Hamilton Grove, IN
Lead detected, under the action levels
Latest 90th-percentile lead: 7.7 ppb (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. 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
Hamilton Grove serves about 384 people through 26 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in St. Joseph County, Indiana. EPA system ID: IN5271024; phone on file: 574-309-2709. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
That is up 7.7 ppb from 0 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Hamilton Grove is 7.7 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 7.7 ppb |
| 2021 | 0 (not detected) |
| 2018 | 0 (not detected) |
Where this result ranks
Of the 687 Indiana systems with a lead result, the median latest reading is 1.31 ppb; 6 are over 15 ppb right now and 36 have gone over at some point. Hamilton Grove's 7.7 ppb sits at the 95th percentile in Indiana and the 95th nationally (higher means more lead).
Neighbouring systems
14 other systems share St. Joseph County; 1 of them has a higher latest lead result than Hamilton Grove. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| South Bend Water Works | 115,000 | 4.7 ppb |
| Mishawaka Utilities | 49,675 | 7.1 ppb |
| University Of Notre Dame | 7,400 | 3 ppb |
| Walkerton Light & Water | 2,262 | 8.2 ppb |
| Sisters Of Holy Cross-St. Marys College | 2,111 | - |
| North Liberty Water Works | 1,896 | 1.42 ppb |
| New Carlisle Water Works | 1,861 | 1.6 ppb |
| Lakeville Water Department | 750 | 0.82 ppb |
| Aqua Indiana - Wedgewood Park Water Util | 645 | 0 (not detected) |
| Sisters-St. Francis Perpetual Adoration | 145 | 5.9 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; South Bend, IN 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 Hamilton Grove 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. Size matters more than most people expect: small vs large water systems.