COOS BAY NORTH BEND WATER BOARD - Executive Summary |
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RISK MANAGEMENT PLAN Executive Summary The Water Board uses chlorine gas for water disinfection. This Risk Management Plan has been developed to identify and document the hazards associated with the storage, handling, and possible release of toxic chlorine gas. The Water Board receives delivery of approximately 10 1-ton chlorine cylinders every four to five months, and as many as 13 1-ton containers may be stored within the Pony Creek Treatment Plant at any one time. The EPA threshold quantity for gaseous chlorine applicable to the RMP regulations is 2,500 lbs. The PCTP exceeds this threshold quantity. There have been no accidental releases from a Water Board chorine process within the past five years that resulted in deaths, injuries, or significant property damage on-site; or known off-site deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage. Off-site consequences analysis was performed for a single worst case chlorine release scenario and a single alternative chlorine release scenario. The area impacted by such releases is shown on Figures 1 and 2 herein. For the worst case scenario, a chlorine toxic endpoint concentration of 3 ppm chlorine may develop within a 2.63 mile radius of the PCTP. Public receptors within the impacted area include schools, residences, a hospital, medical centers, public recreational areas including parks, pools, and sports fields, and major commercial, office, and industrial areas buildings. The affected population for the worst case scenario is estimated at 21,000. For the alternative release scenario, a chlorine toxic endpoint concentration of 3 ppm chlorine may develop within 0.60 mile radius of the PCTP. Public receptors within the impacted area include residences, a hospital, medical centers, and some commercial and office buildings. The affected population for the alternative release scenario is estimated at 900. The prevention program includes the chapter on proce ss hazard analysis for the treatment plant chlorination system from the Water Board's safety manual as well as a supplementary process hazard analysis developed for this RMP. In addition, a training policy for outside contractors and Water Board employees other than treatment plant operators is included, as well as a 1-ton chlorine cylinder change procedure. All required prevention program elements are addressed in this section. The Coos Bay - North Bend Water Board has coordinated with the City of Coos Bay Fire Department for response to a chlorine release at the PCTP. The fire department will respond as the Fire and Rescue Hazmat Team. The primary document describing the response procedures for a chlorine release incident as well as any Water Board hazardous material incident is the Coos Bay - North Bend Water Board Hazardous Materials Annex. Also, the Water Board's specific response to a chlorine release is described. |