Client: Virginia Department of Transportation (VDOT)

ATCS provided engineering services to VDOT, to review, evaluate, and determine implementable improvements to obtain stormwater management (SWM) compliance for Pond 17C at the Gainesville Interchange project in Prince William County. Pond 17C was originally designed as an Enhanced Extended Detention facility. It was found not to be functioning as intended causing the overall project’s ability to close out its VPDES Construction General Permit coverage.  At that point, ATCS was consulted to develop an alternative improvement to retrofit Pond17C to an Extended Detention Facility and purchase remaining nutrient credits. This alternative allowed VDOT to minimize construction costs and minimize long-term maintenance costs while expeditiously obtaining VADEQ water quality and quantity compliance and close-out of the project.