Lucas Water Treatment Plant - Executive Summary |
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Executive Summary Lucas Water Treatment Plant ? Background Glasgow Water Company, located in Glasgow, Kentucky, operates the Lucas Water Treatment plant (WTP). The facility is subject to EPAs Risk Management Program in accordance with Section 112(r) of the Clean Air Act (CAA). The WTP provides the City of Glasgow and surrounding areas with potable water for human consumption. ? Chemical Management Program As a concerned member of the community, the company takes its role as a responsible citizen very seriously. Glasgow Water Company facilities are operated to protect employees, contractors and the public from injury and illness, and to minimize environmental impact. Glasgow Water Companys policy is to inspect, maintain and operate equipment and facilities to prevent accidents, including release of hazardous materials, and to train employees in prevention of accidents. Glasgow Water Company has developed and implemented Process Safety Management (PSM) plans at each operations facility as part of an overall chemical management program. The program involves the Superintendents at each facility along with the plant operators. 1) Accidental Release Prevention and Emergency Response Policies The Lucas WTP has developed a PSM plan as part of the overall chemical management program. The program involves the Superintendent and all operators at the facility. Lucas WTP personnel also provide safety training to staff as part of the accidental release prevention program. 2) Description of Facility and the Regulated Substances The Lucas WTP is located on 1321 Narrows Road near Lucas, Kentucky approximately 10 miles southeast of Glasgow. The Lucas WTP withdraws and treats water from Barren Lake for distribution of potable water to the surrounding areas. The Lucas WTP utilizes a Wallace & Tiernan vacuum operated, manual switchover, gaseous feed system. Two 1-ton containers of chlorine are piped together to provide uninterrupted flow of chlori ne. The maximum inventory at the WTP includes four 1-ton chlorine containers. Under normal circumstances, a full container and a container in use are piped together and situated on the scale apparatus and up to two full containers of chlorine are stored within the same room. The maximum amount of chlorine on-site at one time would be less than 8,000 pounds. Currently, the feed rate for chlorine ranges from approximately 100 200 pounds per day. 3) Worst-Case Release Scenario The predicted worst-case release scenario for chlorine is a catastrophic release of one (full) chlorine container within the chlorination room. This enclosure will limit the dispersion of both liquid and vapor to the atmosphere during a release. For this scenario, 2,000 pounds of chlorine liquefied under pressure are assumed to be released in 10 minutes. Using RMP*Comp Version 1.06 air dispersion modeling software, the distance to a toxic endpoint of 0.0087 mg/l is predicted to be 2.2 miles. A s an input parameter for RMP*Comp the topography surrounding the WTP was considered rural. It should be noted that this parameter is not directly correlated to population density. Rather, the topography surrounding the facility is characterized as either having many obstructions urban or generally flat with few obstacles rural. Because the WTP is located adjacent to the lake, the surface of the water is considered the dominant feature in the topography surrounding the facility (see Section 3.3). For this reason, the topography is considered rural. This radius encompasses approximately 345 residences, and 1 recreation facility. Assuming a population multiplier of 3.5 people per residence, this radius encompasses approximately 1,210 people. The number of residences and other public and environmental receptors associated with this radius was provided by Glasgow Water Company personnel from GIS data using the latitude and longitude of the facility and a radius of 2.2 miles provided by EMPE. 4) Alternative Release Scenarios The alternative release scenario for the WTP chlorination process is based on the events that led to a chlorine release in October 1996 as described in the Five-Year Accident History section of this summary. For this scenario, a lead gasket is not properly installed when the vacuum regulator assembly is leak tested. Before the main valve to the cylinder can be closed, chlorine gas is released, forcing WTP personnel to evacuate the chlorination room. The chlorine container continues to release chlorine gas for one hour until the release is mitigated by emergency responders. This release scenario was modeled using RMP*Comp Version 1.06 software by assuming that the temperature and pressure of the container at the time of the leak are 77 degrees F and 113 pounds per square inch (psi). The release was modeled as discharge of gas from a 1/8 inch diameter hole (area = 0.0123 square inches) at the above temp and pressure. Off-site consequences analysis using RMP*Comp resulted in a radius of impact of 0.1 miles. Visual inspection indicates that there is a recreation area and 2 residences located within this radius, comprising a total population of 6 people. Because the specific gravity of chlorine is 2.49 (air = 1.29), chlorine vapor is more dense than air. As a result, chlorine vapor may collect and/or migrate along low-lying areas in and around the facility. This is particularly important due to the fact that the chlorination room is located immediately adjacent to Barren Lake atop the steep bank of the lake. A release of chlorine gas will tend to migrate down the steep bank and collect on and/or migrate along the surface of the lake. Furthermore, the floor drains within the chlorination room discharge along this steep bank. This results in a short circuit that would allow chlorine gas to travel directly from the floor drains in the chlorination room to near the lake su rface. However, the migration of chlorine vapor in the event of an actual release will be highly dependent upon the atmospheric conditions and release scenario at that time of the release. 5) General Accident Release Prevention Program The Lucas WTP maintains a Process Safety Management (PSM) of Highly Hazardous Chemicals plan prepared in accordance with the Occupational Health and Safety Administration (OSHA) regulation 29 CFR 1910.119. The WTP also utilizes preventative maintenance programs for its system components. The preventative maintenance program for the chlorination system is conducted in conformance with manufacturers recommendations. 6) Five-Year Accident History According to Mr. Tony Turner, Lucas WTP Superintendent, there has been one release meeting the definition provided in Section 1.6 of this RMP within the last 5 years. A release of chlorine gas occurred on October 10, 1996 as WTP personnel were placing a new, full container on-line. According to Mr. Turner, a lead gasket was installed improperly as the vacuum regulator assembly was connected to the valve on the container. The main valve on the container was briefly opened and closed in order to check for leaks when a hissing noise was heard at or near the valve of the container. The chlorine gas detector alarm activated as the WTP personnel quickly evacuated the chlorination room and notified the Glasgow Fire Department. The Hazardous Materials Response Team of the Glasgow Fire Department mobilized to the WTP and entered the chlorination room within approximately 45 minutes to 1 hour of notification. Mr. Turner indicated that the atmosphere of the chlorine room was monitored by the emergency responders prior to entry and chlorine gas was not detected. The valve on the suspect container was found completely turned off, and the hissing noise was not observed. A total of five people were evacuated from the immediate area, including WTP personnel and residents present in two houses located on the WTP property. Also, a portion of Barren Lake was secured by emergency responders such that recreational boats could not come within approximately 0.25 miles of the WTP. Mr. Turner indicated that the emergency responders determined that a small amount of chlorine gas (estimated at 2 pounds) was released from the leak of a small section of piping that had been pressurized during the leak test, rather than from the container itself. There was no foliage damage, fish kill, property damage, human illness or other injury associated with this release. 7) Emergency Response Program The Lucas WTP has implemented an Emergency Action Plan in accordance with OSHA PSM regulations. The facility will rely on the Glasgow Fire Department to respond in the event of a hazardous material release, fire or other emergency situation. The written Emergency Action Plan contains specific information regarding evacuation and notification procedures in the eve nt of a catastrophic chlorine release. The Glasgow Fire Department has conducted a reconnaissance of the facility and trained personnel are ready to respond if requested. 8) Planned Changes to Improve Safety The Lucas WTP is in the process of implementing safety improvements as recommended in the Process Safety Management program. The improvements should be completed by July 1, 2000. Glasgow Water\Reports\WTP RMP ExecSum.doc |