Hennessey, OK
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2025-2025). 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.
Who runs the water here
Hennessey serves about 2,058 people through 1,155 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Kingfisher County, Oklahoma. EPA system ID: OK2003704; phone on file: 405-853-2416. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
Against the period ending 2024 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Hennessey is 1.2 ppb across 11 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1 ppb |
| 2024 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2021 | 1.2 ppb |
| 2020 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2018 | 0 (not detected) |
| 2018 | 0 (not detected) |
Where this result ranks
Of the 870 Oklahoma systems with a lead result, the median latest reading is 0.81 ppb; 6 are over 15 ppb right now and 66 have gone over at some point. Hennessey's 1 ppb sits at the 54th percentile in Oklahoma and the 54th nationally (higher means more lead).
Other water systems in Kingfisher County
7 other systems share Kingfisher County; 4 of them have a higher latest lead result than Hennessey. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Kingfisher | 5,073 | 0 (not detected) |
| Okarche | 1,110 | 7.4 ppb |
| Cashion | 900 | 3 ppb |
| Dover Public Works Trust Auth | 400 | 1.1 ppb |
| Okarche Rwd, Inc | 250 | 0 (not detected) |
| Kingfisher Co Rwd #3 | 237 | 0 (not detected) |
| Loyal | 81 | 2 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Hennessey, OK 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 Hennessey whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1692 ppb (copper action level 1,300 ppb).
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.