Well Water in Pennsylvania
Contaminant risks, testing requirements, and treatment recommendations for private well owners in Pennsylvania.
Pennsylvania Geology and Groundwater
Pennsylvania sits on Appalachian sedimentary and Piedmont crystalline rock. This geology directly determines what contaminants are likely in private well water. Based on this geology, Pennsylvania well owners face elevated risk for radon from granitic geology, PFAS from industrial/military sites, iron and manganese from dissolved minerals. Moderate risk exists for arsenic, nitrate, uranium.
Contaminant Risk Profile
| Contaminant | Risk Level | Why |
|---|---|---|
| Arsenic | Moderate risk | Some geological zones have elevated levels. Test recommended. |
| Nitrate | Moderate risk | Some areas near farmland or septic systems may have elevated levels. |
| Radon | Elevated risk | Granitic and metamorphic bedrock produces radon gas. Inhaled from water during showering. |
| PFAS | Elevated risk | Military bases, industrial sites, or manufacturing in this state have contaminated groundwater. |
| Iron/Manganese | Elevated risk | Very common in this state's groundwater. Causes staining but is not a health risk. |
| Uranium | Moderate risk | Some geological zones may have elevated levels. |
How Pennsylvania Compares: Municipal Water Data
CheckMyTap tracks water quality for 31 cities in Pennsylvania. While these numbers reflect municipal water (not private wells), they indicate the baseline mineral content of Pennsylvania's water sources. Private wells often draw from the same aquifers but with less treatment.
| Metric | Pennsylvania Average | National Average |
|---|---|---|
| Hardness | 97 PPM (moderately hard) | 170 PPM |
| Hardness range | 26 - 170 PPM | 25 - 400+ PPM |
| Lead (avg municipal) | 3.8 ppb | 3.2 ppb |
| Nitrate (avg municipal) | 2.5 mg/L | 1.1 mg/L |
| Cities with PFAS detected | 17 of 31 | ~45% nationally |
| Cities exceeding PFAS MCL (4 ppt) | 16 |
Hardest water in Pennsylvania: Hanover (170 PPM), Camp Hill (160 PPM), State College (150 PPM), Pottstown (150 PPM), Pittsburgh (140 PPM).
Softest water: Reading (26 PPM), Scranton (40 PPM), Wilkes-Barre (48 PPM).
Testing Requirements in Pennsylvania
Pennsylvania does not have a statewide mandatory testing requirement for existing private wells. Regardless of state requirements, the EPA recommends testing annually for:
- Every year: Total coliform bacteria, E. coli, nitrate, pH, and total dissolved solids
- At least once: Arsenic, lead, copper, fluoride, and any contaminant identified as a local risk
- Recommended for Pennsylvania: Radon in water (granitic bedrock states have higher risk)
- Recommended for Pennsylvania: PFAS panel, especially if near military bases or industrial sites
- Recommended for Pennsylvania: Uranium, especially in areas with granitic or metamorphic bedrock
- After events: Retest after flooding, well repairs, nearby construction, or any change in taste/color/odor
Recommended Treatment for Pennsylvania Wells
Based on Pennsylvania's geology and common contaminant risks, these treatment systems address the most likely issues:
Removes arsenic, uranium, and most dissolved contaminants from drinking water
Learn moreWhole-house oxidation filter removes iron staining and manganese discoloration
Learn moreMost effective radon-in-water removal (95-99%). GAC is an alternative for lower levels
Kills bacteria and viruses without chemicals. Recommended for all well water systems
Frequently Asked Questions
Is well water in Pennsylvania safe to drink?
Well water quality in Pennsylvania varies significantly by location and geology. Pennsylvania sits on Appalachian sedimentary and Piedmont crystalline rock. Key concerns include radon from granitic geology, PFAS from industrial/military sites, iron and manganese from dissolved minerals. The only way to know your specific water quality is to test it. Use our free interpreter to understand your results.
How often should I test my well water in Pennsylvania?
The EPA recommends testing annually for bacteria (total coliform, E. coli), nitrate, total dissolved solids, and pH. Given Pennsylvania's arsenic risk, test for arsenic at least once and after any changes to your well. Radon testing is also recommended in Pennsylvania. Test more frequently if you notice changes in taste, color, or odor, or after flooding, nearby construction, or well repairs.
Does Pennsylvania require well water testing?
Pennsylvania does not have a statewide mandatory testing requirement for existing private wells. However, the EPA strongly recommends annual testing regardless of state requirements. Your county health department may have additional local requirements.
What is the average water hardness in Pennsylvania?
Municipal water in Pennsylvania averages 97 PPM across 31 cities tracked by CheckMyTap, ranging from 26 to 170 PPM. Private well water typically runs 20-50% harder than city water because groundwater has more contact time with mineral formations. Many Pennsylvania well owners have manageable hardness levels, though local variation is significant. Check your city's data.