In order to comply with a New York State Department of Environmental Conservation (NYSDEC) directive to reduce concentrations of metals discharged into the Peconic River from Brookhaven National Laboratory’s (BNL) Sewage Treatment Plant (STP), the laboratory decided to upgrade the STP by adding a tertiary treatment component and re-directing the plant effluent away from the Peconic River to groundwater recharge beds.  Unique challenges to the project included the careful siting of the proposed groundwater beds so as not significantly alter the groundwater flow regime beneath the site.  Altering of the flow regime could influence the pathways of several groundwater contaminant plumes that are currently being remedied under CERCLA.  Further, the proposed groundwater recharge beds were required to be located close to the existing STP infrastructure, but not so close to the adjacent Peconic River that treated effluent would contribute base flow the river bed.  PWGC worked closely with BNL and their groundwater modeling support team to identify a location for the groundwater recharge beds that would not negatively impact the local groundwater flow regime and Peconic River base flow.

In addition to the design of the groundwater recharge beds, PWGC prepared detailed plans and specifications for the addition of a tertiary treatment system which included two drum filters and drum filter building.