Greenlawn Water District
EPA ID: NY5103271 · 42,000 people served · 7 ZIP codes
Within the EPA compliance database, Greenlawn Water District shows 3 violations still pending resolution — a status that applies across the full service territory of approximately 42,000 people and reflects findings that have not yet cleared the federal enforcement process or received formal closure.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Greenlawn Water District Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Greenlawn Water District serves a community with a median household income of $163,435 and an estimated 207,474 residents across its service area. Approximately 87% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Greenlawn Water District's water is pumped from underground aquifers. 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.
About 1% of homes in Suffolk County, New York rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 80th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
Detected Contaminants
How Greenlawn Water District compares to EPA limits
What This Means For You
Arsenic at 1 mg/L exceeds the EPA maximum of 0.01 mg/L.
Contaminant 1011 at 1 mg/L exceeds the EPA maximum of mg/L.
Contaminant 1017 at 1 mg/L exceeds the EPA maximum of mg/L.
Contaminant 2049 at 1 mg/L exceeds the EPA maximum of mg/L.
Contaminant 2829 at 1 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 63 detections recorded. 18 exceed federal EPA limits (4 ppt for PFOA/PFOS). 6 exceed state limits.
Comparable Water Systems
Similar-sized systems in New York
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
GREENLAWN WATER DISTRICT (EPA ID: NY5103271) is a community water system in New York that serves approximately 42,000 people from groundwater sources.
This system provides water to 7 ZIP codes across 7 communities.
Average Home Safety Score: C (69/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| April 1, 2025 | Contaminant 2049 | Monitoring | Unresolved |
| January 1, 2025 | Arsenic | Monitoring | Unresolved |
| January 1, 2024 | Contaminant 2829 | Monitoring | Unresolved |
| October 1, 2023 | Contaminant 1017 | Monitoring | Resolved |
| April 1, 2023 | Copper | Monitoring | Resolved |
| April 1, 2023 | Contaminant 1011 | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Contaminant 1011 | Other Violation | 1 | No |
| Contaminant 1017 | Other Violation | 1 | No |
| Arsenic | Inorganic | 1 | No |
| Copper | Inorganic | 1 | No |
| Contaminant 2049 | Other Violation | 1 | No |
| Contaminant 2829 | Other Violation | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 11740 | 0.001 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
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.
- 11721 — Centerport
- 11725 — Commack
- 11731 — East Northport
- 11740 — Greenlawn
- 11743 — Huntington
- 11746 — Huntington Station
- 11768 — Northport
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Greenlawn Water District (NY5103271) on EPA.gov.
Frequently Asked Questions
Is Greenlawn Water District water safe to drink?
Greenlawn Water District has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Greenlawn Water District serve?
Greenlawn Water District serves approximately 42,000 people across 7 ZIP codes in New York.
Where does Greenlawn Water District get its water?
The primary water source is groundwater.
Contact Your Water Utility
Public-record contact information for the water utility serving this system. Use these channels to request water quality reports, ask about service, or report issues directly.
Contact information from Greenlawn Water District Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility, does not act as its agent, and does not provide customer support for it. Contact details shown are public-record information from CCR filings. For service issues, contact the utility directly using the information above.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: Greenlawn Water District Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
The source water assessment has rated most of the wells as having a high susceptibility to industrial solvents and nitrates. The elevated susceptibility to nitrates is due primarily to point sources of permitted discharge facilities and activities associated to unsewered residential land use. The susceptibility to industrial solvents is primarily due to point sources of contamination related to transportation routes and commercial/industrial activities.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Treatment chemicals and what each one does
Chemical names are reported verbatim by the utility. Purpose categories are ZipCheckup annotations based on standard drinking-water treatment practice.
Watershed exposure sources reported
Land-use and natural conditions identified in the utility's source-water assessment as potential contamination sources upstream of treatment.
Treatment classification and chemical list sourced from Greenlawn Water District Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
PFAS Substances Detected in This System
This water system's Consumer Confidence Report disclosed the following PFAS compounds. Levels are from the utility's most recent reporting cycle.
In April 2024, EPA finalized the first National Primary Drinking Water Regulation for six PFAS. Public water systems have until 2029 to comply. EPA — PFAS regulation overview →
Source: Consumer Confidence Report disclosed by Greenlawn Water District.
ZipCheckup is not affiliated with this water utility. PFAS detection data is sourced from public Consumer Confidence Reports filed by the utility itself.
A small portion of water service line material identification within our District remains unknown. If you notice your service line is listed as UNKNOWN on the map, please call the District office at (631) 261-0874 to schedule an appointment for one of our service operators to inspect your water service line at the first point of entry to your home or business.
Lead Service Line Replacement Tracker
This water utility's lead service line (LSL) replacement program is tracked from public Consumer Confidence Report filings. Email signup notifies subscribers when the utility files an updated replacement plan or progress milestone.
Greenlawn Water District
ZipCheckup is not affiliated with this water utility. LSL replacement-program data is sourced from public CCR filings published by the utility. Subscription notifications are based on automated parsing of subsequent CCR releases.
Learn more about Lead and Copper Rule replacement requirements →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Aesthetic water quality
These measurements describe the look, taste, and feel of the water this utility delivers. They are not contaminant violations — they sit alongside federal Secondary Maximum Contaminant Levels (SMCLs) which the EPA publishes as non-enforceable guidance.
Aesthetic measurements from Greenlawn Water District Consumer Confidence Report.
Aesthetic measurements are reported by the utility from its annual sampling. EPA Secondary MCLs are advisory thresholds — values outside them indicate aesthetic concerns such as taste or appearance, not health violations. Federal contaminant testing is shown in the sections above.
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
- #41 / 50 Highest Exposure Burden (New York)
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Greenlawn Water District (EPA ID: NY5103271) — request the latest Consumer Confidence Report or ask about specific contaminants.