Knoxville’s municipal tap water meets or exceeds all federally and state-mandated safety standards. The Knoxville Utilities Board (KUB) ensures a safe supply by operating under the regulations of the Environmental Protection Agency (EPA) and the Tennessee Department of Environment and Conservation (TDEC). While the municipal system maintains high quality, understanding the source, treatment, and potential home-based risks provides a comprehensive view of the water coming from your tap.
The Source and Treatment Process
The primary source for Knoxville’s drinking water is surface water drawn from the Tennessee River system, specifically Fort Loudoun Lake. This large, stable source provides an abundant supply, with KUB drawing and treating an average of 34 million gallons of water daily at its Mark B. Whitaker Water Plant. The raw water is first treated with a disinfectant, such as chlorine dioxide, which begins the process of eliminating viruses and bacteria.
The water moves through physical and chemical purification steps designed to make it potable. Coagulation and flocculation clump together suspended particles and organic matter for easier removal. This is followed by rigorous filtration through layers of filtering media, such as sand and anthracite coal. The final step involves adding chlorine for residual disinfection and a corrosion inhibitor to protect the pipes.
Official Testing and Safety Data
Public water safety is governed by the federal Safe Drinking Water Act, which mandates stringent testing overseen by the EPA. KUB’s state-certified laboratory performs extensive monitoring, conducting over 100,000 tests annually. These tests check for more than 150 different contaminants, exceeding federal requirements, to ensure high water quality throughout the year.
The utility must ensure contaminant levels remain below the Maximum Contaminant Levels (MCLs) established by the EPA for substances like heavy metals and microbial pathogens. Compliance is publicly documented in the annual Consumer Confidence Report (CCR), which details the previous year’s water quality data and any reported violations. The CCR also monitors regulated disinfection byproducts, which are formed when chlorine reacts with organic matter.
KUB has historically maintained a strong compliance record, consistently meeting all health-based drinking water standards. The CCR confirms the system tests for microbial contaminants and reports on naturally occurring elements. This report is easily accessible on the KUB website, providing transparency and detailed evidence of the system’s performance.
Localized Risks and Home Plumbing Concerns
While municipal water is high quality when leaving the treatment plant, its quality can change after entering private property. The most common risk involves the leaching of metals, primarily lead and copper, from household plumbing. Although KUB reports no lead service lines in its public system, lead can originate from older service lines connecting the meter to the home, lead solder used before 1986, or brass fixtures.
To mitigate this risk, KUB adds a corrosion inhibitor, zinc orthophosphate, to the treated water. This creates a protective coating on the interior of pipes, helping prevent metal from dissolving into the water. Homeowners remain responsible for the plumbing materials within their property, from the meter to the tap.
If you live in an older home, you can take simple steps to minimize potential exposure. Water that has been stagnant in plumbing, such as overnight, should be flushed by running the cold tap for 30 seconds to two minutes before use. Always use cold water for drinking, cooking, and preparing baby formula, as hot water dissolves metals more quickly. Homeowners concerned about internal plumbing can have their water tested by a state-certified laboratory.