Marble Rock Water Supply, IA
Lead detected, under the action levels
Latest 90th-percentile lead: 2 ppb (monitoring period 2021-2023). 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.
About Marble Rock Water Supply
Marble Rock Water Supply serves about 272 people through 180 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Floyd County, Iowa. EPA system ID: IA3420031; phone on file: 641-315-2621. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
That is down 10 ppb from 12 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Marble Rock Water Supply is 12 ppb across 3 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 2 ppb |
| 2020 | 12 ppb over 10 |
| 2017 | 4 ppb |
Where this result ranks
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. Marble Rock Water Supply's 2 ppb sits at the 62nd percentile in Iowa and the 71st nationally (higher means more lead).
Neighbouring systems
6 other systems share Floyd County; 4 of them have a higher latest lead result than Marble Rock Water Supply. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Charles City Water Supply | 7,446 | 6.2 ppb |
| Nora Springs Water Supply | 1,369 | 6 ppb |
| Rockford Water Supply | 762 | 2 ppb |
| Rudd Waterworks | 358 | 1.4 ppb |
| Floyd Muni Water Supply | 313 | 10 ppb |
| Colwell, City Of | 55 | 2.46 ppb |
Next steps for Marble Rock, IA
Test your own tap with a certified lab first-draw sample; Marble Rock, 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 Marble Rock Water Supply 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.