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What Are Phoenix Water Hardness Levels?

If you’ve noticed white stains on your glasses and silverware or a slimy feeling while washing your hands, there’s a good chance your water has excessive hardness levels, especially if you don’t have a water softener. While water hardness poses no threat to human health, its aesthetic impact and effect on the taste of your drinking water can be a source of annoyance in your daily life

If you live in Phoenix, you might already be intimately familiar with the issue of water hardness. According to the city’s Water Services Department, sampled hardness levels for 2020 ranged from 9.9-16.1 grains per gallon, meaning that Phoenix residents are faced with some of the hardest water in the country.1

In this blog, we provide important insight on Phoenix water hardness and drinking water quality in Phoenix as well as information on how to purify the tap water you depend on every day.

What Is Water Hardness?

According to the United States Geological Survey, water hardness refers to the measurement of dissolved minerals, mostly calcium and magnesium, present in a source of water. The following guidelines provide classifications for water hardness:

  • 0-60 mg/L – soft
  • 61-120 mg/L moderately hard
  • 121-180 mg/L hard
  • >180 mg/L very hard

While hard water might not sound very appealing to the consumer, it actually contains some nutritional benefits. According to the World Health Organization, the added calcium and magnesium in hard water can actually be a healthy supplement for those whose diet is otherwise deficient in these necessary minerals.2

Water hardness most commonly affects groundwater due to the movement of water through mineral-rich soil and rock, but it also affects surface water sources such as lakes, streams, rivers, and ponds. 

Although it is harmless to human health, hard water can damage water supply lines and kitchen equipment such as dishwashers and coffee makers due to the buildup known as scale. Additionally, hard water can shorten the lifespan of clothing and other washable items.

Last but not least, water hardness is often associated with an undesirable taste in people’s drinking water. For all of these reasons, many industrial and domestic water users choose to invest in filtration systems that purify their water of dissolved minerals while keeping it free of contaminants.

Water Softener Systems starting at only $35/mo. Try before you buy!

Water Hardness in Phoenix

For residents of Phoenix, Arizona, water hardness is a common cause of frustration. Using the city’s own numbers for the year 2020, hardness levels in sampled drinking water ranged between 9.9 and 16.1 grains per gallon. Converting that to the guidelines provided by the USGS, puts Phoenix’s water hardness levels between 169.5 and 275.6 mg/L. 

In other words, Phoenix’s water ranges from hard at best to well over the standard for very hard at worst.

To mitigate water hardness, Phoenix’s water supply undergoes a water treatment process that removes large sediments and debris from the water using screens. Smaller sediments are then collected using a chemical coagulent that aggregates tiny particles so that they fall to the bottom of the basin.3

However, Phoenix provides some seriously hard water to its residents, despite its treatment processes and meeting EPA standards for levels of federally-regulated contaminants in its drinking water.

While only 2% of the city’s water is sourced from groundwater—where water hardness typically derives—it’s clear that the city’s surface water sources, which comprise 97-99% of Phoenix’s water supply, is particularly mineral-rich.

Somewhere along the journey from snowmelt to kitchen tap, these waters pick up enough magnesium and calcium to generate some of the highest water hardness levels in the country.

Now that we know Phoenix has some particularly hard water, what can be said for the safety of the city’s drinking water supply?

Can You Drink Tap Water in Phoenix?

You may be wondering, “Is Phoenix tap water safe to drink?” The short answer is yes. The city of Phoenix must comply with EPA regulations when it comes to monitoring federally-regulated contaminants within the drinking water supply, which are anything other than water molecules.4

Most contaminants in drinking water come from animal waste, agricultural and industrial runoff, and sometimes even household plumbing systems—particularly if they’re older or corroded. However, other contaminants occur naturally. 

