AWWA JAW48191

The Corpus Christi, Texas, water treatment plant treats water from the Nueces River watershed. In the fall of 1998, the plant will begin receiving water from Lake Texana, a source with very different water quality. In this context, this article discusses a comprehensive treatability study which was initiated to identify process changes required at the plant to ensure regulatory compliance and optimal treatment of the individual source water and any blend. The study included jar testing to determine the most effective primary coagulant and polymer order-of-addition testing, pipeline simulation testing to evaluate pretreatment of the Lake Texana water with potassium permanganate and chlorine dioxide, and water stability modeling. The treatment data and evaluation were based on coagulation, sedimentation, and filtration for the removal of turbidity and color along with enhanced coagulation for total organic carbon (TOC) removal. The project focused on determining appropriate water blends for treatment and selecting the type and dosage of coagulant and polymer. This study did not address disinfection selection. The quarterly analyses were run only to compare water sources and blends and not to determine treatment. Results are discussed. Includes 5 references, tables, figures.