What Is The Acceptable Total Dissolved Solids (TDS) Level In Drinking Water?

Total Dissolved Solids (TDS) Level in Drinking Water

Total Dissolved Solids, also known as TDS, are inorganic compounds that are found in water such as salts, heavy metals and some traces of organic compounds that are dissolved in water.

Excluding the organic matters that are sometimes naturally present in water and the environment, some of these compounds or substances can be essential in life. But, it can be harmful when taken more than the desired amount needed by the body.

The total dissolved solids present in water are one of the leading causes of turbidity and sediments in drinking water. When left unfiltered, total dissolved solids can be the cause of various diseases.

Total dissolved solids (TDS) is a measure of the combined total of organic and inorganic substances contained in a liquid. This includes anything present in water other than the pure H20 molecules. These solids are primarily minerals, salts, and organic matter that can be a general indicator of water quality.

Understanding the Total Dissolved Solids (TDS)

All sources of natural water include dissolved substances and minerals on it. These minerals are measured as the total dissolved solids or TDS. It is comprised of the natural minerals which are inorganic salts. Some of these are potassium, calcium, magnesium, chlorides, bicarbonates, and sulfates. In addition, it can have contaminants like heavy metals which are low in concentrations. When you measure the TDS, the presence of heavy metals cannot be exactly determined.

In the water, TDS is identified as parts per million (ppm) or mg/L. Since TDS does not pose a risk to the health of the people, the EPA has not identified a TDS limit. However, it suggests for the drinking water to have a level of up to 500 ppm only.

If the water has above 500 ppm, they can notice deposits on the water, salty taste, or staining on the water. These effects are not harmful however, it can be noticeable.

The TDS in Drinking Water

The TDS in drinking water comes from natural water sources, sewage, urban run-off, industrial wastewater and chemicals used in the water treatment process, and the hardware or piping used to distribute water. In the US, higher TDS was brought by natural environment features like salt deposits, mineral springs, seawater intrusion, and carbonate deposits.

Other sources may include anti-skid materials, salts used for road de-icing, stormwater, and agricultural runoff, water treatment chemicals, and point/non-point wastewater discharges.

In general, the total dissolved solids concentration is the total cations (positively charged) and anions (negatively charged) ions in the water.  Thus, the total dissolved solids test gives a qualitative measure of the number of dissolved ions but does not tell us nature or ion relationships. 

In addition, the test does not provide us insight into the specific water quality issues, such as Elevated Hardness (mineral content in water), Salty Taste, or Corrosiveness (also called as aggressive water which is how water dissolves with other materials).

Therefore, the total dissolved solids test is used as an indicator test to determine the general quality of the water.  The sources of total dissolved solids can include all of the dissolved cations and anions, but the following table can be used as a generalization of the relationship of TDS to water quality problems.

Cations combined with Carbonates
CaCO3, MgCO3, etc

Associated with hardness, scale formation, bitter taste

Cations combined with Chloride
NaCl, KCl

Salty or brackish taste, increase corrosivity

Total Dissolved Solids (TDS) Meters

Many people are conscious about TDS meters. Basically, it measures the water’s electrical conductivity which can be connected with the amount of TDS. Meanwhile, a TDS meter can’t measure directly the heavy metal contaminants like arsenic and lead. It does not indicate whether or not the water filter works properly to decrease this type of contaminants.

The normal TDS level ranges from 50 ppm to 1,000 ppm. On the other hand, the National Sanitary Foundation (NSF) International does not certify the use of the TDS meters.

What Composes Total Dissolved Solids and How Do They Contaminate our Water Supply?

Different substances comprise the total dissolved solids in drinking water. As a natural flora of water and the environment, bacteria and viruses can be found in total dissolved solids, these are the organic compounds found in drinking water.

Chemicals found in the water and water supply include heavy metals, salts, and pharmaceutical drugs that are caused by human waste materials which contaminate the water and water supply.

Water that comes from springs, lakes, and waterfalls has natural microorganisms and salts. This will, in turn, go to public water treatment and are stored for supplying the community.

