CSO CONTROL IN SPRINGFIELD, MASSACHUSETTS BALANCING COST, AFFORDABILITY AND WATER QUALITY

Springfield is located in southwestern Massachusetts, where the Connecticut River forms the city's western border. The city is also bordered on the north by the Chicopee River, which is tributary to the Connecticut. The Mill River is a smaller tributary to the Connecticut which runs through the city. Springfield's 25 permitted combined sewer overflows (CSOs), along with other sources of wet weather pollution, contribute to violations of water quality standards on these three rivers.Just upstream of Springfield, CSOs in the communities of Holyoke and Chicopee contribute additional loads of wet weather pollution to the Connecticut. Stormwater and non-point sources contribute wet-weather pollution along the entire length of river upstream of Springfield, and complicate the assessment of benefits associated with control of the city's CSOs.For each of the three receiving waters impacted by CSOs, a range of technologies that achieved different levels of CSO control was evaluated. Costs for CSO controls ranged from 144 million for alternatives to reduce untreated discharges to approximately 12 events per year, to 525 million for complete sewer separation. Given the multiple sources of wet weather pollution tributary to the Connecticut, concerns were raised that the water quality benefit associated with controlling the city's CSOs would not be commensurate with the cost. The results of an affordability analysis, conducted in accordance with EPA guidelines, showed that any of the CSO control alternatives identified would result in substantial and widespread social and economic harm.In light of the results of the affordability analysis, the Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (DEP) recognized that a comprehensive CSO plan to achieve compliance with state and federal CSO control policies would not be affordable. Nonetheless, EPA and DEP directed that a plan be developed to achieve policy compliance. This comprehensive plan would serve as a guide to assure that affordable CSO controls, which would be implemented over time, would be focused on the proper long-term CSO control plan. It was also agreed that a regional receiving water quality model should be developed to assess the benefits of CSO controls in the context of other sources of wet weather pollution. While the preferred plan for policy compliance is not affordable, and there are outstanding issues related to water quality benefits, a plan has been put forth to implement certain CSO control projects to achieve immediate environmental benefits.