Wastewater Treatment Plant - Executive Summary
1. At the City of Punta Gorda, Florida Wastewater Treatment Plant, chlorine is used for disinfection. Chlorine is considered highly hazardous by the Environmental Protection Agency. The same properties that make chlorine valuable as a disinfectant also make it necessary to observe certain safety precautions in handling to prevent or reduce unnecessary human exposure. It is the Policy of the City of Punta Gorda to adhere to all Federal and state rules and regulations regarding the safe storage and process use of chlorine. |
Emergency response procedures include notification of the local fire departments and the Charlotte County Office of Emergency Management. The chlorine system is located in a roofed bay with one wall-less side for loading/off-loading cylinders, 50%-open side walls, and a solid rear west wall. The chlorine vacuum-feed system is located just west on the other side of the solid wall in a separate, enclosed room. Access to the site is restricted to a gated entrance for
authorized facility employees, management personnel, and contractors.
2. The stationary source and the substance handled:
The regulated substance is chlorine. Chlorine is received in ton-cylinders and stored in the chlorine receiving bay, where it is also fed under vacuum to the chlorine metering room, then to the plant processes. The maximum amount of chlorine stored at the site is 8 tons (16,000 pounds).
3. Worst-case scenario and the alternative release scenario, including administrative controls and mitigation measures such as a substantial nature preserve around the facility, limit the potential impact on human receptors:
*Worst-case scenario. EPA has defined the and specified the worst-case chlorine release scenario. Failure of a chlorine cylinder, when filled to capacity, would release 2,000 pounds of chlorine at a rate of 200 pounds per minute, for 10 minutes, in an open space in direct contact with outside air. The estimated distance to the toxic endpoint of 0.0087 mg/
L is 3 miles.
* Alternative release scenario. A vacuum regulator washer failure at the chlorine container, resulting in a 15-minute release of chlorine gas at a rate of 5.2 pounds per minute in an open space in direct contact with outside air. The estimated distance to the toxic endpoint of 0.0087 mg/L is 0.1 miles (528 feet). The release has the possibility of extending beyond the facility boundary into the C.M. Webb Wildlife Management Area, which is accessible to the public.
4. Administrative Controls and Mitigation Measures:
The employees responsible for overseeing and assisting in the delivery and transfer of chlorine cylinders are limited to Service Worker "IV" classification or higher, as well as the senior maintenance employees. These personnel are also trained in the hazards of chlorine and the steps to be taken in an emergency situation to mitigate a release.
5. The General Accidental Release Prevention Program and the specific prevention steps:
The Wastewater treatment P
lant complies with EPA's Accidental Release Prevention Rule and with the applicable state codes and regulations. The Wastewater Plant operators and other employees are trained in safety policies and procedures that are available to all personnel. The City has written Standard Operating Procedures (SOP's) that are followed in the daily operation of the facility. In addition, each employee receives on-the-job training, as well as special training sessions when new pieces of equipment are installed. The maintenance program is well established and documented to ensure the proper operation and maintenance of equipment. Furthermore, a procedure has been established for compliance audits and incident investigations that will be implemented when necessary. The delivery drivers have been thoroughly trained for safe chlorine handling practices. The facility employees oversee the deliver of each chlorine truck.
6. Five-year accident history: Since June 21, 1994, there have been no accident
al releases, fires, or explosions resulting frolm the chlorine system.
7. Emergency Response Program: The Wastewater Plant's emergency response program is based upon the management system in-place, consisting of the appropriate discovery and notification procedures to ensure coordination with the local emergency planning committee and the local fire department. The City administers an Emergency Action Plan (EAP) at the Wastewater Plant to inform employees of potential emergencies that could occur at the plant and to minimize and mitigate potential impacts to persons and property.
8. Planned changes to improve safety:
A hazard review of the chlorine storage and feed areas was conducted on April 15, 1999. From this review, recommendations were:
a. Develop an Emergency Action Plan (EAP) for damage caused by severe weather, heavy equipment, fire, hunters, damaged caused by vandalism, and terrorism (an EAP for severe weather and fire - complete May 1999).
b. Install "no parking" signs nea
r cylinder storage areas
c. Develop Standard Operating Procedures (SOPs) for moving the cylinders (SOP completed May 1999)
d. Document unacceptable delivery and handling practices by chemical supplier
e. Develop a record keeping system for regulator installation errors, for any pipe/valve failures, and to test system vacuum lines with no demand (This item was completed in May 1999 and is part of the Process Safety Management Plan (PSM))
f. Consider incorporating a chemical scrubber for containment of any potential chlorine release.