Understanding Water pH: What It Is and Why It Matters

Whether you’re measuring the quality of water or identifying the concentration of hydrogen ions, you can measure the acidity or alkalinity of a substance with pH. Highly contaminated water is often acidic. If the water contains high levels of minerals like magnesium and calcium, it will likely have an alkaline pH reading.

This measurement uses a scale that ranges from 0-14. If the pH value is lower than 7.0, the substance will be acidic. Any reading that’s higher than 7.0 is alkaline. When the pH value is around 7.0, it’s neutral. By measuring the pH of water and other solutions, you can better understand what chemicals and materials are present in the substance.

Keep in mind that a point change in the pH scale represents an increase or decrease by a factor of 10. For example, a pH of 5.0 is 10 times more acidic than a 6.0 reading. Chemicals that have a highly acidic or highly basic pH are considered reactive, which means that they can cause significant burns.

Measuring pH is important for many reasons. If you work in an industrial setting, pH measurements may be needed for certain processes. Let’s say that you work in a food manufacturing facility. If pH levels aren’t strictly monitored and controlled, the food that you’re making can become inedible. In this guide, you’ll learn “What is the pH of water?” and why it matters.

The pH of Water

When you’re measuring the pH of water, a 7.0 reading means that the water is neutral. In most cases, pure water will have a neutral pH. When water becomes too basic or acidic, there’s likely a high concentration of hydroxide or hydrogen ions within the solution. As mentioned previously, the substance will be highly reactive. Most living organisms are unable to thrive in acidic or alkaline conditions. Since pure water is chemically stable, it can support life.

According to the Environmental Protection Agency (EPA), water should maintain pH readings between 6.5-8.5. Drinking water is best when it sits at a 7.0 pH. If the water’s pH goes below 6.5 or above 8.5, it likely contains high levels of chemicals or toxic metals.

Several environmental factors invariably affect the water’s pH level. When water moves through the environment, it interacts with soil and bedrock. The composition of the soil and bedrock plays a major role in setting the pH level. Limestone and similar types of rock can make acidic water more alkaline. Other types of rock like granite do not affect the water’s pH.

The pH of the water may also be affected by the amount of organic material and plant growth that’s present in the water. When these materials decompose, they release carbon dioxide.

While there are several environmental factors that cause the pH in a body of water to change, many of the things that contribute to increases or decreases in pH are related to industrial processes. When industries, communities, or individuals place chemicals in the water, the pH will likely decrease. A significant percentage of industrial processes require precise pH readings. If the solution is just outside of the ideal pH range, chemicals will be added to the water to change the pH.

The wastewater that’s created from this process is effluent, which can either be discharged to a sewage treatment plant or a nearby body of water. While the EPA regulates industrial effluent, some facilities attempt to bypass these requirements, which means that the effluent may not be treated before it’s discharged into the environment.

Keep in mind that the pH of water can also be negatively impacted by acid precipitation. Acid rain occurs when sulfur dioxide and nitrogen oxides combine with water vapor in the air. These pollutants seep into the air from power plants and automobile emissions. When snow melts in the spring, it’s common for streams to receive a considerable amount of acid, which can be damaging to the environment.

The pH of Distilled Water

When water is filtered to remove different types of impurities, it becomes distilled. The distillation process involves boiling the water and collecting the steam. The non-volatile organic molecules and inorganic compounds won’t evaporate, which means that they will be left behind during the boiling process.

Once the steam cools, it will condense into purified water that should be free of nearly all contaminants. This filtration technique is highly effective at getting rid of contaminants like:

• Lead
• Sulfate
• Giardia
• Viruses
• Bacteria

Since distilled water is pure, it’s regularly used in laboratories and medical facilities that depend on clean water. Keep in mind, however, that drinking distilled water isn’t the same as drinking filtered water. While it’s free of bad contaminants, it also lacks the minerals that can keep you healthy.

There are many reasons why you should use the water distillation technique to filter contaminants out of drinking water. If you have a weakened immune system, drinking distilled water is an effective method for safeguarding against the health issues that can be caused by bacteria and pesticides. For example, some people with cancer are at a higher risk of developing more severe symptoms by consuming food and water that contain impurities. Drinking distilled water eliminates this problem.

Even though there are a few issues associated with distilled water, some people prefer the taste of it. The distillation process removes any trace of chlorine from the water, which might improve the taste. Keep in mind, however, that other forms of water may be healthier. Distillation gets rid of 99.9% of minerals that are present in tap water.

