Water Hardness by ZIP Code in
Maryland

Browse 2 local reports across Maryland, compare average hardness levels, and spot the cities where hard water is most likely to be a real household problem.

State summary
Maryland
Avg. Hardness
285 PPM
State Risk
Severe

Local reports by city and ZIP code

Open a local page to see the reading, compare nearby ZIP codes, and get a plain-English interpretation.

Annapolis
Zip Code: 21401
Baltimore
Zip Code: 21201

Regional Water Variations

Water hardness often changes from one municipal source to the next in Maryland, so nearby ZIP codes can tell a very different story.

Why compare? A state average can hide local hotspots where scale risk is much higher.

Priority Zones To Audit First

These ZIP codes show the highest recorded hardness in Maryland and are usually the best places to start if you are researching treatment urgency.

Baltimore
ZIP 21201
370 PPM
Annapolis
ZIP 21401
200 PPM