Well Water in Tennessee
Contaminant risks, testing requirements, and treatment recommendations for private well owners in Tennessee.
Tennessee Geology and Groundwater
Tennessee sits on Appalachian karst and Highland Rim limestone. This geology directly determines what contaminants are likely in private well water. Moderate risk exists for radon, nitrate, PFAS.
Contaminant Risk Profile
| Contaminant | Risk Level | Why |
|---|---|---|
| Arsenic | Low risk | Generally low in this region's geology. |
| Nitrate | Moderate risk | Some areas near farmland or septic systems may have elevated levels. |
| Radon | Moderate risk | Some bedrock types in this state produce radon. |
| PFAS | Moderate risk | Some known contamination sites exist. Check EWG's PFAS map for your area. |
| Iron/Manganese | Moderate risk | Found in some wells depending on local geology. |
How Tennessee Compares: Municipal Water Data
CheckMyTap tracks water quality for 20 cities in Tennessee. While these numbers reflect municipal water (not private wells), they indicate the baseline mineral content of Tennessee's water sources. Private wells often draw from the same aquifers but with less treatment.
| Metric | Tennessee Average | National Average |
|---|---|---|
| Hardness | 96 PPM (moderately hard) | 170 PPM |
| Hardness range | 15 - 180 PPM | 25 - 400+ PPM |
| Lead (avg municipal) | 1.3 ppb | 3.2 ppb |
| Nitrate (avg municipal) | 0.5 mg/L | 1.1 mg/L |
| Cities with PFAS detected | 9 of 20 | ~45% nationally |
| Cities exceeding PFAS MCL (4 ppt) | 6 |
Hardest water in Tennessee: Collierville (180 PPM), Murfreesboro (161 PPM), Franklin (161 PPM), Clarksville (140 PPM), Cookeville (140 PPM).
Softest water: Johnson City (15 PPM), Maryville (25 PPM), Memphis (33 PPM).
Testing Requirements in Tennessee
Tennessee does not have a statewide mandatory testing requirement for existing private wells. Regardless of state requirements, the EPA recommends testing annually for:
- Every year: Total coliform bacteria, E. coli, nitrate, pH, and total dissolved solids
- At least once: Arsenic, lead, copper, fluoride, and any contaminant identified as a local risk
- Recommended for Tennessee: Radon in water (granitic bedrock states have higher risk)
- Recommended for Tennessee: PFAS panel, especially if near military bases or industrial sites
- After events: Retest after flooding, well repairs, nearby construction, or any change in taste/color/odor
Recommended Treatment for Tennessee Wells
Based on Tennessee's geology and common contaminant risks, these treatment systems address the most likely issues:
Kills bacteria and viruses without chemicals. Recommended for all well water systems
Frequently Asked Questions
Is well water in Tennessee safe to drink?
Well water quality in Tennessee varies significantly by location and geology. Tennessee sits on Appalachian karst and Highland Rim limestone. No single contaminant dominates statewide, but local conditions vary. The only way to know your specific water quality is to test it. Use our free interpreter to understand your results.
How often should I test my well water in Tennessee?
The EPA recommends testing annually for bacteria (total coliform, E. coli), nitrate, total dissolved solids, and pH. Radon testing is also recommended in Tennessee. Test more frequently if you notice changes in taste, color, or odor, or after flooding, nearby construction, or well repairs.
Does Tennessee require well water testing?
Tennessee does not have a statewide mandatory testing requirement for existing private wells. However, the EPA strongly recommends annual testing regardless of state requirements. Your county health department may have additional local requirements.
What is the average water hardness in Tennessee?
Municipal water in Tennessee averages 96 PPM across 20 cities tracked by CheckMyTap, ranging from 15 to 180 PPM. Private well water typically runs 20-50% harder than city water because groundwater has more contact time with mineral formations. Many Tennessee well owners have manageable hardness levels, though local variation is significant. Check your city's data.