TapSafetyReport
D22/100

Carlisle Tap Water Quality: Is It Safe to Drink? (2026 Report)

Serving 39,682 residents · Pennsylvania

What's In Carlisle's Tap Water?

69
Contaminants Tested
2
Exceed EPA Limits
1
Above EPA Goals
3 contaminants above EPA health goals
ContaminantDetectedLimit (MCL)Status
PFOS
0.008 µg/L0.004 µg/LOver Limit
PFOA
0.005 µg/L0.004 µg/LOver Limit
Lead (90th percentile)
0.011 mg/L0.015 mg/LAbove Goal

EPA Violation History

7

Violations (last 5yr)

0

Unresolved

0

Health-Related

TIER 3Resolved

Failed to complete routine monitoring

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: August 1, 2024 – August 31, 2024Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: August 1, 2024 – August 31, 2024Rule: Stage 1 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved

Disinfection byproduct treatment technique failure

When: April 11, 2024 – May 31, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Disinfection byproduct treatment technique failure

When: April 11, 2024 – May 31, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2023 – June 30, 2023Rule: Stage 1 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: January 1, 2023 – March 31, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: January 1, 2023 – March 31, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway

Understanding violation severity

Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.

Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly

Water Utility Details

CARLISLE WATER TRMT PLT
Population Served

26,000

Water Source

Surface Water

System ID

PA7210002

US ARMY GARRISON
Population Served

1,700

Water Source

Groundwater

System ID

PA7210010

N MIDDLETON WATER AUTH
Population Served

8,455

Water Source

Surface Water

System ID

PA7210049

MIDDLESEX TWP MUNI AUTH
Population Served

3,527

Water Source

Groundwater

System ID

PA7210063

Frequently Asked Questions About Carlisle Water

Is Carlisle tap water safe to drink?

Carlisle, Pennsylvania tap water receives a grade of D (22/100), which is considered poor. 3 contaminant(s) exceed EPA maximum contaminant levels and 220 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

What contaminants are in Carlisle's water?

Of the 69 contaminants tested in Carlisle's water supply, the most notable include PFOS, Lead (90th percentile), PFOA. 3 contaminant(s) exceed EPA legal limits (MCLs). 3 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.

Does Carlisle have any water quality violations?

Yes, Carlisle has 220 EPA violation(s) on record, with the most recent in 2025. Violation types include MR, Other, RPT. 10 of these are health-based violations, which are the most serious category.

Do I need a water filter in Carlisle?

Based on EPA data, using a water filter in Carlisle is recommended. 3 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.

Where does Carlisle's tap water come from?

Carlisle's drinking water is sourced from surface water and supplied by CARLISLE WATER TRMT PLT and 3 other water system(s). The system serves approximately 39,682 people. Surface water sources include rivers, lakes, and reservoirs.

How often is Carlisle's water tested?

Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Carlisle's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.

How does Carlisle's water compare to other cities in Pennsylvania?

Carlisle's water quality score of 22/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our Pennsylvania state page to see how all cities in the state compare.

What should I do if I'm concerned about Carlisle's water quality?

If you have concerns about Carlisle's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (CARLISLE WATER TRMT PLT) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.

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