Westchester Joint Water Works, NY
Lead detected, under the action levels
Latest 90th-percentile lead: 3 ppb (monitoring period 2026-2028). 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 Westchester Joint Water Works
Westchester Joint Water Works serves about 59,629 people through 12,000 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Westchester County, New York. EPA system ID: NY5903435; phone on file: 914-777-7722. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Westchester Joint Water Works's lead record
Against the period ending 2027 (3 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Westchester Joint Water Works is 10.7 ppb across 11 monitoring periods, none of them over 15 ppb (3 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2028 | 3 ppb |
| 2027 | 3 ppb |
| 2026 | 4.5 ppb |
| 2025 | 3.3 ppb |
| 2022 | 8.1 ppb |
| 2021 | 10.7 ppb over 10 |
| 2020 | 10.7 ppb over 10 |
| 2019 | 10.7 ppb over 10 |
| 2018 | 4.8 ppb |
| 2017 | 3.9 ppb |
| 2016 | 4.4 ppb |
Against other New York systems
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. Westchester Joint Water Works's 3 ppb sits at the 75th percentile in New York and the 83rd nationally (higher means more lead).
Nearby utilities
89 other systems share Westchester County; 17 of them have a higher latest lead result than Westchester Joint Water Works. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Yonkers City | 211,569 | 7.14 ppb |
| Veolia Water New York, Inc. Rd-1 | 146,732 | 12.2 ppb |
| Mount Vernon Water Department | 73,893 | 7.12 ppb |
| White Plains City | 59,559 | 1.25 ppb |
| Veolia Water New York, Inc. Rd-2 | 57,301 | 2 ppb |
| Greenburgh Consolidated Wd #1 | 43,312 | 1.29 ppb |
| Yorktown Consold. Water Dist.#1 | 36,000 | 1.2 ppb |
| Ossining Water Department | 30,000 | 3 ppb |
| Cortlandt Consolidated Wd | 28,369 | 1.4 ppb |
| Peekskill City | 24,272 | 2 ppb |
Next steps for Mamaroneck, NY
Test your own tap with a certified lab first-draw sample; Mamaroneck, 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 Westchester Joint Water Works 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. Size matters more than most people expect: small vs large water systems.