J and continued to advocate that MWRA locate the proposed Reserved Channel facility at a site on Massport's Conley Terminal. MWRA earlier rejected this for reasons including the significantly higher cost to construct the facility at a Conley site and a preliminary indication from Massport that no site was available in the terminal. Furthermore, siting the facility at Conley Terminal never received environmental review under the MEPA process, which would be required for MWRA to proceed with the project at that location.

Because opposition to Site J continued, it became obvious that the project could not proceed without further planning review to support the selection of an alternative site or, indeed, a different project. To this end, MWRA proposed to file a Notice of Project Change with MEPA, which would recommend a project reevaluation with the following goals:

The Notice of Project Change, filed in 2001, identified the evaluations necessary to achieve these goals. The three main work efforts to be accomplished in the reevaluation included updating baseline planning and water quality assumptions, evaluating Conley Terminal alternatives, and performing an updated evaluation and comparison of CSO control alternatives for the beaches and the channel.

Court schedule milestones for construction of the projects have not changed, although MWRA was unable to commence construction and is now reevaluating CSO control alternatives.

During the early months of 2001, MWRA finalized the Notice of Project Change with input from EPA, DEP, the Department of Justice, elected officials and others parties who reviewed a draft version. MWRA submitted the Notice of Project Change to MEPA in early April 2001 and distributed it to over 120 recipients. It was noticed in the Environmental Monitor, initiating a 30-day public comment period. During the comment period, MWRA held a public meeting in South Boston to discuss the proposed reassessment, and at the request of the community, the comment period was extended to the end of May.

On June 8, 2001, after receiving public comments, the Secretary of Environmental Affairs issued a Certificate on the Notice of Project Change. The Certificate essentially approved the scope of the reassessment proposed by MWRA, adding a few additional requirements. The Certificate required MWRA to include all CSO control alternatives considered during the development of the Facilities Plan/EIR, including those dismissed in the planning process or in that document. The Certificate also required that the reassessment be responsive to the public comments that had been submitted. MWRA revised the scope of the reassessment accordingly.

MWRA plans to conduct the reassessment in two phases. In September 2001, MWRA began Phase I efforts focusing first on updating water quality and sewer system baseline conditions and initiating the public participation program. Updated assessments of CSO flows, CSO and stormwater pollutant loadings, and receiving water quality are necessary to properly evaluate the performance and benefits of the various CSO control alternatives.

Due to low rainfall over the last several months, MWRA was unable to complete its planned water quality sampling program in the fall, as scheduled. MWRA was able to conduct only one sampling event in late fall and will attempt to complete the program this spring. It was not feasible to conduct wet weather sampling during the winter. The delay in the sampling program will, in turn, delay the completion of Phase I. MWRA now anticipates completing Phase I in Fall 2002 (approximately a nine month delay from the original schedule), if sufficient rainfall occurs this spring to complete the sampling program.

Through the remainder of the fall, other Phase I efforts associated with updating the baseline collection system and planning assumptions continued. This work included location and inspection of the North Dorchester Bay CSO outfalls BOS081-BOS087 by marine divers, obtaining existing and proposed South Boston collection system modifications from BWSC, incorporating these configuration modifications into the collection system model, and preparing draft design criteria for the range of CSO control technologies being considered.

MWRA also initiated its public outreach efforts in the fall, initially conducting stakeholder interviews with community representatives and elected officials to discuss the proposed public participation program. The program’s main element will be regular public meetings to present progress and to get input from the public on key issues. MWRA will supplement these public meetings with articles in local papers and with informational flyers. Because the reassessment is considering a full range of CSO control alternatives and associated siting options, MWRA has reached out to a broad range of interests, including residents throughout South Boston, elected officials, community organizations, neighborhood groups, environmental and scientific interests and regulatory agencies. MWRA held the first public meeting in December to review the scope of work for the reassessment and the MEPA review process, to describe the work performed thus far and to respond to questions.

MWRA expects Phase II of the reassessment to begin at the completion of Phase I and the full reassessment to be completed in early 2003. MWRA will narrow down the full range of alternatives and carry approximately six alternatives forward into Phase II. During Phase II, MWRA will conduct a more detailed evaluation of the shortlisted alternatives, with the aim of selecting a recommended CSO control option that meets federal and state CSO policy and has a level of public support that assures that the project can be implemented. The reassessment efforts, including updated baseline conditions, alternatives evaluation and the selection of the recommended plan will be documented in a Supplemental Environmental Impact Report that MWRA plans to submit to MEPA for public review and comment by March 2003.

MWRA held its second public meeting in January to present the "ABC’s" of CSO control which covered how the combined sewer system in South Boston works, where the flows come from, where and why the overflows occur along the beaches and Reserved Channel, and the types of control technologies that are available. In an effort to welcome a broad range of participants, over 17,000 flyers were sent to residents of South Boston and interested groups and notices were published in local newspapers.

MWRA continues its efforts to update baseline conditions and develop CSO control alternatives. MWRA anticipates resuming the water quality sampling program by the end of March 2002. In addition, MWRA has commenced work preliminary to the initial screening of the full range of CSO control alternatives (approximately 60), to eventually recommend a short list of alternatives that will be evaluated in more detail in Phase II. In doing so, MWRA plans to work with the regulatory agencies and the public, through briefings and public meetings, to ensure agreement at this stage.

