North Castle Water District #4
EPA ID: NY5922909 · 1,225 people served · 1 ZIP code
ZipCheckup's reading of EPA records for North Castle Water District #4 (NY5922909): no drinking-water violations recorded since 2021. Nothing in the federal violation file is listed against North Castle Water District #4, a system that provides water to roughly 1,225 people.
Data: EPA SDWIS
Service Area Map
Coverage area for North Castle Water District #4 Source: EPA SDWIS service area boundaries.
Service area boundary
Demographics of ZIP Codes Served
The ZIP codes associated with North Castle Water District #4 have a median household income of $247,433 and about 7,853 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 60% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
North Castle Water District #4's water is classified in EPA records as a groundwater source. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in New York
System Overview
North Castle Water District #4 (EPA ID: NY5922909) is a community water system in New York that serves approximately 1,225 people from groundwater sources.
This system serves ZIP code 10504 in Armonk.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0025 mg/L | No | 2025-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
1 of 1 ZIP records with known zones is in EPA Radon Zone 3.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by NY or modeled from parcel and building-footprint data.
- 10504 - Armonk
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for North Castle Water District #4 (NY5922909) on EPA.gov.
Frequently Asked Questions
Is North Castle Water District #4 water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for North Castle Water District #4 in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does North Castle Water District #4 serve?
North Castle Water District #4 serves approximately 1,225 people across 1 ZIP code in New York.
Where does North Castle Water District #4 get its water?
The primary water source is groundwater.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). North Castle Water District #4 Water Quality Report, NY. https://zipcheckup.com/water-system/ny5922909/
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author = {{ZipCheckup}},
title = {{North Castle Water District #4 Water Quality Report, NY}},
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url = {https://zipcheckup.com/water-system/ny5922909/}
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