Ctwc - Shoreline Region-Guilford System, CT
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Ctwc - Shoreline Region-Guilford System at a glance
Ctwc - Shoreline Region-Guilford System serves about 33,975 people through 18,424 service connections, which makes it a large system under EPA's size classes. It is privately owned and draws surface water, in New Haven County, Connecticut. EPA system ID: CT0608011; phone on file: 860-664-6125. 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 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Ctwc - Shoreline Region-Guilford System is 3 ppb across 18 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2024 | 1.4 ppb |
| 2024 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2021 | 3 ppb |
| 2020 | 0 (not detected) |
| 2020 | 1.4 ppb |
| 2020 | 0 (not detected) |
| 2020 | 1.4 ppb |
| 2019 | 0 (not detected) |
| 2018 | 0 (not detected) |
| 2017 | 2.8 ppb |
| 2017 | 2.8 ppb |
| 2017 | 0 (not detected) |
| 2016 | 0 (not detected) |
How Ctwc - Shoreline Region-Guilford 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. Ctwc - Shoreline Region-Guilford System's reported as 0 (not detected) sits at the 37th percentile in Connecticut and the 39th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in New Haven County
30 other systems share New Haven County; 13 of them have a higher latest lead result than Ctwc - Shoreline Region-Guilford 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 - 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) |
| Aquarion-East Derby | 1,101 | 0 (not detected) |
What to do in your house
Look up your address in Ctwc - Shoreline Region-Guilford System's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Ctwc - Shoreline Region-Guilford 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. Why sampled homes are the worst-case ones is in the guide to reading the number. A zero today does not rule out a jump later - the rules are tightening in 2027.