Composting started in Southbridge in 1985 during the plant upgrade. Odor problems and citizen concerns were evident within 6 months of startup. The Town took a proactive approach to form an odor committee and to implement odor control process adjustments (different combinations of wood chips, rubber chips and sawdust). The odor persisted until the implementation of a wood ash product into the process. Once the wood ash/sawdust/bio-solids "recipe" was fully in use the odor diminished and successful odor control was achieved and continues today.
Effluent copper concentrations became an issue when the NPDES permit was re-issued in 1988. Strict copper limits were included in permits throughout the state and were almost impossible to meet. The Town again took a proactive approach and began experimenting with chemical addition in an effort to reduce copper levels to meet the permit. Success was achieved using a chemical called poly-aluminum chloride (PAC). The PAC was introduced into the influent stream of the facility that caused copper to be removed in the primary clarifiers. This reduced the loading on the secondary process and lower the effluent copper concentrations to within permit limits.
On January 28, 1998 the facility was awarded the EPA Region 1 award for Operation and Maintenance Excellence. The Superintendent of the Southbridge Wastewater Treatment Facility, Paul Krasnecky, received the award at the EPA awards ceremony in Boston