Suffolk County Water Authority, NY
Lead detected, under the action levels
Latest 90th-percentile lead: 1.25 ppb (monitoring period 2025-2027). 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
Suffolk County Water Authority serves about 1,100,000 people through 336,418 service connections, which makes it a very large 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: NY5110526; phone on file: 631-563-0258. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
Against the period ending 2025 (1.27 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Suffolk County Water Authority is 2.32 ppb across 10 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2027 | 1.25 ppb |
| 2025 | 1.27 ppb |
| 2024 | 2.32 ppb |
| 2023 | 0.9 ppb |
| 2021 | 1.31 ppb |
| 2020 | 1.52 ppb |
| 2019 | 1.97 ppb |
| 2018 | 1.41 ppb |
| 2017 | 2.17 ppb |
| 2016 | 1.2 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. Suffolk County Water Authority's 1.25 ppb sits at the 44th percentile in New York and the 60th nationally (higher means more lead).
Nearby utilities
25 other systems share Suffolk County; 14 of them have a higher latest lead result than Suffolk County Water Authority. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| 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 |
| Brookhaven National Laboratory | 3,500 | 2.7 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Hauppauge, 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 Suffolk County Water Authority 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. The lead result guide covers how utilities pick the homes they sample. The action level is dropping - the 10 ppb rule from 2027.