Calvin, OK
Lead detected, under the action levels
Latest 90th-percentile lead: 3.1 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.
Calvin at a glance
Calvin serves about 300 people through 138 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Hughes County, Oklahoma. EPA system ID: OK2003201; phone on file: 405-645-2434. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is down 11.3 ppb from 14.4 ppb in the period ending 2024. The highest 90th-percentile result EPA holds for Calvin is 14.5 ppb across 9 monitoring periods, none of them over 15 ppb (2 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 3.1 ppb |
| 2024 | 14.4 ppb over 10 |
| 2023 | 3.41 ppb |
| 2022 | 2.06 ppb |
| 2021 | 5.33 ppb |
| 2021 | 4.2 ppb |
| 2020 | 2.3 ppb |
| 2020 | 14.5 ppb over 10 |
| 2017 | 0.43 ppb |
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. Calvin's 3.1 ppb sits at the 85th percentile in Oklahoma and the 83rd nationally (higher means more lead).
Nearby utilities
8 other systems share Hughes County; 2 of them have a higher latest lead result than Calvin. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Holdenville | 4,732 | 1.8 ppb |
| Hughes Co. Rwd #6 (Gerty) | 2,180 | 2.11 ppb |
| Wetumka | 1,451 | 9.66 ppb |
| Hughes Co. Rwd #1 | 1,225 | 0.7 ppb |
| Hughes Co. Rwd #2 | 1,145 | 4.16 ppb |
| Hughes Co. Rwd #5 | 800 | 0.91 ppb |
| Dustin Pwa | 496 | 0.91 ppb |
| Hughes Co. Rwd #3 | 200 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Calvin, 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 Calvin whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1570 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. What a 90th-percentile result does and does not tell you: how to read a lead result. Size matters more than most people expect: small vs large water systems.