Dry Prairie Rural Water Authority, MT
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2025-2027). 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
Dry Prairie Rural Water Authority serves about 3,005 people through 1,911 service connections, which makes it a small system under EPA's size classes. It is under mixed public and private ownership and draws surface water, in Roosevelt County, Montana. EPA system ID: MT0004348; phone on file: 406-787-5382. They can tell you what your service line is made of and whether they pay to replace it.
Dry Prairie Rural Water Authority's lead record
That is down 2 ppb from 3 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Dry Prairie Rural Water Authority is 4 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2027 | 1 ppb |
| 2021 | 3 ppb |
| 2018 | 0 (not detected) |
| 2017 | 4 ppb |
| 2016 | 1 ppb |
| 2016 | 4 ppb |
Against other Montana systems
Of the 753 Montana systems with a lead result, the median latest reading is 1 ppb; 5 are over 15 ppb right now and 28 have gone over at some point. Dry Prairie Rural Water Authority's 1 ppb sits at the 61st percentile in Montana and the 54th nationally (higher means more lead).
Neighbouring systems
3 other systems share Roosevelt County; 0 of them have a higher latest lead result than Dry Prairie Rural Water Authority. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Culbertson Town Of | 714 | 0 (not detected) |
| Froid Town Of | 450 | 0 (not detected) |
| Bainville Town Of | 350 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Culbertson, MT 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 Dry Prairie Rural Water Authority whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1350 ppb (copper action level 1,300 ppb).
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.