Not only that but also phytoplankton, one of the natural floras of water, can sometimes be found. Phytoplankton is a type of microscopic plant that drifts off to different bodies of water.

Sometimes, chemicals such as iron, potassium, sodium, and other chemicals that are known to man are present in drinking water too. These chemicals are caused by human waste products that contaminate these water sources.

Not to mention the volatile organic compounds, they also pollute the water by leaking through the water supply by soil. 

Volatile organic compounds, also known as VOC’s, are rapidly evaporating compounds that are chemically designed for specific use at home, at school and anywhere you can think of.

Other Reason Why Solids End Up Dissolved in Water

Mineral springs contain water with high levels of dissolved solids because the water has flowed through a region where the rocks have a high salt content. For instance, the water in the Prairie provinces in the US tends to have high levels of dissolved solids, because of high amounts of calcium and magnesium in the ground.

These minerals can also come from human activities. Agricultural and urban runoff can carry excess minerals into water sources, as can wastewater discharges, industrial wastewater, and salt that is used to de-ice roads.

What is the Acceptable Total Dissolved Solids (TDS) Level in Drinking Water 

Total Dissolved Solids (TDS) is measured in milligrams per unit volume of water (mg/L) and also referred to as parts per million (ppm). For drinking water, the maximum concentration level set by EPA is 500 mg/L.

Factors Affecting TDS

High Flow Rates

When we talk about the TSS concentrations, the flow rate of a body of water can be a major factor. Fast running water can have large-sized and more sediment. Heavy rains can pick up clay, sand, silt, and other particles like tire particles, leaves, and soil. Moreover, a change in the flow rate can affect total suspended solids. If the direction or the speed of the water current increase, the particulate substance from the bottom sediments may be suspended.

Soil Erosion

Soil erosion is due to the troubles on the surface of the land. It can be caused by illegal logging, forest fires, mining, and construction. The particles of an eroded soil can be carried via the stormwater into the surface water. With this, it can increase the level of TDS and TSS in the water.

Urban Runoff

When the storm comes, the debris and solid particles from the commercial or residential areas can be washed away into the streams. Due to a large amount of pavement in cities, there is an increase in infiltration and increase in velocity. The natural settling areas is removed. Through the storm, the sediments are carried into rivers and creeks.

Overflow of the Septic and Wastewater System

The particles from the wastewater treatment plants can also contribute to the suspension of solids in the stream. The wastewater from residential areas contains human wastes, food residue, and other materials that we flush in the drains. Most of the solids are already eliminated from the water at the plant. However, not everything is eliminated in during the treatment.

Rotting Animals and Plants

As animals and plants decay, there are suspended organic particles which can be released. This can all contribute to TDS and TSS concentration in the drinking water.

Bottom-Feeding Fish

Bottom-feeding fish like carp can disturb the sediments since they have the tendency to remove vegetation. Indeed, these sediments can add to TDS and TSS.

Why Should You Measure the TDS Levels in Your Water?

Numerous water supplies exceed this level. When TDS levels exceed 1000mg/L, it is generally considered unfit for human consumption. A high level of TDS is an indicator of potential concerns, and appeals for further investigation.

Most often, high levels of TDS are caused by the presence of potassium, chlorides, and sodium. These ions have little or no short-term effects, but toxic ions (lead arsenic, cadmium, nitrate, and others) may also be dissolved in the water.

Even the best water purification systems on the market require monitoring for TDS to ensure the filters and/or membranes are effectively removing unwanted particles and bacteria from your water. Here are other applications of the importance of the TDS level:

  • Taste / Health

High TDS results in undesirable taste, which could be salty, bitter, or metallic. It could also indicate the presence of toxic minerals. The EPA’s recommended maximum level of TDS in water is 500mg/L (500ppm).

Health Considerations

In the past studies conducted, there are inverse relationships reported in TDS concentrations on drinking water and coronary heart disease, cancer, cardiovascular heart disease, and arteriosclerotic heart disease. There is an inverse correlation between TDS levels and total mortality rates.

In an Australian study, it has been found out that mortality rates are high in a community with higher levels of soluble calcium, sulfate, magnesium, chloride, and fluoride. This is in comparison in a community with lower levels.

