D&B has been working with several water suppliers on Long Island to address water quality issues from drinking water supply wells. Groundwater aquifers in Nassau and Suffolk Counties provide the sole source of water to these suppliers. The water drawn from these aquifers often must be treated to meet the stringent standards of the New York State Department of Health. D&B is currently engaged in the design and construction of several water supply and treatment facilities throughout Nassau County.
The facilities currently under design and construction include new wells, volatile organic contaminant (VOC) removal, iron and manganese removal, nitrate removal and chemical handling. VOC treatment systems include both packed tower aeration as well as granular activated carbon (GAC) filtration systems. Filtration systems for iron removal include provisions for recycling backwash waste and for dewatering iron sludge. Ion exchange is being used for nitrate removal. Sodium hydroxide (caustic soda) or lime slurry is used for pH adjustment to control corrosion in the distribution system. Liquid sodium hypochlorite or dry tablet calcium hypochlorite is used for disinfection. D&B provides all aspects of design, permitting, bidding assistance and construction services for these groundwater supply and treatment facilities.