Public Nofication

 

City of Chelsea Combined Sewer Overflows

 

The United States Environmental Protection Agency (USEPA) issued National Pollutant Discharge Elimination System (NPDES) Permit #MA101877 to the city of Chelsea, MA on April 11, 2003. According to the terms of the permit it then became effective on June 11, 2003. This permit is in effect for a period of five years. In accordance with this permit, the requirements of the Clean Water Act and the requirements of the Massachusetts Clean Water Act, the city of Chelsea is authorized to discharge from four Combined Sewer Overflows (CSO). The four CSOs and the respective receiving waters are:

 

             CHE002           Located on Broadway and discharges to Boston Inner Harbor

             CHE003           Located on Winnisimmet Street and discharges to Chelsea River

             CHE004           Located on Pearl Street and discharges to Chelsea River

             CHE008           Located on Eastern Avenue and discharges to Chelsea River

 

Each location is indicated by a sign. The signs are easily visible from the street.

 

Dry weather discharges are never allowed. If a dry weather discharge were to occur, the city of Chelsea is obligated to report the incident to the USEPA and the Massachusetts Department of Environmental Protection (MADEP). The CHE-003 & CHE-008 outfalls also have separate storm drains connected them. Storm Water Flows can be seen occurring at both these outfalls when they are not acting as Combined Sewer Overflows.

CSO CHE-002 is located at the southerly end of Broadway by the Chelsea Yacht Club. This CSO was completely rebuilt by P. Gioioso & Sons under contract to the MWRA as part of the Chelsea Trunk Relief Sewer Project in the year 2000.

The new conduit replaced one of the oldest pipes in the City. The old pipe was a wooden box culvert.

CSO CHE-003 is located at the southerly end of Winnisimmet Street under the piers of the shipyard.  This CSO was completely rebuilt by  P. Gioioso & Sons under contract to the MWRA as part of the Chelsea Trunk Relief Sewer Project in the year 2000.

CSO CHE-004 is located at the southerly end of Pearl Street under the McArdle Bridge. Works was performed on the regulator structure of this CSO as part of the Chelsea Trunk Relief Sewer Project in the year 2000.

CSO CHE-008 is located on the Chelsea River on the water side of the Gulf Bulk Oil Storage Terminal on Eastern Avenue. The regulator structure for this CSO was rebuilt and the outfall pipe relined by Modern Continental under contract to the MWRA as part of the Chelsea Branch Sewer Rehabilitation and Relief Project in the year 2000.

Approximately seventy percent of the city of Chelsea’s sewer system is a combined system. In a combined system both stormwater and wastewater are carried in the same conduit. During dry weather periods wastewater is conveyed through the city of Chelsea’s sewer system to the Massachusetts Water Resources Authority (MWRA) system and then to Deer Island for treatment. During periods of heavy rain, dependent on the intensity of the rain and the tide elevation, the combined flow of stormwater and heavily diluted wastewater is permitted to and may overflow at the above locations. By discharge overflows through the CSOs, backups of flows into area homes and businesses are prevented.

The City of Chelsea is in the process of separating Combined Sewers into Separated Storm and Sanitary Sewers throughout the City. In as much as 75% of the City of Chelsea is comprised of combined sewers, this process will take many years and a substantial amount of capital investment. The results of separation will result in both cleaner waterways and a reduced cost for the transportation and treatment of sewer flows from the City of Chelsea.