Other Considerations

The dissolved solids present in the water can affect its taste. In a study, a panel of taster has rated the palatability of drinking water. It is excellent if the TDS is less than 300 mg/L. It is good if the TDS is between 300 to 600 mg/L. It is fair if the TDS is between 600 to 900 mg/L. The water tastes poor if the TDS is between 900 to 1,200 mg/L. Finally, the water tastes unacceptable is the TDS is greater than 1,200 mg/L.

If the water has extremely low TDS level, it can also be unacceptable due to its insipid and flat taste.

Apart from the water’s palatability, there are some components of TDS which can affect the encrustation and corrosion of the water distribution systems. Examples of this are sulfates, chlorides, calcium, carbonates, and magnesium. If there are high TDS levels which is above 500 mg/L, it can result in excessive scaling in the water heater, boilers, pipes, and other appliances inside the house. With the scaling, it can shorten the lifespan of your appliances.

  • Filter performance

Test your water to make sure the reverse osmosis or other types of water filter or water purification system has a high rejection rate and know when to change your filter (or membrane) cartridges.

  • Hardness (and Water Softeners)

High TDS point out the Hard water, which causes scale build-up in pipes and valves. This eventually restricts performance.

  • Aquariums / Aquaculture

A constant level of minerals is needed for aquatic life. The water in an aquarium or tank must have the same levels of TDS and pH as the fish and reef’s original habitat.

  • Hydroponics

TDS is the best measurement of the nutrient concentration in a hydroponic solution.

  • Pools and Spas

TDS levels must be monitored to prevent maintenance problems

  • Commercial / Industrial

High TDS levels could prevent the functions of certain applications, such as boilers and cooling towers, food and water production, etc.

  • Colloidal silver water

TDS levels must be controlled prior to making colloidal silver.

  • Coffee and Food Service

For a truly great cup of coffee, proper TDS levels must be maintained.

  • Car Washing and Window Cleaning

It gives the best result when cleaning.

Options on the Treatment of TDS

NSF International has published a list of certified reverse osmosis system which can reduce the TDS level in the water. This can be extremely helpful as you identify the right unit to install in your house. You can also choose to buy the Berkey Water Filter because this can be an effective solution to eradicate TDS in your water source.

Indeed, NSF International does not approve of the use of the TDS meters. However, it does certify the treatment systems to reduce contaminants like heavy metals.

The system must be effective at reducing the contaminants which the manufacturers claim. There must be structural integrity to see to it that the treatment system or filter does not leak. Also, there is material safety testing to see it that it can identify the impurities that are eliminated when the filter is not in use. Finally, there must be accurate labeling of the product to make sure that it does not contain any misleading information.

If you searching for a product that can eliminate water contaminants, you must select a product that is certified by the NSF International. If the product is not certified to eliminate that specific contaminant, then the product will not necessarily be going to diminish it from your drinking water.

Analytical Methods and Treatment Technology

In water supplies, the most commonly used method for analysis is through the measurement of specific conductivity that determines the presence of ion in water. These measurements are converted to TDS values by a factor which determines the water type.

TDS are not essentially removed with the use of conventional water treatment techniques. As a matter of fact, with the chemicals added during conventional water treatment, it can generally increase the concentration of the TDS. Some treatment techniques like softening through lime-soda ash plus sodium exchange zeolite can increase TDS concentration. The process of demineralization is needed for TDS removal.

Indeed, demineralization is available to decrease the TDS levels but its high cost can be a major constraint. As such, electrodialysis and reverse osmosis can be an economical method to remove TDS in public water supplies.

What are the Ways to Remove Total Dissolved Solids in Drinking Water?

These chemicals are absorbed by the soils that eventually contaminate the water supplies. Though some of the total dissolved solids are natural floras, filtration and purification is an effective way to remove these chemicals out from our drinking water.

To give you a short process of water filtration and purification, the water coming from the water sources goes to the public water treatment to undergo filtering. In this process, large particles or substances are filtered out and removed from the water.