This contract combined two localized hydraulic relief projects, one in Cambridge to minimize CSO discharges at CAM005 and the other in Charlestown to minimize CSO discharges at BOS017. In Cambridge, the 24-inch, 40-foot long dry weather connection between the CAM005 regulator and MWRA’s North Charles Metropolitan Sewer, adjacent to Mt. Auburn Hospital, was relieved with a new 54-inch additional connection. In Charlestown, at BOS017, 190 feet of 36-inch pipe was installed in Sullivan Square to divert two local (BWSC) combined sewers to a more ect connection with MWRA’s Cambridge Branch Sewer. In addition, a 10-foot long restriction between the Charlestown and Cambridge Branch Sewers, adjacent to Sullivan Square, was eliminated. This last improvement was intended to lower hydraulic grade lines in the Charlestown Branch Sewer during wet weather, possibly relieving CSO overflow conditions upstream, at outfall BOS019.

This project calls for relief of the MWRA interceptor system serving most of East Boston, to minimize CSO discharges to Boston Harbor and Chelsea Creek through outfalls BOS003-014. A total of 24,750 feet of existing sewers will be replaced, relieved or rehabilitated using a combination of construction methods, including open cut, pipe bursting, microtunneling, and pipe repair or relining (see figure).

MWRA issued a Notice to Proceed for design services in March 2000. Design efforts will produce three construction contracts: the first to be awarded (Contract 2) will involve rehabilitation of portions of the existing East Boston Branch Sewer with cured-in-place-pipe liner; the second (Contract 1), will involve the installation of a new sewer interceptor along Condor, East Eagle and Border Streets using microtunneling methods; and the third (Contract 3) will involve replacement and upgrade of interceptors in the Jeffries Point area using pipe bursting methods.

In the fall of 2001, MWRA completed the Preliminary Design Report, the Final Geotechnical and Hazardous Materials Reports and the Value Engineering Study, and commenced final design efforts.

The construction cost estimate for this project has increased greatly, from $30 million in the 1997 Facilities Plan/EIR (with inflation) to $50 million in the 2001 Preliminary Design Report. The increase is primarily due to new information about the cost of microtunneling, based on the actual costs of similar tunneling work on the recently completed Chelsea Branch Sewer Relief project.

In addition, the Preliminary Design Report indicated that the hydraulic performance of the relief project and attendant reduction in CSO discharges may not be achieved to the level predicted in the Facilities Plan/EIR. While design efforts are proceeding in accordance with Schedule Six, MWRA is conducting a reevaluation of the project, its cost and performance, and its cost-effectiveness in comparison to other CSO control options, including alternatives that were evaluated in the Facilities Plan/EIR. MWRA expects to complete this reevaluation by April 2002.

Final design activities have continued, in parallel with MWRA’s reassessment of the project’s cost-effectiveness. In February, MWRA received the 50% design submission for Contract 2, which it expects to advertise this fall. Progress was also made towards the 50% design submissions for Contracts 1 and 3. The project continues to be on a schedule that conforms to the milestones in Schedule Six.

This design contract will combine two CSO storage projects, one at Fort Point Channel in South Boston and the other adjacent to the Little Mystic Channel in Charlestown. At Fort Point Channel, a 10-foot diameter, 1,500 foot long conduit will be constructed along A Street in South Boston, using tunneling methods, to capture and store CSO flows from outfalls BOS072 and BOS073 for all but the largest storms in a typical year. The tunnel will provide a storage volume of approximately 0.9 million gallons. In Charlestown, a 380-foot long, 12’x12’ box conduit will be constructed adjacent to the Tobin Bridge to store most of the CSO flows that now discharge at outfall BOS019. Storage volume in the conduit will be approximately 0.4 million gallons. The flows stored in both conduits will be pumped back to the Deer Island transport system after each storm passes and system capacity becomes available.

During storms that result in an amount of flow greater than the design storage volume, hydraulic relief will continue to be provided through the existing outfalls. For this reason, underflow baffles will be designed and constructed within the existing and proposed regulators as part of these projects, in order to provide floatables control. Aboveground structures that will be located ectly over the dewatering chambers will house an activated carbon odor control system, which will treat the air that is displaced when the conduit fills with combined sewage.

In 2001, MWRA began preparation of the Request for Qualifications/Proposals ("RFQ/P") for design services, which must commence by July 2002 in compliance with Schedule Six. MWRA also gathered and evaluated new information about the sewer system and project area conditions to identify any changes from the baseline conditions in the Facilities Plan/EIR and generally assess implications to project design. This included updated information on expected sewer system conditions and flows (including an evaluation of the effects of BWSC’s South End Facilities Plan on Fort Point Channel CSOs), land use changes in the immediate project area, Central Artery/Third Harbor Tunnel facilities, soil and groundwater contamination, and proposals for water-based uses in Fort Point Channel.

MWRA publicly advertised the RFQ/P and scope of design services in March 2002. In addition, MWRA developed work plans to update its sewer system model in the Fort Point Channel and outfall BOS019 areas, to provide accurate hydraulic data to the design consultant early in the design work. Part of the work will involve assessing the effects on Fort Point Channel CSO discharges of the various alternatives that will be considered for CSO control along the Reserved Channel. CSO discharges in both of these areas are affected by hydraulic conditions in the North Branch of the South Boston Interceptor. MWRA expects related flow monitoring and modeling work to be conducted over the next several months.

