Washington County Pwsd 1, MO
Lead detected, under the action levels
Latest 90th-percentile lead: 1.45 ppb (monitoring period 2022-2024). 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
Washington County Pwsd 1 serves about 503 people through 210 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 Washington County, Missouri. EPA system ID: MO6024633; phone on file: 573-760-2655. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
Against the period ending 2021 (1.06 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Washington County Pwsd 1 is 1.45 ppb across 5 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 1.45 ppb |
| 2021 | 1.06 ppb |
| 2021 | 1.06 ppb |
| 2018 | 1.24 ppb |
| 2018 | 1.24 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. Washington County Pwsd 1's 1.45 ppb sits at the 60th percentile in Missouri and the 63rd nationally (higher means more lead).
Nearby utilities
9 other systems share Washington County; 5 of them have a higher latest lead result than Washington County Pwsd 1. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Potosi Pws | 2,527 | 1.61 ppb |
| Potosi East | 900 | 4.36 ppb |
| Irondale Pws | 420 | 1.9 ppb |
| Mo American Rogue Creek Utilities | 276 | 2 ppb |
| Mineral Point Pws | 231 | 2.06 ppb |
| Anthonies Mill Resort Subdivision | 214 | 0 (not detected) |
| Washington County Pwsd 2 | 175 | 1.4 ppb |
| Caledonia Pws | 130 | 0 (not detected) |
| The Legacy Ranch | 25 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Potosi, MO 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 Washington County Pwsd 1 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. 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.