Mclennan County, Texas: drinking water report. McLennan County in Central Texas has about 260,000 residents, centered on Waco and home to Baylor University.
McLennan County in Central Texas has about 260,000 residents, centered on Waco and home to Baylor University. Lake Waco and the Brazos River provide the primary water sources, with the City of Waco operating the main treatment and distribution system. The Brazos River drains a massive watershed stretching from the High Plains to the Gulf Coast, picking up agricultural and municipal inputs along the way.
Lake Waco has experienced recurring taste-and-odor events driven by cyanobacterial growth during summer months. According to the Brazos River Authority's 2024 water quality monitoring data, geosmin and 2-MIB – compounds produced by blue-green algae – were detected at the water intake above taste threshold levels during August and September 2024. These compounds are not harmful but indicate algal activity that may also produce toxins.
Joint Base San Antonio-Fort Cavazos (formerly Fort Hood) lies in neighboring Bell County, but PFAS contamination from the massive military installation has been detected in the Brazos River watershed. A 2024 TCEQ investigation found PFAS at 11 ppt in surface water sampling points downstream of the base, within the watershed feeding Lake Waco.
If your Waco water develops an earthy or musty taste during summer, that is likely geosmin from algal growth – unpleasant but not dangerous. A carbon filter at the tap eliminates the taste effectively.
Start by checking your water for the latest monitoring results. For taste issues and trace PFAS, a reverse osmosis system handles both. Our water filter guide compares systems for surface water supplies. Pull your detailed report for seasonal patterns, and visit our Texas page for statewide data.