Sometimes, in this process, small particles can get through the filters. This is still causing turbidity in drinking water and is not yet safe to be consumed. Once it undergoes filtration, it is then purified using certain methods.

Depending on the company or water treatment facility, some use chemicals, radiation or micro-filtration, and chlorination to remove microscopic particles still present in water.

In the process of removing dissolved solids in drinking water with the use of chemicals as reagents, these reagents help to filter these substances out. Chemicals such as aluminum sulfate and liquid chlorine are used.

These chemicals are flocculating chemicals that help in water filtration. What they do is that they clump the particles together until they form a larger particle.

These flocks can then be easily removed or filtered out. Some chemicals used are fluorosilicic acid, sodium silicofluoride, and sodium fluoride. These chemicals give a unique reaction.

These chemicals give off energy by creating heat when these chemicals are combined with water they burn, thus killing the bacteria, viruses, protozoan, and other organic microorganism found in water.

Once the drinking water is filtered off the impurities, it still has a strange taste that is not drinkable yet. This was when calcium hydroxide was added to water.

Calcium hydroxide, also known as lime water, is a self-regulating chemical that does not affect the alkalinity and the acidity of water. So, it makes it safe to drink and will have the taste of natural water.

While some water treatment facility uses chemical reagent to filter and purify drinking, some public water treatment facility uses filtration, chlorination, and UltraViolet radiation to purify drinking water.

The process of these treatment starts when the water coming from water sources goes to the water supply for particles to be filtered out. Once filtered, it will remain in the water supply for chlorination.

When chlorine is added, it will remain in the water storage until the smell of chlorine cannot be detected. Since chlorine is a derivative of salt and sodium, sometimes it cannot be easily dissolved. When the chlorination process is done, it goes to a special process where radiation is involved.

With the help of Ultra Violet rays, water is then radiated to make sure that the remaining substances of chlorine will be dissolved and the microorganisms that made it through the filtration and chlorination process were killed.

These residues turn into sediments found at the bottom of the water and are the cause of turbidity in water.

How Can We Safely Purify Water?

Well, after knowing a few of the processes to filter and purify water, different questions are forming deep in our head. Like, how safe is it to be consumed? How will it affect our health and our family as well?

Since we all know that radiation is harmful to our health and chemicals, when defined, it always leads to toxicity and disease. However, there is a way to purify water from these contaminants and remove the impurities safely and effectively without the use of chemicals or radiation.

 Another reliable way to purify water is boiling. This is the most basic way of purifying water. Also, when purifying water from doubtful water sources, you must not forget to filter the water as it may still have some sediment or solid particles.

In using a water filter, it is also a good way to remove the bacteria in the water. Carbon filter gets rid of the awful tastes and chemicals while the iodine-coated filter can remove bacteria and viruses. After treating the water, you can already drink the water, and you may notice the water without any taste.

Now you can make sure that your family is drinking safe and potable water without the undergoing these processes and without the presence of sediments or microorganisms that can cause disease.

The Berkey Water Filter aids in removing any inorganic compounds, microorganisms, and other contaminants. Using any water source, filtering it with the Berkey Water Filter will remove health threats to your water.

It only retains the mineral that is why it retains the standard TSD level while leaving your water tastes better. With the help of Berkey Water Filter, you can now assure that your family will remain healthy, hydrated, and free from harm.


TDS is an essential factor in the water quality of the drinking water. It is an indicator of whether the water is too turbid or lacks the essential minerals needed by the body. Elevated total dissolved concentration (TDS) level does not mean that the water becomes a health hazard. But, this doesn’t mean the water may have aesthetic problems or cause nuisance problems.

The problems may be concerned with staining, taste, or precipitation. Concerning trace metals, higher TDS level may indicate that they are present in the water.

Another important thing to keep in mind, the water may be corrosive if the TDS level is very low. The corrosive waters may leak the toxic metals from the household plumbing. Given this situation, it may pose a health hazard as well.

Dealing with this kind of water, hard water can be annoying. So, the initial recommendation would be to get your water tested and determine the general quality and chemistry of your water. Do this before consuming or installing your water treatment system.

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