Hennepin Pwd, IL
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2025-2025). 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.
Who runs the water here
Hennepin Pwd serves about 750 people through 290 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 Putnam County, Illinois. EPA system ID: IL1555100; phone on file: 815-925-7223. 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 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Hennepin Pwd is 5 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2022 | 5 ppb |
| 2019 | 1.7 ppb |
| 2016 | 4.5 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. Hennepin Pwd's reported as 0 (not detected) sits at the 27th percentile in Illinois and the 25th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Putnam County
7 other systems share Putnam County; 1 of them has a higher latest lead result than Hennepin Pwd. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Granville | 1,359 | 0 (not detected) |
| Mark | 555 | 0 (not detected) |
| Lake Thunderbird Subdivsion | 450 | 0 (not detected) |
| Mcnabb | 258 | 0 (not detected) |
| Magnolia | 244 | 0 (not detected) |
| Standard | 225 | 0 (not detected) |
| Oak Park Estates | 185 | 3.72 ppb |
Next steps for Hennepin, IL
Look up your address in Hennepin Pwd'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 Hennepin Pwd 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.