Knox County, Tennessee: drinking water report. Knox County includes Knoxville and surrounding communities in eastern Tennessee, with a population of about…
Knox County includes Knoxville and surrounding communities in eastern Tennessee, with a population of about 480,000. The Knoxville Utilities Board draws water from the Tennessee River (Fort Loudoun Lake) and the Holston River. The county sits downstream of the Oak Ridge National Laboratory and the Y-12 National Security Complex – Department of Energy facilities that produced and processed nuclear materials from World War II through the Cold War.
Oak Ridge's contamination legacy is well documented. According to the DOE's 2024 annual environmental report, mercury, PCBs, and radioactive isotopes from Y-12 operations have contaminated the East Fork Poplar Creek, which flows into the Clinch River and then the Tennessee River upstream of Knoxville's intake. Mercury contamination in East Fork Poplar Creek exceeds water quality standards, and fish consumption advisories remain in effect.
The EPA's UCMR5 data shows PFAS detections at low levels in the KUB system. Knoxville's McGhee Tyson Airport has used AFFF firefighting foam, and PFAS has been detected in nearby monitoring wells. A 2024 TDEC report documented PFAS detections in two water systems in the county, though below Tennessee's screening levels.
Knoxville's treatment plant processes Tennessee River water effectively, but the upstream presence of Oak Ridge facilities means that trace contaminants from decades of nuclear and chemical operations are part of the source water picture.
Check your water to see monitoring data for your ZIP code. For broad-spectrum protection including trace industrial and radiological contaminants, reverse osmosis is the most thorough household option. Our water filter guide covers systems rated for the widest contaminant range. Pull your detailed report for trends, and visit our Tennessee page for statewide context.
Drinking water is one exposure route. These federal datasets also cover Knox County, TN.
The EPA places Knox County, TN in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
45% of homes in Knox County, TN were built before 1980, and 12% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Knox County, TN averages 8.3 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide