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Limestone, PA Tap Water Quality 2026

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

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

Main Utility: Southwest Warren Co Mun Auth PWSID: PA6620032 Updated: 2026 Q2
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Lead above the federal action level

Lead is 19.20 ppb, 128% of the action level and no violations are open. PFAS has never been sampled at this system.

D

Limestone earns a D for water quality

Graded on violations and lead, with state inspection findings. PFAS not tested.

Lead: 19.20 ppb — 128% of the federal action level
PFAS never sampled at this system
36 violations since 2015, 14 health-based
No violations currently open
Limestone's lead level vs. all Pennsylvania community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 19.20 ppb — 100% of the federal action level
✓ Lower lead than 10% of Pennsylvania utilities
Population Served
108
~436 connections
Water Source
Surface water
Drawn from surface water — SDWIS source code SW
Active Violations
0
36 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
100% of EPA action level
19.20 ppb
Action level: 15 ppb
Copper (Cu)
90th percentile of tap samples. SDWIS reports a copper figure only when a system exceeds the action level, so any value here is an exceedance.
138.5% of EPA action level
1,800 ppb
Action level: 1,300 ppb
The 90th-percentile lead result is 19.20 ppb, 128% 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. Copper reached the action level here; a copper figure appears in SDWIS only when a system triggers it.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Surface Water Treatment Rule MONITORING AND REPORTING — — 2026 Archived
Interim Enhanced Surface Water Treatment Rule MONITORING AND REPORTING — — 2026 Archived
Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2026 Archived
Surface Water Treatment Rule MONITORING AND REPORTING — — 2026 Archived
Interim Enhanced Surface Water Treatment Rule MONITORING AND REPORTING — — 2026 Archived
Surface Water Treatment Rule MONITORING AND REPORTING — — 2026 Resolved
Total Haloacetic Acids (HAA5) MONITORING AND REPORTING — 0.060 mg/L 2025 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.062 MG/L 0.060 mg/L 2024 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.07 MG/L 0.060 mg/L 2024 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.064 MG/L 0.060 mg/L 2024 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.069 MG/L 0.060 mg/L 2023 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2023 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2023 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2022 Resolved
Consumer Confidence Rule OTHER — — 2022 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2021 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.074 MG/L 0.060 mg/L 2021 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2021 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2021 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.075 MG/L 0.060 mg/L 2021 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.077 MG/L 0.060 mg/L 2020 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2020 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.063 MG/L 0.060 mg/L 2020 Resolved
Public Notice OTHER — — 2020 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.064 MG/L 0.060 mg/L 2020 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE 0.061 MG/L 0.060 mg/L 2019 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2018 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2017 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2017 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2017 Resolved
Total Haloacetic Acids (HAA5) MONITORING AND REPORTING — 0.060 mg/L 2016 Resolved
Public Notice OTHER — — 2015 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE — 0.060 mg/L 2015 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE — 0.060 mg/L 2015 Resolved
Public Notice OTHER — — 2015 Resolved
Total Haloacetic Acids (HAA5) MCL EXCEEDANCE — 0.060 mg/L 2015 Resolved
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

36 violations are on record since 2015, of which 14 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Southwest Warren Co Mun Auth
PWSID PA6620032
Water source Surface water — Drawn from surface water — SDWIS source code SW
Population served 108
Service connections 436
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Limestone tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 19.20 ppb, 128% of the action level.
Does Limestone water have PFAS? ▼
This system has never been sampled for PFAS. EPA's national monitoring covered systems serving 3,300 people or more, so no results exist — which is not evidence that none is present.
Who supplies water to Limestone? ▼
Southwest Warren Co Mun Auth (PWSID PA6620032). Surface water. Drawn from surface water — SDWIS source code SW
When was this system last inspected? ▼
It was last inspected on 2023-09-07. No significant deficiencies were recorded.

What Should Limestone Residents Do?

1
Consider a filter certified for lead
Look for NSF/ANSI 53 certification for lead reduction.
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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