Groton Utilities, CT
Lead detected, under the action levels
Latest 90th-percentile lead: 1.1 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.
Groton Utilities at a glance
Groton Utilities serves about 30,200 people through 5,261 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 surface water, in New London County, Connecticut. EPA system ID: CT0590011; phone on file: 860-446-4091. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Groton Utilities's lead record
That is up 1.1 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Groton Utilities is 9 ppb across 24 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.1 ppb |
| 2025 | 0 (not detected) |
| 2025 | 1.2 ppb |
| 2024 | 0 (not detected) |
| 2024 | 1.3 ppb |
| 2024 | 2.8 ppb |
| 2023 | 3.7 ppb |
| 2023 | 0 (not detected) |
| 2023 | 4 ppb |
| 2022 | 2.9 ppb |
| 2022 | 0 (not detected) |
| 2022 | 6.6 ppb |
| 2021 | 0 (not detected) |
| 2021 | 2.6 ppb |
| 2021 | 1.6 ppb |
| 2020 | 0 (not detected) |
| 2020 | 7 ppb |
| 2020 | 7 ppb |
| 2019 | 9 ppb |
| 2019 | 0 (not detected) |
| 2018 | 0 (not detected) |
| 2018 | 4 ppb |
| 2017 | 0 (not detected) |
| 2016 | 0 (not detected) |
How Groton Utilities 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. Groton Utilities's 1.1 ppb sits at the 60th percentile in Connecticut and the 58th nationally (higher means more lead).
Other water systems in New London County
82 other systems share New London County; 32 of them have a higher latest lead result than Groton Utilities. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Norwich Public Utilities | 36,163 | 0 (not detected) |
| New London Dept. Of Public Utilities | 27,620 | 0 (not detected) |
| Waterford Wpca | 16,578 | 1.5 ppb |
| East Lyme Water & Sewer Commission | 15,245 | 0 (not detected) |
| Aquarion-Mystic | 10,788 | 0 (not detected) |
| Jewett City Water Company | 6,840 | 0 (not detected) |
| Colchester Sewer & Water Commission | 4,020 | 0 (not detected) |
| Ctwc - Shoreline Region-Sound View | 3,397 | 0 (not detected) |
| Ledyard Wpca - Ledyard Center | 3,294 | 0 (not detected) |
| Scwa, Montville Division (Mtv) | 2,570 | 4.1 ppb |
Next steps for Groton, CT
Test your own tap with a certified lab first-draw sample; Groton, 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 Groton Utilities 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. Why sampled homes are the worst-case ones is in the guide to reading the number. The action level is dropping - the 10 ppb rule from 2027.