Is it bad to drink hard water every day?

Not according to the agencies we read. The World Health Organization says hardness is not of health concern at the levels found in drinking water, and the valley's water district says its minerals pose no health risk.

Why does Las Vegas water upset some newcomers' stomachs?

We found no study of valley water and stomachs. University of Nevada Cooperative Extension notes that magnesium in water can have a laxative effect that newcomers adjust to quickly; valley water has 24 ppm, well under Nevada's 150 ppm taste-and-look standard for magnesium.

Is bottled water healthier than Las Vegas tap water?

Not because of hardness. The World Health Organization notes that bottled waters range from naturally mineralized to soft or demineralized, so the mineral content depends on the brand, just as tap water depends on the source.

Is hard water bad for you? Drinking Las Vegas Valley water

Valley water is very hard, and people who move here often ask whether that is a problem for their health. Here is what the health and water authorities say, set against the water district's own mineral figures.

What makes valley water hard

about 16 grains per gallonVery hard

Las Vegas Valley Water District, water quality summary, 2026 (2025 data). Softener dial setting: 16.

Two minerals are behind this figure: calcium at 75 ppm and magnesium at 24 ppm, both from the Colorado River.

How this figure was measured

Las Vegas Valley: where the figure comes from

Who published it

Water authority

Las Vegas Valley Water District

About the authority

The public water district that serves most of the Las Vegas Valley. This figure is the utility's own. We don't produce or adjust it.

Type of source

Water quality summary: a table of measured minerals that the utility publishes alongside its annual water quality report, which every U.S. community water system must publish under the Safe Drinking Water Act.

Data year

2026 (2025 data)

Last checked

15 October 2026, against the original document

What the figure is

What was measured

Total hardness, in parts per million and grains per gallon: 280 mg/L, published as 16 grains per gallon

Area covered

Most of the Las Vegas Valley (one figure for the whole service area)

How it was sampled

One figure for the whole service area, listed with the other minerals the district measured: calcium 75, magnesium 24, sodium 89 and total dissolved solids 591, all in parts per million.

Where the water comes from

About 90 percent from Lake Mead, fed by Colorado River snowmelt; the other 10 percent from wells that tap the deep Las Vegas Valley groundwater aquifer.

How we use it

Figure we use

The document’s own grains-per-gallon figure (16).

Unit conversion

1 grain per gallon = 17.1 milligrams per litre (mg/L), the same as parts per million (ppm)

How we calculate

Daily hardness to remove = people × 75 gallons × grains per gallon. We pick the smallest standard size that lasts about 7 days between recharges, at 3,300 grains removed per pound of salt.

Limits

The district's own questions-and-answers page gives a slightly different figure (291 parts per million, 17 grains per gallon); we use the newer summary. A home test result is more exact and overrides this figure.

Is hard water bad for your health? What the agencies say

No. Every health and water authority we read puts hardness down as a nuisance, not a health problem:

World Health Organization: its guidelines for drinking-water quality set no guideline value for hardness, giving the reason as “not of health concern at levels found in drinking-water”. Hardness matters, it says, for how the water is accepted by consumers and for pipes and equipment.
U.S. Geological Survey: “Hardness is a property of water that is not a health concern, but it can be a nuisance.”
Las Vegas Valley Water District: the calcium and magnesium the Colorado River brings into Lake Mead give valley water its hardness, “but they pose NO health risk”, in the words of its annual report.
Connecticut Department of Public Health: there is no recognized standard or maximum contaminant level for hardness.

So the honest answer to “is hard water bad for you” is no: the agencies treat it as a matter of scale and spots, covered in what is hard water?, not of health.

Is drinking hard water bad for you at Las Vegas levels?

At valley levels, the agencies’ answer doesn’t change. The district’s water quality summary published in 2026 (2025 data) gives 75 parts per million of calcium and 24 of magnesium, which it reports as the valley’s total hardness of 280 ppm (16 grains per gallon). Measured against the benchmarks that exist:

Magnesium has a Nevada secondary standard of 150 ppm, the kind of limit set for taste, smell and appearance rather than health. Valley water has 24, about a sixth of it. University of Nevada Cooperative Extension’s note on magnesium is that it can have a laxative effect, “quickly adjusted to by newcomers”.
Calcium has no U.S. limit at all. Health Canada put out a draft for comment in 2024 proposing a health-based value of 300 mg/L for calcium, based on the risk of kidney stones, while saying the evidence doesn’t support one for magnesium or hardness. Valley water has a quarter of that proposed figure. The same draft says hardness, magnesium and calcium have low potential for toxicity through drinking water.

Two litres of valley tap water carry about 150 mg of calcium and 48 mg of magnesium (our calculation from the district’s figures). The World Health Organization says drinking water can contribute calcium and magnesium to the diet, and could matter for people whose intake of them is marginal. It also notes that studies suggesting hard water or magnesium protects the heart are debated and don’t prove cause and effect, so it sets no minimum or maximum.

Can hard water cause kidney stones?

