By JOYCE ROWLEY/ecoRI News contributor
NEW BEDORD, Mass. — Starting this week, two of the city’s 27 combined sewer overflow (CSO) outfalls will be removed as part of the $8.2 million Coggeshall Street sewer project. The project will replace collapsed sewer pipes under the street and separate connections between city sewer lines and stormwater drains, reducing the flow of raw sewage into the Acushnet River by about 31 million gallons annually, according to local officials.
This area, known as Inner New Bedford Harbor, flows to Buzzards Bay, a major embayment that stretches from Falmouth to Westport. According to computer stormwater modeling prepared by consultants Camp, Dresser, McKee and Smith (CDM Smith), because of heavier than normal rainfall events in 2014, the total volume of raw sewage emptying into the harbor and bay last year was estimated at 328 million gallons.
More than 20 years after the Environmental Protection Agency (EPA) established the elimination of CSOs as a national priority, many urban sewer systems still have dozens of outfalls that dump untreated sewage into the nation’s waterbodies when it rains. In fact, about 770 communities in the United States have combined sewer systems, serving about 40 million people, according to the EPA.
Like a tree with intertwined branches, CSO tributaries follow old stream beds and old street networks and may even have new tie-ins. Remnants of the earliest sewer systems, CSOs form an underground labyrinth that can cause worse problems if not removed in the right order, said David Turin, EPA’s Region 1 wastewater technical unit enforcement coordinator for southeastern Massachusetts and Rhode Island.
In the past two decades, New Bedford has spent about $250 million on its wastewater system, including building a new wastewater treatment plant, and eliminating 14 CSO outfalls, according to Michele Paul, the city’s environmental stewardship director. After the Coggeshall Street project is completed, the remaining 25 CSOs will continue to contribute about 175 million gallons of sewage annually, he said.
Turin said the city is developing a long-term CSO control plan. But just taking out outfalls could cause sewer backups during rainfall events, he said.
One of the Coggeshall Street CSOs slated for elimination is an ancient 72-inch brick arch outlet that discharges directly into the Acushnet River. At 30.5 million gallons of annual discharge, it’s the city’s second-largest CSO outfall.
The CSOs are authorized discharges under the city’s National Pollutant Discharge Elimination System (NPDES) permit granted in 2008 by the EPA. The permit expired in 2013, and the new permit is likely to be completed this fall.
“The CSOs do not meet the goals of the Clean Water Act long term,” Turin said.
There also are illegal “dry-weather” outfalls found on inspections, but Turin couldn’t elaborate on their location. Common sources of dry-weather discharges in urban areas include apartments and homes, car washes, restaurants, airports, landfills and gas stations, accoridng to the EPA.
During the last NPDES permit review, the Buzzards Bay Coalition (BBC) asked the EPA to target CSOs when granting the city’s permit. Based on 15 years of Baywatchers data, the BBC wrote requesting that the new permit “establish an aggressive CSO reduction timeline.”
The coalition noted that the 2006 CSO Baseline Conditions Report didn’t call for any improvements after 2011, and sought the closure of 13 inner harbor CSOs that discharge into the Acushnet River.
But even as the NPDES permit was being granted, the main discharge from the wastewater treatment plant at Fort Rodman didn’t meet federal Clean Water Act standards. By 2011, the plant had been out of compliance since 2008 for violations of the Clean Water Act on nitrogen and total suspended solids, among other violations, according to the EPA. The wastewater treatment plant discharges directly into Buzzards Bay.
As part of a 2012 enforcement odrer, the city was required to prepare a long-term CSO control plan, as well as more immediate CSO control and monitoring plans. The city also had to begin reporting unauthorized sewage spills.
“New Bedford is far from unique for having unauthorized discharges or having an enforcement order,” Turin said.
During the NPDES process, the city stated that the cost of abating all CSOs was prohibitive. Since then, the state has prioritized New Bedford’s sewer system in its State Revolving Fund (SRF).
Since 2010, New Bedford has received $152 million from the SRF to eliminate CSO connections. Another $5 million in planning funds helped identify CSO discharges and prioritize remediation, and $19.3 million in American Recovery and Reinvestment Act of 2009 (ARRA) funds were used to install an Interceptor PCB Grit Eliminator, which increased the capacity and velocity of the north-south sewer main through the city, allowing it to handle greater flows during storm events and indirectly reducing overflow discharges.
New Bedford’s problems with sewage control date back to the mid-1800s, when the city established a sewage system. Like most urban areas at the time, privy pits were replaced with pipes to the nearest streams. The streams were then piped to carry the raw sewage to the nearest large waterbody.
Here, that meant everything went into the Acushnet River, New Bedford Harbor and Buzzards Bay. In 1870 Edward Haskell sued the city for the accumulation of sewage at the end of his dock that restricted boat access. Thirty-plus years later, in 1904, the harbor had further deteriorated. After hundreds of people contracted typhoid fever from eating contaminated shellfish, the State Board of Health closed the Acushnet River to shellfishing.
Fast forward another 50 years, and the first primary treatment plant was built on Fort Tabor at the south end of the city. State of the art for its time, the 1952 sewage treatment plant removed the solids from wastewater prior to discharge into Buzzards Bay.
In 1987, the city was sued again, this time under the 1972 Clean Water Act, by the state, for failing to upgrade to meet new standards. The current wastewater treatment plant, built in 1996, now provides secondary treatment of waste by chlorination.