Rolling Hills Water Treatment Plant - Executive Summary |
EXECUTIVE SUMMARY The ROLLING HILLS WATER TREATMENT PLANT (RHWTP) is owned and operated by the CITY OF FORT WORTH (CFW). To comply with the requirements in 40 CFR 68 Chemical Accident Prevention Provisions, the CITY OF FORT WORTH WATER DEPARTMENT (CFWWD) developed a Risk Management Program (RMProgram) for the RHWTP including Management System, Hazard Assessment, Accidental Release Prevention Program, and Emergency Response Plan. The RMProgram main goal is to reduce the employee and public risk of injury, death or damage from accidental release of chemicals. 1 MANAGEMENT SYSTEM The CFW has the overall responsibility for implementing and integrating the ARPProgram into their organization. In accordance with the Management System, the CFWWD Director is designated as the RMProgram Director, and the Assistant Water Director in charge of Production is the RMProgram Manager. Other qualified individuals are assigned responsibility for implementing each indiv idual requirement set forth in the Accidental Release Prevention Program and/or Emergency Response Plan. The RMProgram participants include the following positions: A. RMProgram Director B. RMProgram Manager C. Hazard Assessment/Offsite Consequence Analysis Update Officer D. Safety Information Officer E. Hazard Review Update Officer F. Operation Manager/Assistant Operation Manager G. Training Supervisor H. Maintenance Supervisor/Assistant Maintenance Supervisor I. Compliance Audit Officer J. Incident Investigation Officer K. Emergency Planning and Response Officer L. RMPlan Update Officer Management system detailed descriptions and procedures are provide in the Accidental Release Prevention Program to ensure every participant playing a role in the RMProgram understands their responsibilities. 2 REGULATED CHEMICALS AND PROCESSES Regulated toxic chemicals and processes at the RHWTP are: A. Storage, transfer and use of chlorine in the chlorination system B. Storage, transfer and use of anhydrous ammonia in ammoniation system Chlorine gas is stored as pressurized liquid in two (2) side-by-side tanks located outdoors. Maximum liquid chlorine inventory in each tank is 48,000 lbs. The maximum process quantity is 96,000 lbs., ignoring negligible quantities in the piping. Anhydrous ammonia gas is stored as a pressurized liquid in a single (1) tank located outdoors. Maximum liquid ammonia inventory in each tank is 85% of the tank water volume of 20,000 gallons. The ammonia volume is converted to a mass of 97,000 lbs. by assuming an ammonia density of 42.5 lb/ft3. The maximum process quantity is 97,000 lbs., ignoring negligible quantities in the piping. 3 HAZARD ASSESSMENT The Hazard Assessment has been completed for the RHWTP. Offsite consequence analysis modeling was performed based on the following principle elements: A. Meteorological parameters for the dispersion modeling analysis were determined using Nation al Weather Service data collected at the Dallas/Fort Worth International Airport. Highest daily maximum temperature and average relative humidity over the last three-year period were used for worst-case scenarios. Typical meteorological conditions based on the data over the last three-year period were used for alternative release scenarios. B. Total quantity in the single largest tank was used for chlorine and ammonia worst-case scenarios. A leak from a liquid line near the outdoor storage tank was assumed for either chlorine or ammonia alternative release scenario. C. No mitigation measure was considered in worst-case scenarios. The excess flow valve, however, was considered for either chlorine or ammonia alternative release scenario. D. Distances to toxic endpoints for chlorine and ammonia worst-case scenarios were modeled using a dense gas dispersion model, DEGADIS. E. Distances to the toxic endpoints for c hlorine and ammonia alternative scenarios involving vapor release were modeled using the ALOHA model. F. Distance to the toxic endpoint for the ammonia alternative scenario involving two phase release were modeled using a dense gas dispersion model, DEGADIS. G. Offsite impact was evaluated with LANDVIEW III for each release scenario. The accidental release of chlorine from a storage tank is considered the worst-case scenario. A distance of 4.8 miles between the release source and the toxic endpoint was modeled in the offsite consequence analysis. The alternative scenario impact distance is 1.2 miles for chlorine and 0.25 miles for ammonia. For the worst-case scenario, LANDVIEW III estimated a population of 150,000 persons within the worst-case scenario impact radius of 4.8 miles. Populations are 6,900 and 0 persons for chlorine and ammonia alternative release scenarios, respectively. Public receptors within the worst-case scenario impact area include schools, residences, hospitals, correctional facilities, recreation areas and commercial, office, or industrial areas. Public receptors within the alternate release scenario impact area are schools, residences, correctional facilities, recreation areas and commercial, office, or industrial areas. No environmental receptors are within the impact area of the worst-case scenario. 