Mallory Valley U.D., TN
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2023-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Mallory Valley U.D. at a glance
Mallory Valley U.D. serves about 31,703 people through 11,085 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Williamson County, Tennessee. EPA system ID: TN0000428; phone on file: 615-983-0099. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
Against the period ending 2022 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Mallory Valley U.D. is 1.23 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1 ppb |
| 2022 | 1 ppb |
| 2019 | 1.23 ppb |
| 2016 | 1 ppb |
Where this result ranks
Of the 453 Tennessee systems with a lead result, the median latest reading is 1 ppb; 0 are over 15 ppb right now and 10 have gone over at some point. Mallory Valley U.D.'s 1 ppb sits at the 71st percentile in Tennessee and the 56th nationally (higher means more lead).
Other water systems in Williamson County
6 other systems share Williamson County; 1 of them has a higher latest lead result than Mallory Valley U.D.. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Franklin Water Dept | 77,222 | 1 ppb |
| H.B.& T.S. Utility District | 40,094 | 1 ppb |
| Milcrofton Utility District | 38,032 | 0.58 ppb |
| Nolensville-College Grove U.D. | 34,159 | 6.17 ppb |
| Brentwood Water Department | 30,645 | 1 ppb |
| Gateway Utility Company, Inc. | 1,070 | 0.55 ppb |
Next steps for Franklin, TN
Test your own tap with a certified lab first-draw sample; Franklin, TN may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Mallory Valley U.D. whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. Why sampled homes are the worst-case ones is in the guide to reading the number. The action level is dropping - the 10 ppb rule from 2027.