While the tap water in Phoenix is safe to drink, it still may contain some harmful contaminants. More specifically, Phoenix’s Water Services Department conducted a 2020 water quality report that found quantities of certain potentially harmful contaminants:5

  • Manganese
  • Germanium 
  • HAA6Br
  • HAA9 
  • Total Organic Carbon 
  • Bromide 

In addition to such potential risks as gas stations, landfills, dry cleaners, agricultural runoff, wastewater treatment, and mining, Phoenix’s drinking water is also threatened by climate change—particularly in relation to the region’s 22-year drought, which is draining significant resources from the Colorado River. 

Overall, Phoenix provides dependable clean drinking water to a population of 1.6 million and counting. In terms of hardness, however, the city’s water can certainly be improved to ensure its residents peace of mind and fresh-tasting water when they turn on the tap.

How to Treat Phoenix Tap Water

To provide extra protection from potential contaminants and to reduce the hardness of their drinking water, many Phoenix residents invest in water filtration systems for their homes and businesses. 

These systems, including water softeners, salt-free systems, and reverse osmosis systems, can filter out harmful contaminants and reduce water hardness to ensure your water remains healthy and tastes good to drink, all while reducing your dependence on environmentally-hazardous plastic water bottles.

To decrease the hardness of your water supply, you might want to invest in a water softener. These systems remove mineral ions from your water through a process known as ion exchange. 

While a salt-based water softener uses chemicals to trap hard minerals in the system’s resin bed, a salt-free water softener is a chemical-free system that conditions water to prevent it from sticking to surfaces, thereby reducing stains and scaling.

Beyond improving the taste of your drinking water, water softening systems provide the following benefits to home and business owners:

  • Better plumbing By removing hard minerals from your water, you prevent buildup in pipes and plumbing equipment that can lead to clogs, reduced flow rate, and even serious damage over time.
  • Reduced soap and detergent use – Softening your water can help you save money by reducing the amount of soap you need for washing dishes and clothes. Additionally, it can get rid of that dreaded slimy feeling you get while washing your hands in hard water.
  • Cleaner dishes – No one likes stains on clean dishes and cutlery. By softening your home’s water, you can eliminate those pesky chalk marks left behind by dissolved minerals like calcium and magnesium.
  • Cleaner kitchen and bathroom appliances The same goes for your sinks, tub, shower, and faucets. Hard water can make even the cleanest home look messy. If you use a water softening system, however, you can reduce these stains without having to spend endless hours scrubbing them clean.

Since water hardness is typically thought of as an aesthetic issue as opposed to a matter of personal health, it’s easy to dismiss water softeners as an extraneous addition to the many appliances and systems you rely on to keep your home or business functioning the way they should. 

The truth is, however, that investing in a water filtration system can go a long way in preventing expenses down the road for costly repairs and even replacements to your plumbing system. Not only that, but water softeners and other filtration systems can provide peace of mind through their added protection to the water you depend on. 

With so much uncertainty swirling around the effects of climate change and the environmental impact of potential contaminants, it’s important to weigh all of your options when it comes to purifying your water.

Better Water Quality with Rayne Water Conditioning

While the hardness levels of water in Phoenix are high, the city regularly monitors drinking water to ensure that it meets EPA standards and is safe for its 1.6 million residents. However, to mitigate mineral build-up in your morning coffee and evening tea, it’s beneficial to invest in a water softener system to remove any unwanted mineral ions.

At Rayne Water, we bring nearly a century of experience to the table to ensure the safety of your home’s drinking water. Contact us today to learn more about our water filtration systems and see if one of our water softeners could help you reduce water hardness levels to provide the purity you need.

Just because Phoenix offers some of the hardest water in the country doesn’t mean you can’t take steps to protect the taste of your tap and the integrity of your plumbing appliances. Find a Phoenix water softener or any water solution with Rayne Water today.


  1. City of Phoenix. 2020 Water Report. 
  2. World Health Organization. Hardness in Drinking-water. 
  3. City of Phoenix. ​Understanding Phoenix’s Water Quality.
  4. United States Environmental Protection Agency. Types of Drinking Water Contaminants. 
  5. Buzzfeed News. People In Arizona Are About To Face The West’s First Major Water Crisis.