Lake Michigan Water Filtration Plant - Executive Summary |
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A. FACILITY DESCRIPTION AND NATURE OF REGULATED SUBSTANCES HANDLED The primary business of this facility is the treatment of potable drinking water for a resident population of approximately 275,000 persons. This activity requires the use of chlorine gas as a disinfection agent. Chlorine, in the form of a liquid under pressure, is delivered to the facility via truck. The chlorine is stored in one-ton steel cylinders, with 24 cylinders being the average number on site on most occasions. Liquid chlorine is distributed by piping into evaporator units where it is converted into gaseous form, and it is then injected into the filtered water at various points. B. ACCIDENTAL RELEASE AND EMERGENCY RESPONSE POLICIES It is the general policy of the Grand Rapids Water Filtration Plant to take all precautions and preventative measures necessary to ensure against unplanned releases of any hazardous subst ances that might prove harmful, either to plant employees, or to persons in the vicinity of the plant facility. There are numerous structural and administrative safeguards in place which are intended to prevent hazardous material releases. Structural elements and mechanical systems are subject to a rigorous inspection and preventative maintenance program to ensure proper operating capabilities. Plant personnel receive extensive training concerning safe handling procedures for the chemicals they utilize in their work, as well as specialized training concerning procedures to follow in the event of an unexpected release of hazardous materials. In addition to safety policies unique to the Water Filtration Plant, this facility is also subject to numerous safety policies and requirements applicable to departments of the City of Grand Rapids in general. The general safety program policy for the City states: "The City will comply with all safety laws and regulations". Compliance with this edict is enforced via implementation of an active City safety program, administered by staff of the Office of Risk Management. C. MEASURES FOR PREVENTING ACCIDENTAL RELEASES OF HAZARDOUS MATERIALS The Lake Michigan Water Filtration Plant is subject to two major regulatory programs which address the prevention of accidents and injuries resulting from hazardous chemical releases. The first of these is the Process Safety Management Program (PSM), conducted under authority of the MIOSHA General Industry Rule 91. The PSM program requires comprehensive assessment and analysis of all chlorine related processes, with the objective of ensuring that all systems are capable of functioning in a safe manner at all times. The second of these programs, the Hazardous Waste Operations and Emergency Response Program ("HAZWOPER") is conducted under authority of the MIOSHA Occupational Health Rules 325.52101 - 52137). The HAZWOPER Program requires development of a detailed plan outlining all steps which will be undertaken in the event of a hazardous materials release, and which personnel will be responsible for various actions. A formal HAZWOPER Plan is currently in effect at the facility, and regular test exercises of the plan are conducted by facility staff. There are a variety of structural and mechanical safeguards at the facility which are designed to prevent the release of hazardous materials, and to mitigate the effects of any release that might occur. Security of the facility has recently been upgraded by the installation of perimeter fencing and the installation of a video monitoring system for surveillance of exterior areas of the premises. A chlorine gas detection system is in place to provide instant warning of any unexpected chlorine release. A chlo rine gas scrubber device has been installed to collect and chemically neutralize chlorine from an accidental release before the chlorine can be released to the exterior environment. Repair kits are located at strategic points in the facility to allow prompt control of any chlorine leakage which might occur. D. EMERGENCY RESPONSE PREPARATIONS Because of the quantity of chlorine handled by this facility, it is subject to to regulation under authority of Title III of the Superfund Amendments Reauthorization Act, also referred to as the "Emergency Preparedness - Community Right-To-Know Act". This law requires that the facility, working in cooperation with local governmental agencies and officials, must establish a formal plan for responding to off-site chemical emergency incidents. The facility has established such an emergency plan, the most current edition of which is dated March 5, 1997. The plan outli nes the nature and quantity of hazardous products stored and used at the facility, the projected areas around the facility which would be impacted in the event of a release, and protective actions that should be taken by public safety officials to ensure the safety of persons within the affected areas. The plan also contains detailed information regarding emergency contacts that are to be made in the event of a chemical release from the facility. In addition to the plan noted above, the facility's emergency plans in response to HAZWOPER program requirements are also of significance. Although the emergency response measures outlined in the facility's HAZWOPER plan are focused on protecting employees of the facility, the same measures are effective in preventing chemical releases to the exterior environment as well. E. FIVE-YEAR ACCIDENT HISTORY In the five-year period preceeding the dat e of this plan, there have been no releases of hazardous substances from the facility which have produced any off-site effects to persons or properties in the plant vicinity. F. HAZARDOUS MATERIAL ACCIDENTAL RELEASE SCENARIOS Two hypothetical chlorine release scenarios were considered in conjunction with this risk management plan. The first of these, the "worst case" scenario, involved the release of the entire contents of one one-ton cylinder of chlorine within the facility over a ten-minute period of time. This scenario also assumed no mitigation of the release through the institution of either administrative or mechanical controls. Other assumptions included an ambient air temperature of 77 degrees F. (25 degrees C.), a wind speed of 3.36 miles-per-hour, and a relative humidity of 50%. Given these defined criteria, the calculated distance from the plant to the limits of the "toxic end-point" (i.e., the point at which chlorine concentrations would be such that persons could typically be exposed for periods of up to one hour without experiencing irreversible effects or other serious health symptoms that might impair an individual's ability to take protective action) is 3.0 miles. The second situation considered was for an "alternative" scenario - that is, one having a somewhat greater potential for actual occurrance than the "worst case" scenario cited previously. The specifications selected for modeling the "alternative" scenario included the release of the entire contents of one one-ton cylinder of chlorine within the plant, due to a broken valve on the bottom of the container. It was assumed that the total duration of the chemical release would be 31 minutes, and that no mitigation of the release would occur through institution of either administrative or mechanical controls. Climatic conditions projected for this scenario included an ambient air temperature of 77 degrees F. (25 degrees C.), a wind speed of 6.72 miles-per-hour, and a relative humidity of 50%. Given these specifications, the calculated distance to the limits of the "toxic end-point" from the plant is 1.5 miles. Parameters and projected effects for both scenarios noted above were based on chemical release modeling conducted by the American Water Works Association Research Foundation, which utilized the ALOHA (Areal Locations of Hazardous Atmospheres), Version 5.2.1 software as the instrument for its calculations. G. PROJECTED SAFETY ENHANCEMENTS As of the date of this plan, the only proposed safety-related enhancement involves changes by the City's chlorine supplier to the cylinders in which it distributes its product. Future chlorine cylinders will be equipped with a new style of valve in corporating Teflon components. These components will reduce possibilities for sticking valves, thereby reducing the possibilities for valve damage or breakage caused by personnel attempting to "free up" valves which are not operating properly. Effective imediately, all future shipments of chlorine cylinders provided by the City's supplier will be equipped with the new-style valves. |