St. Paul Water Utility - McCarron Treatment Plant - Executive Summary |
|
EXECUTIVE SUMMARY This document was developed for the City of St. Paul Water Utilitys McCarron Water Treatment Plant (McCarron) in an effort to fulfill criteria of the RMP, as required by section 112(r) of the Clean Air Act, and regulated by 40 CFR, Part 68. McCarron is a conventional water treatment plant utilizing filtration, sedimentation, and disinfectant. McCarrons average daily production is 50 MGD with a typical range of 42 MGD to 95 MGD and a maximum of 144 MGD. The quantity of chlorine and anhydrous ammonia used at the facility is greater than the Threshold Quantities of 2,500 pounds and 10,000 pounds respectively, which is EPAs criteria for requiring the development and submittal of information found in this RMP. Chlorine and ammonia are considered hazardous by EPA standards. The same properties that make these chemicals valuable for water treatment, also make it necessary to observe certain safety precautions in handling these chemicals to prevent unnecessary human exposure and to reduce the impact or threat to nearby members of the community. Safety depends upon the manner in which we handle the chemicals; combined with safety devices inherent in the design of this facility; and the training of our personnel. ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES It is this facilitys intent to uphold industry standards in the operation of the facility and it is our policy to adhere to all applicable federal, state, and local laws. We have designed and constructed a state-of-the-art facility employing numerous release identification and prevention measures. If an emergency were to occur, our in-house staff are trained and equipped to perform isolation measures and secure leaking systems. We have also coordinated with the St. Paul Fire Department and requested that they respond to emergencies at our facility. THE STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED The primary purpose of the chlorine and ammonia at this facility is to be used as a water disinfectant. Chlorine is received, stored and dispensed from a 90-ton rail car. The liquid chlorine passes from the rail car storage, through one-inch black iron piping and into 1 or more of the 3 vaporization units. After being gasified, it passes through a vacuum regulator, which transitions the chlorine transfer line from a pressurized line to a vacuum feeding line before the chlorine is fed into the water supply. Physical access to the chlorine tanker car room and chlorination room is restricted by locked doors with only limited maintenance and operator staff having keys to these areas. Ammonia is received by truck and stored in two 9,230 gallon tank. Similarly, it passes through piping to a nearby room containing vaporizers, which vaporizes the ammonia. The gaseous ammonia then flows through the ammonianator and into the water supply. WORST-CASE RELEASE SCENARIO AND THE ALTERNATIVE RELEASE SCENARIOS Worst-Case Scenario (WCS) - Release of the entire contents of the largest single container or piping configuration of chlorine would be 180,000 pounds. For WCS, according to EPAs RMP Guidance Document criteria (EPA 550-B-98-010), the distance to toxic endpoint for this worst-case scenario is 14 miles. The facility is located in a heavily-populated urban area, with an estimated population of 1,300,000 persons living within the 14 mile radius. The WCS also reaches several environmental receptors as defined by the standard. Alternative Release Scenario (ARS) for chlorine - A release of 1.0 lb. per minute of chlorine results in a distance to toxic endpoint of 0.1 miles. This reaches the nearest public receptor (residential housing) Alternative Release Scenario (ARS) for ammonia - A release of 5 lb. per minute of ammonia results in a distance to endpoint of 0.1 miles. This reaches the nearest public receptor (residential housing). THE GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND THE SPECIFIC PREVENTION STEPS This facility complies with EPAs Accidental Release Prevention Rule and with all applicable state codes and regulations. St. Paul takes a systematic, proactive approach to evaluating chemical processes. Using this approach, the design, technology, operation and maintenance activities, emergency preparedness plans, training, process changes, and other elements that affect the covered processes are all considered. By conducting thorough evaluations, accidental releases are prevented and the consequences of releases are minimized. By fulfilling the required elements of the RMP standard, St. Paul intends to prevent releases of hazardous substances and minimize the impacts of accidental releases into locations that could expose employees, the community or the environment to serious hazards. Our program addresses each of the key features of a successful release prevention program including: ( Maintaining Process Safety Information (PSI): St. Paul maintains up-to-date technical information about saf e operating limits of the components and the associated hazards of the chemicals involved. ( Conducting Process Hazard Analyses (PHA): St. Paul performs technical analyses of the plants processes in order to anticipate what might go wrong and recommend approaches to minimize the possibilities and affects of such occurrences. ( Standard Operating Procedures (SOP): We have written technical and administrative procedures used to operate the plant safely. ( Training: St. Paul provides employees with information necessary to ensure safe operation. ( Mechanical Integrity: We ensures proper maintenance of the process equipment on an ongoing basis. ( Management of Change (MOC): St. Paul analyzes changes in process equipment, procedures and personnel to understand the impact of those changes in the safe operation of our plant. ( Pre-Startup Safety Review: We ensure all necessary elements for operating a safe process are in place prior to introducing the hazardous chemical into a new or modified system. ( Compliance Audits: We conduct periodic evaluation and updating of the process operation to ensure all RMP elements are being applied properly. ( Incident Investigation: St. Paul has procedures for investigating the causes of near-miss or accidental releases and developing measures to prevent future similar occurrences. ( Employee Participation: We maintain a philosophy and approach of incorporating the knowledge and experience of our employees from all facets of operation regarding the covered processes. ( Hot Work Permit: We have a documented program for controlling the hazards associated with ignition source activities, thereby minimizing potential catastrophic release. ( Contractors: St. Paul upholds policies and procedures for ensuring safe work practices of contractors on the facility and a systematic approach of communicating hazards inherent to the covered processes which the contractor may be working on or near. Our employees are committed to the standar ds that the RMP regulation sets. We do business, and have specific accountabilities and controls to ensure that we are meeting high standards for accident prevention. St. Paul has also developed a risk management system which identifies specific job positions and responsibilities to ensure proper management and implementation of this RMP. There have been no accidental releases of chlorine, ammonia, or other toxic/extremely hazardous chemicals in the past 5 years, which have resulted in off-site consequences such as personal injury, death, or response/ restoration activities. THE EMERGENCY RESPONSE PROGRAM We rely on our trained, in-house staff and on-site equipment for initial response (if safe to do so) and acquire backup support from the St. Paul Fire Department as needed. We have discussed the content and intent of this program with the St. Paul Fire Department. PLANNED CHANGES TO IMPROVE SAFETY The City of St. Paul is completing the construction of a state-of-the art facil ity designed with extensive process area monitors, detectors and alarm systems. Employees have recently completed upgraded training regarding the new system. A thorough hazard analysis of the system has been conducted to identify possible hazards. The system has been constructed to incorperate the safest operating systems feasible. |