Measuring Total Dissolved Solids To Evaluate Water Quality

As long as the water coming from the faucet is clear, most residents will assume it’s safe. However, water is an excellent solvent, and a clear stream may hide many impurities. Measuring the level of total dissolved solids in water can determine whether the local water treatment system is doing its job of solids handling.

What Are Total Dissolved Solids?

Total dissolved solids are typically ions or molecules that the water supply picks up on its journey to a residential water fixture. Some occur naturally, like minerals that improve the taste and health benefits of the local water supply. Dissolved solids like heavy metals, pesticides, and herbicides make water unsafe.

Common Types of Total Dissolved Solids

Total dissolved solids come in several different forms from a variety of sources. The total amount provides a guideline for municipal water suppliers. However, knowing the breakdown of TDS components is another factor in water safety.


As water flows through rivers and underground, it passes by and through rocks and picks up some of their mineral content. Minerals like potassium, magnesium, and calcium give water a pleasant taste. These ionic minerals are also something that the human body needs to function well.


There have been several stories about unsafe lead levels in local water supplies. Because of aging pipes and poor water infrastructure, metals may leech into the supply. Lead, arsenic, and chromium are all metals of concern for safe water.


Road treatments and water softening equipment increase salt levels in the local supply. At higher levels, such impurities can affect water taste.

Organic Components

Water from a natural reservoir may sometimes come out of the faucet with a yellow or orange tint. The breakdown of fallen leaves and other organic material leads to this shade. Other organic solids come from human sources, such as pesticides used in the agricultural industry.

Measuring TDS Levels in Water

A total dissolved solids meter is an inexpensive tool for making a baseline measurement. Homeowners may want one of these devices to see if they need additional water treatment equipment. Water suppliers can use a total dissolved solids meter to measure the effectiveness of their current treatment regimen.

The ideal TDS measurement falls somewhere between 300 and 500 ppm. This level indicates the presence of sufficient mineral content to provide a pleasant taste. At over 500 ppm, the water supply should have additional treatment. The EPA does not recommend drinking water with a TDS level of 1,000 ppm or more. Traditional treatments may not be enough to make water with 2,000 ppm safe for drinking.

Benefits of Monitoring Dissolvable Solids in Water

Monitoring TDS levels in water is a critical task for water supply companies. Paying attention to this measurement will keep the organization ahead of health and safety issues.


Public safety is the primary reason to monitor the levels of dissolvable solids in water. High numbers will trigger the additional analysis to prevent a health emergency.


A low TDS level will result in flat, tasteless water. Numbers in the 300 to 500 range will have a refreshing taste that encourages consumption. Higher levels can cause a bitter, metallic taste.

Water System Maintenance

The TDS number can demonstrate the effectiveness of the current TDS treatment strategy. Rising numbers may indicate changes in the water source or equipment approaching the end of its useful life.

How to Reduce TDS in Water

Many consumers wonder how to reduce TDS in water in their homes. The most popular solutions mimic commercial water treatment strategies on a smaller scale.

Reverse Osmosis

In reverse osmosis, untreated water flows under pressure through a membrane that captures ions and other dissolved molecules. It can decrease TDS levels to 50 ppm or lower.


Distillation is simply evaporating water in one chamber and condensing it in another. The steam will leave behind any impurities.

Ion Exchange

An ion exchange filter removes impurities by passing water over a specially-designed resin. This system trades dissolved ions for additional water molecules. Many water systems use ion exchange to soften hard water.

SCADA Technology and TDS Treatment

Monitoring the total dissolved solids in water can be part of a supervisory control and data acquisition system. Sensors will track TDS levels in real-time and report them back to a central location. The system can also throw alerts when dissolved solid levels get near unsafe levels.

At High Tide Technologies, we specialize in SCADA systems for municipal water collection, treatment, and distribution organizations. Our cloud-based model allows managers to monitor TDS levels from any location. Contact us today for more information on how a SCADA system can improve efficiency and safety.