Grand Haven Spring Lake WWTP - Executive Summary |
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Grand Haven/Spring Lake Wastewater Treatment Plant (GH/SL) is a municipal wastewater treatment plant. Their facility is located at 1525 Washington in Grand Haven, Michigan. As required in the U.S. Environmental Protection Agency (EPA) Clean Air Act Risk Management Program rules listed in 40 CFR Part 68, this document contains information intended to analyze the impacts of an accidental release of an extremely hazardous substance and to highlight the steps the facility is taking to prevent a release from occurring. The intent of the rule is to reduce the likelihood of a chemical release and the consequences of a release if one were to occur. The process utilizes chlorine and sulfur dioxide which are both regulated substances under the Risk Management Program. GH/SL has a maximum inventory of 10,000 pounds of chlorine and 6,000 pounds of sulfur dioxide, which both surpass the EPA threshold of 2,500 pounds and 5,000 pounds, respectively. The facility is also subject to the Occupati onal Health and Safety Association (OSHA) Process Safety Management (PSM) program. Modeling results indicate the worst-case release would cause an offsite impact. Due to these factors, GH/SL is subject to Program 3 requirements under 40 CFR Part 68. Because of the potential hazards when using chlorine and sulfur dioxide, it is essential that steps be taken to minimize the risk of a catastrophic release. The prevention program for GH/SL complies with 40 CFR 68 Subpart D and includes process safety information(PSI), a process hazard analysis (PHA), and procedures for the following: operating, training, mechanical integrity, management of change, pre-startup safety review, compliance audit, incident investigation, employee participation, hot work permit and contractors. The purposes of the PSI are to compile and update written process safety information for use by employees, PHA Teams, and auditors. The PHA identifies, evaluates, and controls the hazards and risks associated with p rocesses using regulated substances. The operating procedures are instructions for operating (initial and emergency startup; normal, temporary, and emergency operations; and emergency and normal shutdown). Training ensures that the operators and other personnel working on or near regulated processes are properly instructed in the hazards and response actions associated with the release of regulated substances. Mechanical integrity requires the identification, inspection, and testing of the process equipment. Furthermore, mechanical integrity creates and implements written practices for maintaining the mechanical integrity of the process equipment. Management of change reviews the changes made to process chemicals, technology, equipment, and procedures. The Pre-Startup Safety Review is to be performed in conjunction with the management of change. The review examines the safety of new and modified regulated processes. The purpose of the compliance audit is to analyze the owner's or operator's compliance with the requirements of Program 3. Incident investigations review all occasions that resulted in or had the possibility of resulting in a release of the regulated substance. Employee participation is the involvement of operators or other personnel in the creation and implementation of Program 3 provisions. Hot work permits are to be issued for all hot work performed on or near a regulated process. The purpose of the contractor review is to ensure that all contractors are evaluated in their safety performance and programs and to prepare the contractors against the hazards associated with the regulated substances. To predict the off-site impact in the event of a release, a hazard analysis was conducted according to the procedures outlined in the rule. The worst-case release quantity for toxic gases is assumed to be a release of the largest container in the process over a period of 10 minutes. The maximum quantity of chlorine and sulfur dioxide stored in any one container at the facility is 2,000 pounds. Therefore, the release rate used in the consequence modeling was 200 pounds per minute for the entire 10-minute release period. No mitigation or administrative controls were considered. The worst-case release for the facility is that of sulfur dioxide. Due to the extensive preventative maintenance procedures, training, and emergency response procedures that have been implemented at GH/SL, it is highly unlikely that this scenario would occur. For Program 3 processes, the rule requires that at least one alternative release scenario be analyzed for each regulated toxic substance. The alternative release scenario must be more likely to occur than the worst-case and must have an offsite impact whenever possible. Potential alternative release scenarios for GH/SL include valve leaks, regulator breaks, gasket leaks, and pipe breaks. Because a regulator break would result in the greatest quantity released and the greatest release rate, this was determined to be the alternative release scenario. Monitoring equipment located inside GH/SL will detect low levels of chlorine or sulfur dioxide and alert staff of a possible leak. In the event of a release inside the facility, there would be prompt response and proper measures would be implemented to control the release. However, for purposes of this analysis, the entire contents of one container (2,000 pounds) were assumed to be released over a one-hour period. The chlorine and sulfur dioxide containers are stored in an enclosed room which would provide mitigation of a release should one occur. The RMP Offsite Consequence Analysis Guidance published by the EPA recommends applying a 55% mitigation factor to the release rate for releases in enclosures. This factor was used in the alternative release scenario for GH/SL. The hazard analysis performed for the facility also includes a review of its five year accident history. During the past five years, GH/SL has not ha d an accidental release that met the criteria of 40 CFR 68.42(a). GH/SL has been actively involved in emergency response planning. They have worked closely with the Ottawa County Local Emergency Planning Committee (LEPC) to develop standard operating procedures (SOPs) for offsite response. GH/SL is a Program 3 source and a non-responding facility. The GH/SL Emergency Response Plan outlines procedures for internal response to incidental releases and notification and coordination with the local emergency response organizations in the event of an incidental release which cannot be contained and will have offsite impacts. |