Water Hardness by City: What Your Local Water Does to Your Equipment

Water hardness by city

Most pages that answer this question give you one number for your city and move on. That number is usually undated, usually unsourced, and in at least one large American city it is quietly wrong.

This page does it differently, and slower. Every figure below was read out of the water utility's own published report, in the utility's own units, with the data year attached. Where a utility publishes a range rather than an average, you get the range. Where a utility does not publish hardness at all, we say so instead of substituting somebody else's guess.

Figures current as of September 2026, for the 2025 data year. Utilities reissue these reports annually, usually between April and July. Check the linked report before you spend money on the strength of a number here.

The finding that matters most

Here is the useful thing, and it is not a per-city trivia answer.

La Marzocco publishes a water specification for its commercial espresso machines. The hardness window is 70–100 ppm — a minimum and a maximum.

Compare that to the utility figures below and the picture is stark: almost every major American metro we checked sits above the maximum, several of them by a factor of two or three. Phoenix runs up to 302 ppm. Las Vegas publishes 280. Indianapolis reaches 460.

Which means that in most of the country, the question is not whether your espresso water is outside the manufacturer's published range. It is by how much, and what you are going to do about it.

The table

City	Utility's published hardness	Units, as printed	Data year	Shape
Minneapolis, MN	Avg 94 · min 80 · max 113	ppm	2025	Average + range
Phoenix, AZ	172 – 302 · 10 – 17.6	ppm; grains/gallon	2025	Range, system-wide
Las Vegas, NV	280 ("or 16 grains per gallon")	ppm	2025	Average, main system
Indianapolis, IN	Avg 317 · system range 148 – 460	ppm (grains/gal alongside)	2025	Average + range
Tampa, FL	211 ("or 12.3 grains/gallon")	mg/L	2025	Average
Denver, CO	Avg 105,009 · range 55,000 – 124,000	ppb — see below	2025	Average + range
Columbus, OH	Dublin Rd 125 (122–132) · Hap Cremean 98 (85–118) · Parsons Ave 123 (122–127)	ppm / gpg	2025	Varies by plant
Chicago, IL	126 – 143 across plants and quarters	mg/L as CaCO₃	2025	Varies by plant and quarter
San Diego, CA	Alvarado 237 (203–270) · Miramar 242 (200–285) · Otay 243 (201–271) · Purchased 145 (54.4–232)	ppm / gr per gallon	2025	Varies by plant
Dallas, TX	Not published	—	2025 report checked	—

Two more cities publish a figure but do not date it, so they are kept out of the table above deliberately — see The two we won't put in the table below.

A city is not a hardness figure

This is the single most important thing on the page, and it is why a one-number answer is worse than useless for specifying equipment.

Indianapolis publishes a system-wide range of 148 to 460 ppm — 8.7 to 27 grains per gallon. That is one utility, one city, and a spread that covers the distance between "barely needs treatment" and "will destroy an espresso boiler." Two restaurants four miles apart can need genuinely different equipment.

It is not unusual. Columbus runs three treatment plants, and Hap Cremean delivers 98 ppm against Dublin Road's 125 — a 27% spread depending on which side of the city you are on. San Diego ranges from 145 ppm on purchased treated water to 243 at Otay. Chicago varies by plant and by quarter.

Multi-source systems blend. Which source is feeding your address can change with demand, with season, and with maintenance schedules.

So use the table to know roughly what you are dealing with, and then test your actual tap if you are about to spend real money. A test kit costs a fraction of a service call, and it is the only figure that describes the water arriving at your building after the mains and your own plumbing have had their say.

Three traps we hit compiling this

Worth publishing, because they are the reasons the numbers you find elsewhere disagree with each other.

Denver publishes in parts per billion

Denver Water's report gives hardness as an average of 105,009 with a range of 55,000 – 124,000, in ppb. Not mg/L.

Divide by a thousand and that is roughly 105 mg/L average, 55–124 range — that division is ours, not Denver Water's, and we flag it rather than quietly presenting it as their figure.

