Water Pollutional Control Plant - Executive Summary
FEDERAL MANDATED RMP SUBMISSION
1. Accidental Release Prevention and Emergency Response Policies
The West County Wastewater District's Water Pollution Control (WCWD-WPCP) stores and uses chlorine which is considered a hazardous material and is a regulated substance under the California Accidnetal Release Program (CalARP). This Risk Management Plan (RMP) is a requirement of the CalARP. The properties of chlorine make it necessary to observe safety precautions to prevent human exposure and to reduce the threat to the facility's workers and nearby members of the community. It is the facility's policy to adhere to all applicable Federal and State of California rules and regulations. Safety depends upon the chlorine operating procedures, the construction design and safety features of the facility, and the training of the personnel.
2. Stationary Source and Regulated Substances Handled
This treatment plant has a wet weather desig
n flow of 21.5 million gallons per day (MGD) for wastewater from domestic and industrial sources with average dry weather flow of 7.8 MGD. The plant treatment process consists of screening, grit removal, flow equalization, primary sedimentation, high-rate trickling filter, activated sludge, secondary clarification, and chlorination. Treated effluent is conveyed via a force main to a junction structure at the City of Richmond treatment facility. Sludge is anaerobically digested, dried in open lagoons, and disposed of by landfill burial at an authorized disposal site. Disinfection of the wastewater with chlorine is performed prior to discharge to protect public health.
The WCWD-WPCP uses one ton (2000 lb.) containers of chlorine and stores a maximum of 14 full containers at any one time. Four containers may be connected online at any one time and the remaining ten containers are stored under a canopy outside the chlorine room. Chlorine usage is approximately ten tons per month, an
d deliveries of one ton containers are made in batches of ten about once a month.
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).
The one ton container of chlorine is the largest vessel in the chlorine feed system. The one ton container is, at most, filled with 2,000 lb of liquid chlorine which is 67% of tank capacity. The Worst Case release scenario for the one ton container of chlorine is the release of the 2,000 lb of chlorine at the rate of 200 lb/minute for 10 minutes.
The distance to the endpoint of 3 ppm for the Worst Case scenario for the chlorine one ton container is 0.9 miles. This release will extend beyond the boundaries of the stationary source.
3b. Alternative R
The Alternative Release scenario for the one ton container is complete failure and separation of a quarter-inch fuse plug insert in the bottom area of the one ton container. All 2000 lbs of chlorine is assumed to flash to vapor.
The distance to the end point of 3 ppm for the Alternative Release scenario for the chlorine one ton container is 0.2 miles. This release will extend just 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 container if an accidental release were to occur; and preferably to not have a release occur. This administrative control is inherent in the operational procedures for the chlorine process system and the training provided to the operators.
3d. Mitigation Measures
Mitigation measures to limit the distances for each reported scenario exists to retrict the amount of
chlorine released to a minimum, if a release were to occur; and preferably to not have a release occur. The mitigation measures are based upon the design, inspection, testing, and maintenance of the chlorine process systems and their related equipment and components.
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 process system and the related activities and equipment represents the facility's main active commitments to an accidental release prevention program.
5. Five Year Accident History
There has been no accidental release of chlorine in the last five years.
6. Emergency Response Program
The Emergancy Response Program is based upon the alerting of personnel at the facility to evacuate the facility and await the arriv
al of responders from the City of Richmond Fire Department at the evacuation assembly location if a release occurs that causes the evacuation to be initiated.
7. Planned Changes to Improve Safety
There were commitments made under the Risk Management Planning and Prevention (RMPP) program and also the Process Hazard Analysis element of the Process Safety Management (PSM) program that were scheduled to be implemented by December 1995. Current applicable codes and regulations are reviewed as part of the PSM to determine if other commitments need to be made to achieve increased operational safety for the regulated chlorine process systems. These commitments will be prevention and mitigation measures for accidental releases of the regulated substance.