Houma Water Treatment Plant - Executive Summary
27837 LDEQ Facility ID Number |
1. Facility accidental release prevention and emergency response policies:
Terrebonne Parish Consolidated Waterworks (TPCW) District No.1 pledges to protect the environment and the health and safety of employees and the community in which we operate. As a public body, we recognize the continuing challenge of fulfilling this pledge while accomplishing our goals. Each of us shares this responsibility to ensure our long-term success. To achieve our goals, we will:
a. Commit to leadership by operating and growing our business in compliance with legal requirements and TPCW District No. 1 environmental, health and safety operating standards, which may be more stringent.
b. Safeguard our employees' health by promoting an accident-free workplace, minimizing exposure to hazardous substances, and providing preventive health care systems.
c. Promote safe handling, use and disposal of our products by acquiring and communicating information a
nd education to our employees and customers.
d. Minimize the environmental impact of our operations by promoting pollution prevention and environmental conservation.
e. Anticipate, evaluate and manage risks by maintaining crisis management programs that emphasize prevention and effective emergency preparedness, response and recovery plans.
f. Commit to continuous improvement by monitoring compliance with regulations and our internal standards and by striving for performance, which compares favorably with industry leaders.
g. Earn the public trust by communicating openly about our policies, programs and performance and advocating sound laws and regulations.
2. Facility description and regulated substances handled:
The Houma Water Treatment Plant provides drinking water to the City of Houma and Districts 2 (Bayou Grand Caillou) and 3 (Bayou Dularge) via Munson Pumping Station. The facility has a treatment capacity of 8-million gals/day. On average, the facil
ity treats approximately 5.5-million gals/day.
At this facility, chlorine is the only regulated substance that exceeds the threshold quantity for toxicity listed under section 112(r) of the Clean Air Act. The average inventory includes six (6) one-ton (2,000 lb.) containers on stand-by and four (4) on-line, for a total of 17,000 lbs. The maximum inventory includes nine (9) one-ton (2,000 lb.) containers on stand-by, four (4) on-line and four (4) 150-lb. cylinders, for a total of 23,000 lbs.
3. The worst-case and alternative release scenario's:
The worst-case release scenario is failure of a one-ton (2,000 lb.) chlorine container resulting in a direct release. The entire contents would be released in 10-minutes (200 lbs./min.). The resulting radius to the toxic endpoint (ERPG-2) is 1.30 miles, with an estimated population of 1,900 people.
The alternative release scenario is based on failure of a 1-inch schedule 80 pipe connected to three (3) one-ton (2,000 lb.) chlo
rine containers resulting in a release of gas. It is assumed that the release is limited by the flow of gas through the 5/16-inch valves on each of the 1-ton containers, rather than through a 1-inch pipe, and that 1,053-lbs. is released over 30-minutes (estimated release rate = 35.1 lbs./min.). The resulting radius to the toxic endpoint (ERPG-2) is 0.10 miles, with an estimated population of 40 people.
No passive or active mitigation was considered in the release scenario. The releases were assumed to occur outdoors (e.g., garage door open in facility chlorine process area) in an urban area.
The American Water Works Association (AWWA) Compliance Guidance and Model Risk Management Program for Water Treatment Plants manual was used for reference in preparing the RMProgram submittal. RMP*Comp (Ver. 1.06) was used to perform the offsite consequence analyses. LandView ?III mapping software was used to obtain census data for the release scenario.
4. The general accidental rel
ease prevention program and the specific prevention steps:
The facility complies with EPA / LDEQ accident prevention rule and all applicable state and local codes and regulations. This facilities chlorine system was designed and constructed in accordance with standards from the Chlorine Institute. All facility personnel are certified in safely operating the Chlorine processes performed at this facility.
5. Five year accident history:
The Houma Water Treatment Plant has had one accidental release of chlorine gas in the past five (5) years; the release was approximately 4 lbs. No on-site or off-site impacts occurred or were reported as a result of the chlorine release. Off-site responders to the release included the Houma Fire Department and personnel from TPCW's District No. 1 and Terrebonne Parish Consolidated Government (TPCG) Office of Emergency Preparedness.
6. The emergency response program:
In the event of an accident or incident involving the facilities chl
orine system, the first responder will notify the Terrebonne Parish Consolidated Government (TPCG) Office of Emergency Preparedness and request that they respond to the emergency. The TPCG Office of Emergency Preparedness is the primary response service and will work with Fire and Law Enforcement personnel to minimize effects of a hazardous material (HAZMAT) incident. Depending on the severity of the incident, additional local, state, federal and private resources may be called upon to assist in HAZMAT response.
7. Planned changes to improve safety:
No changes to improve safety have been reviewed at this time.