Northwest Aluminum Company - Executive Summary |
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Northwest Aluminum Company owns and operates a primary aluminum smelter in the Dalles, Oregon. Nothwest Aluminum Company is dedicated to protecting the environment and complying with all applicable environmental rules and regulations. This Risk Managment Plan (RMP) was prepared to comply with requirements of the Clean Air Act Ammendments of 1990. The purpose of the RMP is to address potential accidential releases of toxic chemicals. Northwest Aluminum Company uses one chemical on the list of substances covered by this rule. Chlorine is used as part of the aluminum production process in limited quantities. The use of chlorine at the facility has been covered by OSHA requirements for several years. The RMP process allowed Northwest Aluminum Company to review existing process and procedures to assure that chlorine is being used in the safest manner possible. Employees are trained to respond to a chlorine leak. Any leak would trigger the process alarm and trained employees would i mmediately respond and eliminate or mitigate the leak. No reportable accidents have occurred in the last five years. No evacuations or injuries due to chlorine have occurred in the last five years. The safety department gets occassional reports from employees that they have smelled chlorine, but this has not resulted in a doctor visit or lost time by the employees. The worst-case chlorine release scenario assumes that the entire contents of two one-ton cylinders are released in a ten minute period. Two cylinders were chosen as representative of the worst-case scenario because the process has two cylinders connected together at any one time. While this type of release is very unlikely, its analysis is required by the RMP process. A release of this magnitude would result in an off-site impact area of 1.3 miles. The distance was determined using RMPComp. RMPComp is a computer program supplied by EPA to estimate the impact of accidential releases. A release of this magnitude is v ery unlikely because the faciltiy is manned on a 24-hour basis and any significant leak would trigger an alarm that would alert the operator. The cylinders are used inside of a building and any leak would be mitigated by the building. The operator would initiate Emergency Response procedures and the leak would be stopped. The chlorine tanks are used inside of a building and a large release would be partially contained inside of the building. The alternative release scenario assumes that the connecting lines at the tanks fail. It is estimated that a maximum of 2,000 pounds of chlorine would be released in this scenario. The offsite impact area of this release would be 0.2 miles. The distance was determined using RMPComp. There are a few residences, and some light industrial/commercial facilities within 0.2 miles of the facility. The alternative release assumes that one full cylinder is released before the leak could be repaired. It is assumed that the release occurs over a per iod of ten minutes. The facility has never had a release of this magnitude. In fact, the only releases of chlorine have be very small and while there are no records of actual release amounts, it is estimated that the largest historical release was less than ten pounds. |