This project was intended to minimize CSO discharges to the Inner Harbor at outfalls CHE002, CHE003 and CHE004. The existing Chelsea Trunk Sewer, which varies in diameter from 8 to 15 inches, was replaced with 2,300 feet of 30-inch diameter pipe, using open cut and jacked casing methods. Information obtained during design about the physical conditions of the CHE002, CHE003 and CHE004 outfalls, led to a decision to add replacement or rehabilitation of sections of the CHE002 and CHE003 outfalls to the trunk sewer replacement contract. MWRA managed the construction, but the City retains ownership and responsibility for operation and maintenance. The Chelsea Trunk Sewer Replacement project was completed in 2000, on schedule.

The CSO plan recommended relieving MWRA’s Chelsea Branch Sewer to minimize CSO discharges to Chelsea Creek at outfall CHE008 and reduce surcharging in the upstream transport system. The construction contract also included repairs to the existing CSO outfall at CHE008. MWRA installed 4,200 feet of 42-inch pipe and 3,500 feet of 66-inch pipe along or near Cabot Street and along Eastern Avenue, to replace or relieve MWRA’s Chelsea Branch Sewer and Revere Extension Sewer, which lie parallel along Eastern Avenue. The new pipes were constructed primarily using microtunneling methods.

Outfall repairs at CHE008 included relining approximately 540 feet of the existing 42-inch outfall pipe, replacing 35 feet of the pipe at its downstream end, replacing the headwall and laying new riprap shore protection. An underflow baffle was installed at the sole regulator structure associated with this outfall, to provide floatables control.

On June 28, 2001, MWRA substantially completed construction of the Chelsea Branch Sewer Relief Project and outfall repairs and floatables control at CHE 008, in compliance with Schedule Six, and brought the new pipelines on-line. In August, MWRA awarded a $3.4 million contract to reline older sections of the Chelsea Branch and Revere Extension Sewers, which is now 80% complete. The relining work is outside the scope of the CSO plan.

This project is intended to improve water quality in the Fort Point Channel by providing treatment of CSO flows that are discharged through BWSC’s Union Park Pumping Station. The existing pumping station, constructed in 1976, provides flood control for the South End neighborhood of Boston. The Facilities Plan/EIR calls for the detention treatment facility to be constructed adjacent to the existing pumping station, on property now owned by BWSC at the intersections of Albany, Malden and Union Park Streets in the South End. Flows will pass through the new treatment facility before entering the pumping station wet well.

The recommended plan calls for adding finer screens, chlorination with sodium hypochlorite, dechlorination with sodium bisulfite and below-ground detention tanks measuring approximately 90 ft. x 140 ft. and 20 ft. deep. The buried tanks, which will have a combined storage capacity of 2.2 million gallons, are intended to reduce the average annual number of pumping station discharges to the Fort Point Channel (from 25 to 17 per year) and to detain flows that exceed the storage capacity in larger storms, to allow a level of solids removal. While a large portion of the new facility will be below ground, the plan includes a significant addition to the above-ground structure of the existing pumping station, to house treatment system components and accommodate operation space needs.

In 2001, MWRA’s design consultant completed the Final Preliminary Design Report, the Value Engineering Study, Final Geotechnical and Hazardous Materials Reports and 50% design plans and construction specifications.

In January 2001, MWRA received a copy of the BWSC’s draft South End Facilities Plan, which addresses the causes of serious flooding in that neighborhood over the last few years and recommends measures to control the risk of flooding in the future. The recommendations in the BWSC plan and their effects on the hydraulic conditions in the Union Park pumping station system have been addressed in MWRA’s design of the treatment facility. MWRA and BWSC continued to work closely to ensure that the new treatment facility will not compromise the flood control capabilities of the existing pumping station, to coordinate the treatment facility construction with BWSC’s planned pumping station improvements, and to begin to develop a plan for long-term, integrated operation of both facilities.

In addition, MWRA continued discussions with the Union Park neighborhood regarding the effect of the project on a playground that covers approximately half of the proposed treatment facility site. As discussed at public meetings during facilities planning and as stipulated in a lease agreement signed by Boston Parks, BWSC and MWRA in 1997, MWRA will remove the playground during construction and replace it over the buried detention tanks when completed. As a measure of mitigation of project impacts to the community, MWRA has agreed to construct a temporary playground that will replace the current playground during construction of the treatment facility. MWRA has completed preliminary work to develop plans to replace the current playground over the tanks when construction is complete.

In January, MWRA and BWSC executed a Memorandum of Agreement ("MOA") that identifies the responsibilities of each agency during design, construction and long-term operation of the existing pumping station and proposed treatment facility. Among other provisions of the MOA, MWRA and BWSC agreed to jointly procure a service contract for the combined operation of the facilities.

