Ocmulgee River Water Treatment Plant - Executive Summary
The Risk Management Plan for the Ocmulgee River Water Treatment Plant minimizes the likelihood and effects of a chemical accident involving chlorine by identifying and reducing potential hazards as well as preparing employees and responders to handle a chemical emergency. This is accomplished by establishing a program in accordance with the EPA's requirements outlined in 40 CFR Part 68 providing for employee and public safety. |
The importance dedicated to the safe operation of the Ocmulgee plant is reflected in it's record of no reportable releases or accidents involving chlorine over the past 5 years. The continued safety to the plants employees and the surrounding community will be further ensured through the implementation of the Risk Management Program.
The Ocmulgee River Water Treatment Plant, located below Lake Jackson east of Jackson, Georgia, uses chlorine to disinfect water taken from the nearby Ocmulgee River as part of the treatment process necessary to provide clean dr
inking water for Butts County. The plant stores as much as 10,000 lbs. of chlorine in one ton containers that hold 2,000 lbs. each of liquified chlorine under pressure. The chlorination process involves a system where chlorine gas is piped from these containers and then controlled and metered until being applied as a solution to the raw water.
Atmospheric dispersion modeling was conducted, using software provided by the EPA for this purpose called RMP*Comp, to assess the potential off-site area at risk given an accidental release of chlorine from the plant were to occur. A worst-case scenario was first considered involving an unlikely event in which the entire contents of a single container, 2,000 lbs., escaped over a ten minute period. An alternate-case scenario was then conducted to assess a potential accident thought to be more likely to occur than the worst-case. This situation assumed chlorine was released at a rate of 10.5 lbs./sec. for 60 minutes consistent with what would
be expected from a leak involving a faulty valve or bad connection. In each case, the modeling was performed to determine the distance a chlorine cloud could possibly reach before dissipating to an acceptable level, called the toxic endpoint, at which it is believed that an individual can be exposed for up to an hour without experiencing significant effects.
The worst-case scenario resulted in an endpoint distance of 3.0 miles. Within this radial distance from the plant, there live an estimated population of 547 people who could potentially be effected. The alternate-case produced a distance of 0.2 miles effecting approximately 4 people.
For each of these scenarios it is important to point out that the modeling results are intended to serve as a simplistic guide to establish the entire area surrounding the plant that could possibly be at risk in the event of a chlorine release. The behavior of a chlorine cloud would actually be more predictable than is indicated by creating a
circular zone around the plant based on a radial toxic endpoint distance. Since chlorine is 2.5 times as heavy as air, it will most likely flow downhill rather than being carried in any one direction due to prevailing winds as the model implies. Furthermore, no mitigation measures such as enclosures and the abundance of trees in the area, which would each hinder the advance of a toxic cloud, were considered when inputting information into the models.
Due to the topography surrounding the Ocmulgee River plant, a significant release of chlorine would most likely flow down hill to the river and then continue along its downstream path regardless of wind direction. For this reason, the distances established by the model will more likely apply to the less populated region down river from the plant rather than the more densely populated area surrounding Lake Jackson.
To lessen the likelihood and mitigate the effects of a potential release of chlorine, the Ocmulgee River WTP's Risk Ma
nagement Program covers the following subjects
1. Chlorine hazard and safety
2. Operating procedures for safely operating the chlorine system
3. Operator training on operating procedures and emergency response
4. Preventive maintenance
5. Emergency action and emergency response
The Emergency Response Plan (ERP) incorporated into this program has been coordinated with Butts County Emergency Services, the Jackson Fire Dept., and the 911 Dispatcher's office and will be incorporated into the community's emergency response plan. The ERP includes the area most likely to be at risk in the event of a chlorine release, a list of residents in this area to be notified, and instructions for establishing appropriate roadblocks.
Effective emergency action and response is ensured through initial and ongoing training concerning emergency response procedures. Plant operators are trained on chlorine hazards, stopping chlorine leaks, and emergency procedures and equipment.
This Risk Manage
ment Program is designed so that each element may be easily implemented and maintained and that potential hazards are closely monitored, operators stay sufficiently trained, and an emergency situation will be handled as efficiently as possible. This will assure that the Ocmulgee River Water Treatment Plant will continue the safe operation of its chlorination process in providing high quality drinking water for Butts County.