WF1 Calvine Meadows WTP - Executive Summary
Sacramento County Water Quality Department has instituted a Risk Management Program for the Calvine Meadows Water Treatment Plant (WF1), as required by Federal Accidental Release Prevention (ARP) Program regulations at 40 CFR Part 68. The Risk Management Program identifies the equipment, procedures, maintenance, inspection, and training associated with Regulated Substances (RS's) handled at this facility in excess of Federal threshold quantities; describes the structured assessment of hazards which was conducted to assess possible effects on employees and offsite public and environmental receptors; provides the results of an offsite consequences analysis; defines a prevention program, emergency response program, and mitigation measures to reduce the probability and magnitude of accidental releases of RS's; and establishes a schedule and responsibilities for implementation of mitigation measures and auditing of program elements. This Risk Management Plan (RMP) is being filed as requir |
ed by ARP regulations in order to report the elements of the current Risk Management Program and to describe further measures planned to mitigate or prevent accidental releases of RS's. The RMP is being filed concurrently with the local Administering Agency, Sacramento County Environmental Management Department, Hazardous Materials Division, as required by California regulations.
STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED
Sacramento County WQD will operate and maintain a new water treatment plant designated WF1, Calvine Meadows, located at 10140 Calvine Rd. in Elk Grove, CA in Sacramento County, and uses chlorine, an RS, for treatment of well water in quantities greater than the Federal threshold quantity for this RS. There are no full-time employees at this site. Operators visit the site on a regular basis and also respond to alarm conditions.
Chlorine is received in ton containers by truck, handled with an electric hoist, and stored strapped to trunnions inside the bui
lding. The chlorine is used for oxidation of iron and manganese in well water prior to filtration, and to maintain a disinfectant residual in the distribution system. Pressurized chlorine gas within a ton container is reduced to vacuum by tank-mounted vacuum regulator valves, metered through manually-adjusted rotameters, and drawn into water solution by the passage of pressurized water through an injector.
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES
It is the policy of Sacramento County WQD that the receipt, storage and handling of chlorine at its facilities be done in a manner which meets regulatory requirements and minimizes the probability and severity of accidental releases of chlorine to the atmosphere, in order to protect the health and safety of its workers, the public, and the environment. In order to accomplish this goal, Sacramento County WQD has gathered safety information on chlorine and on the process, equipment and procedures involving chlorine; pe
rformed a structured assessment of hazards of the process and external events which might affect the process; performed an offsite consequences analysis of defined release scenarios; established a written program for prevention and mitigation of accidental releases; and established a written emergency response program coordinated with emergency response agencies.
WORST CASE RELEASE SCENARIO
A single "worst case" release scenario is required to be considered for each stationary source, resulting in the maximum distance to an endpoint for all toxic RS's contained on site above the threshold quantity.
The worst case release scenario for toxic chemicals is defined in the ARP regulations as the release of the contents of the largest single container of RS (in this case chlorine) over a period of 10 minutes. The scenario considered the release of the contents of the largest container of chlorine on site, in this case 2000 lb. This release scenario is not physically possible, due to the ch
aracteristics of chlorine.
ALTERNATIVE CASE RELEASE SCENARIO
An "alternative case" release scenario is required to be considered for each toxic RS handled in quantities greater than the threshold quantity at the site.
The "alternative case" scenario is described in the ARP regulations as a likely release resulting in offsite effects, considering administrative controls and mitigation measures in place, and is to be determined by the facility operators as part of the Process Hazard Analysis required to be performed during RMP development. The "alternative case" considered for this facility is the release of chlorine from a pinhole leak in a fusible plug of a ton container received by truck prior to offloading, with the release secured by emergency responders by applying a Chlorine Institute Type "B" rpair kit device after 60 minutes.
Administrative controls in effect at Sacramento County WQD which were considered to mitigate the severity of the Worst Case a
nd Alternative Case release scenarios include Sacramento County WQD's written policies and procedures for training of operators and maintenance personnel, written procedures for control of the inventory of chlorine at the facility, and policies regarding quality level of replacement materials and components for the chlorine system.
No mitigation measures were considered to limit the severity of the Worst Case scenario. No passive mitigation measures were considered to limit the severity of the Alternative Case scenario. Active mitigation was considered for the Alternative Case, in the form of the timely response of properly trained and equipped personnel following established emergency response procedures.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAMS
General accidental release prevention programs instituted by Sacramento County WQD are categorized as administrative (management) programs; procedures, training, and engineering controls; and emergency response
Sacramento County WQD has instituted a Process Safety Management (PSM) Program meeting OSHA requirements at 29 CFR 1910.119 covering the chlorination process at the Calvine Meadows WTP. This constitutes the general accidental release prevention program for Sacramento County WQD's operations at this facility. The program and document management procedures included in the PSM Program will be used as the management system for the Risk Management Program.
CHEMICAL-SPECIFIC RELEASE PREVENTION STEPS
Release prevention steps specific to chlorine have been identified and are being implemented. These include relocation of the chlorine leak sensor and relief vents, and installation of seismic restraints for the ton container scales if these do not exist. A Pre-Startup Safety Review will be conducted according to the procedures in the Process Safety Management Program document prior to admitting chlorine into the new system.
FIVE YEAR ACCIDENT HISTORY
This is a new facility jus
t beginning operation. There have been no accidents involving chlorine at this facility within the past five years resulting in injuries or offsite consequences.
EMERGENCY RESPONSE PROGRAM
Sacramento County WQD's Emergency Response Program applicable to chlorine has been coordinated with Sacramento County Environmental Management Department, Hazardous Materials Division, the agency responsible for hazardous materials inventory reporting and release response coordination, and with the Elk Grove Fire Department, the local agency responsible for Incident Command activities. Sacramento County WQD maintains First Responder capability with respect to chlorine releases at sites which it operates and maintains.
PLANNED CHANGES TO IMPROVE SAFETY
Planned changes include extending the vacuum valve relief vents and relocating the leak sensor to a point adjacent to the neutralization scrubber intake vent, installing panic hardware on the personnel door to the chlorine storage room, and insta
lling a wind sock. All of the improvements and mitigation measures identified in the process hazard analysis which Sacramento County WQD committed to accomplish are in progress.