Sanford M. Anderson Water Treatment Plant - Executive Summary
1.0 EXECUTIVE SMMARY |
This document is the Risk Management Plan for storage and use of chlorine at the City of Inglewood Sanford M. Anderson water treatment facility (City of Inglewood water treatment plant) in Inglewood, California. Under the U.S. Environmental Protection Agency (EPA) Risk Management Program (RMP) regulations (FR 61 , p.31668) issued on June 20, 1996, the City of Inglewood is required to develop a formal Risk Management Program (RMProgram) and to Register and submit a Risk Management Plan (RMPlan), based on quantities of stored chlorine above the threshold levels.
Accidental Release Prevention and Emergency Response Policies
The City of Inglewood staff has a high degree of commitment to public safety and service. The City's water treatment plant personnel has taken a number of steps to prevent accidents within its premises; to properly train its employees; and to take an active roll in developing various accidental release prevention and emergency response prog
rams to minimize accidents at its facility. Management promotes a proactive attitude toward a safety environment with its employees and enforces health and safety regulations to its optimum. The City of Inglewood staff completed a review and updated key aspects of its existing risk management program to assess and improve safety conditions within critical areas of its premises.
City of Inglewood Water Treatment Plant Processes and Regulated Substances
The City of Inglewood water treatment plant treats approximately 7.4 million gallons per day (MGD) of ground water from three production wells located at the West Coast Basin of Los Angeles County. The City of Inglewood supplies potable water to approximately 95,000 residents through 15,000 connections. The City uses chlorine as a disinfecting agent for water treatment. Water chlorination is a standard technique that is widely practiced throughout the United States.
Chlorine is stored and dispensed from one-ton chlorine containers at
the water treatment facility. All chlorine at the water facility is stored and dispensed from U.S. Department of Transportation (DOT) specified containers that are specifically designed and maintained to provide a high degree of reliability and safety in storing and dispensing chlorine.
Worst-case Release and Alternate Release Scenarios
As part of a Hazard Assessment conducted in our water treatment process at our subject facility, the City conducted an off-site consequence analysis using the EPA RMP Offsite Consequence Analysis Guidance. The purpose of this off-site consequence analysis was to identify the worst-case and alternate scenarios in case of a release of a regulated substance such as chlorine. It also defined the areas of potential off-site impacts to the environment in case such potential incidents would occur.
The City identified a release of 2,000 pounds of chlorine gas as the worst-case scenario with a release rate of 200 lb./min of gas and a duration of 10 minutes.
Based on EPA's guidance tables, this corresponds to distance to endpoint of 2.6 miles, and an estimated residential population of 21,000 within distance to endpoint.
The City identified a release of 634 pounds of chlorine gas as the alternate scenario with a release rate of 23.4 lb./min of gas with a duration of 27 minutes. The distance to endpoint was estimated to be 0.72 mile with a residential population of 6,100 within distance to endpoint.
These data do not, in fact, consider the benefits of passive mitigation features the water treatment plant has in its premises such as the storage of the above quantities of chlorine contained in a building. In addition, the newly installed chlorine detection system will prevent any chlorine release from reaching its worse-case or its alternate scenario. Although no scientific analysis was conducted on the impact of these passive mitigation features, it is estimated that the quantities obtained in both worse-case and alternate scenarios abo
ve are greatly reduced by a factor of 2.
The General Accidental Release Prevention Program and Prevention Steps
Under the threshold limits of regulated substances contained in the Occupational Safety and Health Administration (OSHA) regulations in Part 1910.119 of Volume 40 of the Code of Federal Regulations (CFR (40 CFR 68), the City of Inglewood is subject to comply with the Process Safety Management (PSM) requirements. This rule was reviewed, adopted, and incorporated into the treatment plant policies and safety requirements. The City currently complies with all PMS rule requirements.
Five-year Accident History
There has been no accidental releases of chlorine within the water treatment plant premises for the last five years.
Emergency Response Program
The City's Emergency Response Program includes an emergency response plan that will be implemented in case of an accidental release of chlorine. The emergency response plan includes sending a two-man team during business hour
s and one man after hours to respond to any chlorine alarms and investigate minor releases of chlorine.
Anything beyond any minor releases or beyond simple maintenance activities will involve calling to and a response from Los Angeles County HAZMAT Unit
Water treatment operators are trained in the Emergency Response Plan procedures and in the evacuation routes to take in case of an emergency.
Planned Changes to Improve Safety
Among the upcoming changes within the treatment plant there is a proposal to evaluate the reduction of chlorine stored within the premises, or the evaluation to switch to a disinfectant method to reduce the hazard category at the treatment facility to exempt levels.