Suffolk County Water Authority
EPA ID: NY5110526 · 1,100,000 people served · 102 ZIP codes
Pulled from the federal compliance ledger, 3 violations at Suffolk County Water Authority remain without resolution — the utility delivers drinking water to roughly 1,100,000 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 7 (2023) to 3 (2024). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Suffolk County Water Authority Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
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.
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 Suffolk County Water Authority compares to EPA limits
What This Means For You
Arsenic at 1 mg/L exceeds the EPA maximum of 0.01 mg/L.
Lead at 1 mg/L (action level) exceeds the EPA maximum of 0.015 mg/L (action level). Brain damage in children, kidney & blood pressure in adults. Consider reverse osmosis filtration.
Uranium at 1 mg/L exceeds the EPA maximum of 0.03 mg/L. Kidney toxicity, increased cancer risk. Consider reverse osmosis filtration.
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Consumer Confidence Report Rule at 3 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. 787 detections recorded. 234 exceed federal EPA limits (4 ppt for PFOA/PFOS). 77 exceed state limits.
Lead was detected in this water system. reverse osmosis filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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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.
Average Home Safety Score: C (60/100)
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 |
|---|---|---|---|
| January 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| January 1, 2025 | Contaminant 1028 | Monitoring | Unresolved |
| December 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| November 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| November 1, 2024 | Contaminant 1028 | Monitoring | Unresolved |
| May 1, 2024 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| May 1, 2024 | Contaminant 3000 | Monitoring | Unresolved |
| January 1, 2024 | Contaminant 1905 | Monitoring | Unresolved |
| July 1, 2023 | Contaminant 2829 | Monitoring | Resolved |
| March 1, 2023 | Contaminant 2049 | Monitoring | Resolved |
| January 1, 2023 | Contaminant 2959 | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting Failure | 3 | No |
| Contaminant 1028 | Other Violation | 2 | No |
| Arsenic | Inorganic | 1 | No |
| Lead | Inorganic | 1 | No |
| Contaminant 1066 | Other Violation | 1 | No |
| Uranium | Radionuclides | 1 | No |
| Contaminant 1905 | Other Violation | 1 | No |
| Contaminant 2049 | Other Violation | 1 | No |
| Contaminant 2428 | Other Violation | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
| Contaminant 2829 | Other Violation | 1 | No |
| Contaminant 2959 | Other Violation | 1 | No |
| Contaminant 3000 | Other Violation | 1 | No |
| Radium-228 | Radionuclides | 1 | No |
| Stage 1 DBP Rule | Treatment Failure | 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 |
|---|---|---|---|
| 11763 | 0.005 mg/L | No | N/A |
| 11768 | 0.0033 mg/L | No | N/A |
| 11795 | 0.003 mg/L | No | N/A |
| 11933 | 0.003 mg/L | No | N/A |
| 11719 | 0.0027 mg/L | No | N/A |
| 11721 | 0.0013 mg/L | No | N/A |
| 11788 | 0.00127 mg/L | No | N/A |
| 06390 | 0.001 mg/L | No | N/A |
| 11751 | 0.001 mg/L | No | N/A |
| 11770 | 0.001 mg/L | No | N/A |
| 11777 | 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.
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?
Suffolk County Water Authority has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
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.
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 SUFFOLK COUNTY WATER AUTHORITY 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: SUFFOLK COUNTY WATER AUTHORITY Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Contaminated soil identified to date poses no threat to the groundwater. It would take decades for any contamination found in the soil to reach groundwater and even if traces of contamination do ultimately reach groundwater, the Suffolk County Water Authority will remove any contaminants from the water before supplying it to you.
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.
Treatment classification and chemical list sourced from SUFFOLK COUNTY WATER AUTHORITY 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: 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 →
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 SUFFOLK COUNTY WATER AUTHORITY.
ZipCheckup is not affiliated with this water utility. PFAS detection data is sourced from public Consumer Confidence Reports filed by the utility itself.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
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 SUFFOLK COUNTY WATER AUTHORITY 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.
- #14 / 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
Suffolk County Water Authority (EPA ID: NY5110526) — request the latest Consumer Confidence Report or ask about specific contaminants.