Dering Harbor Water District, NY
Lead detected, under the action levels
Latest 90th-percentile lead: 1.24 ppb (monitoring period 2023-2023). 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
Dering Harbor Water District serves about 14 people through 37 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 Suffolk County, New York. EPA system ID: NY5103700; phone on file: 631-749-0020. 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 2022 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Dering Harbor Water District is 9.1 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 1.24 ppb |
| 2022 | 1 ppb |
| 2021 | 1.1 ppb |
| 2019 | 1.62 ppb |
| 2018 | 2.02 ppb |
| 2017 | 9.1 ppb |
| 2017 | 1.15 ppb |
Where this result ranks
Of the 2,077 New York systems with a lead result, the median latest reading is 1.5 ppb; 17 are over 15 ppb right now and 165 have gone over at some point. Dering Harbor Water District's 1.24 ppb sits at the 43rd percentile in New York and the 60th nationally (higher means more lead).
Neighbouring systems
25 other systems share Suffolk County; 15 of them have a higher latest lead result than Dering Harbor Water District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Suffolk County Water Authority | 1,100,000 | 1.25 ppb |
| South Huntington Water District | 81,760 | 1.3 ppb |
| Greenlawn Water District | 42,000 | 1 ppb |
| Riverhead Water District | 35,000 | 2 ppb |
| Dix Hills Water District | 34,522 | 1 ppb |
| Smithtown Water District | 19,635 | 1.2 ppb |
| Hampton Bays Water District | 12,500 | 1.3 ppb |
| Robert Moses State Park | 11,600 | 1 ppb |
| St James Water District | 10,587 | 1 ppb |
| Ocean Beach Water District | 4,500 | 1 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Shelter Island Heights, NY 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 Dering Harbor Water 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. The action level is dropping - the 10 ppb rule from 2027.