Penn Township WWTP - Executive Summary |
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Penn Township Wastewater Treatment Plant 996 Ridge Avenue Hanover, PA 17331 Penn Township takes pride in observing the required safety precautions in preventing hazards in the workplace, and has an emergency response plan in effect in the event of accidental releases of regulated substances. The Penn Township wastewater treatment plant (WWTP) employs the latest technology in process controls and monitoring detection systems. Active and passive mitigation systems are designed to minimize the impacts of any accidental releases of regulated substances. The Penn Township WWTP, owned and operated by Penn Township, provides sewer service to residential, commercial and industrial users located in Penn Township and in portions of Hanover Borough and Heidelberg Township. The Penn Township WWTP utilizes one (1) chemical onsite which is subject to the Chemical Accident Prevention provisions found at 40 CFR Part 68. This toxic substance is Chlorine. Chlorine is used for disinfection of the tre ated effluent prior to its discharge to Oil Creek. Typically, there are seven (7) one-ton cylinders of Chlorine present onsite at any given time. These cylinders are located in a block chemical storage room of the garage facility. The chlorine room has an intake vent and an exhaust vent equipped with a fan which vents to the outside atmosphere. The chlorination feed system has manual and automatic shutoffs. A remote alarm system is employed to notify employees of any releases of chlorine gas. This alarm system also ties into a security system which dials the telephone numbers of response personnel. Safety equipment is located nearby in the garage portion of the building. The facility is manned 8 hours per day, five days per week and 3 hours per day on the weekends. Gates to the facility are locked when personnel are not on duty, therefore, the chlorination building is not accessible to the public. The door to the chlorine room is kept locked at all times. The offsite consequence ana lysis conducted for the Penn Township WWTP consisted of two scenarios, worst-case release and alternative release. The parameters for the worst-case release scenario are established by EPA. These parameters assume the maximum quantity in the largest vessel is released over a 10-minute period with default wind speed, temperature and humidity conditions. The only passive mitigation present at the Penn Township WWTP is the fact that the chlorine cylinders are stored in a building which vents to the outside air. Using EPA's RMP*Comp model, the estimated distance to the toxic endpoint for a worst-case release is 0.9 miles. The estimated residential population within the 0.9 mile radius of the facility is 1,752 persons based on 1990 U.S. census data. Other than the residential population, there is a school, several commercial and industrial establishments, and a recreational area located within this measured radius. The proposed alternative release scenario assumes a release will occur due to equipment failure. The assumed parameters used in the RMP*Comp model are based on an actual incident that occurred at a similar WWTP, in which a screw on the yoke assembly of the regulator could not be tightened and a small amount of chlorine was released. It is estimated that the duration of the release was less than one minute and that no more than one pound of chlorine was actually released into the room atmosphere. The estimated distance to the toxic endpoint for the alternative release is less than 0.1 miles. The estimated residential population within the 0.1 mile radius of the facility is 55 persons based on 1990 U.S. census data. Tthere is only one industry located within this measured radius. A prevention program policy document was developed for the Penn Township WWTP in accordance with regulations found at 40 CFR ''68.48-68.60. The facility is classified as a Program 2 facility. Penn Township WWTP's Program 2 Prevention Program summarizes the pertinent safety informatio n, hazard review procedures, operating procedures, training requirements, maintenance procedures, compliance audits and incident investigation policies. The facility has standard operating procedures (SOPs) in effect for operation and maintenance of the chlorination system. These SOPs are readily accessible to the chlorine room. Safety precautions include, checking the chlorine detector before entering the cylinder room, use of a face mask or other appropriate personal protective equipment, and testing for leaks with ammonia solution. Training offered to plant employees includes confined space entry procedures. Documentation of the training events for each employee will be maintained in the employees' personnel files. The Penn Township WWTP has an Off-Site Response Plan which has been coordinated through the York County LEPC. The Plan provides notification procedures, emergency response procedures, reporting requirements, and coordination efforts of all involved parties. The plan is reviewed and revised periodically to ensure contact names and telephone numbers are correct. |