Scwa, Montville Division (Mtv), CT
Lead detected, under the action levels
Latest 90th-percentile lead: 4.1 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.
Scwa, Montville Division (Mtv) at a glance
Scwa, Montville Division (Mtv) serves about 2,570 people through 422 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 New London County, Connecticut. EPA system ID: CT0860011; phone on file: 860-464-0232. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Scwa, Montville Division (Mtv)'s lead record
That is up 1.6 ppb from 2.5 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Scwa, Montville Division (Mtv) is 4.3 ppb across 11 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 4.1 ppb |
| 2025 | 2.5 ppb |
| 2024 | 3.1 ppb |
| 2023 | 0 (not detected) |
| 2022 | 1.6 ppb |
| 2021 | 2.3 ppb |
| 2020 | 2.8 ppb |
| 2019 | 1.2 ppb |
| 2018 | 0 (not detected) |
| 2017 | 4.3 ppb |
| 2016 | 0 (not detected) |
Against other Connecticut systems
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. Scwa, Montville Division (Mtv)'s 4.1 ppb sits at the 89th percentile in Connecticut and the 88th nationally (higher means more lead).
Other water systems in New London County
82 other systems share New London County; 8 of them have a higher latest lead result than Scwa, Montville Division (Mtv). 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) |
| Groton Utilities | 30,200 | 1.1 ppb |
| 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) |
Your move
Test your own tap with a certified lab first-draw sample; Gales Ferry, 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 Scwa, Montville Division (Mtv) 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.