Tap Water Results

Is Horsham, PA tap water safe?

Data: U.S. EPA · How we read the data · How we check it

Summary

Aqua Pennsylvania Main System, the largest system here, had PFAS above the 2024 federal limits (PFOA, PFOS) in EPA's 2023–2025 testing.

Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility issues a boil-water or do-not-drink notice, follow it.

3 public water systems serve parts of Horsham. The largest, Aqua Pennsylvania Main System, serves 822,600 people, and 3 systems here had PFAS above a federal limit. Your water bill names your system.

Largest system

Aqua Pennsylvania Main System

822,600 people · Surface water · EPA ID PA1460073

Buys treated water from Aqua Pennsylvania West Chester, Aqua Pennsylvania Bensalem, Phoenixville Water Dept, Aqua Pennsylvania Uwchlan, BCWSA Main Lower South, Philadelphia Water Department, Chester Water Authority.

PFASHighest averageLimitStatus
PFOA
Above limit
11.8 ppt4 pptAbove limit
PFOS
Above limit
8.9 ppt4 pptAbove limit
PFHxS
Detected, below limit
7.4 ppt10 pptDetected, below limit
PFNA
Detected, below limit
8.82 ppt10 pptDetected, below limit
HFPO-DA (GenX)
Not detected
–10 pptNot detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

For context: the PFOA average is higher than at 95% of the Pennsylvania systems EPA tested and the PFOS average is higher than at 91% of the Pennsylvania systems EPA tested.

Lead: 0 ppb at the 90th percentile (Sep 2025, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 2

Full Aqua Pennsylvania Main System results

Across Pennsylvania, 85 of 360 water systems EPA tested had PFAS above a 2024 federal limit, and 76 systems were above the lead action level in results from the last five years. Pennsylvania results.

Horsham homes and lead pipes

50%
of homes built before 1980 (Pennsylvania 67%, US 50%)
8%
built before 1950 (Pennsylvania 32%)
28%
of households rent (Pennsylvania 31%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Horsham township (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Horsham

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
Upper Dublin 3 mi
Aqua Pennsylvania Main System
Aqua Pennsylvania Main SystemAbove limit0 ppb
Warrington 3 mi
Aqua Pennsylvania Main System
Aqua Pennsylvania Main SystemAbove limit0 ppb
Warminster 4 mi
Aqua Pennsylvania Main System
Aqua Pennsylvania Main SystemAbove limit0 ppb
Upper Moreland 4 mi
Aqua Pennsylvania Main System
Aqua Pennsylvania Main SystemAbove limit0 ppb
Montgomery 5 mi
North Penn Water Authority
North Penn Water AuthorityAbove limit0.5 ppb
Abington 7 mi
Aqua Pennsylvania Main System
Aqua Pennsylvania Main SystemAbove limit0 ppb
Horsham ZIP codes (2)
  • 19002
  • 19044

Questions

Is Horsham tap water safe to drink?

Aqua Pennsylvania Main System had 2 health-based violations since 2016, and EPA testing found PFAS above the 2024 federal limits, which it must meet by 2029. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Horsham, PA?

3 public water systems serve parts of Horsham. The largest is Aqua Pennsylvania Main System (822,600 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Horsham tap water have PFAS?

Yes. EPA's 2023–2025 testing found entry-point averages above the 2024 federal limits for PFOA and PFOS at Aqua Pennsylvania Main System. Systems have until 2029 to meet them.

Do Horsham homes have lead pipes?

Census estimates put 50% of Horsham homes as built before 1980 (Pennsylvania: 67%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Aqua Pennsylvania Main System's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.