WMWA Filtration Plant - Executive Summary |
|
Williamsport Municipal Water Authority Filtration Plant Executive Summary This executive summary is intended to present a basic description of the Williamsport Municipal Water Authority (WMWA) Risk Management Program (RMP). U.S. Environmental Protection Agency (EPA) Risk Management Program (RMP) regulations (FR 61 [120], p31668) issued on June 20, 1996, require facilities that have a regulated substance above the listed threshold quantities to develop and implement a formal Risk Management Program. The management of the WMWA is committed to safe handling and use of regulated hazardous substances. Benefits of the RMP include an understanding of the hazards of regulated substances by the employees, improved process control, maintenance and equipment availability, emergency preparedness, and reduced costs related to accidents, injuries, and insurance. The RMP provides for procedures necessary for safe plant operations. The WMWA Filtration Plant was officially commissioned on Se ptember 9, 1992. The plant is designed to filter and treat the surface water supplies of the Greater Williamsport Area, serving a population of 51,000 persons. The watersheds of Hagermans Run and Mosquito Creek, supply raw water of high quality to the plant. The new plant replaces two chemical treatment facilities constructed in 1965 which provided chlorine disinfection, fluoride and corrosion control treatment for the water from the Hagermans Run and Mosquito Creek distribution reservoirs. Built in response to Federal and Pennsylvania Safe Drinking Water Act regulations, which require that all surface supplies be filtered, the Filtration Plant addresses current and future water quality issues, including pathogen removal, taste and odor control, corrosion control, and reduction of disinfection by products. The computer-controlled Filtration Plant is rated to deliver 12.5 million gallons per day of treated water. The primary objective of the Filtration Plant is to provide safe dri nking water to its customers. To accomplish this, chlorine is added as a disinfectant to inactivate bacteria, viruses and Giardia cysts. Because more than 2,500 pounds of chlorine is stored for this purpose, the WMWA Filtration Plant is subject to the RMP regulations. Chlorine is stored in pressurized one ton containers. The WMWA Filtration Plant maintains a maximum inventory of 16,000 pounds of chlorine. The RMP regulations require each site to conduct an offsite consequence analysis which provides information to the government and the public about the potential consequences of an accidental chemical release at the facility. The offsite consequence analysis consists of a worst-case release scenario and an alternative release scenario. The worst-case scenario is defined as the release of the largest quantity of a regulated substance in 10 minutes from a single vessel or process line failure that results in the greatest distance to an endpoint. For offsite consequence analysis, the WMWA used the American Water Works Association Compliance Guidance and Model Risk Management Program for Water Treatment Plants which uses the ALOHA Model. The WMWA used the worst-case scenario of a catastrophic failure due to corrosion, impact, or construction defects of a one ton container. In this scenario, 2,000 pounds of chlorine is released in 10 minutes. The distance to end-point is 3.0 miles. The alternative scenario, which is more likely than the worst-case scenario, is a tubing failure, bad connection, or valve failure resulting in the release of gas through a 5/16 inch diameter valve opening. In this scenario, 317 pounds of chlorine is released and the distance to end-point is 0.56 miles. Both the worst-case and alternative scenarios involve offsite impact. Estimates of population affected are made based on 1990 census data. WMWA employees are trained in the proper handling of the chlorine containers and also in the repair of incidental leaks. The WMWA Filtratio n Plant is equipped with a chlorine scrubber capable of neutralizing the entire contents of a one-ton container and chlorine gas monitors which would immediately notify employees of an incident so they can take action to prevent a worst-case scenario from occurring. The most likely time for an accident to occur is during delivery or during the change to a new container. For this reason, deliveries and changing of containers are only performed on first shift weekdays, and when at least two employees are present using defined procedures. Deliveries are escorted through the rural residential neighborhood to the plant. Each container is inspected prior to unloading. Each WMWA employee working with the chlorine process receives classroom and hands-on training in the safe handling of chlorine, preventative maintenance, and incidental repair of leaks. Each employee is also trained in the procedures to be taken in the event of an accidental release. The WMWA response program is coordi nated with the Lycoming County Emergency Planning Committee. Training drills have been coordinated with the Lycoming County Emergency Planning Committee, local fire departments, and the county's hazmat response team. Public notification of an accidental release would be through the civil defense siren, emergency broadcasting system and telephone notification of immediate neighbors by the WMWA. The WMWA will use a contracted emergency response team whose response time is approximately thirty minutes to handle the repair and cleanup of any accident. There have been no accidental releases at this facility in the past five years. The WMWA management is committed to continued review and implementation of the RMP. The RMP regulation has helped to enhance our existing safety programs. It also ensures that in the unlikely event of an accidental release, employees and local area emergency responders are fully trained and ready to engage specific plans to remediate the situation quickly. The added protection of the RMP will ensure the safety of our personnel, the environment and the community. |