Groundwater Extraction, Treatment and Discharge System (GWETS) Installation

NAVFAC Mid-Atlantic, Site 6A Fenceline GWETS, NWIRP Calverton, NY

KGS constructed the GWETS and building using in-house construction management, S&H, engineering, and QC staff.  KGS managed construction of the 25’ x 35’ x 14’ GWETS building and installation of the GWETS components including extraction well pumps, air stripper skid including blower and transfer pumps, chemical feed pump, and corresponding Facility Control Panel.  The system was designed to pump at a maximum rate of 120-140 gallons per minute depending on extraction well recharging capacity and seasonal levels of rainfall.

Throughout the construction phase, approximately 42 inches of rain were recorded (via Hurricane Sandy and subsequent storms) which caused a higher water table than anticipated in the design and technical specifications. Wet site conditions and the higher than anticipated groundwater table necessitated additional excavation around the building footprint to remove unsuitable soils (materials) which were replaced with structural fill. Modifications allowed the concrete foundation and footers to be constructed in accordance with the design drawings and the building elevation remained as depicted on the contract drawings.