Port Lavaca Water Treatment Plant - Executive Summary
The Port Lavaca Water Treatment Plant is operated by the Guadalupe-Blanco River Authority for the production of a dependable supply of potable water that meets or exceeds state and federal standards. GBRA is strongly committed to safe work practices and procedures at all levels to insure the safety of its employees and the public which it serves. Senior management has promoted chemical safety through the implementation of written procedures, training on-the-job and in the classroom, regular safety meetings, and the formation of a very active employee safety committee. The Treatment Plant is located about 5 miles south of Port Lavaca, Texas and treats surface water from the Guadalupe River at a maximum rate of 6 million gallons per day and an average rate of 1.7 million gallons per day for delivery to approximately 4500 urban and 1700 rural customers. A conventional treatment process is used consisting of flocculation and coagulation of suspended particles, followed by settli |
ng and draining off of these solids, disinfection, filtering of the decanted clear water from the settling basin through a medium of gravel, graded sand, and anthracite coal, and final storage in a clearwell tank prior to pumping to customers. The Plant was expanded in 1992 to meet more stringent requirments of the federal Safe Drinking Water Act and its present-day performance is considered to be state-of-the-art with a drinking water product of near optimum quality. In 1997 the Plant untook a voluntary Comprehensive Performance Evaluation conducted by outside team members under the guidance of TEEX, TWUA, and the TNRCC, and received good marks. Annual inspections conducted by the State of Texas insure that quality standards are being met.
At several points in this process, disinfectant chemicals are added, the most important being chlorine. Chlorine is widely used in the United States for disinfection and protection of the nation's drinking water, and has been instrumental
in securing the health and well-being of millions against water-borne pathogens which in days of old caused much sickness and death. This gaseous product is fed in a water-carrying solution at this GBRA Plant and, at the last feed point, is combined with ammonia to form a more stable (longer-lasting) disinfectant. While several 1-ton containers are routinely on hand at the plant, only one container is on-line (feeding) at any one time. These containers are extremely robust and the feed mechanism is based on a vacuum draw principle which has an inherent safety feature of shut-off should the vacuum be lost due to leakage. Suppliers of this most useful but hazardous chemical must comply with rigid standards for the transport and sale of chlorine.
For this Risk Management Plan on chlorine at this facility, three scenarios were considered using a commercial modeling program. A Worst Case Toxic Release, while extremely unlikely, would occur if a container's entire contents were
lost. It is estimated that container failure of this magnitude would result in a discharge of 2000 pounds of chlorine in a liquid / gaseous state in 10 minutes. The radius of influence or distance to the end point of dissapation of the chemical is estimated to be 1.9 miles. An estimated population of 400 residents (persons) reside in this area, as measured from the center of the Treatment Plant. Two businesses of moderate size which have daily contact with the public, one being GBRA itself, are also present.
Two Alternate Release Scenarios were also developed in which atmospheric conditions and / or container and attached equipment breakage was less severe. A distance to end point of 1.5 miles for one scenario would encompass an area which includes about 240 residents, while the last scenario with a distance to end point of 1.2 miles includes an area in which about 220 residents reside.
The Treatment Plant division of GBRA complies on an annual basis with requirement
s for Hazardous Communication Training and reporting of any hazardous materials stored on site. This information is made available to the Calhoun County Fire Department and the Emergency Management Coordinator's office.
No accidental releases of chlorine have occurred at this facility in the past five years.
GBRA personnel are trained on the job in procedures for handling, feeding, and storage of chlorine. In addition, HAZWOPER and dedicated leak repair seminars are attended on an annual or bi-annual basis. Self-contained breathing apparatus, a chlorine "B" leak repair kit, and hazmat suits are on hand at this facility. A major leak would be repaired jointly with the assistance of the Calhoun County Fire Department. This effort would also be coordinated with the Emergency Management Coordinator's office, which is very active in county-wide industrial safety operations. The Coordinator's office also has a county-alert ring-down system ("CAN") which can be used to aler
t residents by phone of severe weather or industrial incidents.
Development of a comprehensive chlorine response program that goes behond emergency-action response and that is specific to this facility and to area responders, is needed. A more rigid schedule of training and inspection to prepare for chlorine-related incidents, beyond and more frequent than the formal annual training, is needed.