Water Treatment Plant - Executive Summary |
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RISK MANAGEMENT PLAN FOR CHLORINE HANDLING AT THE WATER TREATMENT PLANT BROKEN ARROW, OKLAHOMA IN COMPLIANCE WITH 40 CFR 68 JUNE 1999 CITY OF BROKEN ARROW PUBLIC WORKS DEPARTMENT EXECUTIVE SUMMARY a. The City of Broken Arrow Public Works Department accidental release prevention policy involves a unified approach that integrates technologies, procedures, and management practices. All applicable procedures of the U.S. Environmental Protection Agency (EPA) Prevention Program are adhered to. The City of Broken Arrow Public Works Department emergency response policy involves the preparation of response plans which are tailored to each facility and to the emergency response services available in the community, and is in compliance with t he EPA Emergency Response Program requirements. b. The Water Treatment Plant has been installed to treat the flow of potable drinking water in the City of Broken Arrow. This water serves the City of Broken Arrow. The chlorination station is located on Kenosha Street in Wagoner County. The station includes a chlorination room, which contains liquid chlorine containers, a chlorinator, and various safety equipment, and an instrument room, which contains a flow recorder, various electrical panels, and additional safety equipment. The amount of chlorine handled is two one-ton containers. The facility is normally manned during regular working hours, with employees living on site and an on call system is available. Water treatment operators work in the facility daily and respond to any trouble area which may occur. c. The offsite consequence analysis includes consideration of two chlorine release scenarios, identified as "worst cas e release" and "alternative scenario". The first scenario is defined by EPA, which states that "the owner or operator shall assume that the "maximum quantity in the largest vessel" is released as a gas over 10 minutes, due to an unspecified failure. The alternative scenario is defined as "more likely to occur than the worst-case release scenario". Atmospheric dispersion modeling has to be performed to determine the distance traveled by the chlorine released before its concentration decreases to the "toxic endpoint" selected by EPA of 3 ppm which is the Emergency Response Planning Guideline Level 2 (ERPG-2). This is defined by the American Industrial Hygiene Association (AIHA) as the "maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing irreversible or other serious health effects or symptoms which could impair an indivi dual's ability to take protective action." The residential population within a circle with a radius corresponding to the toxic endpoint distance, as to be defined, "to estimate the population potentially affected". Actuation of the chorine detector is an active mitigation measure considered. An additional active mitigation system isthe building which acts as a n enclosure, with the chlorine cylinder located in the basement of the facility. d. The general D accidental release prevention program is based on the following key elements: High level of training of the operators Preventive maintenance program Use of state-of-the-art process and safety equipment Use of accurate and effective operating procedures, written with the participation of the operators and owners Performance of a hazard review of equipment and procedures e. Implementation of an audi ting and inspection program. Chemical-specific prevention steps include availability of self-contained breathing apparatus (SCBA), worn by the operators during connection/disconnection of chlorine supply, awareness of the hazardous and toxic properties of chlorine, and presence of chlorine detectors. No accidental releases of chlorine have occurred at this facility in the past five years. f. The facility has an emergency response program, which has been coordinated by the City of Broken Arrow Fire Department. Emergency response drills and drill evaluations are conducted along with emergency operation and response procedures. |