Water Hardness Atlas ZIP / postcode

Water hardness in Poquoson

5.3 gpg moderately hard

Tap water in Poquoson is moderately hard: 5.3 gpg (91 mg/L · 5.1 °dH · 9.1 °fH).

<6060–120120–180>180 mg/L

Source: Newport News Waterworks Annual Water Quality Report (lower Peninsula, serves Poquoson) (2024) · data checked 2026-10-29

Range across supply zones: 61–120 mg/L.

Poquoson is supplied by Newport News Waterworks, whose annual report covers the lower Peninsula. The 2024 report gives a computed median of 90.5 mg/L as CaCO₃, with a range of 61 to 120 mg/L. That is moderately hard water, and the figure describes the wider system rather than Poquoson alone.

USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.

Water data

Total hardness5.3 gpg
UtilityNewport News Waterworks

How Poquoson compares

Ranking of the hardest and softest water in the United States →

What it means at home

How much salt will you use for softening?

Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.

Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).

Estimates for planning, not a quote. Check your appliance manual for exact settings.

Dishwasher setting in Poquoson

BrandSetting for this water
BoschH00
Miele5 °dH
AEG / Electrolux2
Beko2nd
HooverS1
LGH1

From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →

FAQ

Is Poquoson water hard or soft?

It is moderately hard: 91 mg/L as CaCO₃ (5.3 gpg, 5.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.

Is tap water in Poquoson safe to drink?

Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.

How many grains per gallon is Poquoson water?

5.3 gpg, equal to 5.1 °dH, 9.1 °fH or 91 mg/L calcium carbonate.

What dishwasher salt setting should I use in Poquoson?

For 91 mg/L (5.1 °dH) check your manufacturer's table: level 2–3.

Do I need a water softener in Poquoson?

Not essential; a scale inhibitor protects the heater cheaply.

Source

Source: Newport News Waterworks Annual Water Quality Report (lower Peninsula, serves Poquoson) (2024). Method: computed from supplier's calcium and magnesium. Newport News Waterworks Annual Water Quality Report (lower Peninsula, serves Poquoson) · Outdated figure? Tell us

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