Mount Kisco Water Department, NY
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2025-2025). 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
Mount Kisco Water Department serves about 11,187 people through 2,700 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: NY5903437; phone on file: 914-864-0033. 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 (2 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Mount Kisco Water Department is 3.7 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1 ppb |
| 2025 | 2 ppb |
| 2024 | 2 ppb |
| 2021 | 3.7 ppb |
| 2020 | 2.8 ppb |
| 2017 | 0 (not detected) |
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. Mount Kisco Water Department's 1 ppb sits at the 38th percentile in New York and the 55th nationally (higher means more lead).
Nearby utilities
89 other systems share Westchester County; 48 of them have a higher latest lead result than Mount Kisco Water Department. 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 |
| Westchester Joint Water Works | 59,629 | 3 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 |
What to do in your house
Test your own tap with a certified lab first-draw sample; Mount Kisco, 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 Mount Kisco Water Department 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. The action level is dropping - the 10 ppb rule from 2027.