Projects

In 2015, the Town of Yarmouth Massachusetts expressed an interest in better understanding the costs associated with the then-upcoming Municipal Separate Storm Sewer System (MS4) permit in relation to work already completed under the 2003 MS4 permit. In response, CEI completed a comprehensive program review with accompanying recommendations in order to fully meet the requirements of the upcoming MS4 permit. CEI also completed budget estimates looking out over a 10-year period to allow the town to adequately budget for program implementation. 

Since the permit became effective in 2018, CEI has worked with Yarmouth to complete all permit requirements required to date, including preparation of a Notice of Intent (NOI), a written Stormwater Management Program (SWMP) Plan, an Illicit Discharge Detection and Elimination (IDDE) Plan including prioritization of areas for illicit discharge investigations, and an Operation and Maintenance (O&M) Plan. CEI also completed a review of existing bylaws and regulations to recommend changes to comply with the requirements of the 2016 MS4 Permit. CEI has also conducted extensive field work to evaluate outfalls for potential illicit discharges during dry weather flows and inspect town-owned stormwater Best Management Practices (BMPs) such as infiltration and detention basins. All work is documented in an Annual Report for submittal to the U.S. EPA.

CEI and the Town have also partnered on a number of grants through the Massachusetts Office of Coastal Zone Management (CZM) to prioritize areas for structural stormwater BMPs to improve downstream water quality. The first grant targeted waterbodies listed as impaired for total nitrogen and bacteria, and CEI first conducted a desktop analysis of Town-owned roadway areas using GIS software to evaluate nitrogen and bacteria pollution sources for all known outfall catchment areas. CEI then prioritized based on the location of outfalls, such that outfalls contributing directly to a waterbody rank highest, while outfalls discharging to a tributary or disconnected area rank lower. Once the prioritization was completed, CEI developed 3 conceptual designs capable of being implemented at multiple locations. 

Since that time, CEI has designed and constructed several additional subsurface gravel wetlands to improve downstream water quality in received waterbodies.