Aquarion-Marlborough, CT
Lead detected, under the action levels
Latest 90th-percentile lead: 0.6 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.
Who runs the water here
Aquarion-Marlborough serves about 1,348 people through 148 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 Hartford County, Connecticut. EPA system ID: CT0798013; phone on file: 203-926-4320. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Aquarion-Marlborough'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 Aquarion-Marlborough is 9 ppb across 15 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0.6 ppb |
| 2025 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2023 | 2 ppb |
| 2022 | 2 ppb |
| 2022 | 9 ppb |
| 2021 | 2 ppb |
| 2020 | 3 ppb |
| 2019 | 2 ppb |
| 2019 | 3 ppb |
| 2018 | 3 ppb |
| 2018 | 2 ppb |
| 2017 | 2.4 ppb |
| 2016 | 3 ppb |
How Aquarion-Marlborough 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. Aquarion-Marlborough's 0.6 ppb sits at the 46th percentile in Connecticut and the 45th nationally (higher means more lead).
Neighbouring systems
46 other systems share Hartford County; 15 of them have a higher latest lead result than Aquarion-Marlborough. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Metropolitan District Commission | 390,887 | 0 (not detected) |
| Ctwc - Northern Reg-Western System | 101,313 | 0 (not detected) |
| New Britain Water Department | 73,534 | 0 (not detected) |
| Bristol Water Department | 52,079 | 0 (not detected) |
| Manchester Water Department | 51,198 | 0 (not detected) |
| Southington Water Department | 43,069 | 0 (not detected) |
| Hazardville Water Company | 18,544 | 0.7 ppb |
| Aquarion-Plainville Regional | 18,231 | 0 (not detected) |
| Ctwc - Unionville System | 14,693 | 2.4 ppb |
| Aquarion-Simsbury Regional | 14,691 | 0.3 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Shelton, 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 Aquarion-Marlborough 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. The action level is dropping - the 10 ppb rule from 2027.