East Water Purification Plant - Executive Summary |
|
Executive Summary for the City of Houston East Water Purification Plant Risk Management Plan 1. Accidental Release Prevention and Emergency Response Policies The East Water Purification Plant is strongly committed to employee, public, and environmental safety. This commitment is demonstrated by the facility's comprehensive accidental release prevention program that covers design, installation, operating procedures, maintenance, and employee training associated with the processes at the facility. It is the East Water Purification Plant's policy to implement appropriate controls to prevent possible releases of regulated substances. If such a release does occur unforeseeably, the East Plant's emergency response personnel are at hand to control and mitigate the effects of the release. The facility is also completely coordinated with the City of Houston's Hazardous Materials Response Unit and the City of Galena Park Fire Department, which provide additional emergency response expertis e. 2. The Stationary Source and the Regulated Substances Handled The East Water Purification Plant's function is to purify surface water for the purpose of providing drinking water to the surrounding area. There are two regulated substances present at the facility, chlorine and ammonia. The regulated substances are both used in the disinfection process. The maximum inventory of chlorine at the facility is 568,000 pounds, while ammonia is present at the facility in a maximum quantity of 67,600 pounds. 3. The Worst Case Release Scenario and the Alternative Release Scenario, Including Administrative Controls and Mitigation Measures to Limit the Distances for Each Reported Scenario To perform the required offsite consequence analysis for the facility, the East Water Purification Plant has used the tables and equations provided by the EPA in its RMP Offsite Consequence Analysis Guidance. The following paragraphs provide details of the chosen scenarios. The worst case release scenar io submitted for Program 2 toxic substances involves a catastrophic release from the chlorine storage area. The scenario involves the release of 180,000 pounds of chlorine in a gaseous form over a period of 10 minutes from an exposed 90-ton chlorine railcar. At Class F atmospheric stability and 1.5 m/s windspeed, the maximum distance of 14.2 miles is obtained, corresponding to a toxic endpoint of 0.0087 mg/L. At least one alternative release scenario will be submitted for each toxic substance present in Program 2. One alternative release scenario for chlorine involves a release from the ton container storage building on West Street at the south gate. The scenario involves the release of 800 pounds of chlorine in a gaseous form over a period of 30 minutes. No passive mitigation controls are taken into account to calculate the scenario. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.0087 mg/L of chlorine is 0.1 miles. Another alternative release scenario for chlorine involves a release from the ton container storage building on West Street at the south gate. The scenario involves the release of 600 pounds of chlorine in a gaseous form over a period of 60 minutes. Passive mitigation controls such as enclosures are taken into account to calculate the scenario. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.0087 mg/L of chlorine is 0.1 miles. The alternative release scenario for ammonia involves a leak from the day storage tank. The scenario involves the release of 6,100 pounds of ammonium hydroxide over a period of 90 minutes. Passive mitigation controls such as enclosures are taken into account to calculate the scenario. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.14 mg/L of ammonia is 0.1 miles. 4. The General Accidental Release Prevention Program and the Chemical- Specific Prevention Steps The facility has taken all the necessary steps to comply with the accidental release prevention requirements set out under 40 CFR part 68 of the EPA. The facility is also subject to EPCRA Section 302 notification requirements. The following sections briefly describe the elements of the release prevention program that is in place at the East Water Purification Plant's stationary source. Process Safety Information The East Water Purification Plant maintains a detailed record of safety information that describes the chemical hazards, operating parameters, and equipment designs associated with all processes. Process Hazard Analysis The facility conducts comprehensive studies to ensure that hazards associated with its processes are identified and controlled efficiently. The methodology used to carry out these analyses is inspection of the plant to identify deficiencies throughout the system. Work orders are then generated for corrective measures. The studies are undertaken by a team of qualified personnel with expertise in engineer ing and process operations, and are revalidated routinely. Any findings related to the hazard analysis are addressed in a timely manner, with hazard items being deemed high priority and corrected first. Operating Procedures For the purposes of safely conducting activities within its covered processes, the East Water Purification Plant maintains written operating procedures. These procedures address various modes of operation, such as initial startup, normal