Is Nashville-Davidson metropolitan government (balance), TN Tap Water Safe to Drink?

Where Does Nashville-Davidson metropolitan government (balance) Get Its Water?

Nashville's primary drinking water comes from surface water, with the Cumberland River serving as the main source for the city. Nashville Water Department is the largest utility supplying the metropolitan area, drawing and treating river water before delivering it to homes across Davidson County.

The two major treatment facilities for Nashville are the Omohundro Water Plant and the K.R. Harrington Water Plant (also called the Harrington Water Plant). Both plants process Cumberland River water through multi-step treatment before it reaches your tap.

Several smaller utilities also serve portions of the broader Nashville-Davidson area. These include Harpeth Valley Utility District, Madison Suburban Utility District, Gladeville Utility District, and Pleasant View Utility District, each serving specific communities within or adjacent to the metro area.

How Is Nashville-Davidson metropolitan government (balance) Tap Water Treated?

Nashville's larger water plants use a conventional treatment process that includes coagulation and clarification to remove suspended solids, followed by filtration to further reduce particles, and powdered or granular activated carbon to help control taste, odor, and certain chemical contaminants. Membrane filtration is also part of the treatment toolbox for some facilities in this system.

Disinfection is handled using free chlorine or chloramines, depending on the stage of treatment. These disinfectants kill bacteria and viruses that could otherwise cause illness. A residual amount of disinfectant remains in the distribution pipes all the way to your tap, which is required by EPA rules.

Some facilities in the system use additional steps such as sedimentation and pH adjustment to stabilize water chemistry before distribution. The combination of these treatment layers is designed to meet all federal drinking water standards under normal operating conditions.

What's in Nashville-Davidson metropolitan government (balance) Tap Water?

Lithium was detected in all 26 ZIP codes included in the monitoring dataset, with a maximum recorded value of 9 micrograms per liter. There is no federal enforceable maximum contaminant level for lithium in drinking water, so this detection does not represent a legal violation. EPA has established a non-regulatory health reference level for lithium, and all detections in Nashville fell at or below the reporting threshold rather than above any guideline.

Several PFAS compounds were also detected at trace concentrations. PFTrDA, a long-chain PFAS, was found across all 26 monitored ZIP codes at a maximum of 0.007 micrograms per liter. Two additional PFAS compounds, 8:2 FTS and 11Cl-PF3OUdS, and a PFAS called HFPO-DA (sometimes referred to as GenX) were each detected at or below 0.005 micrograms per liter. None of these values exceeded EPA guidelines.

PFAS compounds are a family of man-made chemicals that have been used in industrial and consumer products for decades and can enter water supplies through environmental contamination. Lithium occurs naturally in some rock formations and soils and can leach into source water. The presence of these substances at very low levels is consistent with what EPA's national monitoring program has found in many urban water systems.

Health Risk Profile for Nashville-Davidson metropolitan government (balance)

For most healthy adults, the detected levels of PFAS and lithium in Nashville tap water do not represent an immediate health concern. No contaminant in the EPA monitoring data exceeded a federal regulatory limit or a non-regulatory health reference benchmark. The PFAS detections are at the low end of what EPA's national surveillance has found across the country.

Sensitive groups, including infants, pregnant individuals, and people with certain kidney or thyroid conditions, may want to take extra precautions. Some PFAS compounds are associated with effects on the immune system, thyroid function, and developmental outcomes at higher long-term exposures. Lithium at elevated concentrations has been studied in relation to kidney and thyroid effects, though the levels detected here are at the reporting threshold.

Given the PFAS detections and the presence of chlorine-based disinfection, a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI 58 combined with NSF/ANSI P473 is the most effective option for reducing PFAS at the tap. NSF/ANSI is an independent third-party certification program, so when you see that label on a filter box, it means the product has been tested and verified to reduce specific contaminants. Filters certified to NSF/ANSI 42 can also reduce chlorine taste and odor if that is your primary concern.

EPA finalized enforceable limits for PFOA and PFOS in 2024, and the science on other PFAS compounds continues to evolve. The PFAS compounds detected in Nashville other than PFOA and PFOS do not currently have individual federal MCLs, which is why their risk is evaluated against health reference levels and screening benchmarks rather than legal limits.