Walnut Hills Water Association, OH
Lead detected, under the action levels
Latest 90th-percentile lead: 0.9 ppb (monitoring period 2026-2026). 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.
About Walnut Hills Water Association
Walnut Hills Water Association serves about 583 people through 158 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws groundwater, in Richland County, Ohio. EPA system ID: OH7005032; phone on file: 614-598-0503. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is down 1.8 ppb from 2.7 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Walnut Hills Water Association is 5.7 ppb across 10 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0.9 ppb |
| 2025 | 2.7 ppb |
| 2024 | 4.4 ppb |
| 2023 | 1.3 ppb |
| 2022 | 1.6 ppb |
| 2021 | 1.8 ppb |
| 2020 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2018 | 5.7 ppb |
| 2017 | 0 (not detected) |
Where this result ranks
Of the 1,079 Ohio systems with a lead result, the median latest reading is 0.7 ppb; 1 are over 15 ppb right now and 27 have gone over at some point. Walnut Hills Water Association's 0.9 ppb sits at the 54th percentile in Ohio and the 49th nationally (higher means more lead).
Neighbouring systems
44 other systems share Richland County; 28 of them have a higher latest lead result than Walnut Hills Water Association. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mansfield City | 51,000 | 0 (not detected) |
| Shelby City | 9,453 | 0 (not detected) |
| Ontario City | 6,756 | 2.7 ppb |
| Lexington Village | 4,825 | 0 (not detected) |
| Madison Water District | 2,050 | 0 (not detected) |
| Bellville Village | 1,918 | 0.9 ppb |
| Plymouth Village | 1,874 | 0 (not detected) |
| Eastview Community Water Association | 1,100 | 2.6 ppb |
| Butler Village | 940 | 1.1 ppb |
| Aqua Ohio - Mansfield System #01 | 813 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Mansfield, OH 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 Walnut Hills Water Association 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. The lead result guide covers how utilities pick the homes they sample. Systems that went over once often dip back under; here is what that means.