WHAT ARE TOTAL DISSOLVED SOLIDS?
The measurement, “total dissolved solids” (TDS), refers to the total amount of all inorganic and organic substances in water. This includes minerals, salts, metals, cations or anions within a volume of water. TDS concentrations are equal to the sum of positively charged ions (cations) and negatively charged ions (anions) in the water. This reading does not specify exactly what is in the water, but gives an indication of “how much stuff” is in there. Further testing is required to get the actual breakdown of what exactly is in the water and at what quantities.
Sources for TDS include agricultural run-off, urban run-off, industrial wastewater, sewage, and natural sources such as leaves, silt, plankton, and rocks. Piping or plumbing may also release metals into the water. Water is an excellent solvent, therefore, it can pick up a little bit of most things it touches.
ARE THERE HEALTH AFFECTS OF HIGH TDS LEVELS?
While TDS is not considered a primary contaminant, high TDS levels can indicate the presence of other minerals or contaminants . These may lead to scale buildup in pipes, reduced efficiency of hot water heaters, and other problems. Also, aesthetic problems such as a bitter or salty taste, scale build-up on fixtures or other symptoms may arise. Finally, there may be health threat contaminants lurking within that TDS number.
Notably, the United States Environmental Protection Agency (EPA) recommends treatment when TDS concentrations exceed 500 mg/L, or 500 parts per million (ppm). The TDS concentration is considered a Secondary Drinking Water Standard, which means that it is not a health hazard. However, further testing may be warranted, as water with a high TDS concentration may indicate elevated levels of ions that do pose a health concern, such as aluminum, arsenic, copper, lead, nitrate, and others.
HOW DO I TEST FOR TDS IN WATER?
A TDS meter is commonly used to determine the amount of total dissolved solids in the water. Dissolved solids in water can conduct electricity. The meter measures the electrical conductivity in the water to determine the concentration of dissolved solids.
HOW CAN I REDUCE THE LEVEL OF TDS IN THE WATER?
To reduce TDS (Total Dissolved Solids) in water, the most effective method is to use a reverse osmosis (RO) system. RO forces water against a semi-permeable membrane to remove dissolved solids. This is the same technology used to desalinate seawater and it creates clean, good tasting water. Additionally, distillation (boiling water and collecting the steam) and deionization will remove TDS, although not practical for drinking water solutions. For more on TDS, see the link at https://www.lapl.org/neisci/kits/water-quality/why.
Water Testing and Filtration
H2O Care is an established, full-service water filtration and testing organization originally formed in 1989 with offices in Middleton, Stow & Lakeville, MA. Service area includes Eastern Mass., Southern NH & ME and Northern RI. Also, see our published articles in Water Technology Magazines at http://h2ocare.com/publications. Contact us at service@h2ocare.com or 800-539-1100.
