Water Treatment Process
There are several steps in the treatment process.
(1) Pre-treatment
Texarkana Water Utilities owns and operates two water treatment plants which supply treated water to Texarkana and the surrounding communities. The Wright Patman plant's water source is Lake Wright Patman and the Millwood plant's water source is Lake Millwood.
(2) Coagulation
When the lake water reaches the water treatment plant, lime, polymer and alum are added to the water. The water and chemicals are then mixed by large motor driven impellers. The chemicals bond with particles in the water to help form "floc".
(3) Flocculation
The water then proceeds to the flocculators. A chemical/physical reaction begins here where a sticky, heavy compound forms that attracts the pollutants and binds them; this compound is called "floc". The "floc" travels a short distance to the basins until it gets too heavy to stay suspended in the water. The heavy floc falls by gravity to the bottom of the basin.
(4) Sedimentation
A blanket of sludge accumulates at the bottom of the basin and is removed by the under drain and then sent to the Wastewater Plant for treatment. The purest water, found on the surface of the basin, is sampled every couple of hours to ensure the treatment process is working properly. The clarified water flows by gravity toward the filters.
(5) Disinfection
Chlorine, in the form of a gas, is added at this point for disinfection.
(6) Filtration
A state of the art filtration system ensures that any remaining sediment is removed. A regulated disinfection contact time begins on top of the filter.
(8) Chloramine
Almost immediately after filtration, ammonia is added to form a compound called chloramine. The addition of ammonia creates a very stable, long lasting disinfectant without the swimming pool taste and odor.
(9) Distribution
After all the treatment and tests are complete the water leaves the filter plant and is transported to our customers' homes, overhead storage tanks, 7 member cities, and 16 wholesale customers.
Extensive testing is performed every step of the way. At least one licensed operator is on duty at all times during plant operation.
Water Quality
Texarkana Water Utilities is unique in that we are regulated by two different states, Texas and Arkansas. We are proud to say that we meet and exceed the standards of both states.
Operators of the water treatment plants collect at least 238 samples each 24 hour period from various points throughout the plant to ensure that our treatment process is running smoothly.
At least 70 bacteriological samples are collected each month from the distribution system and the results are sent to both Texas and Arkansas regulatory agencies.
At least one chloramine residual is collected every day of the year from the distribution system.
Our bacteriological laboratory is certified by the Texas Commission on Environmental Quality to analyze water for coliform organisms. The laboratory is open to the general public for individual water well testing. For further information on well testing, call 903-798-3850.