Stormwater Outfall Inspection, Sampling, Evaluation & Recommendation
The Environmental Protection Agency (EPA) issued a letter to the City of Revere requesting information pursuant to Section 308 of the Clean Water Act (“308 Letter”). The letter requested response to a variety of questions regarding the sewer and drainage systems owned by Revere. One requirement of the request was for the city to locate, inspect, and sample all known city-owned stormwater outfalls. Through competitive selection, Revere retained the services of Weston & Sampson in July 2006 to assist with the outfall inspection and sampling.
Weston & Sampson attempted to locate each of the 65 outfalls and completed dry-weather inspection and sampling. Wet-weather inspection and sampling of outfalls was also completed. Inspections included locating each outfall, recording pipe diameter and material, photographing, and collecting Global Positioning System (GPS) coordinates. The inspection also included observation of whether the outfalls were discharging any flow during the dry-weather inspection and, if so, documentation of observed quantity and visual characteristics of the flow. For each outfall observed to have dry-weather flow, samples were collected and analyzed in accordance with EPA-approved methods (40 CFR 136). As required by the 308 Letters, samples were analyzed for fecal coliform, Escherichia coliform (E-coli), surfactants, and ammonia-nitrogen.
Weston & Sampson prepared a report on the inspection and sampling program and recommended a plan and schedule to investigate the cause, location, and remediation of identified discharges of bacteria or other pollutants. Weston & Sampson also assisted the City of Revere with preparation of the required response letters to the EPA and continues to assist with prioritization/investigation/remediation efforts resulting from the stormwater inspection and sampling.
Although not required by the 308 Letters, Weston & Sampson also included tasks in this project to improve the city’s existing drainage mapping. Weston & Sampson collected GPS coordinates for each of the outfalls located and GPS coordinates were provided to the city in digital format for incorporation into its future Geographic Information System (GIS).
Weston & Sampson also assisted the City of Revere with preparation of the required response letters to the EPA and continues to assist with prioritization/investigation/remediation efforts resulting from the stormwater inspection and sampling.