Tri-County Rural Water System, SD
Lead detected, under the action levels
Latest 90th-percentile lead: 4 ppb (monitoring period 2023-2023). 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.
Tri-County Rural Water System at a glance
Tri-County Rural Water System serves about 2,190 people through 876 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws surface water, in Dewey,Meade,Ziebach County, South Dakota. EPA system ID: SD4600112; phone on file: 6059647766. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
That is up 2 ppb from 2 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Tri-County Rural Water System is 4 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 4 ppb |
| 2020 | 2 ppb |
| 2017 | 4 ppb |
Against other South Dakota systems
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. Tri-County Rural Water System's 4 ppb sits at the 87th percentile in South Dakota and the 88th nationally (higher means more lead).
What to do in your house
Test your own tap with a certified lab first-draw sample; Eagle Butte, 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 Tri-County 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. Why sampled homes are the worst-case ones is in the guide to reading the number. The action level is dropping - the 10 ppb rule from 2027.