Two consequences. Anyone who copies 105,009 into a table of mg/L values publishes a number wrong by a factor of a thousand. And more interestingly: at around 105 mg/L, Denver is moderately hard — not the very hard water its reputation suggests.

Kansas City's CCR hardness number is not Kansas City's water

KC Water's report contains exactly one hardness row: 123 mg/L. It sits under a table headed "Reseller Secondary Contaminants" and it belongs to Independence PWS, a separate upstream system.

KC Water's own secondary-contaminants table has no hardness row at all.

We nearly published 123 as Kansas City's figure. It would have been a flat factual error, and it is exactly the kind that propagates — because the number is right there in the official document, just describing somebody else's water.

Chicago's annual report omits hardness entirely

If you look for Chicago hardness in the Consumer Confidence Report you will not find it. The figures above come from the Department of Water Management's own quarterly comprehensive chemical analysis — a different document on the same utility's site.

Which also settles a common misconception. Chicago is Lake Michigan water and is widely assumed to be soft. At 126–143 mg/L as CaCO₃, it is not.

The two we won't put in the table

San Antonio publishes a typical range of 15–20 grains per gallon, and Kansas City publishes an average of 100 mg/L. Both come from the utility's own website. Neither carries a sampling year, and neither appears in a Consumer Confidence Report.

They are almost certainly about right. But this page's entire claim is that every figure on it is dated and traceable to a published report, and quietly mixing in two that are neither would undermine the other ten. So they sit here, described honestly, rather than in the table.

If you are in either city: treat those as indicative, and test.

Dallas is a different case. Dallas Water Utilities does not publish a hardness figure anywhere in its water quality report. We checked, and we archived the report to evidence the absence. You will find Dallas hardness numbers on aggregator sites; we cannot tell you where they came from, and neither can they.

What these numbers mean for your equipment

Hardness is dissolved calcium and magnesium. When water is heated, frozen or evaporated, those minerals come out of solution and deposit on whatever surface was doing the work.

On an ice machine, that surface is the evaporator plate. Scale there is an insulator on a component whose entire job is moving heat, so harvest cycles lengthen, daily yield drops, and eventually the pump fails. Our ice machine filtration guide covers the mechanism and how to size a filter against it.

On an espresso machine, hardness is bounded on both sides. La Marzocco's published window is 70–100 ppm, and the minimum matters as much as the maximum — water stripped too far extracts badly and tastes hollow. This is why a salt softener is not a substitute for a scale-reduction cartridge, and why La Marzocco explicitly "recommends caution when using sodium and hydrogen based ion-exchange water softeners." The full specification is in our espresso water guide.

On steamers and combi ovens, the water is boiled continuously, which concentrates everything left behind. These are the fastest-scaling machines in a commercial kitchen.

Grains or ppm?

You will see both, sometimes on the same page, because utilities print both. Several of the reports above give their figure in each unit — Las Vegas states "280 parts per million or 16 grains per gallon," Tampa "211 mg/L or 12.3 grains/gallon."

Where a utility printed both, we have reproduced both. We have not converted anything ourselves, apart from the Denver division noted above, which is labelled. Equipment manufacturers usually specify in ppm or mg/L, and those two are interchangeable for this purpose; water treatment equipment is often sold in grains.

How to get your own number

Find your utility's annual water quality report. Search for your water provider's name plus "water quality report" or "Consumer Confidence Report." It is published free and it is the primary source.
Look for hardness, and note the units and the year. If the report gives a range or a per-plant breakdown, that tells you your address matters.
Then test your actual tap. The utility reports what leaves the plant. Your building's plumbing sits between that and your machine.
Compare against your equipment's published specification, not against a general "is this hard water" scale. Your espresso machine's manual has numbers in it.

Water test kits are the cheapest step in that list and the one people skip.

Send us your city and your machine

Tell us where you are and what equipment you run, and we will tell you what your utility publishes, what your manufacturer specifies, and whether the gap needs treating. That costs nothing.

If your water is already inside your machine's range, we will say so — which happens more often than you would think in soft-water cities, and is not something a filter dealer has much incentive to tell you.

Ask us about your city →

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