Water in Pennsylvania.
Pennsylvania's older industrial cities (Pittsburgh, Philadelphia) have among the country's highest lead service line counts. Fracking-related groundwater contamination affects multiple rural communities. PFAS plumes from military bases (Willow Grove, Warminster) are well-documented.
Pittsburgh's lead-in-water exceedances in 2016 triggered a multi-year emergency response.
How Pennsylvania regulates drinking water.
Federal SDWA primacy. State PFAS MCLs adopted 2023: PFOA 14 ng/L, PFOS 18 ng/L. Active lead-line-replacement programs in Pittsburgh and Philadelphia.
Pennsylvania Department of Environmental Protection — Bureau of Safe Drinking Water
Pennsylvania's water history, in order.
The contamination events, regulatory shifts, and major settlements that define how this state thinks about drinking water today.
- 2014
PFAS contamination identified at Willow Grove and Warminster Naval Air Stations.
- 2016
Pittsburgh's water authority exceeds lead action level; emergency filter distribution begins.
- 2023
Pennsylvania sets state MCLs for PFOA and PFOS.
The actual water you drink.
The physical rivers, aquifers, lakes, and reservoirs that feed Pennsylvania's public water systems. Source quality is the foundation of tap quality — and where the long-term protection fights happen.
- riverSchuylkill River
Philadelphia supply.
- riverAllegheny + Monongahela Rivers
Pittsburgh.
- riverDelaware River
Eastern PA + NJ shared supply.
- aquiferMarcellus Shale Aquifer Zone
Western and northern PA with fracking contamination concerns.
Source-water mix
~70% surface water, ~30% groundwater
Major cities served
Philadelphia · Pittsburgh · Allentown · Erie · Reading · Scranton
Who actually serves the water.
The largest public water systems in Pennsylvania by population served. Click your ZIP after to see the full live EWG report for your specific utility.
- Philadelphia Water DepartmentPhiladelphia1,600Kserved
- Pittsburgh Water and Sewer AuthorityPittsburgh300Kserved
- Aqua PennsylvaniaMulti-region1,400Kserved
Where the contamination comes from.
Every state has a different industrial fingerprint. The industries below are the dominant historical and active contamination sources in Pennsylvania's drinking water systems.
Willow Grove and Warminster Naval Air Stations are major PFAS sources affecting Bucks and Montgomery counties. Pittsburgh / Philadelphia legacy lead service lines (200,000+ statewide). Marcellus Shale fracking-related groundwater contamination documented in multiple rural communities.
What state data flags most consistently.
Drawn from EPA SDWIS sampling records, EWG state summaries, and regional regulatory action over the past five years. Read the full deep dive on each.
Lead
A neurotoxic metal that leaches from old pipes and solder. No safe level for children.
PFAS (Forever Chemicals)
A class of ~15,000 synthetic chemicals that don't break down. Now regulated for the first time.
Trihalomethanes (TTHMs)
Byproducts of chlorinating water. Linked to bladder cancer at chronic exposure.
Chromium-6 (Hexavalent Chromium)
The Erin Brockovich chemical. A known carcinogen with no federal-specific limit yet.
Risk isn't evenly distributed.
Pittsburgh and Philadelphia residents in pre-1986 housing face significant lead exposure. Bucks and Montgomery County residents face military-base PFAS. Marcellus Shale region faces fracking contamination.
Pittsburgh and Philadelphia each have tens of thousands of lead service lines.
~17% on private wells, with significant fracking-related contamination in Marcellus shale region.
What's coming for Pennsylvania's water.
Marcellus Shale fracking-related groundwater contamination intensifies with drought-flood cycles. Schuylkill flooding events disrupt Philadelphia treatment. Allegheny River algal bloom risk increases.
Voluntary statewide
PA Department of Education + DEP provide voluntary testing assistance. Philadelphia and Pittsburgh school districts have published results.
Five questions for your next Consumer Confidence Report.
Your utility is required to send you a Consumer Confidence Report annually. Most are dense and procedural. These are the questions worth following up on for Pennsylvania specifically.
- 1
If I'm in Bucks or Montgomery County, has my well been impacted by Willow Grove / Warminster PFAS?
- 2
What is my Pittsburgh / Philadelphia lead service line replacement schedule?
- 3
If I'm in Marcellus country, has my well been tested for methane and brine?
Most state regulators allow public records requests for the underlying lab reports behind your CCR — your utility should be able to provide them on request.
What's changed in Pennsylvania water law.
Drinking water regulation moves at the state level as much as the federal level. Below are notable recent bills and regulatory actions specific to Pennsylvania.
- 2023
PA PFAS MCLs set — PFOA 14 ng/L, PFOS 18 ng/L.
- 2017
PA Lead Service Line Replacement legislation expanded.
For lead: NSF/ANSI 53 carbon block. For PFAS in PA: NSF/ANSI P473 or RO.
We don't recommend brands — the NSF/ANSI certification number matters more than the name on the box.
This is the state. Your address is the answer.
State-level patterns don't tell you about your specific tap. Run your ZIP for the live EWG contaminant report on your utility — or build a personalized Water File for your household.
Source-water mix, utility counts, lead-service-line estimates, and private-well shares are approximate, drawn from EPA SDWIS public data and state primacy-agency summaries. Contaminant rankings reflect EWG state-level monitoring data and regional regulatory action — they are not exhaustive. Timeline events are publicly documented. See methodology for the full sourcing. Search EPA SDWIS for Pennsylvania