Not according to the kidney specialists’ own guidance: the National Kidney Foundation’s page on what causes kidney stones puts most of them down to a mix of diet, lifestyle, genetic and medical factors, and doesn’t mention hard water. The research is less tidy, so here is all of it that we found:

What the specialists stress. The National Kidney Foundation lists diets high in sodium, added sugar and meat, fish and seafood, and too little calcium, fruit, vegetables and water, among the causes. It adds that not getting enough calcium can contribute to calcium oxalate stones, the most common type. The National Institute of Diabetes and Digestive and Kidney Diseases says calcium sounds like the cause of calcium stones but isn’t, and that in the right amounts it can block other substances that form them.
A review of three decades of studies. Urologists at University Hospital Southampton and Sorbonne University reviewed the research in 2020 and found the results on hardness varied, and that patients get varying advice because there is no consensus. Their reading of the literature was that hard water and mineral water “might be helpful” for people who form calcium stones.
A large UK study. Researchers at Sun Yat-sen University followed about 288,000 UK Biobank participants and published in 2025. Across everyone, they found no significant effect of water hardness or calcium on kidney stones, and fewer stones where water had more magnesium. In two groups, people over 60 and women, harder water and more calcium went with a higher risk.
The draft limit. Health Canada’s proposed 300 mg/L calcium value, above, rests on stone risk; valley water has 75.

If you have had a kidney stone, the step every source agrees on is drinking enough fluid, mainly water, and asking your doctor how much to drink and which type of stone you had.

Hard water or softened water for drinking?

For drinking, neither is a health upgrade on the other by what the agencies say. Softening removes the calcium and magnesium and puts sodium in their place: on 16-grain valley water that is about 126 mg/L of added sodium, on top of the 89 already there. That matters most if you’ve been told to limit sodium; see softened water and sodium in Las Vegas for the amounts and the ways around it.

The water district’s view of home treatment in general is that systems can improve the look, taste and hardness of water, that the public supply already meets every state and federal standard, and that home systems may suit people with specific medical conditions, who should discuss options with their physicians. If you want drinking water without the minerals or the added sodium, reverse osmosis in Las Vegas explains what an under-sink unit removes.

How clean is Las Vegas tap water, minerals aside?

Clean by the legal measure: the water district says the water it delivers meets or surpasses every State of Nevada and federal Safe Drinking Water Act standard, and its report lists no violations. In 2025 it ran more than 328,000 analyses on more than 67,000 samples, from Lake Mead and its reservoirs to 380 sampling stations around the valley.

The hardness is part of that same water and is not one of the things those standards limit. For the full picture, substance by substance against each legal limit, read Is Las Vegas tap water safe to drink? and our Las Vegas water quality breakdown.

When to ask a doctor about your water

The sources above point to a doctor, not a water company, in these cases:

You have had kidney stones (the National Kidney Foundation and the institute both say the advice depends on the stone type).
You are on a low-sodium diet and have, or are thinking of, a salt-based softener.
Your softener runs on potassium chloride and you’ve been told to watch potassium; see potassium chloride for water softener for the amounts it adds.
You are thinking of a home treatment system for a medical reason, which the water district says to discuss with your physician.

To check what your own tap delivers, see water testing in Las Vegas.

Sources for this page

World Health Organization · chemical fact sheet on hardness in its guidelines for drinking-water quality (assessment revised 2011) · no guideline value; not of health concern; calcium and magnesium in the diet; heart studies debated; bottled water mineral range.
U.S. Geological Survey · Water Science School page on water hardness (checked October 2026) · hardness not a health concern.
Las Vegas Valley Water District · annual water quality report and water quality summary (2026, 2025 data), water quality questions page · calcium 75, magnesium 24, Nevada’s magnesium standard, sodium 89; no health risk; standards met, testing counts; home treatment and physicians.
Health Canada · draft guidance on operational parameters for drinking water, put out for comment in 2024 · proposed 300 mg/L calcium value; no value for magnesium or hardness; low toxicity.
National Kidney Foundation · kidney stones page (checked October 2026) · causes and the role of calcium and water.
National Institute of Diabetes and Digestive and Kidney Diseases · eating, diet and nutrition for kidney stones (checked October 2026) · calcium is not the cause; drink enough liquid.
University Hospital Southampton and Sorbonne University · systematic review in Current Urology Reports, 2020 · no consensus; hard water might help calcium stone formers.
Sun Yat-sen University · UK Biobank cohort study in the International Journal of Surgery, 2025 · no overall effect of hardness; higher risk in over-60s and women; magnesium protective.
University of Nevada Cooperative Extension · guide to water testing for private well owners (2012) · magnesium’s laxative effect.
Connecticut Department of Public Health · fact sheet on hard water and softeners (updated 2023) · no recognized standard for hardness.

Questions we get asked

Is it bad to drink hard water every day?: Not according to the agencies we read. The World Health Organization says hardness is not of health concern at the levels found in drinking water, and the valley's water district says its minerals pose no health risk.
Why does Las Vegas water upset some newcomers' stomachs?: We found no study of valley water and stomachs. University of Nevada Cooperative Extension notes that magnesium in water can have a laxative effect that newcomers adjust to quickly; valley water has 24 ppm, well under Nevada's 150 ppm taste-and-look standard for magnesium.
Is bottled water healthier than Las Vegas tap water?: Not because of hardness. The World Health Organization notes that bottled waters range from naturally mineralized to soft or demineralized, so the mineral content depends on the brand, just as tap water depends on the source.