Irvine Lake Pipeline Chlorination Facility - Executive Summary |
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RISK MANAGEMENT PLAN - INITIAL DISINFECTION FACILITY, DYER ROAD WELLFIELDS EXECUTIVE SUMMARY Irvine Ranch Water District (IRWD) has established a risk management plan according to EPA's regulations (40 CFR Part 68) to enhance already existing safety and emergency response programs. IRWD is extremely cautious in the handling of all chemicals and is very diligent about safety for its employees and its communities. IRWD staff is highly trained and utilizes modern equipment to monitor its facilities to provide safeguards, while effectively employing these useful chemicals. These chemicals play an important role in water treatment and water reclamation, enabling everyone to lead healthier lives. Accidental Release Prevention and Emergency Response Policies IRWD has an emergency response plan in effect to handle potential emergency situations at this facility. This plan was designed to meet the following objectives: 1.) To save lives. 2.) To minimize and avoid injuries. 3.) To protect the environment. 4.) To minimize property damage. Key elements of the Emergency Response Plan include: - A detailed Emergency Response Action Guide - Key phone numbers and contact points for the IRWD Emergency Response Team - Incident Command System (ICS) w/Unified Command interface - ICS position descriptions w/responsibilities - Vicinity and evacuation maps - Detailed task-by-task plans for: - Evacuation - Fire in a Process or Non-Process Area - Injuries - Threats/Civil Disorder - Wildland or Adjacent Property Fire - External Events (e.g., seismic) - Potential Imminent Danger to Personnel - Chemical Spill (e.g., caustic, aqueous ammonia) - Chlorine Release - Off-Site Event Involving a Hazardous Material IRWD maintains a safety committee whose members are the designated emergency coordinators for the facility. IRWD has 26 employees that are specialists, trained and fully equipped to handle hazardous spill containment and cle anup. These employees train monthly and run drills twice a year. The Emergency Response Plan provides the response organization and notification procedures, evacuation routes, chlorine health hazards, and mitigation procedures, which will be implemented to respond effectively to emergency situations that may arise at the facility. This Plan is reviewed and updated at least once per year. This Plan has been reviewed and updated to ensure compliance with the PSM, RMP, and CalARP regulations Stationary Source and Regulated Substance The chlorine system at Irvine Ranch Water District's Irvine Lake Pipeline Facility (ILP) is used for the treatment of raw water from Irvine Lake. This is an unmanned facility. An operator visits the site at least once per week. If maintenance on the chlorine is required, two operators/maintenance personnel are present. Typically, chlorine is not stored at the facility during winter months. Chlorine is stored in one-ton containers (3) within a fenced area when the system is on-line during the summer months. Chlorine gas leaving the three one ton containers passes through a pressure regulator and vacuum regulator to the chlorinator. Still under vacuum from the chlorinator, it is drawn to an injector and mixed with water from the lake. The chlorine solution is delivered to various locations. Three ton containers are connected to a common header that feed into the chlorine system. Chlorine gas is drawn from the one-ton containers through a pressure regulator and a vacuum regulator to the chlorinator. Still under vacuum from the chlorinator, it is drawn to an injector and mixed with water from the lake. Tanks are replaced in groups of three. A crane on an Irvine Ranch Water District service truck is used to transfer containers to and from the site. Each container is positioned so that the valves are vertically aligned. A vacuum is created when process water is pumped through the injector. This flow generates a vacuum (approx imately 1-3 in. Hg) which opens the vacuum regulator. Upon loss of vacuum in the line, a diaphragm in the vacuum regulator will close, stopping any chlorine from escaping. Any chlorine in the piping upon loss of vacuum will be drawn through the chlorinator and into solution. The maximum quantity of chlorine that can be stored on site is 6,000 pounds - 3 one ton containers. Hazard Assessment Summary Worst Case Release Result Summary Scenario Description: Release of the maximum quantity of chlorine that can be stored in the largest vessel - 2,000 pounds in 10 minutes. The container is located outside; therefore, passive mitigation measures were not incorporated in the release rate calculations. The most pessimistic meteorological conditions were used as specified in the regulation. The reference table included in EPA's RMP Guidance for Wastewater Treatment Plants was used to determine the maximum downwind distance to 3 ppm. The result shows that offsite areas may be affected. A lternative Release Result Summary Scenario Description: A release of chlorine gas from 1/4-inch diameter leak until the container is empty (2,000 pounds). The release rate is based on the pressure within the three ton containers, hole or puncture area in the pipe, tank temperature, and a gas factor, which incorporates a discharge coefficient, ratio of specific heats, molecular weight, and conversion factors. The containers are located outside. This scenario was proposed to last for one hour. This is based on the fact that there is a chlorine detector near the containers that would alert the dam keeper who would contact the emergency response team who is trained to repair leaks and/or install a B-kit which will contain a release at the cylinder valve. The meteorological conditions specified in the regulation for alternative scenarios were used. The reference table included in EPA's RMP Guidance for Wastewater Treatment Plants was used to determine the maximum downwind distance to 3 ppm. The downwind distance for this scenario is significantly less than that for the worst case scenario. However, in this case also offsite areas may be affected. Accidental Release Prevention Program and Chemical-Specific Prevention Steps IRWD has a Process Safety Management program in place to manage the handling of chlorine. In addition, common industry standards, policies, and procedures are utilized to ensure safe practices are being performed. This includes common practices outlined by the Chlorine Institute. In addition to the Management Programs, there is a chlorine leak detector situated near the chlorine container. In the event of a chlorine leak that reaches a concentration of 1ppm, a yellow alarm light is illuminated. A resident dam keeper for the Irvine Lake checks the site daily when chlorine is brought on-line. The dam keeper will notify IRWD if the alarm light is activated. Five Year Accident History There have been no reportable releases of chlorine at the facility during the five year perios of June 1994 through June 1999. Planned Changes to Improve Safety Several studies have been conducted recently to examine mitigation measures to improve safety at the Irvine Ranch Water District Initial Disinfection Facility. These studies include the following: Process Hazard Analysis, Seismic Assessment, Hazard Assessment, and PSM Compliance Audit. The recommendations from these studies will be completed by January 30, 2000. Some of the recommendations are listed below. 1. Change the system from a pressurized system to a vacuum system before the containers are brought on-line by installing a vacuum regulator to each ton container. 2. Install a horn that is connected to the chlorine sensor in addition to the beacon to alert the dam keeper. Investigate the feasibility of having telemetry installed in order to monitor the site. 3. If the frequency of usage is anticipated to increase substantially, consider the feasibility of building a secondary containment around the ton containers. 4. Provide a sign that reads "Chlorine" outside of the main gate. 5. Reinstall the wind sock so that responders would know the plume direction in the case of a release. 6. Ensure that the PreStart-up Safety Review form is used prior to placing chlorine on-line. 7. Include in the training program a requirement to document each training and have both supervisor and trainee sign completion forms. 8. Consider using an outside agency to train operators. 9. Post arrow signs on piping to indicate the flow of chlorine. |