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 are served by a cesspool. 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, permittng, and bid and contract administration for construction of an I/A wastewater treatment plant (WWTP) to provide required wastewater treatment for the resort. Our services began with a review of available documents and records followed by preliminary discussions with MassDEP regulators. The second phase was a hydrogeologic evaluation to determine soil characteristics, groundwater flow direction and rate, and potential impacts to downgradient receptors, followed by the preparation of an engineering report. The third phase was the preparation of WWTP design plans. The fourth phase was filing of a GWDP application with MassDEP. The final phase will be providing construction phase services, including bidding assistance, construction layout, and construction contract administration.