Update on MWRA s Fort Point Channel CSO Project

Transcription

1 Massachusetts Water Resources Authority Update on MWRA s Fort Point Channel CSO Project Frederick A. Laskey Executive Director August 6, 2003

2 The Boston Harbor Project: An Environmental Success Story In 2002, the 15-year, $3.8 billion Boston Harbor Project was completed About 380 million gallons of wastewater is treated at the new Deer Island Treatment plant every day Treated wastewater is discharged 9.5 miles out into the deeper waters of Massachusetts Bay Sludge is transported to Quincy where it is recycled into fertilizer 2

3 The Harbor Is Recovering Water quality in Boston Harbor has improved dramatically Sewage solids discharged from Deer Island have been reduced by 85% Toxic pollutants have been reduced by 90% Water is twice as clear 3

4 Solids And Metals Discharges Have Been Reduced 4

5 Dramatic Improvements In Bacterial Water Quality (Before Secondary Treatment and South System transfer) Elevated bacteria around outfalls, rivers, Inner Harbor, shoreline (Before New Outfall) Most of Harbor well within swimming criteria, most remaining problems in rivers Average Enterococcus counts in Boston Harbor 5

6 What Is A CSO? Some older sewer systems, like Boston's, have "combined" sewers that carry both stormwater and sewage flows together During heavy rains, when flows sometimes double and even triple, these systems become overloaded CSOs are designed to act as relief points by discharging excess flows upstream of sewage treatment plants, into the nearest body of water preventing sewage backups into homes and onto area streets 6

7 How CSOs Work: Dry Weather Headworks To Deer Island CSO Outfall 7

8 How CSOs Work: During Heavy Rains Headworks To Deer Island 8

9 How Sewer Separation Works 9

10 MWRA s CSO Communities Boston, Cambridge, Chelsea and Somerville have combined sewer systems that connect to MWRA's sewer system Boston Harbor, the Charles, the Mystic and the Neponset Rivers are subject to overflows of combined stormwater and sewage during heavy rains 10

11 The CSO Problem In 1985, the service area had: 84 combined sewer outfalls Thousands of overflows per year Over 3 billion gallons of CSO discharges 11

12 CSO Project Status Project Completed In Construction In Design Reassessment Neponset River Sewer Separation Constitution Beach Sewer Separation Somerville Baffle Manhole Separation CAM 005 Hydraulic Relief BOS 017 Hydraulic Relief Chelsea Trunk Sewer Relief Chelsea Branch Sewer Relief CHE 008 Outfall Repair Cottage Farm CSO Facility Upgrade Prison Point CSO Facility Upgrade Somerville Marginal CSO Facility Upgrade Commercial Point CSO Facility Upgrade Fox Point CSO Facility Upgrade MWRA Floatables /Outfall Closings South Dorchester Sewer Separation Stony Brook Sewer Separation Cambridge/Alewife Sewer Separation Community Floatables Control East Boston Branch Sewer - Contract 1 Union Park Treatment Facility Charlestown Storage Conduit Fort Point Channel Sewer Separation North Dorchester Bay CSO Conduit Reserved Channel CSO Conduit Reserved Channel CSO Facility Cambridge/Alewife Sewer Separation East Boston Branch Sewer 12

13 Annual CSO Volume Has Been Reduced Dramatically Annual CSO volumes have already been reduced by 2 billion gallons By 2008, 95% of the remaining CSO flows will be treated Billions of Gallons Untreated Treated 13

14 CSO Project Costs $1,000 $900 $879.9M $800 $700 Risk of cost increases - $261.1M $618.8M Millions $600 $500 Court-approved plan $440.7M $400 $370.8M $300 $200 $100 $0 Conceptual Plan (Dec 1994) Facilities Plan/EIR (Aug 1997) Current Estimated Cost (Aug 2002) Current Estimate with Risks (Aug 2002) Does not include overall system improvements (Deer Island, etc.) 14

15 Status Of CSO Control Nation-Wide 772 CSO communities 32% have submitted documentation on Nine Minimum Controls MWRA 19% have approved long-term control plans MWRA 17% have initiated implementation of long-term control plans or other CSO facility plans MWRA 15

16 The Charles River: A National Model For CSO Control The MWRA has already achieved significant reduction of CSO related impacts to the Charles River: Sewer separation and hydraulic relief projects have dramatically reduced combined sewer overflows Much more flow is sent to MWRA s new Deer Island Treatment Plant Upgrades to Cottage Farm and Prison Point facilities have improved disinfection 16