4 ACCIDENTAL RELEASE PREVENTION PROGRAM A comprehensive Accidental Release Prevention Program Manual was developed. The main purpose of the manual is to provide operation and maintenance personnel detailed standard procedures to reduce employee and public risk to injury, death or property damage from accidental chemical releases. The manual includes the following elements and complies with requirements set forth in 40 CFR 68 Chemical Accident Prevention Provisions. A. Management B. Safety Information C. Hazard Review D. Operating Procedures E. Training F. Maintenance G. Compliance Audits H. Incident Investigation Detailed procedures for the Accidental Release Prevention Program were developed and are undergoing implementation and integration into routine operation and maintenance practices at the RHWTP. Historical and future significant efforts focus on the following areas: A. Development of a safety information database essential for the successful implementation of other procedures, including operation, maintenance, training, compliance audits, incident investigation, and emergency planning and response. B. Implementation of corrective actions recommended during the most recent hazard review completed on April 22, 1999. This effort is one of the most important steps for preventing a chemical release or minimize its effects on plant personnel or the public. C. Regular review and revision of operating procedures to address the safely operating procedures for regulated process systems, including all eight (8) element s set forth in the regulation. When combined with the operator training program, current operating procedures are essential in ensuring safe operation of systems and preventing accidental releases. D. Regular review and revision of training programs to ensure plant personnel working on or near regulated processes are adequately trained and understand both inherent process hazards and appropriate response actions to accidental chemical releases. Employees who have received adequate classroom and/or on-the-job training and are currently qualified to safely operate the regulated systems have received certifications in writing by the RMProgram Manager. A special training session will be provided to plant personnel working on or near regulated processes as soon as final revisions to operating procedures are completed. E. Regular review and revision of the maintenance program to ensure that current, accurate, and com plete procedures are provided for process equipment in regulated processes. Efforts were and are continuously made for the preventative maintenance of equipment per manufacturer's recommendations. Effective maintenance procedures are integral to preventing chemical releases that may result from mechanical failure of improperly maintained equipment. 5 THE FIVE-YEAR ACCIDENT HISTORY No accidental releases of regulated chemicals from a regulated process at the RHWTP has occurred in the past five years resulting in any death, injury, or property damage on site, or known offsite impacts (i.e., deaths, injuries, evacuations, sheltering-in-place, or property damages, or environmental damages). 6 EMERGENCY RESPONSE PLAN CFWWD personnel do not respond to uncontrolled releases of chemicals from any regulated process at the RHWTP. Plant employees are limited to responding only to incidental releases covered by maintenance procedures. Appropriate procedu res have been developed and are in place that provide clear instructions on 1) how to determine if a leak is considered an incidental release, and 2) how to notify local emergency responders in the event of an uncontrolled release. Current procedures were reviewed and revised to meet regulatory requirements, such as emergency notification, evacuation, training, documentation, availability, etc., under 29 CFR 1910.38(a). Regulated processes at the RHWTP are not included in the community emergency response plan developed under 42 U.S.C. 11003. The local emergency responder is the Emergency Management Office in association with the City of Fort Worth Fire Department. Adequate safety information regarding regulated processes has been provided to the Emergency Management Office who has developed and implemented specific emergency response plans, provided suitable training, and conducted necessary drills in emergency response for regulated chemical releases from regulated processes. Alt hough it will not be the responsibility of the plant employees to evacuate offsite areas, addresses and telephone numbers of major public receptors inside a one (1) mile radius are provided in the plan. The CFWWD will work closely with the Emergency Management Office and document coordination activities and communications. 7 ON-GOING AND UP-COMING SAFETY IMPROVEMENTS To improve the safety of regulated facilities at the RHWTP, the following plant expansion, process modification and facility upgrade projects are under construction or are scheduled to begin soon: A. Installation of additional warning signs B. Installation of bollards around tanks to provide additional vehicular protection C. Implementation of modified leak detector testing and documentation procedures D. Implementation of revised operational, maintenance, and training procedures E. Implementation of revised contractor notification and monitoring programs |