The SRVSA discovered a significant sanitary sewer overflow (SSO) within the conveyance system, resulting in the closure of a public park. Kleinfelder is designing, permitting, and managing construction of a Sanitary Sewer Overflow treatment facility to solve this significant public health problem.
During extreme wet-weather conditions when the SRVSA’s interceptor reaches its conveyance capacity, raw wastewater is escaping from Somerville’s sewer trunk onto a baseball field in a municipal park. In addition to ponding on the field, sewage flows are contaminating local waterways. Kleinfelder overcame significant technical and regulatory challenges, including determining when untreated discharges occur, designing an intermittent treatment system, and obtaining a NPDES permit for this wet-weather facility.
Phase I (Planning) is complete; Phase II (Design) is 90% complete, and will be followed by Phase III (Construction). Phase I included an alternatives analysis, whereby Kleinfelder worked with state regulators to permit a high-flow treatment facility. It also involved a wasteload allocation study with monitoring and modeling to ensure water quality criteria are satisfied, as well as hydraulic modeling of the sewer and interceptor systems using the Environmental Protection Agency’s Storm Water Management Model (SWMM).
Kleinfelder obtained regulatory approval for its Quality Assurance Project Plan in less than two weeks. Seven storms were sampled, yielding considerable information that Kleinfelder used to develop models of the sewer system and surface waters. Phase I culminated with regulatory approval of Kleinfelder’s Alternatives Analysis—paving the way for design and construction of a SSO treatment facility.