Wright Chemical Corporation - Executive Summary |
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Wright Chemical Corporation (Wright) is a chemical manufacturing facility located in a rural area of Acme, North Carolina, in Columbus County. Wright manufactures several types of products including formaldehyde, formaldehyde-based products and silanes. This report documents the risk management program required at the Wright facility in Acme, North Carolina. Wright began operation in 1959 and has produced a variety of products throughout its history. As a member of the Synthetic Organic Chemical Manufacturers Associations Responsible Care program, Wright is committed to safeguarding the community, workplace and environment. The management team, including Wrights chairman of the board, is an advocate of this program and supports it fully. In response to these requirements, Wright continually reviews its environmental compliance and pollution prevention goals. Wrights Environmental Commitment Policy (dated January 1995) outlines significant operation upgrades and capital projec ts aimed at reducing Wrights environmental impact. This policy is reviewed and reevaluated on an annual basis. In the past three years alone, Wright has reduced emissions at the plant by over 70 percent and has exceeded regulatory requirements in several cases. Wright is also ISO 9002 certified. This certification assures that Wright follows regimented procedures for purposes of quality control. In doing so, this encompasses safety and environmental goals for efficient and continuous operations. The ISO program also serves as a basis for well organized procedures and programs, which is an important aspect of RMP. The RMP regulation is closely associated with the Occupational Safety and Health Administration (OSHA) Process Safety Management (PSM) regulation. Wright complies with PSM and has completed PSM requirements for ammonia, formaldehyde and propane. Compliance with the PSM provisions establishes a program for Wright to apply to RMP. Specifically, the components of the L evel 3 RMP prevention program elements are identical to the components required by PSM. Wright is committed to making significant efforts to prevent situations which would pose threats to employees, the surrounding public, and the environment. The five year accident history for the facility indicates this, as there have been no accidental releases that resulted in any deaths, injuries or significant property damage on or off site. Wright Corporation has not had any major releases of ammonia, formaldehyde, or propane in the past 5 years. The processes are designed and operated with numerous automatic and manual fail safe measures. All operators undergo continuos training on proper operation of the equipment in addition to receiving routine safety training. However, in the event of an unforeseen release, Wright has a written emergency response plan that provides for immediate response by trained, onsite personnel. All response efforts are coordinated with the Columbus County Local Emergency Planning Committee and the Acme-Delco Fire and Rescue teams. This ensures that Wright is prepared to quickly mitigate and control any accidental release, even the remotely possible catastrophic event. All of Wrights programs aimed at safety and response are routinely reviewed and updated. The employees are involved in this process with the management team. The substances at Wright that are present in sufficient quantity to require Risk Management Plans (RMP) are ammonia (both anhydrous and aqueous), formaldehyde and propane. Ammonia and formaldehyde are both listed as regulated toxic substances and propane is a regulated flammable substance. Anhydrous and aqueous ammonia are stored in 30,000 gallon cylindrical tanks. There are two tanks containing anhydrous ammonia and one tank containing aqueous ammonia at a concentration above 20 percent. A fourth ammonia tank is also present at the facility, which contains aqueous ammonia at a concentration less than 20 percent, and is therefore not subject to the RMP regulation. Formaldehyde is stored in several tanks at the Wright facility. The two main 100,000 gallon tanks (one containing a 37 percent formaldehyde/water solution and the other containing an approximate 50 percent formaldehyde/water solution) were the focus of this RMP program. Propane is used as a fuel for the catalytic oxidizer on the hexamine plant and the dowtherm heater in the formaldehyde plant. It is stored in one 30,000 gallon tank on site. As required by the RMP regulation, both worst case and alternative case scenarios were analyzed for these three regulated substances. For all worst case scenarios, it was assumed that the entire contents of a tank would be released in ten minutes. In each case, administrative controls of not filling a tank to maximum capacity were considered (e.g., the propane tank is not filled above 88 percent of the maximum). Passive mitigation measures were considered for ammonia and formaldehyde as bo th substances are stored within concrete diked areas that would limit the exposed area of a pool and thereby reduce the release rate to the environment. However, this mitigation measure had little or no affect on the results for ammonia as it was assumed to be released as a vapor. None of the worst case scenarios are expected to occur because of Wrights operational, safety and response programs. Alternative release scenarios were based on line ruptures, which are more likely possible events. In addition to the administrative control and passive mitigation measures mentioned previously, other active mitigation systems were also considered for the alternative case scenarios. Specifically, emergency or excess flow valves were considered in determination of the maximum amount that could be potentially released. In addition, Wright has the capability of neutralizing a formaldehyde release by either spraying the pooled spill with water or aqueous ammonia. Either would reduce the am ount released to the atmosphere by approximately 75 percent. Of the two toxics, ammonia presented the worst case potential area of influence of 4.2 miles. This distance does extend off Wrights property and could potentially affect residents and other industry sectors in the area if such a catastrophic event were ever to occur. However, the alternative release scenario modeled for ammonia indicated a maximum endpoint distance of 0.3 miles, which briefly extends off Wrights southern property boundary. Propane was the only flammable substance required to be modeled for RMP. The worst case scenario of a vapor cloud explosion indicated a potential area of influence of 0.4 miles. This extends slightly off Wrights southern property boundary, but would potentially affect no more than 30 residents in the area. The alternative case modeled for propane does not result in any off site impacts. All modeling was completed using EPAs RMP*Comp model, with the exception of the modeling for ammonia. This modeling was completed using the Process Hazard Analysis Software Tools (PHAST) model, which is a more sophisticated model than the conservative algorithms utilized in the RMP*Comp model. This model was chosen to more accurately represent the characteristics of anhydrous ammonia. A conservative approach was still followed to examine the consequences of the worst alternative release case. In summary, the conservative approach that Wright used to prepare its Risk Management Program and Risk Management Plans indicated that potential releases were not likely to affect the surrounding public. |