The Eastside Utility District (EUD) had a chlorine feed system for disinfection of their 32 mgs water treatment plant that used gaseous chlorine stored under pressure in one-ton cylinders. This type of system, though common in the water and wastewater treatment industries and subject to well-defined safety procedures and protocols, involves handling an inherently dangerous chemical that can be released into the environment suddenly and with catastrophic results. A recent trend has been to convert from this type of system to safer alternatives involving the use of sodium hypochlorite solutions.
WK Dickson developed a preliminary engineering report to establish the required feed rates for sodium hypochlorite, as well as the associated storage requirements. The report also developed the layout of storage tanks and pumping systems to supply the disinfectant to the treatment process at several locations. Following approval of the PER, a new sodium hypochlorite storage and feed system were installed at the existing facility, with the new sodium hypochlorite storage tanks being located within the existing containment area. The sodium hypochlorite storage consists of two new fiberglass reinforced plastic (FRP) bulk storage tanks for receipt and storage of bulk sodium hypochlorite.