Rock Island, IL
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2026-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Rock Island at a glance
Rock Island serves about 39,018 people through 15,072 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Rock Island County, Illinois. EPA system ID: IL1610650; phone on file: 309-732-2231. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Rock Island's lead record
Against the period ending 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Rock Island is 6 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2025 | 5.6 ppb |
| 2025 | 6 ppb |
| 2023 | 1.8 ppb |
| 2020 | 5.7 ppb |
| 2017 | 1.4 ppb |
Where this result ranks
Of the 1,744 Illinois systems with a lead result, the median latest reading is 0 ppb; 22 are over 15 ppb right now and 152 have gone over at some point. Rock Island's reported as 0 (not detected) sits at the 54th percentile in Illinois and the 39th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
46 other systems share Rock Island County; 28 of them have a higher latest lead result than Rock Island. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Moline | 44,500 | 1.3 ppb |
| East Moline | 21,374 | 16 ppb |
| Rock Island Arsenal, Us Army | 7,800 | 0 (not detected) |
| Silvis | 7,473 | 4.1 ppb |
| Milan | 4,945 | 7.18 ppb |
| Coal Valley | 3,873 | 0 (not detected) |
| Carbon Cliff | 2,134 | 0 (not detected) |
| Hampton | 1,863 | 1.3 ppb |
| Port Byron | 1,668 | 6 ppb |
| Silvis Heights Water Corp | 1,450 | 9.68 ppb |
What to do in your house
Look up your address in Rock Island's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Rock Island 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. The lead result guide covers how utilities pick the homes they sample. A zero today does not rule out a jump later - the rules are tightening in 2027.