Is tap water safe in Frederick?

EPA SDWIS shows no active health-based violation in this profile's reporting window. That is not the same as proving every contaminant is absent, and federal data can lag state and utility records.

How hard is the water in Frederick, MD?

Nearby USGS observations produce an estimate of 83.6 ppm (4.9 grains per gallon), classified as moderately hard. This is not a tap measurement.

Do I need a water softener in ZIP code 21701?

There is no high-hardness trigger in this profile. Confirm conditions with an at-home hardness test before purchasing equipment.

City water profile

Frederick water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Frederick, Maryland.

Median indexed hardness

83PPM

3 indexed ZIPs

Range 81–83.6 PPM

State comparison: 7 PPM below
State hardness rank: #8 of 15
Matched utilities: 1
Active health records: 0

City summary

What the indexed records say

Frederick has 3 published ZIP profiles across Frederick County. The indexed median is 83 PPM, compared with 90 PPM across Maryland.

Among the 15 Marylandcities with an indexed median, Frederick ranks #8from highest to lowest. Across all 42 state ZIP profiles, available estimates run from 57.8to 167 PPM.

The 81–83.6 PPM range shows how much the available ZIP estimates vary within the city label.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs

Moderately hard3 ZIPs

Hard0 ZIPs

Very hard0 ZIPs

3 of 3 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance: 3.3 miles
Profiles with evidence: 3/3

Confidence labels

High: 0Moderate: 3Low: 0

Observation window: Jan 6, 2016 to Jun 30, 2026.

ZIP directory

Water reports in Frederick

Open a ZIP for site-level provenance and measurements.

ZIP code

21701

Moderately Hard

83.6 PPM

Nearest site: 3.3 mi
Confidence: Moderate

View full ZIP evidence →

ZIP code

21702

Moderately Hard

82.7 PPM

Nearest site: 6.7 mi
Confidence: Moderate

View full ZIP evidence →

ZIP code

21705

Moderately Hard

81 PPM

Nearest site: 2.4 mi
Confidence: Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

City Of Frederick

PWSID MD0100015

Surface water

System population served: 54,000
Last reported: May 18, 2026

A municipal system, in-state city, and served county all agree with this Census ZCTA.

Compliance history

What EPA records show

No active health-based violation appears among the associated systems in the represented EPA reporting quarter. This does not mean every contaminant was tested at every tap.

No violation records are included in the current lookback window.

Practical next steps

Move from index to evidence

1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
3. Test the tap when needed. Confirm health concerns or treatment sizing with the right method.

Continue comparing

Other Maryland communities

Brunswick

Frederick County

85 PPM median

Hagerstown

Washington County

81 PPM median

Aberdeen

Harford County

88 PPM median

Baltimore

Baltimore City County

90 PPM median

Westminster

Carroll County

93 PPM median

Havre De Grace

Harford County

94 PPM median

Search all 15 Maryland cities →

Questions people ask

About water in Frederick

Is the water hard?

The indexed city median is 83 PPM. Open the ZIP report to verify the distance and confidence behind that estimate.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.