City of Elgin - Airlite facility - Executive Summary |
|
FACILITY BACKGROUND The City of Elgin Water Department (Elgin) stores chlorine, a regulated toxic substance, in one-ton cylinders at their Airlite facility. Currently, the quantities of chlorine stored at the Airlite facility are greater than the threshold quantity; therefore, Elgin is required to prepare an RMP for the Airlite facility. The Airlite facility does not qualify as a Program 3 facility, because its SIC code (5169 - SIC Designation) is not specified under 40 CFR 68.10(d)(1), and because Airlite's chlorine storage is not subject to OSHA's PSM standard or located in close proximity (co-located) to other vessels containing another OSHA PSM-regulated substance. However, Airlite's worst-case accidental release endpoints do extend beyond the Airlite's property, and would affect the surrounding public receptors, thereby resulting in Airlite being a Program 2 facility. As designated by the applicability requirements of 40 CFR 68.10, the Airlite facility in Elgin, Illinois is r egulated under the Program 2 eligibility requirements of 40 CFR 68.12(c). It should be noted that, as required in 40 CFR 68.190(b), Elgin shall revise and update its RMP at least every five (5) years after its initial submission or most recent update, whichever is later. WORST-CASE RELEASE SCENARIO The following is the worst-case release scenario analysis for chlorine at the Airlite facility in Elgin, Illinois. 7 The worst-case release scenario considers the potential failure of seven (7) 2,000 pound cylinders, resulting in a toxic chemical spill. A computer-based version (i.e., US EPA's RMP*Comp, version 1.06) of the methodology presented in US EPA's RMP Offsite Consequence Analysis Guidance (US EPA, May 24, 1996) was used to complete the worst-case release scenario modeling analysis. Utilizing RMP*Comp, the distance to the toxic endpoint was determined to be 2.6 miles. The affected public receptors under this worst-case release scenario include: private residences; major com mercial, office, and industrial facilities, schools, hospitals, nursing homes, and daycare centers. No potentially affected environmental receptors were identified. The total residential population within this 2.6-mile radius is approximately 39,687, which was estimated based on data provided by the U.S. Census Bureau. ALTERNATIVE RELEASE SCENARIO Chlorine The following alternative release scenarios were identified at the Airlite facility: 7 Process piping releases from failures at flanges, joints, welds, valves and valve seals, and drains or bleeds; 7 Process vessel or pump releases due to cracks, seal failure, drain bleed, or plug failure; 7 Vessel overfilling and spill, or overpressurization and venting through relief valves or rupture disks; and, 7 Shipping container mishandling and breakage or puncturing leading to a spill. The following is the alternative release scenario analysis for chlorine stored at the Airlite facility in Elgin, Illinois. 7 Alternative release scenar io considers the potential release of chlorine contained in one-2,000 pound cylinder (due to a 0.05 square inch rupture of the cylinder), resulting in a toxic chemical spill. 7 This scenario assumes a release rate of 157 pounds per minute and that the release occurs over a 30-minute period. Therefore, this alternative release scenario modeled the release of a total of 2,000 pounds of chlorine Utilizing RMP*Comp, the distance to the toxic endpoint for this alternative release scenario was determined to be 0.2 miles. The affected public receptors under this alternative release scenario include: private residences, a hospital, a school, and a nursing home. The total residential population within this 0.2-mile radius is approximately 200, which was estimated based on data provided by the U.S. Census Bureau. This facility complies with all applicable state and local codes and regulations. The chlorine system is designed, installed, and maintained in accordance with all applicable industry standards and state laws. Based on facility records and interviews with Airlite personnel, no accidental releases of the covered chlorine storage processes has occurred at the Airlite facility in Elgin, Illinois over the past five (5) years. An accidental release from a covered process is one which results in deaths, injuries, or significant property damage on-site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage (40 CFR 68.42). Elgin has coordinated response actions with the local and fire department (City of Elgin Fire Department) in the event of a chlorine release. In the event of an accidental release, Elgin employees will respond to the emergency themselves in accordance with Elgin's written emergency response plan. If there is a minor leak that is easily controlled, Elgin's employees are instructed to repair the leak immediately and report the leak to their supervisor. If the leak is a major emergency, t he person in charge will assign someone to contact the Elgin Fire Department and the supervisor if not on the scene. If chlorine is entering the building, a chlorine emergency will be announced over the intercom and an evacuation will take place. A chlorine sensor is located within the chlorine storage and feed rooms. If the chlorine concentration inside the chlorine storage or feed rooms reaches 1 part per million (ppm) the system sounds an audible alarm and notifies the control room in the City of Elgin Water Department Riverside facility via the computer system. The facility plans to continue the employee training program and update the Emergency Response Plan where appropriate and in accordance with applicable regulations. |