Williamsville 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
Williamsville Pws serves about 342 people through 182 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 Wayne County, Missouri. EPA system ID: MO4010861; phone on file: 573-998-2745. 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 1.48 ppb from 1.48 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Williamsville Pws is 2.94 ppb across 8 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 1.48 ppb |
| 2023 | 1.48 ppb |
| 2022 | 0.52 ppb |
| 2020 | 0.52 ppb |
| 2019 | 2.94 ppb |
| 2017 | 2.94 ppb |
| 2016 | 0.64 ppb |
Where this result ranks
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. Williamsville Pws's reported as 0 (not detected) sits at the 20th percentile in Missouri and the 19th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Wayne County
14 other systems share Wayne County; 8 of them have a higher latest lead result than Williamsville Pws. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Piedmont Pws | 1,987 | 0 (not detected) |
| Wayne & Butler County Pwsd 4 | 1,400 | 0 (not detected) |
| Wayne County Pwsd 2 | 950 | 0 (not detected) |
| Greenville Pws | 497 | 0 (not detected) |
| Community Water System | 378 | 6.15 ppb |
| Wayne County Pwsd 3 | 300 | 7.1 ppb |
| Ridgetop Waterworks Corp Subdivision | 227 | 1.77 ppb |
| Liberty Utilities Whispering Hills Subd | 150 | 0 (not detected) |
| Lost Creek Water Company | 133 | 0.63 ppb |
| Mill Spring Pws | 112 | 1.1 ppb |
Next steps for Williamsville, MO
Look up your address in Williamsville 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 Williamsville 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. The lead result guide covers how utilities pick the homes they sample. Small systems behave differently: why small systems go over more often.