If you want to know “What is the pH of distilled water?”, the answer depends on the amount of time it’s exposed to air. If the water remains open to the air, there’s a good chance that the pH will dip below 5.5. Otherwise, you can expect the pH of distilled water to range from 5.5-6.9.

If you don’t get the micro-nutrients that are found in water, your health could be negatively affected. Keep in mind that distillation gets rid of fluoride in drinking water, which means that consuming this type of water can increase your risk of cavities. If you choose to drink distilled water, make sure you practice good oral hygiene.

Differences Between Regular Water and Distilled Water

There’s a major difference between the tap water that comes out of your faucet and distilled water. While tap water is typically free from impurities, it will likely have been disinfected with chlorine, which means that this residue will remain in the water.

Tap water is also filtered to get rid of sediments before being treated with various chemicals to ensure any dirt in the solution is neutralized. Before tap water is sent to residential homes, fluoride is usually placed within it to keep tooth decay at bay. Even though tap water is typically healthy for you, its pH can vary. Before leaving the treatment facility, the pH level will be slightly alkaline to ensure the pipes don’t reduce the pH too much.

When the water is distributed to your home, it will travel through pipes, some of which may be corroded. The amount of pH fluctuation depends on the source or region of the water. This water will be exposed to a certain amount of minerals as it flows to your home. It can also be influenced by rainwater, which is more acidic than the tap water. Once tap water reaches your home, you can expect the pH level to range from 7.2-7.8.

Keep in mind that impurities can have different effects on pH levels. The types of contaminants that might reduce the water’s pH include the following:

• Landfill leachate
• Mine wastes
• Coal pile runoff
• Oxidation process
• Draining of floodplain or wetlands
• Industrial effluents
• Coal pile runoff
• Acid-generating soils and rocks

There are also numerous impurities that can cause the pH of water to increase and become more alkaline. The types of impurities that might cause your pH readings to rise are:

• Cement manufacturing
• Industrial discharges
• Gas and oil brines
• Soap manufacturing
• Agricultural lime
• Limestone gravel roads
• Alkaline soils
• Asphalt disposal or production

There are several types of filtered and purified water that you can drink alongside tap water. Even though tap water might contain some pollutants, it’s considered filtered water. The water goes through filters to get rid of chlorine, chemicals, and bacteria. Bottled water is also filtered. However, the filtration process is usually more comprehensive than the one that’s used for tap water.

Purified water is free of chemicals and microbes. It’s possible to remove all these contaminants through techniques like ozonation, reverse osmosis, and distillation. Ozonation is an effective treatment method that involves disinfecting the water with ozone instead of a chemical.

The reverse osmosis process pushes the water into a membrane to ensure all microbes, chemicals, and minerals are left behind. Based on EPA requirements, purified water can’t have a concentration of total dissolved solids that’s higher than 10 parts per million.

Distilled water is one type of purified water. All minerals, salts, and organic materials are removed from the water by steaming it. Like tap and other types of purified water, you can drink distilled water. However, the taste is often bland and flat. Magnesium, sodium, and calcium provide tap water with the flavor you’re likely familiar with. When purity is required, distilled water is used for the following applications:

• Lab tests
• Cosmetics, such as shampoo, deodorant, and moisturizers
• Medical procedures and tools
• Automobiles
• Neti pot
• CPAP machine
• Infant formula
• Iron

Practical Implications of Water pH

The pH of drinking water doesn’t play a major role in health and hydration. There are, however, some minor benefits of drinking slightly alkaline water. If the water has a pH reading of 8.0-8.5, you may be able to reduce symptoms of acid reflux. Some studies have also indicated that alkaline water can reduce bone degradation. However, research into the health effects of different pH values is limited.

Even drinking acidic water isn’t always unhealthy. If the acidity is caused by dirt and other organic organisms, the water might only taste bad. On the other hand, water that’s contaminated by solvents and chemicals can be dangerous to drink. The standard effects of consuming acidic water include the following:

• Blue-green stains in your sinks and around other fixtures in your home
• Stained laundry
• Sour or metallic taste in your drinking water

Some of the effects associated with alkaline water are:

• Scale buildup in your plumbing system
• Reduced efficiency of your electric water heater
• Coffee might have a more bitter taste to it

The EPA suggests that public water systems should maintain pH levels between 6.5-8.5. However, these recommendations aren’t formal regulations, which means that the public water systems don’t need to abide by them.

