Clark Rural Water System, SD
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. 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.
About Clark Rural Water System
Clark Rural Water System serves about 2,325 people through 1,080 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws groundwater, in Clark,Codington,Day,Hamlin County, South Dakota. EPA system ID: SD4600881; phone on file: 6055325201. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
Against the period ending 2022 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Clark Rural Water System is 1 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 1 ppb |
| 2019 | 1 ppb |
| 2016 | 0 (not detected) |
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. Clark Rural Water System's reported as 0 (not detected) sits at the 7th percentile in South Dakota and the 31st nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Your move
Look up your address in Clark Rural Water System'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 Clark Rural Water System 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. Small systems behave differently: why small systems go over more often.