Miramar Water Treatment Plant - Executive Summary |
|
EXECUTIVE SUMMARY The Miramar Water Treatment Plant was built in the early 1960's and treats water for the northern portion of the City of San Diego. The Miramar Water Treatment Plant has a maximum water treatment capacity of 140 million gallons per day, with a future capitol improvement project goal of expanding capacity. The Miramar Water Treatment Plant is located on the south shore of Miramar Reservoir in the north-central portion of the of the City of San Diego, just east of Interstate 15. The Plant is located on relatively flat terrain, but there is elevated terrain immediately to the east. Miramar Reservoir lies immediately north of the Plant, with additional elevated terrain across the Reservoir. Residential areas lie mainly to the south and east, while the area to the west is mainly industrial. Historically, the Miramar Water Treatment Plant has used liquid chlorine to treat and disinfect water from the Miramar Reservoir and the San Diego County Water Authority as the t wo main sources, making it suitable for use in the City of San Diego's drinking water distribution system. The one-ton pressurized liquid cylinders are received at the loading dock of the Chlorine Room. The Miramar Water Treatment Plant has a well trained and committed operations and maintenance staff with a record of nearly 30-years of using chlorine safely. To support the efforts of continued safe handling and use of chlorine at the Miramar Water Treatment Plant, senior management has committed to the development of a comprehensive Process Safety Management Program under the guidelines of State and Federal mandates which has involved complete engineering reviews of the chlorine feed system and design certification. As with the use of any hazardous chemicals, the use of chlorine in this treatment process poses the potential for an accidental release that could have offsite consequences. It is for this reason that several years ago, under the provisions of the recently pr omulgated Risk Management Program Rule (40 CFR 68), the Miramar Water Treatment Plant conducted an assessment of offsite consequences of accident scenarios involving the uncontrolled release of chlorine to the surrounding environment. Under the provisions of the rule, the treatment process used at the Miramar Water Treatment Plant is considered a "Program 3" process, and as such we conducted an analysis (a) a "worst-case" release scenario and (b) one or more alternative release scenarios. The analysis of offsite consequences produced information incorporated into the Risk Management Plan (RMP) which covers population and environmental receptors in the environs within the affected areas. Several technological upgrades were made to enhance our emergency response capabilities if a chlorine leak were to occur: 1) Chlorine leak detection sensors were added from the chlorine cylinder storage room throughout the feed system which activates an alarm in the plant when low-levels of chlorine are detected, 2) A computerized program called "Wonderware" allows the Duty Plant Operator to see immediately from the Operations Control Room what part of the chlorine feed system is alarming without leaving the control room, 3) An automatic chlorine shut-off system was installed to minimize a chlorine release by securing the chlorine at the cylinder, 4) Several safe-work-practices for the operations and maintenance sections have been developed in conjunction with other safety programs to insure employees work and respond safely. The Miramar Water Treatment Plant, in conjunction with the Water Department Emergency Management Coordinator, have developed and tested a Chlorine Emergency Response Plan. The Emergency Response Plan was developed to support the Water Plant Operator in the event a chlorine release occurs and additional resources are needed to mitigate the situation. The San Diego Fire Department, Hazardous Materials Incident Response Team is dedicated to respond to our wat er plants if we have an incident. The Miramar Water Treatment Plant has a Business Plan that identifies evacuation points on the site and provides additional emergency information about chlorine and additional contacts if needed. The Miramar Water Treatment Plant has had no significant accidental releases of chlorine within the last five years requiring offsite evacuation or producing offsite consequences. The Miramar Water Treatment Plant is currently going through the final design phase for upgrading its treatment processes. One of the most significant additions will be a new Chlorine Facility with complete containment and scrubbers. Additionally, upgraded security systems will be added to all access points to allow the duty operator to monitor the complete facility with ease. |