You’ll also discover that pH plays a major role in environmental science and ecology. For example, the biological effects of low pH among marine life include the following:

• Respiratory inhibition
• Mortality
• Acid-sensitive species being replaced with tolerant ones
• Reproductive failure
• Reduced growth
• Mucus on gills
• Lower number of species

There are also some biological effects of high pH levels, which involve:

• Damage to skin, eyes, and olfactory organs
• Decreased growth
• Reduced reproduction
• Lower biodiversity

The main reason why water becomes more acidic is because carbon dioxide is introduced to it. Decomposition, respiration, and photosynthesis are a few environmental processes that cause pH fluctuations. Carbon dioxide can also react with water to produce carbonic acid, which is a chemical compound that can decrease the water’s pH.

Several natural substances can influence the pH of water. Limestone and carbonate materials can buffer pH shifts. When calcium carbonate combines with hydroxyl ions or hydrogen, the water’s pH will be neutralized. Even if you add bases or acids to the water, the buffering capacity of the carbonate minerals will keep the pH close to neutral. If you add more carbonate materials, the water will become alkaline.

When it rains, the water is usually slightly acidic. If you collect rainwater, a pH measurement will likely yield a reading that ranges from 5.6-5.8. The pH of rain can drop when it comes into contact with lightning, particulates from wildfire, sulfate-reducing bacteria, and volcanic ash. If rain happens to fall on a water source that isn’t properly buffered, the pH of the nearby water will likely drop.

The water’s pH may also decrease when pine needles decompose. Fir or pine needles are able to reduce the pH of soil. When water reaches this soil, the byproducts will get into the liquid and reduce the pH.

Man-made pollution influences the pH of water as well. If pollution gets into the water, air, or soil, it can affect the pH. As mentioned previously, acid rain is a common man-made influence on pH levels. Acid rain occurs when the pH is lower than 5.0. While these emissions can be produced from many industrial operations, they typically come from smelting and mining processes. Fossil fuel combustion can also bring about acid rain.

If chemicals are directly added to the water, the pH can increase or decrease depending on the ones that are involved. Many chemicals come from industrial and agricultural runoff. However, they can also reach groundwater through wastewater discharge, which contains soap-based products and detergents that increase alkalinity.

The pH of water may also be affected by the acidity of the environment. Acid runoff will reduce the water’s alkalinity and cause pH levels to drop considerably. While frogs and similar aquatic species can thrive in low-pH waters, most fish require healthier environments.

Seawater usually has a pH of around 8.0-8.4 depending on the local salinity. When salinity increases, pH levels will also rise. Oceans typically have higher pH readings because of the greater concentration of carbonate content. On the other hand, freshwater streams, lakes, and ponds usually have pH levels that range from 6.0-8.0. It’s possible for pH levels to be as high as 8.5 in freshwater bodies if stratification occurs. This process mainly takes place in deep lakes.

How to Test Water pH

There are several methods and tools you can use to identify the pH of water, which include everything from pH sensors to litmus paper.

pH Sensor

A pH sensor uses two probes to provide you with accurate measurements. These sensors allow you to test for chemicals and other contaminants in your water system. Try to maintain a pH level that’s close to 7.0.

pH Test Strips

While they aren’t as accurate as sensors, you can also use pH test strips to find out if your water is alkaline or acidic. Once you place a test strip in a sample of water for a few seconds, the water will change color. You can match this color with the test strip to identify the pH range.

Litmus Paper

Litmus paper uses the same concept as pH test strips. However, this paper will only inform you if the water is basic or acidic. Once you fill up a container with water, place the litmus paper inside for several seconds. The paper should respond by turning blue or red. If the paper is blue, the water is likely alkaline. Red litmus paper indicates acidic water. When the water is neutral, the paper shouldn’t change color.

Conclusion

In industrial facilities, wastewater treatment plants, and drinking water suppliers, controlling the pH of water is crucial to ensure these processes are completed without issue. The pH of the water you drink can impact its taste and appearance. In the environment, pH can influence biological and chemical processes in the water.

If your tap water has an alkaline pH, you might notice scale deposits on your dishes and around your drains. An acidic pH can lead to corrosion and other issues with your plumbing system. If your water is too contaminated, you can treat it with distillation, reverse osmosis, or filtration. Monitor the pH levels in your home to maintain your health and avoid damage to your appliances.