Woonsocket, SD
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 13 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. Under the current 15 ppb rule this is not an exceedance, but it is above the 10 ppb action level that takes over in Nov 2027. Test your own tap; filter if your result shows lead.
Woonsocket at a glance
Woonsocket serves about 618 people through 330 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 Sanborn County, South Dakota. EPA system ID: SD4600376; phone on file: 6057964275. 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 up 7 ppb from 6 ppb in the period ending 2024. The highest 90th-percentile result EPA holds for Woonsocket is 28 ppb across 6 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 13 ppb over 10 |
| 2024 | 6 ppb |
| 2023 | 5 ppb |
| 2023 | 12 ppb over 10 |
| 2021 | 28 ppb over 15 |
| 2018 | 6 ppb |
Where this result ranks
Of the 458 South Dakota systems with a lead result, the median latest reading is 2 ppb; 0 are over 15 ppb right now and 6 have gone over at some point. Woonsocket's 13 ppb sits at the 99th percentile in South Dakota and the 98th nationally (higher means more lead).
Neighbouring systems
2 other systems share Sanborn County; 0 of them have a higher latest lead result than Woonsocket. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Upland Colony | 198 | 0 (not detected) |
| Letcher | 159 | 1 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Woonsocket, SD 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 Woonsocket 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. See what changes at 10 ppb in 2027.