MWRA’s design consultant continued final design services towards submission of the 90% design plans and construction specifications, due in April 2002. MWRA held a public meeting in February to discuss project impacts and architectural design of the new building with Union Park neighborhood residents and will continue to work closely with the neighborhood on these issues. MWRA has commenced design of the temporary playground, which is scheduled to be constructed this fall, under a separate contract that is scheduled to be completed before treatment facility construction begins in the spring of 2003. MWRA plans to commence facility construction by March 2003, on schedule.

MWRA has upgraded five of its six existing CSO facilities (Commercial Point, Cottage Farm, Fox Point, Prison Point and Somerville Marginal) to improve treatment performance and meet new residual chlorine discharge limits. The work generally includes replacement and upgrade of the existing chlorine disinfection systems and construction of dechlorination systems, as well as other process control and safety improvements.

At the Cottage Farm and Prison Point facilities, the upgrade work was located entirely within the existing facility site bounds. The Commercial Point upgrade included construction of a remote 36'x36' dechlorination building nearly one-half mile downstream of the facility, on Massachusetts Highway Department property adjacent to the Southeast Expressway.

The Fox Point upgrade included construction a new chlorination and dechlorination building next to the existing facility and installation of a 2,700 foot force main from the new building to the dechlorination point on the existing outfall, where a 12'x12' process control and sampling building was constructed adjacent to Morrissey Boulevard. The work at Somerville-Marginal was similar to that for Fox Point. A new chlorination and dechlorination building was constructed adjacent to the existing facility under the elevated portion of Route 93. A force main was installed to the dechlorination point 1,800 feet downstream of the facility, where a 12'x12' process control and sampling building was constructed on the Assembly Square Mall property.

In June, MWRA completed acceptance testing at the upgraded Cottage Farm CSO Facility and entered the period of start-up and optimization referenced in footnote 35 of Schedule Six. By September, MWRA had completed construction and begun acceptance testing at the Prison Point, Commercial Point, Fox Point and Somerville-Marginal facilities. MWRA continued to make adjustments to the control systems at Commercial Point, Fox Point and Somerville Marginal, but had limited success in performing acceptance testing due to few storms and very low precipitation levels, which hindered completion of this effort.

MWRA continued to monitor and adjust new systems at all five upgraded facilities. It has made little progress in completing acceptance testing at Prison Point, Commercial Point, Fox Point and Somerville-Marginal, and start-up and optimization monitoring at Cottage Farm, because of the continued lack of significant rainfall events and facility activations.

This project is intended to eliminate CSO discharges to South Dorchester Bay by separating combined sewer systems in Dorchester. Separation work will primarily involve the construction of new storm drains and appurtenant structures, relocation of storm runoff connections from the existing combined sewer to the new storm drains, and rehabilitation of the existing combined sewers for use as sanitary sewers. The plan calls for approximately 140,000 feet of new storm drains. BWSC is implementing the project with MWRA funds.

Table 5 shows project design and construction progress. Construction is about 27% complete as of March 15, 2002, as measured by linear feet of installed storm drain. Schedule Six requires construction progress at 10% per year, for a total of 30% from the commencement of construction in April 1999 through April 2002. In general, awarded contracts have progressively increased in size. The largest of the contracts awarded to date (Contract 6) commenced in August 2001. In addition to the sewer separation contracts shown in Table 5, which primarily involve storm drain construction, BWSC has awarded a related paving contract that is now at 80% complete and plans to award additional paving contracts, sediment cleaning contracts and downspout disconnection contracts. BWSC proposes a total of 17 construction contracts to complete the project.

This project is intended to minimize CSO discharges to the Stony Brook Conduit and the Back Bay Fens, both of which drain to the Charles River, by separating combined systems in parts of Roxbury and Jamaica Plain. The separation work involves constructing approximately 73,300 feet of new storm drain pipe. BWSC is implementing the project with MWRA funds.

Table 6 shows project design and construction progress. Construction is about 13% complete as of March 15, 2002, as measured by linear feet of installed storm drain. Schedule Six requires construction progress at 15% per year, for a total of about 25% since the commencement of construction in July 2000. Contract 1, which includes 37% of the project’s total proposed storm drain construction, was awarded in April 2001. Contract 2, which includes another 37% of the storm drain construction, is at 100% design and is scheduled to be advertised this spring. BWSC also proposes to award paving and downspout disconnection contracts, the first of which will be advertised later this year. The project involves a total of seven construction contracts.

This project involved sewer separation in the Neponset section of Dorchester, to eliminate CSO discharges to the Neponset River, at outfalls BOS093 and BOS095. The separation work included construction of approximately 10,000 feet of new storm drains. BWSC performed the work with MWRA funds.

BWSC completed storm drain construction and closed the last remaining CSO outfalls to the Neponset River in June 2000. It continues to perform downspout disconnection work to remove additional stormwater inflow from the sewer system, in order to minimize the risk of surcharging and flooding. BWSC plans to commence a new contract in the spring of 2002, which will further reduce storm runoff to the sewer system by removing non-residential, private connections, such as connections from private parking lots.

This project involved sewer separation in a section of East Boston, to eliminate CSO discharges at the Constitution Beach CSO facility (outfall BOS002/MWR207). The separation work included construction of approximately 14,000 feet of new storm drains. BWSC performed the work with MWRA funds.

