Rock Rapids Municipal Water Works, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 1.5 ppb (monitoring period 2022-2024). 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
Rock Rapids Municipal Water Works serves about 2,611 people through 1,147 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 Lyon County, Iowa. EPA system ID: IA6065092; phone on file: 712-472-2511. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2021 (1.6 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Rock Rapids Municipal Water Works is 3.3 ppb across 5 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 1.5 ppb |
| 2021 | 1.6 ppb |
| 2018 | 3.3 ppb |
| 2018 | 3 ppb |
| 2017 | 3.1 ppb |
Against other Iowa systems
Of the 1,066 Iowa systems with a lead result, the median latest reading is 1.4 ppb; 4 are over 15 ppb right now and 36 have gone over at some point. Rock Rapids Municipal Water Works's 1.5 ppb sits at the 52nd percentile in Iowa and the 64th nationally (higher means more lead).
Nearby utilities
11 other systems share Lyon County; 11 of them have a higher latest lead result than Rock Rapids Municipal Water Works. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Lyon-Sioux Rws-Doon | 1,765 | 4 ppb |
| Lyon-Sioux Rws-Big Sioux | 1,530 | 4 ppb |
| Lyon-Sioux Rws-Rock Rapids | 1,187 | 2 ppb |
| George Water Supply | 1,082 | 2 ppb |
| Inwood Water Supply | 928 | 2.1 ppb |
| Larchwood Water Supply | 926 | 2.4 ppb |
| Doon Water Supply | 619 | 4 ppb |
| Lyon-Sioux Rws-Boyden | 605 | 5.3 ppb |
| Little Rock Water Supply | 441 | 9.1 ppb |
| Lester Water Supply | 296 | 2.2 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Rock Rapids, IA 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 Rock Rapids Municipal Water Works 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.