How does Saint Marys's water compare to the national average?

The USA national average is 151 mg/L. Saint Marys (140.5 mg/L) is 10 mg/L softer than average.

Saint Marys Water Hardness & Quality Report (2026)

Water Hardness

140.5mg/L

Hard

8.2 grains per gallon

Source

reservoir

pH Level

7.2

neutral = 7.0

Lead

0.004 mg/L

✓ Below action level

TDS

56 mg/L

Est. Daily Cost

$0.37

energy & soap waste

Source: See methodology section below · Updated 2026

140.5mg/L as CaCO₃Hard

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Saint Marys, your appliances are currently losing 19% efficiency due to mineral buildup.

Appliance	In Saint Marys	Soft Water City	Efficiency Loss
Kettle	6.9 yrs	8.5 yrs	-19%
Washing Machine	9.7 yrs	12 yrs	-19%
Water Heater	12.2 yrs	15 yrs	-19%

Regional Water Comparison

How Saint Marys compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Saint Marys, Pennsylvania	140.5 mg/L	0 ppt	🟠 Hard	reservoir
Shiloh, Pennsylvania	≈ 120–179 mg/L	5.2 ppt	🟠 Hard	reservoir
Olean, New York	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Altoona, Pennsylvania	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
State College, Pennsylvania	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir

National Benchmark

How Saint Marys compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Saint Marys	140.5 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Saint Marys's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 56 mg/LpH: 7.2

The St. Marys Area Water Authority supplies water to St. Marys and surrounding areas in Elk County, Pennsylvania. Its primary source is the Thomas J. Gerg Plant and Reservoir, located at 967 State Street, St. Marys, PA 15857. This supply is a mix of surface water from the reservoir, which collects local watershed runoff, and supplemental groundwater. The authority routinely monitors constituents like pH, manganese, iron, alkalinity, calcium, chloride, and hardness, adhering to federal and state regulations.

The water originates from the Appalachian Basin, specifically from Pennsylvanian-age sandstones and shales. Groundwater contributions in this area interact with geology influenced by carbonates, a characteristic of northwestern Pennsylvania. This geological makeup is responsible for dissolving minerals, including calcium and magnesium, into the water supply, giving it a distinct mineralized quality that mirrors the composition of the local bedrock.

Water from this region is generally considered hard to moderately hard, which can lead to scale buildup on household fixtures and appliances. Homeowners might find that installing a whole-house water softener or point-of-use treatment systems can help manage mineral accumulation. Consistent upkeep of water heaters and plumbing is advisable to prevent issues. The St. Marys Area Water Authority confirms its compliance with the Safe Drinking Water Act, with lead levels consistently reported within safe limits through ongoing monitoring.

Geology & Source: Pennsylvanian sandstones and shales; carbonate-influenced geology contributes moderate hardness

Other Pennsylvania Water Reports

Shiloh

≈ 120–179 mg/L

🟠 Hard

Olean

≈ 120–179 mg/L

🟠 Hard

Altoona

≈ 120–179 mg/L

🟠 Hard

State College

≈ 120–179 mg/L

🟠 Hard

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Saint Marys's water safe to drink?

Yes. Saint Marys's water meets all federal safety standards. The hardness is 140.5 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Saint Marys?

At 140.5 mg/L (Hard), Saint Marys's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 19%.

How does Saint Marys compare to the USA average?

The USA national average is 151 mg/L. Saint Marys (140.5 mg/L) is 10 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Saint Marys is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.