A Guide to Chloride: Its Effects, How to Test for It Chloride is one of the most common anions found in tap water. It generally combines with calcium, magnesium, or sodium to form various salts: for example, sodium chloride (NaCl) is formed when chloride and sodium combine. Chloride occurs naturally in ground water, but is found in greater concentrations where seawater and run-off from road salts (salts used to de-ice icy roads) can make their way into water sources. As such, well owners near snowy roads or road salting storage facilities are especially at risk for high levels of sodium chloride.
Although chlorides are harmless at low levels, well water high in sodium chloride tastes very unpleasant, and can damage plants if used for gardening or irrigation. Over time, sodium chloride’s high corrosivity will also damage plumbing, appliances, and water heaters, causing toxic metals to leach into your water.
Interestingly, there is no federally enforceable standard for chlorides in drinking water, though the EPA recommends levels no higher than 250 mg/L to avoid salty tastes and undesirable odors. At levels greater than this, sodium chloride can complicate existing heart problems and contribute to high blood pressure when ingested in excess.
Fortunately, testing for and removing chloride is fairly easy. We offer two tests that will detect chloride in your water: the Clean Water Laboratory Test Kit and the WaterCheck Laboratory Test Kit. The latter will test for 115 water contaminants, including chloride. To use these kits, simply fill the included bottle with a water sample, send it to our lab, and wait a couple weeks for results.
After you’ve got your results, assuming you are indeed experiencing water contamination, you’re ready to start looking for a treatment system. To remove chloride, your best bet is either a reverse osmosis system or a distiller:
Reverse osmosis works by passing water through a semi-permeable membrane that separates pure water into one stream and salt water into another stream. In regular osmosis water flows from a lower concentration of salts to higher concentrations; in reverse osmosis the application of pressure greater than the osmotic pressure reverses the water flow from higher concentrations to much lower concentrations, producing pure water. With this method, about 50% of water can be recovered as pure water, while about 50% becomes salty wastewater. (If you’d like, you can read the reverse osmosis FAQ on our website for more info.)
Distillers, on the other hand, use evaporation and condensation to separate pure, fresh water from its contaminants. The prolonged boiling process kills virtually all types of microorganisms, including bacteria, viruses and parasites. Microorganisms are not evaporated into the product water but remain in the boiling chamber as part of the residue. Distillers work very well, but use a lot of electricity.
If you’ve already tested your water and found high chloride levels, see our web store for a wide selection of distillers and both point-of-use and point-of-entry RO systems.