Wastewater Department

Report a problem

If you have an emergency related to the sewer collection system, or if you need to report a problem with the sewer infrastructure, you may call 508-764-4927 at any time. Simply tell the operator the nature of your emergency and the appropriate party will be notified.

Questions regarding billing & consumption

If you have questions regarding payments or need to set up a payment plan, you should contact the Town Collector at 508-764-5410.

If you have questions regarding regarding consumption amounts or need to file an abatement of water or sewer charges, you should contact the Town Assessor at 508-764-5404.


The Southbridge Sewer Collection System consists of about 48 miles of gravity sewer mains and 11 pump stations with associated force mains. Sewage is conveyed to the  Wastewater Treatment Plant on Dresser Hill Road, where it is treated and discharged to the Quinebaug River.

The Wastewater Treatment Plant (WWTP) is permitted to treat 3.77 million gallons per day (MGD), with an average daily flow of 2.5 MGD. Due to inflow and infiltration of stormwater and groundwater into the collection system, flows can peak at over 10 MGD during storm events. 

The plant utilizes a number of treatment processes to produce a finish effluent suitable for discharge into the Quinebaug River. These processes are described schematically in this Southbridge WWTP Process Flow Diagram (PDF).

A portion of the effluent is re-filtered and pumped to Millennium Power Plant in Charlton for cooling purposes. Any water not lost to evaporation is returned to the WWTP and treated along with the rest of the incoming effluent.

Residual organic solids resulting from the wastewater treatment process are mixed with a composting amendment (such as ground wooden pallets), and composted in static aerated piles.  The resulting compost is approved for unrestricted beneficial use and is available for free to residents of Southbridge, for pickup during normal business hours.

The Wastewater Department administers an Industrial Pretreatment Program which involves sampling and analysis of wastewater discharges from certain industrial users. This allows us to place limits on wastewater components which may cause treatment challenges or lead to permit exceedances, and to enforce those limits.