SMD-1 Wastewater Treatment Plant - Executive Summary |
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Placer County Dept. of Facilities Services has instituted a Risk Management Program for their wastewater treatment facility, SMD-1 Wastewater Treatment Plant, as required by Federal Accidental Release Prevention (ARP) Program regulations at 40 CFR Part 68. The Risk Management Program identifies the equipment, procedures, maintenance, inspection, and training associated with Regulated Substances (RS's) handled at this facility in excess of Federal threshold quantities; describes the structured assessment of hazards which was conducted to assess possible effects on employees and offsite public and environmental receptors; provides the results of an offsite consequences analysis; defines a prevention program, emergency response program, and mitigation measures to reduce the probability and magnitude of accidental releases of RS's; and establishes a schedule and responsibilities for implementation of mitigation measures and auditing of program elements. This Risk Management Plan (RMP) is being filed as required by ARP regulations in order to report the elements of the current Risk Management Program and to describe further measures planned to mitigate or prevent accidental releases of RS's. STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED Placer County Dept. of Facilities Services operates numerous wastewater collection systems and two wastewater treatment plants in Placer County. Its wastewater treatment facility, SMD-1 Wastewater Treatment Plant, is located at 11755 Joeger Rd., Auburn, CA in Placer County, and uses chlorine and sulfur dioxide, for disinfection and dechlorination in quantities greater than the Federal threshold quantity for these RS's. The facility is located in a suburban area in the Sierra foothills. There are 9 full-time employees at this site. Chlorine and sulfur dioxide are received in ton containers by truck, handled with an electric hoist, and stored outdoors under a sun shade on rails. The chlorine is used for odor control of the in fluent wastewater, to disinfect the wastewater effluent, and for other process uses. The sulfur dioxide is used to dechlorinate the disinfected effluent for aquatic toxicity control. Pressurized gas within a ton container is reduced to vacuum at a vacuum regulator valve mounted directly onto the ton container's gas valve. From there, the gas under vacuum is metered through rate valves and rotameters in chlorinators or sulfonators located in a separate room, and drawn into water solution by the passage of pressurized water through an injector. ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES It is the policy of Placer County Dept. of Facilities Services that the receipt, storage and handling of chlorine and sulfur dioxide at its facility be done in a manner which meets regulatory requirements and minimizes the probability and severity of releases of chlorine or sulfur dioxide to the atmosphere, in order to protect the health and safety of its workers, the public, and the environment. In order to accomplish this goal, Placer County Dept. of Facilities Services has gathered safety information on chlorine and sulfur dioxide and on the process, equipment and procedures involving chlorine and sulfur dioxide; performed a structured assessment of hazards of the process and external events which might affect the process; performed an offsite consequences analysis of defined release scenarios; established a written program for prevention and mitigation of releases; and established a written emergency response program coordinated with emergency response agencies. WORST CASE RELEASE SCENARIO A single "worst case" release scenario is required to be considered for each stationary source, resulting in the maximum distance to an endpoint for all toxic RS's contained on site above the threshold quantity. The worst case release scenario for toxic chemicals is defined in the ARP regulations as the release of the contents of the largest single container of RS (in this case chlorine) over a period of 10 minutes. The scenario considered the release of the contents of the largest container of chlorine on site, in this case 2,000 lb. This release scenario is not physically possible, due to the characteristics of chlorine. ALTERNATIVE CASE RELEASE SCENARIO An "alternative case" release scenario is required to be considered for each toxic RS handled in quantities greater than the threshold quantity at the site. The "alternative case" scenario is described in the ARP regulations as a likely release resulting in offsite effects, considering administrative controls and mitigation measures in place, and is to be determined by the facility operators as part of the Process Hazard Analysis required to be performed during RMP development. The "alternative cases" considered for this facility are the release of liquid chlorine or sulfur dioxide from a pinhole in one of the fusible plugs on a ton container stored outdoors, due to a supplier error or damage in transit, with the release secured by application of a Type "B" Ton Container Repair Kit fixture after 2 hours. ADMINISTRATIVE CONTROLS Administrative controls in effect at Placer County Dept. of Facilities Services which were considered to mitigate the severity of the Worst Case and Alternative Case release scenarios include Placer County Dept. of Facilities Services's written policies and procedures for training of operators and maintenance personnel, written procedures for control of the inventory of chlorine and sulfur dioxide at the facility, and policies regarding quality level of replacement materials and components for the chlorine and sulfur dioxide system. MITIGATION MEASURES No mitigation measures were considered to limit the severity of the Worst Case scenario. No passive mitigation measures were considered to limit the severity of the Alternative Case scenarios. Active mitigation was considered for the Alternative Cases, in the form of the timely response of proper ly trained and equipped responders. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAMS General accidental release prevention programs instituted by Placer County Dept. of Facilities Services are categorized as administrative (management) programs; procedures, training, and engineering controls; and emergency response programs. Placer County Dept. of Facilities Services has instituted a Process Safety Management (PSM) Program meeting OSHA requirements at 29 CFR 1910.119 covering its disinfection and dechlorination process. This constitutes the general accidental release prevention program for Placer County Dept. of Facilities Services's operations. The program and document mangement procedures included in the PSM Program will be used as the management system for the Risk Management Program. CHEMICAL-SPECIFIC RELEASE PREVENTION STEPS Release prevention steps specific to chlorine and sulfur dioxide have been identified and implemented. These include, among other things, installing sun s hades and seismic hold-downs for containers stored outdoors, and creation of numerous facility-specific operation procedures with check boxes for completion of critical steps. FIVE YEAR ACCIDENT HISTORY There have been no accidents involving chlorine or sulfur dioxide at this facility within the past five years resulting in injuries or offsite consequences. EMERGENCY RESPONSE PROGRAM Placer County Dept. of Facilities Services's Emergency Response Program applicable to chlorine and sulfur dioxide has been coordinated with Placer County Environmental Health Department, the local agency responsible for hazardous materials inventory reporting and release response coordination. It consists of notification of the public agency assigned responsibility for First Response to hazardous materials release emergencies and evacuation of persons on site to designated areas up wind of the released gas. First Responders have participated with Placer County Dept. of Facilities Services personnel i n response drills. PLANNED CHANGES TO IMPROVE SAFETY Placer County Dept. of Facilities Services plans to change the treatment chemicals at the SMD-1 Wastewater Treatment Plant to aqueous solution forms, and to eliminate chlorine and sulfur dioxide, at the time of the next plant expansion due to occur within the next two years or so. All of the improvements and mitigation measures identified in the process hazard analysis which Placer County Dept. of Facilities Services committed to accomplish have been completed or are in progress. Any other measures identified by employees during workplace hazard surveys, or as a result of audit activities, will be thoroughly reviewed and considered for implementation in the interim period prior to decommissioning the chlorine and sulfur dioxide facilities. |