BWSC completed storm drain construction and closed the last remaining CSO regulator in September 2000, allowing MWRA to decommission the Constitution Beach CSO Facility. BWSC continues to perform work to disconnect downspouts to further reduce stormwater inflow to the sewer system and to lay final roadway paving.

The 1994 CSO Conceptual Plan recommended this project to minimize CSO discharges from the Dorchester Brook Conduit to Fort Point Channel. MWRA’s final plan for CSO control (1997) deleted this recommendation. MWRA had determined from additional modeling efforts that CSO discharges to the Dorchester Brook Conduit were less than earlier estimated and that further reductions would occur by bringing the full planned pumping capacity at Deer Island on-line.

Although EPA and DEP approved MWRA’s decision to eliminate this project from the final CSO plan, the project remained on the Court’s schedule. EPA and DEP indicated a willingness to consider deleting the project from the schedule pending the results of field verification of the predicted CSO activation frequencies and volumes. MWRA planned to conduct this verification after achieving "future planned conditions" in the sewer system, defined as full planned hydraulic capacity at the new Deer Island Treatment Plant and at the headworks facilities. The Authority considered these conditions to be achieved in 2000, with full pumping capacity available at the plant and completion and start-up of the Deer Island outfall.

MWRA performed evaluations of the activation frequency and volume of CSO discharges to the Dorchester Brook Conduit in 2000 and submitted a report on the results to EPA and DEP in January 2001, in compliance with Schedule Six.

The updated estimate of current total annual CSO volume to the Dorchester Brook Conduit (2.67 million gallons) was slightly lower than predicted in the 1997 Facilities Plan (2.88 million gallons), although frequency of discharge was higher.

At CSO regulators where activation frequencies were higher than predicted in 1997, discharge volumes were very low, suggesting that system optimization projects ("SOPs"), such as adjustment of weir elevations, might be effective in reducing the activation frequencies. MWRA conducted additional inspections, flow metering and modeling in the spring to determine if CSO discharges could be further reduced and submitted a supplemental report to EPA and DEP in July, recommending a set of system optimization measures, including raising a weir at one regulator, cleaning the dry weather connection at another regulator and installing a new tide gate if confirmed to be effective to reduce stormwater backflow into the combined sewer system.

Following submission of the supplemental report, MWRA worked with DEP to address questions and concerns raised in DEP’s review of the original and supplemental reports. With those questions and concerns apparently addressed, and in light of the results of the evaluations, which showed that updated estimates of current and future CSO discharges to the Dorchester Brook Conduit are in line with predictions presented in the 1997 Final CSO Facilities Plan and Environmental Impact Report, MWRA filed a motion requesting revisions to Schedule Six deleting the design and construction milestones for the Dorchester Brook Conduit In-Line Storage project. The motion was allowed by the Court on August 8, 2001.

MWRA and BWSC intend to complete the system optimization measures by July 2002, following the completion of additional system inspections and evaluations to determine the design and construction requirements for raising the weir and possibly reinstalling an underflow baffle that was recently constructed in the same regulator for floatables control, to verify the level of sediment deposition in the dry weather connection and to further evaluate the hydraulic benefits of the proposed tide gate.

This project is intended to minimize CSO flows to Alewife Brook, primarily by separating combined sewer systems in parts of Cambridge. The separation work is being done by the City of Cambridge with MWRA funds.

On April 30, MWRA and the City of Cambridge submitted the Notice of Project Change describing the revised plan to control CSO discharges to Alewife Brook (the "Alewife NPC"). MWRA and Cambridge had filed the document several months later than originally planned, to ensure that the document would be fully responsive to concerns raised at public meetings, especially concerns related to flooding impacts and construction within the Metropolitan District Commission (MDC) Alewife Brook Reservation.

Many public comments were received, and the Secretary of Environmental Affairs issued a Certificate on the Alewife NPC on June 15. The Secretary’s Certificate required the MWRA and Cambridge to prepare a document responding to all public comments, including comments related to the feasibility of obtaining necessary federal and state permits and other approvals to build the project. Since June, MWRA and Cambridge staff have had discussions with several regulatory agencies at the federal, state and local levels, in an attempt to assure responsiveness and consistency with all regulatory requirements.

Key issues raised in the public comments included: 1) the appropriateness of the recommended level of CSO control, which would necessitate changing water quality standards from Class B (CSO discharges prohibited) to Class B(cso) (minimal CSO impacts); 2) the impact of separated stormwater flows on flood elevations along the Little River and Alewife Brook; 3) the impacts of a proposed stormwater detention basin on the MDC Alewife Reservation; and 4) the appropriateness of using public parkland for stormwater management purposes (potentially requiring legislative approval under Article 97).

Of particular note, the Secretary’s Certificate on the NPC ected MWRA and Cambridge to respond to public comments on the applicability of Article 97, which requires a two-thirds vote of the legislature to use parkland for non-park/open space purposes. Specifically, MWRA and Cambridge staff reconsidered the applicability of Article 97 with respect to constructing the stormwater detention basin within the Alewife Reservation. MWRA and Cambridge now plan to file the legislation, to be responsive to public concern. The project schedule calls for filing the legislation in January 2003. Assuming that federal and state approvals are issued in the fall and legislative approval is obtained by the summer of 2003, construction could resume as early as August 2003.

