Lehigh County, Pennsylvania: drinking water report. Lehigh County – Allentown – serves about 380,000 residents in Pennsylvania's Lehigh Valley.
Lehigh County – Allentown – serves about 380,000 residents in Pennsylvania's Lehigh Valley. The Lehigh County Authority and the City of Allentown's water system draw from the Lehigh River, Little Lehigh Creek, and groundwater wells. The Lehigh Valley's industrial heritage – steel, cement, and manufacturing – has left contamination in some areas, though much of the county's water comes from relatively clean mountain streams.
Allentown's water system made news when the city leased its water and sewer operations to the Lehigh County Authority in 2013 to address municipal budget shortfalls. The transition has been contentious, but the underlying water quality has remained stable. UCMR5 data shows PFAS detections in some county systems.
According to the Pennsylvania DEP's 2024 monitoring data, one Lehigh County system reported PFAS above state-proposed MCLs. The Lehigh River provides generally clean source water from the Poconos, though urban runoff in the Allentown area affects tributary water quality.
Lehigh County's water quality is generally good, with mountain-fed source water providing a clean baseline.
Check your water for data specific to your provider. An activated carbon filter addresses taste and provides some PFAS reduction. Our water filter guide covers options. Pull your detailed report, and visit our Pennsylvania page for statewide data.
Drinking water is one exposure route. These federal datasets also cover Lehigh County, PA.
The EPA places Lehigh County, PA in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
66% of homes in Lehigh County, PA were built before 1980, and 30% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Lehigh County, PA averages 8.3 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide
12 public water systems serving Lehigh County, PA have EPA lead testing on record. The reported lead sample skews toward systems that already flagged a problem, so its exceedance rate is not directly comparable with other areas. 11 water systems serving Lehigh County, PA carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Ground Water Rule | 6 |
| Revised Total Coliform Rule | 3 |
| Interim Enhanced Surface Water Treatment Rule | 1 |
| Surface Water Treatment Rule | 1 |
| Di(2-ethylhexyl) phthalate (DEHP) | 1 |
Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.