Huntley, IL
Lead detected, under the action levels
Latest 90th-percentile lead: 1.1 ppb (monitoring period 2026-2028). 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
Huntley serves about 28,495 people through 12,956 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 groundwater, in Mchenry County, Illinois. EPA system ID: IL1110350; phone on file: 847-515-5285. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is up 1.1 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Huntley is 3.5 ppb across 8 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2028 | 1.1 ppb |
| 2025 | 0 (not detected) |
| 2025 | 1 ppb |
| 2025 | 0 (not detected) |
| 2025 | 3 ppb |
| 2022 | 3.5 ppb |
| 2019 | 1.2 ppb |
| 2016 | 0 (not detected) |
Against other Illinois systems
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. Huntley's 1.1 ppb sits at the 62nd percentile in Illinois and the 58th nationally (higher means more lead).
Neighbouring systems
31 other systems share Mchenry County; 18 of them have a higher latest lead result than Huntley. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Crystal Lake | 40,661 | 6.8 ppb |
| Algonquin | 30,700 | 1.96 ppb |
| Lake In The Hills | 28,661 | 0 (not detected) |
| Woodstock | 25,630 | 1.5 ppb |
| Mchenry | 22,335 | 6.7 ppb |
| Cary | 17,826 | 1.7 ppb |
| Harvard | 9,469 | 7.1 ppb |
| Il American-Whispering Hills | 8,300 | 0 (not detected) |
| Marengo | 7,572 | 0 (not detected) |
| Fox River Grove | 4,702 | 6.4 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Huntley, IL 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 Huntley 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. Systems that went over once often dip back under; here is what that means.