South Austin Regional Wastewater Treatment Plant - Executive Summary
SOUTH AUSTIN REGIONAL WASTEWATER TREATMENT PLANT |
CITY OF AUSTIN, WATER AND WASTEWATER UTILITY
RISK MANAGEMENT PLAN (RMP), EXECUTIVE SUMMARY
The accidental release prevention and emergency response policies for the facility:
The City of Austin Water & Wastewater Utility owns and operates the South Austin Regional Wastewater Treatment Plant (SAR WWTP). The Utility's mission is that it will protect our community's public health and environment by effective management of our water resources.
The SAR WWTP has established an effective chemical release prevention and emergency response plan. It is the policy of the SAR WWTP to take all necessary actions to prevent the release of a hazardous chemical. Even with an effective prevention program in place, a chemical release incident may still be a remote possibility. Through planning, procedures, training, monitoring, and mitigation systems, the facility is prepared to promptly perform emergency actions to minimize and contain the release
of a hazardous chemical. Highly trained SAR WWTP technicians, with the aid of the Austin Fire Department Hazardous Materials Team, are prepared to respond to the scene, evacuate the immediate area (if necessary), and control the release.
The facility and the regulated substance handled:
The SAR WWTP provides wastewater treatment services to citizens, businesses, and industries of the City of Austin. In the process of treating domestic and industrial wastewater, the regulated chemicals used at SAR, currently chlorine and anhydrous sulfur dioxide, are stored at the facility. The chlorine is used to disinfect the treated water and the sulfur dioxide is used to neutralize the chlorine before the water is discharged into the Colorado River. Pressurized and liquefied chlorine and anhydrous sulfur dioxide is delivered to the facility in one ton containers. A maximum of 28 containers of chlorine and 20 containers of sulfur dioxide will be kept on site at any time. The containers are st
ored in specially designed buildings with administrative controls placed on the amount stored to allow the facility to maintain safe operating and design conditions.
The worst-case release scenario(s) and the alternative release scenario(s):
The Environmental Protection Agency (EPA) defines a "worst-case" scenario as the release over a ten-minute period of the largest amount of a listed chemical under very extreme conditions. These conditions include extreme weather and the total, simultaneous failure of all active safety and emergency backup systems and personnel. The probability of this scenario is so extremely remote that the EPA's basic intention is to identify any potential offsite impacts. The facility has defined the worst-case scenario as the total release of a one ton container due to impact, without consideration of any of the enclosure or mitigation systems. The EPA developed model, RMP* Comp Version 1.06, was used to calculate endpoint distances as reported in the pla
n. The facility has determined that a remote potential for offsite public and environmental impact does exist.
The EPA requires facilities to plan for a more realistic "alternative-release" scenarios. The EPA characterizes an alternative release scenario as "more likely to occur than the worst-case scenario" and allows sites to include active and passive control/mitigation systems and more realistic weather conditions in the assumptions.
The chlorine and sulfur dioxide storage facilities are specifically designed to limit the release of the process chemicals. The design includes both active and passive mitigation systems. The passive mitigation systems include enclosures and sumps. The active mitigation systems include a scrubber system on the sulfur dioxide, and soon to be included on the chlorine. The process controls used include alarms, gas leak detection systems, and automatic/manual shut-off. The facility defines the alternate case scenario for both chemicals as a flexib
le tubing leak occurring inside a storage building with the consideration of active and passive mitigation systems. Active and passive mitigation systems are designed to contain or neutralize alternative scenario releases. The EPA developed model, RMP* Comp Version 1.06, was used to calculate endpoint distances as reported in the plan. The facility reports that the potential for offsite public impact does not exist.
The general accidental release prevention program and chemical-specific prevention steps:
SAR WWTP complies with the Design Criteria for Sewage Systems Rules issued by the Texas Natural Resource Conservation Commission (TNRCC). The rules require the facility to construct, maintain, and operate the chemical facilities in accordance with OSHA, ASTM, ANSI, and ASME Standards. These rules are intended to ensure the safe operation of the facility.
SAR WWTP has established a comprehensive accidental release prevention program. The prevention program is intended to assure
that the facility design and procedures are reviewed and conform to safe design principles and practices. The operations, maintenance, and training program elements assure that the processes are within the safe design and operating conditions. Highly trained employees are on duty 24 hours per day to inspect, maintain, and operate the process chemical systems. Operational, maintenance, and emergency response procedures are periodically reviewed and updated. The facility has established a training program that consist of classroom, on-the-job, and demonstration training. The facility has an established maintenance program that requires equipment identification, testing and inspections, preventative maintenance, training and documentation. This is accomplished with the assistance of Year 2000 compliant maintenance software.
The five-year history:
The facility has not had an accidental release of any regulated chemical (chlorine or sulfur dioxide) in the past five years. No docum
ented offsite injuries or environmental impacts have occurred due to a chemical release in the 15 year history of the facility's operation.
The emergency response program:
SAR WWTP has established an emergency response program which involves training of employees and a partnership with the Austin Fire Department Hazardous Materials Team (AFD HazMat). The Utility has spent considerable time, money, and effort to train every employee at the facility to respond to a chemical release. All facility employees have received Hazardous Waste Operations and Emergency Response (HAZWOPER) awareness, operations, or technician level training. Selected employees have received extensive training in emergency response from AFD HazMat instructors equal to that received by the HazMat Team. In the case of a hazardous chemical release, the facility operators would determine the severity of the situation and, if warranted, would call the HazMat Team to respond to the facility. After an assessment of
the situation has been made by AFD and facility personnel, a partnered response to alleviate the problem would be performed. This partnership makes the best use of the expertise of the facility employees and the HazMat Team. The Austin Office of Emergency Management would notify citizens via television and radio broadcast of the hazard.
Planned changes to improve safety:
SAR WWTP is in the process of designing modifications to the chlorine process, which will upgrade the safety systems in the building. The sulfur dioxide building has already been modified. The facility is continuously evaluating new safety systems, process control equipment, and procedures that would improve the safety of the employees, the public, and the environment.