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Southold, NY Tap Water Quality 2026

Water quality report for Southold, NY — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Southold's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Suffolk County Water Authority PWSID: NY5110526 Updated: 2026 Q2
⚠️

PFAS above the federal limit at 10 of 238 sampling points

Lead is 1.27 ppb, 8% of the action level and no violations are open. However, PFAS exceeds the federal limit at 10 of 238 sampling points, running as high as 3.03 times the limit.

C

Southold earns a C for water quality

Graded on violations, lead, and PFAS, with state inspection findings.

Lead: 1.27 ppb — 8% of the federal action level
PFAS above the federal limit at 10 of 238 sampling points
3 violations since 2015, 1 health-based
No violations currently open
Southold's lead level vs. all New York community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 1.27 ppb — 8% of the federal action level
✓ Lower lead than 80% of New York utilities
Population Served
16444
~336418 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
3 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
8% of EPA action level
1.27 ppb
Action level: 15 ppb
The 90th-percentile lead result is 1.27 ppb, 8% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Asbestos MCL EXCEEDANCE 26.62 MFL 7 MFL 2020 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2018 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2017 Archived
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

3 violations are on record since 2015, of which 1 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Suffolk County Water Authority
PWSID NY5110526
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 16,444
Service connections 336,418
Systems serving this area 4
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Southold tap water safe to drink? ▼
It meets most federal standards, but PFAS exceeds the federal limit at 10 of 238 sampling points. No violations are currently open. Lead is 1.27 ppb, 8% of the action level.
Does Southold water have PFAS? ▼
Yes. PFAS exceeds the federal limit at 10 of 238 sampling points, running as high as 3.03 times the limit. Limits are enforced on a running annual average at each sampling point, not on a single sample.
Who supplies water to Southold? ▼
Suffolk County Water Authority (PWSID NY5110526), one of 4 systems serving this area. Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2024-01-02. No significant deficiencies were recorded.

What Should Southold Residents Do?

1
Consider a reverse-osmosis filter
Reverse osmosis removes more than 95% of PFAS. Standard carbon pitchers do not.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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