MWRA and Cambridge staff have notified EPA, DEP and the public that additional work necessary to meet regulatory requirements and prepare the Response to Comments document will take several more months, and the document will not be available for MEPA filing and public distribution until September 2002. If that schedule holds, MWRA expects that a MEPA certificate on the Response to Comments document would be issued by November, 2002, after public review. Much of the ongoing work relates to concerns raised by the public and regulatory agencies on the potential for the separated stormwater to aggravate flooding along Alewife Brook and the impacts of proposed construction of a stormwater detention basin within the MDC Alewife Brook Reservation. On these issues, MWRA and Cambridge continue to work with the Arlington and Cambridge Conservation Commissions, the MDC, the Department of Environmental Management, DEP, local elected officials and others parties. Cambridge has developed a more detailed computer model to further evaluate the potential for flooding impacts.

Upon submission of the Response to Comments document, MWRA expects MEPA to notice the document in the Environmental Monitor, commencing a public comment period. At the close of this comment period, MEPA is expected to issue a second certificate on whether MWRA and Cambridge have fulfilled the original certificate requirements and have completed the MEPA process. At that time, MWRA and Cambridge will resume the construction permit application processes. These permitting processes will provide additional avenues for public review.

Cambridge began construction in July 1998, based on the original (1997) plan for sewer separation in compliance with Schedule Six, and has completed three of the four construction contracts awarded to date. The fourth construction contract (Contract 2B) is expected to be completed by July 2002, 16 months later than the original contract schedule. The time extensions were primarily driven by non-CSO related construction issues that are not eligible for funding under the MWRA agreement. At this time, MWRA and Cambridge anticipate that additional construction contracts will not commence until the summer of 2003, after MEPA review is completed and permits are obtained.

MWRA and Cambridge recently held a briefing to update EPA, DEP and the Department of Justice on the status of the project, the ongoing evaluations, and the anticipated schedule to complete the MEPA process and finish design and construction. While understanding the work and time necessary to complete the MEPA process, these parties expressed concern with the overall project duration, which calls for completion of construction in 2009, compared to the original court milestone of January 2000. MWRA and Cambridge are evaluating the possibility of completing portions of the project on a more accelerated schedule.

On a related subject, DEP recently proposed extending the Alewife Brook/Upper Mystic River variance by eighteen months, from March 2002 to September 2003. The variance was issued to allow continued discharge of CSO flows to these waters while work continues in support of a future decision on the appropriate water quality standard for these areas. The additional time will allow more water quality information to be collected and should allow MWRA and Cambridge to propose a final plan for CSO control, approved by MEPA with assurance of necessary regulatory approvals.

The Facilities Plan/EIR calls for the control of floatable materials in all remaining CSO discharges in accordance with the National CSO Policy. Floatables controls will be installed at many of the CSO outfalls as part of the larger CSO control projects described above. The Region-wide Floatables Control and Outfall Closing Projects involve recommended floatables controls and regulator or outfall closings that are independent of those larger projects.

MWRA, BWSC, Cambridge and Somerville are responsible for implementing these controls in their respective systems. MWRA met the March 1999 milestone for commencement of construction with work at outfalls MWR018-022. Schedule Six required the completion of all related construction work by May 2001.

CSO outfalls MWR018, 019, 020, 021 and 022 convey overflows from MWRA's Boston Marginal Conduit ("BMC") to the Lower Charles River Basin in very large storms. The project calls for closing outfalls 021 and 022 and providing floatables control at the remaining locations. The original plan for floatables control proposed the installation of underflow baffles at eleven CSO regulator structures upstream of outfalls 018-020.

MWRA completed the installation of underflow baffles in four of the eleven BWSC regulators (MC-12, MC-15, MC-19 and MC-25) in late 1999. In March 2000, MWRA closed outfalls MWR021 and MWR022 to CSO discharges.

During preliminary design of the seven remaining CSO regulators, which are located in the Old Stony Brook Conduit System, it was determined that the installation of underflow baffles at these regulators or other in-line structures (e.g. tidegate structures) would not be feasible due to extensive construction requirements, construction impacts and/or cost. Outfalls MWR018, 019 and 020 only rarely activate. The main problem at each location is the lack of physical space to permit the installation of the baffle and weir in the existing structures while maintaining the capacity of the regulator structure to relieve the system and prevent upstream flooding during very large storms. In most cases, existing regulators would have to be replaced with much larger structures, requiring major and difficult construction in busy streets and intersections and within railroad rights of way, at certain locations.

In 2000, MWRA conducted modeling evaluations to update and confirm the predictions of annual CSO activation frequencies and volumes at outfalls MWR018, 019 and 020. The updated prediction enabled a better understanding of floatables control benefits for these outfalls. The hydraulic model was re-calibrated within the Prison Point/BMC system, which improved the model predictions. In addition, MWRA performed a preliminary review of the how the Prison Point CSO Facility is operated and determined that by opening the gates to this facility earlier, hydraulic grade lines in the BMC could be lowered and overflows at outfalls MWR018, 019 and 020, could be reduced. This new operational condition was incorporated into the model. The updated model showed that the outfalls activate only in the largest storm in a typical year (or about once per year on average). An activation was predicted for the 2.79-inch, 24-hour, one year design storm included in the typical rainfall year.

