Statewide Compliance and Testing

• Overall Compliance: The majority of Tennessee’s 474 public water systems continue to meet federal Safe Drinking Water Act standards. TDEC’s completed statewide PFAS sampling initiative — covering source waters for all public drinking water systems — collected over 1,400 samples between August 2023 and October 2025, with results publicly available on the TDEC PFAS dashboard (last updated February 2026). Contamination has been confirmed at varying levels across the state, with the highest concentrations near military and industrial sites.
• EPA UCMR 5 Testing Ongoing: EPA’s Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) programme, which tests for 29 PFAS chemicals and lithium in finished drinking water, is running through Summer 2026. Not all Tennessee water systems fall under UCMR 5, which is why TDEC’s parallel source water sampling effort was critical in filling coverage gaps. Results will inform future EPA regulatory decisions. Follow updates in our water news section.
• Infrastructure Investment Rounds: TDEC’s State Revolving Fund Loan and State Water Infrastructure Grant programmes ran two funding rounds in 2025 (August and December), accepting applications for emerging contaminants, lead service lines, and asset management plans. Additional funding is available for communities impacted by Hurricane Helene. Applications for SFY 2026 funding were accepted through January 2026.

Major Water Sources and Challenges

• Tennessee River System: Serves much of East and Middle Tennessee, with documented PFAS contamination near military installations including the Holston Army Ammunition Depot. PFOS has been detected in fish tissue — including largemouth bass — in the Tennessee River by EPA national surveys, prompting fish consumption advisories in affected stretches.
• Cumberland River Basin: Primary source for Nashville Metro Water Services and surrounding communities. Metro Water Services has reported non-detect levels for regulated PFAS in recent finished water testing, while continuing to plan Granular Activated Carbon (GAC) post-filter adsorber installations at both treatment plants as a precautionary measure.
• Aging Infrastructure: With $8.7 billion needed over the next 20 years, Tennessee faces challenges from aging distribution systems, water loss rates exceeding 40% in some utilities, and the additional strain placed on East Tennessee infrastructure by Hurricane Helene in 2024. Track any ongoing boil water notices affecting Tennessee in real time.

Emerging Contaminant Response

• PFAS Compliance Deadline Extended: On May 14, 2025, EPA confirmed it would retain the enforceable MCLs of 4 ppt for PFOA and PFOS, but extended the compliance deadline for public water systems from 2029 to 2031. The MCLs for PFHxS, PFNA, GenX (HFPO-DA), and the hazard index for PFAS mixtures are being rescinded and reconsidered. Initial monitoring deadlines remain in place for April 2027.
• Advanced Treatment Planning: Water utilities are implementing Granular Activated Carbon (GAC) and reverse osmosis technologies to address PFAS. Metro Water Services — which has used powder activated carbon since before 1980 — is planning additional GAC post-filter adsorbers at both treatment plants, expected to be operational well ahead of the 2031 compliance deadline.
• Legal Accountability: Tennessee Attorney General Jonathan Skrmetti has filed suit against 20 PFAS manufacturers including DuPont, 3M, and Chemours for allegedly concealing health risks. Separately, 3M settled for $98.4 million to address contamination in Tennessee. Ongoing litigation aims to direct funds toward source water cleanup and treatment infrastructure.

Rural and Disadvantaged Communities

• Infrastructure Disparities: Smaller systems in rural East and West Tennessee face disproportionate challenges with aging infrastructure, limited technical capacity, and higher per-capita compliance costs. PFAS-contaminated sewage sludge spread on farmland has affected private wells and groundwater in multiple communities.
• Vanderbilt PFAS Risk Modelling: A Vanderbilt University team — funded by a $352,944 TDEC grant, kicked off in October 2024 — is developing machine learning models to predict PFAS contamination levels across West, Middle, and East Tennessee, and a geospatial tool to identify communities at greatest risk. Results will directly inform TDEC’s resource allocation decisions.
• Hurricane Helene Recovery: Severe infrastructure damage across East Tennessee from Hurricane Helene (2024) prompted TDEC emergency water conservation orders and boil water advisories affecting multiple counties. Federal and state funding is now available specifically for Helene-impacted communities to repair and upgrade water systems.

Looking Forward: 2026–2031

Tennessee’s water quality landscape is at a turning point. TDEC’s completed statewide PFAS source water sampling — the most thorough in the state’s history — has given regulators and utilities an unprecedented picture of contamination across all 474 public water systems. With EPA’s PFOA/PFOS compliance deadline now set at 2031, Tennessee utilities have additional time to design and fund treatment solutions, but the urgency remains high in communities where contamination is already confirmed. The Vanderbilt machine learning risk model, ongoing SRF funding rounds, and EPA UCMR 5 data flowing through Summer 2026 will collectively shape the regulatory and investment priorities of the coming years. Residents in affected areas are strongly advised to invest in certified home filtration, review their utility’s Consumer Confidence Report annually, and monitor the TDEC PFAS dashboard for their local system’s results.