The first public system report of sanitary sewers and sewage treatment for the Town of Southbridge was completed on February 21, 1898. The system has been expanded as the growth of the Town progresses and new State and Federal regulations are implemented to protect the Quinebaug River.
The original plant has been upgraded several times to add additional treatment units for increased pollutant removal to include, increased BOD & TSS removal, nitrification, phosphorus removal, effluent dechlorination and a covered composting building to treat 100% of the bio-solids generated at the treatment facility. Also, in 1985 the Town was required to institute an EPA, approved Industrial Pretreatment Program for all industrial users. This program has been successful in keeping the finished compost generated at the facility in the category of Type I, suitable for beneficial use.