Lavon Lake Water Quality Modeling – Total Dissolved Solids

Plummer developed a monthly water balance model of Lavon Lake and the NTMWD water supply system to support evaluation of different water supply and water treatment management options. Plummer characterized the total dissolved solids (TDS) of all NTMWD water supply sources and tracked the volume and projected TDS concentration of the water supplied to each NTMWD customer from the source(s), through the water treatment plant(s), through the wastewater treatment plant(s), and back to Lavon Lake. Plummer used this model to project TDS concentrations at key locations for:

• Baseline operations
• Baseline operations with seasonal pumping of water from Lake Texoma to Lavon Lake
• Addition of a Leonard Water Treatment Plant (WTP) that uses blended water from Lake Texoma and the future Bois D’Arc Lake
• Addition of a Leonard WTP that uses desalination instead of blending

Plummer also evaluated the impact of different blends of Lake Texoma and Lavon Lake water at the Wylie WTP.

Plummer later modified the model to also project likely worst-case TDS concentrations in the water imported from Lake Texoma and potential short-term impacts to drinking water quality. Based on up-to-date concentrations, Plummer provided weekly forecasts, which NTMWD used to determine whether to change the blend of Texoma and Lavon water at the Wylie Water Treatment Plant (WTP).