Pennsylvania Water Quality Rankings 2026: Best & Worst Cities

This page ranks the 4 Pennsylvania cities whose water systems we have matched to EPA records. Every city starts at 100 points and loses points for health-based EPA violations in the last five years (SDWIS 2026Q2), its most recent Lead and Copper Rule 90th-percentile result, PFAS detected in EPA's 2023–2026 UCMR5 monitoring, and 2012–2019 compliance samples that averaged near or above a limit. Letters follow fixed bands (A ≥90, B ≥80, C ≥70, D ≥60, F below 60). Cities run from the highest score (Pittsburgh) down to the lowest (Philadelphia); ties are ordered by population served. See the full scoring methodology for every deduction and the data vintages.

What your city's grade means

An A or B grade points to water that consistently tests within federal safety limits, while a C suggests moderate issues worth watching and a D or F flags contaminants or compliance problems serious enough to act on. These grades describe system-level water leaving the treatment plant — they can't account for your home's own plumbing, so older houses with lead service lines or fixtures can add contaminants after the water arrives. For a contaminant-by-contaminant view, see the Pennsylvania contaminant breakdown or drill into the county-level rankings.

What Pennsylvania residents should do

• Find your city in the ranking below and open its full report for its violation history, lead results and PFAS table.
• See how Pennsylvania compares against the best-rated and worst-rated cities nationwide.
• Test your home's water if you have concerns — the most common issues involve lead, PFAS, and arsenic.
• Check whether your utility still has lead service lines in Pennsylvania — EPA's inventory counts lead pipes by water system, a risk that plant-level grades cannot capture. Read the lead guide for testing and filter options.
• If treatment makes sense for your situation, compare certified water filters matched to the contaminants found in your area.

This ranking covers 4 Pennsylvania cities. 4 of them are matched to an active EPA-registered community water system (PWSID). Those 4 systems report serving 2,624,001 people in EPA's Safe Drinking Water Information System (SDWIS).

Of all 4 cities Pennsylvania cities we can grade from EPA records, 2 cities (50%) grade B or better, 1 sit in the C range and 1 grade D or F. The average score is 84/100.

None of the 4 graded systems has a health-based EPA violation in the last five years; the 23 violations on file in that window are monitoring or reporting lapses.

4 cities have a Lead and Copper Rule 90th-percentile result from 2020 or later: 1 city at 5 ppb or more.

EPA's UCMR5 PFAS monitoring (2023–2026) covers 4 cities: PFAS were detected in 2 cities, and PFOA or PFOS reached EPA's 4 ppt limit in 2 cities.

Pittsburgh scores highest (100) and Philadelphia lowest (69), a 31-point spread.

The clearest hard data for Pennsylvania is EPA's service line inventory, updated 2026-08-18 (Q2 2026). 2,908 Pennsylvania systems inventoried 3,929,613 service lines: 65,295 confirmed lead plus 48,443 galvanized lines requiring replacement, spread across 173 systems. The bigger number is 2,057,908 lines (52%) whose material is still unknown — more than one line in four — and EPA treats unknown lines as possible lead until a utility verifies them.

Of the 4 city-linked Pennsylvania utilities with an inventory on file, 4 report at least one lead or galvanized-requiring-replacement line. The largest, PHILADELPHIA WATER DEPARTMENT (Philadelphia, 1,600,000 served), reports 16,805 lead lines and 1,777 galvanized requiring replacement.

Our Pennsylvania water guide flags lead, radium, trihalomethanes, and PFAS as the contaminants of regional concern. Lead (EPA action level 0.015 mg/L (15 ppb); health goal 0) harms brain development in children and raises blood pressure and kidney risk in adults; Radium (EPA MCL 5 pCi/L (combined radium-226/228)) increases cancer risk with long exposure; Disinfection byproducts (regulated as TTHM (80 ppb) and HAA5 (60 ppb)) are associated with increased cancer risk over long exposure; PFAS (EPA 2024 MCLs of 4.0 ppt for PFOA and PFOS) are linked to immune, developmental, liver and some cancer effects.

Source water explains a lot of the pattern in Pennsylvania. Disinfection byproducts are a surface-water signature: chlorine reacts with organic matter in rivers and reservoirs, so byproducts tend to run higher where systems chlorinate surface water. Radium is naturally occurring and tends to show up in groundwater, leaching from bedrock into aquifers rather than arriving from pollution. PFAS are tied to specific sites — industrial discharges, firefighting-foam use at airports and bases — rather than to geology, so contamination is local and can affect either source type. Lead is different again: it enters after treatment from service lines and household plumbing, which is why the inventory figures above matter more than plant-level results. The Consumer Confidence Report your Pennsylvania utility mails each year states whether your system draws surface water or groundwater.

The best water quality in Pennsylvania is found in Pittsburgh with a score of 100/100 and a grade of A. This puts Pittsburgh among the top-performing cities in the country for drinking water safety.

The most concerning water quality is in Philadelphia scoring 69/100 with a grade of D. Residents may want to consider home water testing and filtration options.

The statewide average score is 84/100, which is 4 points below the national average of 88/100. Over half (50%) of Pennsylvania cities score above the national average, though some areas face challenges.