Cumberland Wastewater Treatment Plant - Executive Summary
Executive Summary |
Release Prevention and Response Policy
In compliance with the provisions of Title 40 of the Code of Federal Regulations Part 68 and as part of an on-going effort to be prepared for emergencies, the City of Cumberland, Utilities Division is preparing an Integrated Process Safety and Risk Management Plan for both the Cumberland Wastewater Treatment Plant located on the south side of the City adjacent to the Potomac River, and the Water Filtration Plant in Bedford County, Pennsylvania. It is the policy of the Utilities Division to operate all of the water and wastewater treatment facilities within its jurisdiction in the safest and most efficient manner possible, with due regard for the health and safety of Utilities Division employees, the Public, and our environment.
Stationary Source and Chemicals
The City of Cumberland Wastewater Treatment Plant employs gaseous chlorine for the disinfection of the wastewater. Sulfur dioxide gas is used to de-chlorinate the
treated effluent prior to discharge to the environment. This is considered to be a single, continuous process.
The gasses are delivered, stored, and drawn from one-ton containers. The gasses are liquified by the pressure in the containers and gas is drawn from a vapor layer at the top of the container. The Emergency Response Plan has been in existence in some form since 1990, and is coordinated with the local emergency response organizations.
The worst case scenario for the Wastewater Treatment Plant assumes the Environmental Protection Agency mandated elements as defined in 40 CFR 68. The basis for the calculation is the release of two tons (4,000 pounds) of chlorine or sulfur dioxide during 10 minutes at 0 feet elevation and 100 degrees Fahrenheit, with an atmospheric stability class F. This is a very stable atmosphere with the highest temperature recorded for Cumberland.
The Alternative scenario assumes a break in the gas withdrawal tubing at the ton c
ontainer connection, a temperature of 100xF (the maximum temperature, at the closest reporting station), and an atmospheric stability class of D. Procedures prohibit lifting containers over in- service containers, reducing the likelihood of breaking multiple lines, and all container changes are done during normal duty hours on weekdays. This scenario also assumes the failure of the vacuum-controlled chlorine regulators.
The general release prevention program is based on training, standard operating procedures, material selection, and automatic shut-off flow control valves which will be installed when and if the proposed budget is approved. The operating personnel are trained in the proper operation, maintenance, connection-disconnection, and emergency response for the chemicals employed at the Wastewater Treatment Plant. Emergency shut-off valves are budgeted and will be mounted directly on the container outlet. With regard to chlorine and sulfur dioxide, th
e two chemicals are similar enough that the operations are essentially the same.
All gas-containing tubing and control devices are selected for specific material compatibility and Codes and Standards compliance. The systems are regularly and routinely inspected, and maintenance is performed as appropriate.
The Wastewater Treatment Plant did have a release of 200 pounds of chlorine on October 30, 1997. There were two employees transported to a local hospital as a precautionary measure. The accidental release resulted in no damage on-site, and there were no off-site consequences. The accident resulted in improvements to gas removal equipment, revised Standard Operating Procedures and revised training for operators.
Emergency Response Program
The Emergency Response Program is based on the use of Utilities Division WWTP employees who are trained to respond to, and control, an accidental release of either chlorine or sulfur dioxide. The employees are trained i
n the use of appropriate Personal Protective Equipment and specialized ton-container patching kits (Chlorine Institute Kit B).
With regard to flammable gasses, the WWTP has small quantities of methane and propane. The City of Cumberland Fire Department is available, and Allegany County does have a Hazardous Incident Response Team and an Emergency Response Plan. Emergency Response Plans have been mutually coordinated.