Quonnipaug Hills - Main System, CT
Lead detected, under the action levels
Latest 90th-percentile lead: 2.3 ppb (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. 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.
Quonnipaug Hills - Main System at a glance
Quonnipaug Hills - Main System serves about 564 people through 187 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws groundwater, in New Haven County, Connecticut. EPA system ID: CT0600041; phone on file: 203-415-4316. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
Against the period ending 2025 (2.8 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Quonnipaug Hills - Main System is 7.7 ppb across 11 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 2.3 ppb |
| 2025 | 2.8 ppb |
| 2025 | 3.3 ppb |
| 2024 | 1.2 ppb |
| 2024 | 2.8 ppb |
| 2023 | 1.4 ppb |
| 2023 | 1.2 ppb |
| 2022 | 4.5 ppb |
| 2022 | 3.9 ppb |
| 2021 | 7.7 ppb |
| 2018 | 2.2 ppb |
How Quonnipaug Hills - Main System compares
Of the 493 Connecticut systems with a lead result, the median latest reading is 0.8 ppb; 2 are over 15 ppb right now and 49 have gone over at some point. Quonnipaug Hills - Main System's 2.3 ppb sits at the 78th percentile in Connecticut and the 76th nationally (higher means more lead).
Other water systems in New Haven County
30 other systems share New Haven County; 4 of them have a higher latest lead result than Quonnipaug Hills - Main System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Regional Water Authority | 418,900 | 0 (not detected) |
| Waterbury Water Department | 107,271 | 0.01 ppb |
| Meriden Water Division | 58,441 | 0 (not detected) |
| Wallingford Water Department | 37,267 | 0 (not detected) |
| Ctwc - Shoreline Region-Guilford System | 33,975 | 0 (not detected) |
| Ctwc - Naugatuck Region-Central System | 22,735 | 0 (not detected) |
| Aquarion-Valley | 13,080 | 1.1 ppb |
| Heritage Water Company | 7,300 | 0.7 ppb |
| Wolcott Water Department | 2,550 | 0 (not detected) |
| Ctwc - Legend Hill System | 1,368 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Branford, CT 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 Quonnipaug Hills - Main System 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. Size matters more than most people expect: small vs large water systems.