With minor increases to the overflow weir elevations at MWR018, 019 and 020 and slight modifications to the activation elevation at the Prison Point facility during large storm events, model predictions indicated that overflows at these sites can be eliminated in the typical year. Predicted overflow volumes have been reduced to 0.09 MG, resulting in a greater than 99% capture of system combined sewage during this design storm.

Given the predictions of minimal overflows and the excessive cost and minimal benefit of constructing floatables control as originally proposed, as well as a potential for future flow reductions due to sewer separation proposed in related systems in the West End, MWRA now recommends best management practices for floatables control, in lieu of baffles at regulators tributary to the BMC.

In April, MWRA submitted a report entitled Re-assessing Long Term Floatables Control for Outfalls MWR018, 019, and 020 to EPA and DEP, with final recommendations for reducing CSO discharges at these outfalls.

Earlier in the year, MWRA raised weirs at each of the three outfalls and completed installation of a permanent level monitoring system in the upstream end of the BMC, to allow MWRA to identify hydraulic grade line changes and overflow conditions for each storm. MWRA has used the data to evaluate the performance of the Prison Point CSO Facility and the BMC during significant storms, although few storms occurred through the latter half of 2001. In addition, the standard operating procedures at Prison Point were changed. MWRA operations staff now allow flows to enter the facility earlier, when a large storm is predicted, in an attempt to control the level of backwater in the BMC and reduce untreated overflows into the Charles River Basin. The effect of the Prison Point changes has not been realized consistently, because of the sudden and unpredictable nature of most storms, as well as a lower than usual number of storms, in 2001. Once sufficient storm-related information is collected at Prison Point and at the level monitoring location, MWRA can make decisions relative to the feasibility of further raising weir elevations at CSO outfalls MWR018, 019 and 020.

In January 2002, MWRA maintenance staff completed work to clean the BMC, optimizing the conveyance capacity of this conduit and further lowering CSO discharges. MWRA plans to monitor sediment deposition in the BMC, in part to identify routine cleaning needs. MWRA’s April 2001 report concluded that removing sediments in the BMC could further reduce CSO discharges at these outfalls.

The recommended plan for eliminating CSOs at MWR010 was to seal off the four CSO regulators tributary to this outfall and keep the outfall pipe in service to convey separate stormwater to the Charles River. The CSO regulators were previously believed to be the only sources of CSO to the MWR010 outfall. However, in November 1999, the Town of Brookline released a Wastewater Master Plan, which identified that flow MWRA had believed was separate stormwater from an area of Brookline tributary to the MWR010 outfall was in fact combined sewage. In addition, Brookline’s Master Plan concluded that these flows could not be separated cost-effectively. In light of this new information, MWRA began work in 2000 to update the MWRA system hydraulic model, for the purposes of accurately representing hydraulic conditions and reevaluating the feasibility of closing the MWR010 regulators.

MWRA completed recalibration of the updated model in February 2001, allowing the evaluations to proceed. In early April, MWRA submitted its Report on Re-Assessment of CSO Activation Frequency and Volume for Outfall MWR010 to EPA and DEP. The results of the re-assessment included an updated model prediction that outfall MWR010 does not discharge CSO in a typical rainfall year under present system conditions.

On May 31, 2001, MWRA submitted to EPA and DEP the results of supplemental evaluations that were recommended in the April report. The additional evaluations were conducted to determine the size of storm predicted to cause a CSO overflow and to assess the potential upstream impact of closing the outfall. Based on these additional evaluations, MWRA has concluded that MWR010 should not be permanently closed, since closure of the outfall is predicted to result in upstream flooding during extreme storms.

MWRA pursued recommendations presented in the May report, including working with the Town of Brookline, to coordinate the cleaning of a blocked 18-inch Town connection to MWRA’s interceptor. MWRA’s report also recommended that Brookline implement non-structural best management practices (BMPs) to minimize the potential for the discharge of sediments and floatable materials during the infrequent CSO activations.

MWRA assisted in the cleaning of the Town connection, which was completed in January, providing for system conditions that eliminate the potential for CSO discharge at MWR010 during a 2-year storm. MWRA plans to seek EPA and DEP approval to remove the closing of this outfall from the long-term CSO control plan.

MWRA continues to conduct system investigations in the MWR010 area, including assessments of system performance using the updated model and evaluations on the potential for further system optimization, in part to update CSO predictions at other outfalls hydraulically related to MWR010. MWRA expects to complete these evaluations this spring.

Floatables control included in this project involves the installation of underflow baffles in ten existing CSO regulator structures. BWSC is implementing the project with MWRA funds.

BWSC commenced a construction contract in October 2000 and completed the work in February 2001. Under this contract, underflow baffles were installed at the following regulators: RE060-20, RE065-2, RE068-1A, RE070/6-1, RE070/8-3, RE070/8-15, RE070/9-4 and RE070/10-5. Labor issues related to the proximity of the CA/T project have delayed the installation of baffles at the two remaining locations, RE057-6 and RE064-5, and necessitated transferring this remaining work to a CA/T contract. Further delays were experienced within the CA/T contract, due to problems in procuring and receiving materials necessary to construct the baffles. BWSC had earlier arranged for this work to be completed by the CA/T contractor by August 2001. However, the underflow baffle was installed in regulator RE064-5 in December, and BWSC expects the contractor to complete installation of the baffle in regulator RE057-6 by April 2002.

