Ridgewater Improvement District, WY
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2023-2025). 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.
About Ridgewater Improvement District
Ridgewater Improvement District serves about 218 people through 94 service connections, which makes it a very small system under EPA's size classes. It is under mixed public and private ownership and draws surface water, in Converse County, Wyoming. EPA system ID: WY5600285; phone on file: 307-359-3365. They can tell you what your service line is made of and whether they pay to replace it.
Ridgewater Improvement District's lead record
Against the period ending 2022 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Ridgewater Improvement District is 5 ppb across 5 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1 ppb |
| 2022 | 1 ppb |
| 2019 | 5 ppb |
| 2019 | 5 ppb |
| 2018 | 2 ppb |
Where this result ranks
Of the 311 Wyoming systems with a lead result, the median latest reading is 1 ppb; 0 are over 15 ppb right now and 16 have gone over at some point. Ridgewater Improvement District's 1 ppb sits at the 42nd percentile in Wyoming and the 52nd nationally (higher means more lead).
Neighbouring systems
7 other systems share Converse County; 5 of them have a higher latest lead result than Ridgewater Improvement District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Douglas, City Of | 6,400 | 2 ppb |
| Glenrock, Town Of | 2,466 | 2 ppb |
| Lone Tree Village Mhp | 475 | 3 ppb |
| Rolling Hills, Town Of | 450 | 1 ppb |
| Douglas Koa Cg & Pine Meadows Mhp | 165 | 0 (not detected) |
| Fairway Estates | 135 | 2 ppb |
| Sundance Meadows Spid | 50 | 3 ppb |
Next steps for Douglas, WY
Test your own tap with a certified lab first-draw sample; Douglas, WY 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 Ridgewater Improvement District 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.