Water Hardness in 20678
Prince Frederick, Maryland · Calvert County
Dataset updated March 9, 2026Matched to 17 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology
How this ZIP reading is built
This ZIP reading is built from 17 matched water systems. When more than one system is matched, the displayed value is weighted toward larger known service populations when that data is available.
Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.
Water Systems Serving 20678
These are the systems matched to this ZIP code. The displayed ZIP value is weighted toward larger known service populations when population data is available.
| Water System | Source | Hardness | Pop. Served |
|---|---|---|---|
Prince Frederick MD0040011 | groundwater | 109 PPM Slightly Hard | |
Solomons MD0040027 | groundwater | 109 PPM Slightly Hard | |
Chesapeake Heights (Bayside Forest) MD0040018 | groundwater | 109 PPM Slightly Hard | |
Summit/Highlands MD0040026 | groundwater | 109 PPM Slightly Hard | |
Cross Point Subdivision MD0040052 | groundwater | 109 PPM Slightly Hard |
Nearby Zip Codes
What This Means For You
Recommendations are based on the displayed ZIP hardness reading. Confirm your tap reading before sizing or buying treatment equipment.
Slightly Hard Water
Your water is slightly hard. You may notice minor spotting on dishes or a slight film on faucets. A water softener is optional but can improve water quality.
Recommended Products
Learn more: Do I Need a Water Softener? | Salt-Based vs Salt-Free | How to Test Your Water
Know your water hardness?
If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Prince Frederick, MD (20678).
Frequently Asked Questions
Is the water hard in Prince Frederick, MD (20678)?
The average water hardness in 20678 is 109 PPM (6.3 GPG), which is classified as slightly hard.
Do I need a water softener in 20678?
At 109 PPM, your water is relatively soft. A water softener is generally not necessary.
Is hard water in 20678 safe to drink?
Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.
How many water systems serve 20678?
Zip code 20678 in Prince Frederick, Maryland is served by 17 water systems.
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