Floatables control at nine outfalls in Cambridge are included in this project (including one MWRA outfall, MWR003). Cambridge will also design and construct floatables control for outfall SOM001A (see "Somerville Floatables Controls," below). Since Cambridge will be responsible for the operation and maintenance of its floatables control devices, MWRA has agreed to allow Cambridge to install devices of its choice, provided they meet or exceed the level of floatables control that would be achieved by MWRA’s recommended plan. At five locations along Alewife Brook, the floatables controls are being designed and installed in conjunction with the Cambridge/Alewife Brook Sewer Separation Project. Controls at four other locations, along the Charles River, are being designed and installed by Cambridge independent of any large project. At these locations, Cambridge discovered structural problems with the existing outfalls, which have increased the scope of its work and delayed installation of floatables control.

Design work on floatables control is approximately 80% complete, and Cambridge expects to complete construction at all locations by June 2005, considerably later than expected a year ago because of further delay in resuming design and construction work for Alewife Brook CSO control and because of competing wastewater improvement projects throughout the city. Floatables controls at outfalls along the Alewife Brook are part of the revised Alewife Brook CSO control plan and Notice of Project Change. MWRA and Cambridge plan to resume design work at these locations only after final MEPA approval of the revised Alewife plan is issued. However, in October, Cambridge commenced construction of floatables control at outfall CAM401 as part of a Cambridge storm drainage contract titled "Bellis Circle Improvements."

The final CSO plan called for the control of floatable materials in the CSO discharges at outfall SOM001A (Tannery Brook outfall) by installing an in-line net.

This project, like Cambridge Floatables Control, is ectly associated with the Alewife Brook Sewer Separation project. The revised Alewife plan in part calls for enlarging the local system connection to the MWRA interceptor at SOM001A. As part of the larger plan, MWRA and the City of Cambridge plan to commence final design, and then construction, after MEPA approval of the revised plan. In the meantime, the City of Somerville maintains a boom as an interim floatables control measure at this outfall.

MWRA will continue to comply with the conditions of the Charles River Variance, including conducting water quality sampling at the Cottage Farm CSO Facility. MWRA will continue to collect receiving water quality data, as well, under its long-term harbor monitoring program. MWRA plans to submit the final report evaluating additional storage at Cottage Farm by July 1, and expects that DEP will make a determination on the appropriate water quality standard and level of CSO control for the Charles River in October, when the variance term ends. If this is the case, MWRA will report, no later than four months following that determination, on whether the CSO facilities recommended in MWRA’s long-term plan comply with then-existing water quality standards, as required by Schedule Six (milestone at July 1998).

DEP is expected to make a decision soon on the proposed 18-month extension of the variance term. MWRA plans to continue its related stormwater monitoring and sampling program this spring and fall and collect receiving water quality data, as well.

The first construction contract (pipeline rehabilitation) related to the East Boston Branch Sewer Relief project and the construction contracts related to the Union Park Detention/Treatment Facility will be advertised in 2002. Construction of a temporary playground to replace an existing playground during construction of the Union Park facility is scheduled to commence this fall. MWRA plans to award a contract for design of the Fort Point Channel and BOS019 Storage Conduits in July. In addition, MWRA will continue its efforts related to start-up and optimization of the five upgraded CSO facilities, to ensure optimized treatment performance and compliance with NPDES permit limits. These efforts will be dependent upon rainfall conditions and facility activations.

MWRA will continue to administer the provisions of the MOUs and Financial Assistance Agreements with BWSC and Cambridge and otherwise work with the communities on the CSO projects that the communities are responsible for implementing. MWRA expects that BWSC will make significant progress towards completing the South Dorchester Bay and Stony Brook Sewer Separation projects and that both communities will make progress in implementing floatables controls.

MWRA plans to complete its water quality sampling program by June, weather permitting, and other Phase I work by September. Phase II activities will then commence. MWRA’s revised schedule for the reassessment calls for the Supplemental Environmental Impact Report to be completed by early 2003. Through the year, MWRA will continue its public participation program and coordination with EPA and DEP.

MWRA and the City of Cambridge will continue to work with regulatory agencies and the public to support the preparation of a document that responds to the public comments on the April 2001 Notice of Project Change. MWRA expects to submit the Response to Comments document to MEPA by September, for public review and MEPA certification. MWRA and Cambridge also plan to coordinate the project plan with the Metropolitan District Commission’s Alewife Reservation master planning efforts, in part to support drafting Article 97 legislation for proposed construction within the Reservation.

MWRA plans to seek regulatory and Court approval of its proposal to remove the requirements to close outfall MWR010 and construct floatables controls for outfalls MWR018, 019 and 020 from the Facilities Plan and the court schedule. MWRA will continue to monitor the effectiveness of system optimization measures it has implemented, including monitoring flow elevations in the BMC to assess the feasibility of raising weirs at the outfalls.

In compliance with its NPDES permit, MWRA plans to submit its report on CSO discharge estimates for storms in 2001 to EPA and DEP soon. MWRA will continue to conduct monitoring and modeling activities to estimate CSO discharges during 2002.