Knollcrest Tax District, CT
Lead detected, under the action levels
Latest 90th-percentile lead: 0.8 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.
About Knollcrest Tax District
Knollcrest Tax District serves about 356 people through 89 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Fairfield County, Connecticut. EPA system ID: CT0910081; phone on file: 203-746-1356. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Knollcrest Tax District'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 Knollcrest Tax District is 10 ppb across 13 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0.8 ppb |
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2023 | 1.8 ppb |
| 2022 | 10 ppb |
| 2021 | 1.1 ppb |
| 2020 | 2 ppb |
| 2019 | 2 ppb |
| 2018 | 2 ppb |
| 2017 | 1 ppb |
| 2016 | 1 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. Knollcrest Tax District's 0.8 ppb sits at the 50th percentile in Connecticut and the 48th nationally (higher means more lead).
Other water systems in Fairfield County
58 other systems share Fairfield County; 32 of them have a higher latest lead result than Knollcrest Tax District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Aquarion-Eastern Fairfield County | 351,756 | 0 (not detected) |
| Aquarion-Stamford | 119,214 | 0 (not detected) |
| Danbury Water Department | 62,055 | 0 (not detected) |
| Aquarion-Greenwich | 53,297 | 0 (not detected) |
| South Norwalk Electric & Water | 42,000 | 0 (not detected) |
| Norwalk First Taxing District | 40,256 | 0 (not detected) |
| Aquarion-Darien | 18,737 | 2 ppb |
| Aquarion-New Canaan | 10,097 | 0 (not detected) |
| Bethel Water Dept | 9,507 | 0 (not detected) |
| Aquarion-Ridgefield | 7,476 | 3.1 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; New Fairfield, 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 Knollcrest Tax District 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. Systems that went over once often dip back under; here is what that means.