Lemoore Wastewater Treatment Plant - Executive Summary
1. Accidental Release Prevention and Emergency Response Policies
The City of Lemoore uses chlorine gas stored at the North Well Field, Well Location #10, and Well Location #8 and 9 chlorination facilities, for the purpose of treating the ground water pumped to the City of Lemoore's water distribution system to be used by the City's water users. The City of Lemoore also uses chlorine gas at its Wastewater Treatment Plant (LWWTP) as a disinfectant to lower the total and fecal coliform counts to within the requirements of the State of California. This report discusses the LWWTP chlorination facility and also the chlorination facility for Well Location #8 and 9 since it is also located on the LWWTP property.
The chlorine stored at the two chlorination facilities on the LWWTP property is liquified gas under pressure, therefore it is considered a hazardous material and is a regulated substance under the California Accidental Release Program (CalARP). The Kings County Health Department'
s Division of Environmental Health Services recognized the LWWTP facility as a Stationary Source under the CalARP regulations and requested this Risk Management Plan (RMP). The City of Lemoore's policy is to adhere to all applicable Federal and State of California rules and regulations. Safety depends upon proper construction design and safety features of the facility, accurate operating and emergency procedures, and effective training of personnel.
2. Stationary Source and Regulated Substances
Each of the chlorination facilities that serve Well Location #8 and 9, and the one that serves the LWWTP are housed in a separate steel-frame/concrete-slab shed located about 100 meters apart on the contiguous LWWTP property near the southwest corner of Cinnamon Drive and Liberty Drive in Lemoore, California. These chlorination facilities are considered to be a single Stationary Source with one regulated substance and two regulated processes. Each regulated process includes the chlorine g
as storage, the chlorinator, and the chlorine well-water injector. When chlorine gas is dissolved in water, it is no longer a regulated substance under the CalARP regulations.
For Well Location #8 and 9, chlorine is used to help resolve hydrogen sulfide which is a problem or issue with the localized ground water. The water is pumped from the underground aquifers through the well into the well header line and past the chlorinator intake or suction line. Water is pulled from the well header line by a chlorine booster pump which pumps water through a chlorine injector that creates a vacuum that pulls chlorine gas from a one-ton storage cylinder. There are two one-ton cylinders stored at the Well Location #8 and 9 chlorination facility; both of the one-ton cylinders are connected to the chlorinator.
For the LWWTP chlorination facility, chlorine is used as a disinfectant to lower the total and fecal coliform counts to within the regulatory requirements. The process consists of chlori
ne gas being drawn from a one-ton cylinder by vacuum and injected into the wastewater flow with a submersible pump. There are four one-ton chylinders at the LWWTP chlorination facility; two of the one-ton cylinders are connected to the chlorinator and two chylinders are kept in reserve.
3a. Worst Case Release Scenario
The Worst Case release scenario for interconnected equipment must consider the largest quantity of a regulated substance handled on site in a single vessel at any time, taking into account administrative controls on the vessel's contents and usage as per the CCR Title 19 Division 2 Chapter 4.5 Article 2 Section 2750.3(b).
One of the 2,000-lb chlorine cylinders is considered the largest vessel in the chlorine feed system. The one-ton cylinder is, at most, filled with 2,000 lb of liquid chlorine which is 67% of the cylinder's capacity. The Worst Case release scenario for a chlorine cylinder is the release of the entire capacity at a rate of 200 lbs per minute for a t
en minute duration.
The distance to the endpoint of 3 ppm (0.0087 mg/L) is 3 miles. This release would extend over a large area beyond the boundaries of the stationary source.
3b. Alternative Release Scenario
The Alternative Release scenario for the one-ton cylinder is complete failure and separation of a quarter-inch fuse plug in the end of the cylinder. All 2,000 lbs of chlorine is assumed to flash to vapor.
The distance to the endpoint of 3 ppm (0.0087 mg/L) is 0.6 miles and would be beyond the boundaries of the stationary source.
3c. Administrative Controls
Administrative controls to limit the distances for each reported scenario exist to restrict, to a minimum, the amount of chlorine lost from a one-ton cylinder if an accidental release were to occur; and preferably to not have a release occur. These administrative controls are inherent in the operational procedures for the chlorine unloading process system and the training provided to the operators. Administrative co
ntrols are also in place for the ammonia unloading system.
3d. Mitigation Measures
Mitigation measures to limit the distances for each reported scenario exist to restrict the amount of chlorine releases to a minimum, if a release were to occur; and preferably to not have a release occur. The mitigation measures are based on the design, inspection, testing, and maintenance of the chlorine unloading process system and their related equipment and components. Mitigation measures are also in effect for the ammonia unloading system.
4. General Accidental Release Prevention Program and Chemical Specific Prevention Steps
The facility complies with all applicable Federal and State codes and regulations. There are safety meetings and safety training. The Process Safety Management (PSM) program implemented at the facility for the chlorine and the ammonia unloading systems and the related activities and equipment respresent the facility's main active commitments to an accidental release
5. Five-Year Accident History
There have been no accidental releases of chlorine in the last five years.
6. Emergency Response Program
The Emergency Response Program is based upon the alerting of personnel at the facility to evacuate or shelter-in-place and await the arrival of responders from the City of Lemoore Fire Department at the assembly location if a release occurs that causes the evacuation or the shelter-in-place to be initiated.
7. Planned Changes to Improve Safety
Current applicable codes and regulations are reviewed as part of the Process Hazard Analysis element of the Process Safety Management (PSM) program to determine if commitments need to be made to achieve increased operational safety for the regulated chlorine process. These commitments address prevention and mitigation measures for accidental releases of the regulated substances. The completion schedules for these commitments are included in the PSM.