Warrenton Pws, MO
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2024-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Who runs the water here
Warrenton Pws serves about 8,208 people through 3,908 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Warren County, Missouri. EPA system ID: MO6010834; phone on file: 636-456-3535. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Warrenton Pws's lead record
That is down 1.68 ppb from 1.68 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Warrenton Pws is 8.44 ppb across 9 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 1.68 ppb |
| 2023 | 1.68 ppb |
| 2023 | 1.71 ppb |
| 2022 | 2.12 ppb |
| 2020 | 2.12 ppb |
| 2019 | 4.49 ppb |
| 2017 | 4.49 ppb |
| 2016 | 8.44 ppb |
Against other Missouri systems
Of the 1,674 Missouri systems with a lead result, the median latest reading is 1.04 ppb; 2 are over 15 ppb right now and 74 have gone over at some point. Warrenton Pws's reported as 0 (not detected) sits at the 38th percentile in Missouri and the 36th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
15 other systems share Warren County; 9 of them have a higher latest lead result than Warrenton Pws. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| St Charles Co Pwsd #2 Wright City | 3,550 | 1.14 ppb |
| Marthasville Pws | 1,200 | 0 (not detected) |
| St Charles County Pwsd 2 Warren | 1,192 | 1.22 ppb |
| Lake Sherwood Subd | 1,100 | 3.83 ppb |
| Truesdale Pws | 853 | 0 (not detected) |
| Innsbrook | 810 | 0 (not detected) |
| St Charles County Pwsd 2 North Oak Dr | 660 | 1.26 ppb |
| St Charles County Pwsd 2 Dutzow | 400 | 3.92 ppb |
| Pleasant Oak Mhp | 150 | 0.56 ppb |
| Maple Ridge Mhp | 140 | 0 (not detected) |
Your move
Look up your address in Warrenton Pws's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Warrenton Pws 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. Small systems behave differently: why small systems go over more often.