The microorganisms then settle out of the treated water. Here, Treatment Plant Operator Gillen Waite checks the dissolved oxygen content of the aeration basin. The organisms present in the water require a certain level of oxygen for proper growth. Advanced treatment further reduces specific contaminants, organic matter, suspended solids and phosphorus to very low concentrations to meet strict effluent standards and prepare water for contact and non-contact recreation, propagation of fish and wildlife, and domestic raw water supply. Advanced treatment may be physical, chemical, biological or combinations of these processes.
Chlorine is added to the water for a final disinfection.
Chlorine destroys or inactivates organisms that might cause disease. This neutralizes any remaining chlorine in the water, returning it to its most natural state prior to release into the Trinity River. Sludge, a by-product of wastewater processes, is treated by stabilizing the organic material. This is accomplished by aerobic digestion which involves the direct oxidation of a biologically active mass of organisms and the oxidation of microbial cellular material by aeration. Other sludge processes are thickening, conditioning, dewatering and final disposal in the landfill.