17 Water Quality Improvements At Charles River CSO-related impacts to the Charles River have been reduced: EPA rated Charles River B for 2002 Up from D in 1995 Report Card D 1996 C C 1998 B B 2000 B 2001 B 2002 B Thursday, May 2, 2002 Love that cleaner water: Charles River OK for Swimming by Jules Crittendon The federal Environmental Protection Agency is giving the Charles River a B grade in a report card due to be released today, indicating that it is acceptable for swimming and boating most of the year. 17

18 Water Quality Improvements At Charles River MWRA has greatly reduced CSO discharges to river Boston and Cambridge sewer separation projects have increased natural stormwater flows to river Municipalities have implement Best Management Practices to improve stormwater quality Charles River water quality continues to improve 18

19 The Fort Point Channel The Fort Point Channel in the Inner Harbor is a narrow, artificial embayment with granite walls Historically, the heavily industrialized Channel has been subjected to pollution from a number of sources, both CSO and non-cso 19

20 The Fort Point Channel The Fort Point Channel is undergoing a dramatic transformation into the city's next great parkland 20

21 Tributary Areas To The Fort Point Channel 21

22 Union Park CSO Facility The new, $40 million Union Park CSO Facility will detain and treat wet weather flows from the South End It features 2.2 million gallons of underground storage, screening, disinfection and dechlorination facilities 22

23 Union Park CSO Facility Flows from the existing Union Park Pump Station account for 88% of all untreated CSO discharges to the Fort Point Channel This project will eliminate 20 out of 26 discharges will be eliminated by the increased detention capacity 100% of the remaining flows will be treated by screening, disinfection and dechlorination 23

24 MWRA CSO Projects For Fort Point Channel At $43 million, these projects represent the largest public improvement investment for the Fort Point Channel Union Park Treatment Facility 24

25 MWRA s 1997 Plan For Outfalls BOS027 And BOS073 BOS072 and BOS073 account for 2% of CSO discharges to the Fort Point Channel MWRA s 1997 Plan for the Fort Point Channel recommended a 10-foot diameter, 1,500-foot long conduit along A Street in South Boston The 1997 Plan would capture and store CSO flows from outfalls BOS072 and BOS073 for all but the two largest storms in a typical year The 1997 would have reduced CSO flows by 80% at a cost of $13 million 25

26 Fort Point Channel Reassessment In July 2002, preliminary design began for the Fort Point Channel storage conduit and baseline flow conditions were updated The analysis showed improved system performance and a potential for changes in system flows due to planned development Given the large reduction in the combined sewer area tributary to outfalls BOS072 and BOS073, sewer separation was reexamined 1997 Conditions 2003 Conditions 144 acres tributary 55 acres tributary 7 million gallons/year CSO 3 million gallons/year CSO 15 overflows/year 9 overflows/year 26

27 Reassessment Findings The Reassessment found that sewer separation in the BOS073 tributary area and optimization at the BOS072 outfall will Meet the 1997 goals for the project Result in greater CSO elimination - 87% - than the 1997 Plan at a cost of $3 million Result in a slight increase - 2.5% - in stormwater volume 27

28 Annual CSO Flows From Outfalls BOS027 And BOS073 Sewer separation will result in less CSO volume to the Fort Point Channel than expected under the 1997 Plan The Revised Plan increases CSO reductions from 80% to 87% Annual CSO Volumes (Million Gallons) Plan Revised Plan Before After 28

29 CSOs VS. Stormwater CSOs are far more concentrated pollutants than stormwater 18 x Stormwater Untreated CSOs vs. Stormwater Fecal Coliform Counts Counts 10(9)/100 ml 600, , , , , ,000 - Untreated CSOs Stormwater 29

30 Major Water Quality Improvements In Fort Point Channel: Fecal Coliform Bacteria Fecal Coliform Bacteria Total loadings to Fort Point Channel reduced by 77% Loadings decreases from CSOs outweigh slight stormwaterrelated increases 217 to 1 counts x 10(9) 3,500,000 3,000,000 2,500,000 2,000,000 1,500,000 1,000, ,000 - Fecal Coliform Loadings to Fort Point Channel Before and After MWRA Projects CSOs Stormwater Total 30

31 Summary The Revised Plan is better than the original 1997 Plan More pollutants removal No additional permanent wastewater facilities adjacent to the Fort Point Channel Less cost with better results 31