Suffolk County Water Authority
EPA ID: NY5110526 · 1,100,000 people served · 102 ZIP codes
ZipCheckup's reading of EPA SDWIS for Suffolk County Water Authority (NY5110526): PFAS sampling above the current EPA limit (UCMR5). Suffolk County Water Authority's five-year compliance history is clean by every EPA metric - no health-based violations, no monitoring lapses, no enforcement actions on record, reflecting consistent performance for a utility that supplies water to approximately 1,100,000 residents year after year.
Data: EPA SDWIS
Service Area Map
Coverage area for Suffolk County Water Authority Source: EPA SDWIS service area boundaries.
Service area boundary - Grade B
Service Area Demographics
The Suffolk County Water Authority serves a community with a median household income of $128,632 and an estimated 1,465,975 residents across its service area. Approximately 73% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Suffolk County Water Authority'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.
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
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 787 detections recorded. 234 exceed federal EPA limits (4 ppt for PFOA/PFOS). 77 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
Suffolk County Water Authority (EPA ID: NY5110526) is a community water system in New York that serves approximately 1,100,000 people from groundwater sources.
This system provides water to 102 ZIP codes across 101 communities.
ZIP-Area Home Safety Context: B (83/100)
This is the average Home Safety Score for 72 of 102 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.00125 mg/L | No | N/A |
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
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.
This system serves 102 ZIP codes:
06390 · 11701 · 11702 · 11703 · 11704 11705 · 11706 · 11713 · 11715 · 11716 11717 · 11718 · 11719 · 11720 · 11721 11722 · 11724 · 11725 · 11726 · 11727 11729 · 11730 · 11731 · 11733 · 11735 11738 · 11739 · 11740 · 11741 · 11742 11743 · 11746 · 11747 · 11749 · 11751 11752 · 11754 · 11755 · 11757 · 11763 11764 · 11766 · 11767 · 11768 · 11769 11770 · 11772 · 11776 · 11777 · 11778 11779 · 11780 · 11782 · 11784 · 11786 11787 · 11788 · 11789 · 11790 · 11792 11794 · 11795 · 11796 · 11798 · 11901 11930 · 11932 · 11933 · 11934 · 11935 11937 · 11939 · 11940 · 11941 · 11942 11944 · 11946 · 11948 · 11949 · 11950 11951 · 11952 · 11953 · 11954 · 11955 11956 · 11957 · 11958 · 11959 · 11960 11961 · 11962 · 11963 · 11967 · 11968 11971 · 11972 · 11975 · 11976 · 11977 11978 · 11980
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Suffolk County Water Authority (NY5110526) on EPA.gov.
Frequently Asked Questions
Is Suffolk County Water Authority water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Suffolk County Water Authority 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 Suffolk County Water Authority serve?
Suffolk County Water Authority serves approximately 1,100,000 people across 102 ZIP codes in New York.
Where does Suffolk County Water Authority get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Above Current MCL
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). One or more PFAS compounds were measured above 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 →
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.
- #14 / 50 Highest Exposure Burden (New York)
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Suffolk County Water Authority, NY: Serves 1.1M People. https://zipcheckup.com/water-system/ny5110526/
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