Brunswick-Glynn County Joint Water and Sewer Commission (BGJWSC) implemented a sanitary sewer flow monitoring project in an effort to address the excessive stormwater inflow and groundwater infiltration (I/I) levels experienced during and after significant rainfall events.
McKim & Creed conducted wastewater collection system flow metering, rainfall monitoring and groundwater gauging to identify I&I sources in the Dunbar Creek Water Reclamation Facility (WRF) service area. The Dunbar Creek WRF serves St. Simons Island and includes approximately 950,000 linear feet of gravity sewer. The WRF had an average dry weather flow equal to approximately 3.2 mgd and a discharge limit of 4 mgd. During significant rainfall periods, the WRF experienced flow rates greater than 5 mgd.
This project involved deployment of 44 open channel flow meters, six rainfall gauges, and 12 groundwater gauges throughout the island. The equipment remained in place for 90 days. After completion of the flow monitoring effort, our team prepared a Technical Memorandum that identified the results of the I/I analysis and provided recommendations for completing both stormwater inflow source and groundwater infiltration source investigations.