operations, temporary operations, emergency shutdown, emergency operations, and normal shutdown. The information is regularly reviewed and is readily accessible to operators involved in the processes. Training The East Water Purification Plant has a training program in place to ensure that employees who are responsible for processes are competent in the operating procedures associated with these processes. Refresher training is provided as needed. Mechanical Integrity The East Water Purification Plant carries out highly doc umented maintenance checks on process equipment to ensure proper operations. Process equipment examined by these checks includes, among others: pressure vessels, storage tanks, piping systems, relief and vent systems, emergency shutdown systems, controls, and pumps. Maintenance operations are carried out by qualified personnel who have previous training in maintenance practices. Furthermore, these personnel are offered specialized training as needed. Any equipment deficiencies identified by the maintenance checks are corrected in a safe and timely manner. Management of Change Written procedures are in place at the East Water Purification Plant to manage changes in process chemicals, technology, equipment, and procedures. Process operators, maintenance personnel, or any other employee whose job tasks are affected by a modification in process conditions are promptly made aware of and offered training to deal with the modification. Pre-Startup Reviews Pre-startup safety reviews rel ated to new processes and to modifications in established processes are conducted as a regular practice at the East Water Purification Plant. These reviews are conducted to confirm that construction, equipment, and operating and maintenance procedures are suitable for safe startup prior to placing equipment into operation. Compliance Audits The East Water Purification Plant conducts audits on a regular basis to determine whether the provisions set out under the RMP rule are being implemented. These audits are carried out at least every three years, and any corrective actions required as a result of the audits are undertaken in a safe and prompt manner. Incident Investigation The East Water Purification Plant promptly investigates any incident that has resulted in, or could reasonably result in, a catastrophic release of a regulated substance. These investigations are undertaken to identify the situation leading to the incident and any corrective actions to prevent the release from reoccurring. All reports are retained for a minimum of five years. Employee Participation The East Water Purification Plant truly believes that process safety management and accident prevention is a team effort. Company employees are strongly encouraged to express their views concerning accident prevention issues and to recommend improvements. In addition, the East Water Purification Plant's employees have access to all information created as part of the facility's implementation of the RMP rule, particularly including information resulting from process hazard analyses. Contractors On occasion, the facility hires contractors to conduct specialized maintenance and construction activities. Prior to selecting a contractor, a thorough evaluation of safety performance of the contractor is carried out. The East Water Purification Plant has a strict policy of informing the contractors of known potential hazards related to the contractor's work and the processes. Contractors are also informed of all the procedures for emergency response in the event of an accidental release of a regulated substance. 5. Five-year Accident History The East Water Purification Plant has had an excellent record of preventing accidental releases over the last five years. Due to its stringent release prevention policies, the number of accidental releases has been reduced to a minimum. There have been three accidental releases of regulated substances from the facility within the last five years. The first release took place on May 15, 1995, and involved 800 pounds of chlorine. The incident was a result of equipment failure. There were no known impacts either onsite or offsite. A release of an additional 600 pounds of chlorine occurred on June 28, 1995, as a result of equipment failure. There were no known impacts either onsite or offsite. The most recent release took place on June 10, 1998, and involved 6,100 pounds of ammonium hydroxide. The incident was a result of human er ror. The release did cause some soil contamination on the property. 6. Emergency Response Plan The East Water Purification Plant maintains a written emergency response plan to deal with accidental releases of hazardous materials. The plan addresses all aspects of emergency response, including adequate first aid and medical treatment, evacuations, notification of local emergency response agencies and the public, and post-incident decontamination of affected areas. To ensure proper functioning, the emergency response equipment is regularly inspected and serviced. In addition, the plan is promptly updated to reflect any pertinent changes taking place within the processes that would require a modified emergency response. The Local Emergency Planning Committee (LEPC) with which the East Water Purification Plant's emergency plan has been coordinated and verified is the Galena Park LEPC. |