Local water. Clear answers.

Water hardness
by ZIP code.

Understand the water where you live. Explore municipal reports, check the source, and find your next step.

Check your local water

City references for 12 cities in the Las Vegas and Phoenix metro areas. ZIP codes can cross utility boundaries.

Find a possible water supplier

If you are at the property, use your location to check EPA service-area boundaries. Some boundaries are modeled; confirm the supplier on your bill.

Only when you select the button: your browser asks for location permission, then coordinates are sent through this site to EPA's map service. We do not include them in analytics.

Utility-reported figuresSources you can checkPractical tools for your home

Explore local data

Recently checked water reports

Browse by state

Reported hardness for utility service areas. Ranges stay ranges; these are not measurements at an individual address.

Las Vegas

NV

16.4GPG

280 ppm · Utility-reported average

2026 summaryView report

Henderson

NV

17.8GPG

304 ppm · Utility-reported typical value

2025 monitoringView report

Boulder City

NV

17GPG

290 ppm · Utility-reported average

2025 reportView report

Phoenix

AZ

10.1–17.7GPG

172–302 ppm · Utility-reported range

2025View report

Mesa

AZ

12–22GPG

205–376 ppm · Utility-reported range

Utility guidance (undated)View report

Chandler

AZ

10.1–16.8GPG

173–288 ppm · Utility-reported range

2025View report

Gilbert

AZ

8–10GPG

137–171 ppm · Utility-reported range

Utility FAQ (undated)View report

Glendale

AZ

13.9GPG

237 ppm · Utility-reported average

2025View report

From data to decisions

What to do next

Start with a measurement, then choose what makes sense for your household.

01

Test your tap water

Find a hardness test and get a reading for the water you actually use.

Compare test kits 02

Understand your result

Convert grains per gallon to parts per million, or the other way around.

Convert GPG / ppm 03

Size a water softener

Use measured hardness and household water use to estimate capacity.

Open calculator

Understand the source

Good water data
comes with context.

Our sources and methodology

Municipal reports, with the details intact

We check utility reports and guidance for hardness. Each report shows the source, reporting period, and whether the figure is an average, typical value, or range.

Local context for your next step

The optional supplier lookup uses EPA water-system boundaries. Confirm your supplier and test untreated tap water before setting a softener.