Holland Wastewater Treatment Plant - Executive Summary |
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Executive Summary The Wastewater Treatment Plant of the Holland Board of Public Works is a 16-MGD sewage plant serving industrial, commercial, and residential customers in the Holland area. Although the WWTP uses various chemicals in its operation, liquefied chlorine gas is the only chemical handled that is a potential serious threat to the community and requires the submission of a Risk Management Plan. The chlorine gas is handled in pressurized 1 ton cylinders and is used to disinfect wastewater from municipal sewage treatment. The chlorine gas is fed under vacuum from the cylinders to a chlorinator that generates a nonhazardous solution with the gas and municipal water. The solution is then fed to the wastewater for disinfection. The WWTP is currently in the engineering stages of substituting liquid bleach for the chlorine gas and should have the substitution completed by the fall of 1999. All use of chlorine gas at the WWTP will be eliminated at that time. The liquid bleach remains in liquid state under normal conditions and represents a significantly less hazard to human health and the environment than the chlorine gas. Over the past several years the Holland WWTP has handled chlorine gas and has become very experienced in the characteristics and safety concerns of the gas. The plant personnel are continuously improving the management and technical aspects of chlorine handling. To further reduce the potential for a release, the WWTP implemented a process safety management program for the handling of chlorine liquid. The process safety program was a team effort of plant personnel and included a detailed review of the entire system. Each piece of equipment and procedure was evaluated for potential failure, the consequences of a failure, and preventative measures taken to reduce the potential. A preventative maintenance program is in place to maintain the integrity of the system. Training on the chlorine system is required for any employee who becom es involved in the operation or maintenance of the system. To further minimize potential for a chlorine release, the WWTP feeds the chlorine under vacuum rather than pressure. The vacuum regulators controlling the feed system operate only when the integrity of the chlorine system is intact and will automatically shutdown when a leak is detected. Additionally, the chlorine storage and feed rooms are equipped with chlorine gas monitors and will sound alarms immediately if a leak occurs. Operators trained in proper handling techniques and emergency response measures for chlorine gas continuously staff the plant and are fully prepared to handle any potential releases. The WWTP has also taken steps to properly manage a release by developing and implementing emergency plans. WWTP employees have been trained in these plans and in Hazwoper response techniques. Additionally, the WWTP was one the first organizations to formalize response plans with the Ottawa County LEPC. These plans will prepare local fire and police units to properly response to the WWTP in case of a release. The Holland Fire Department has been on site numerous times for tours and training and has conducted chlorine response drills at the plant. |