The Old Chatham Road RV Resort is a 50-acre seasonal vacation recreational vehicle resort that was established in 1963 in Dennis, MA. There are 56 mobile homes and 258 RV sites on the property. Each of the sites is served by a cesspool or a Title 5 sewage disposal system. As a property that predates 1995 and has a design sewage flow greater than 15,000 gallons per day, Old Chatham RV Resort falls under the jurisdiction of the MassDEP Groundwater Discharge Permit (GWDP) program. Coastal Engineering assisted with design, permitting, and bid and contract administration for construction of a wastewater treatment plant (WWTP) to provide required wastewater treatment for the resort. Our services began with a preliminary discussions with MassDEP regulators and evaluation of wastewater treatment system options. The second phase was a hydrogeologic evaluation to determine soil characteristics, groundwater flow direction and rate, and potential impacts to downgradient receptors. The third phase was the preparation of WWTP design plans and preparation of an engineering report. The fourth phase was filing of a GWDP application with MassDEP. The final phase is providing construction contract administration services.