After nearly 20 years in the market, potassium chloride has earned its place as a significant water softener regenerant. It adds healthful potassium to the homeowner’s drinking water and is gentler to the environment than sodium chloride.
When dealing with health and environmentally conscious communities and consumers, the use of potassium chloride should be encouraged and promoted by water treatment dealers as an advantageous alternative to sodium chloride.
Sodium chloride solution
Since the inception of the modern water softener to soften water, salt (sodium chloride) has been the agent of choice to regenerate softener resin. The earliest work done by German scientist Gans in 1905 determined that the water softener resin could be regenerated with salt.
Since that time, the use of salt has been the standard approach for regeneration. However, in the late 1980s, as the water softener market continued to expand at a rapid pace and the demand for salt tracked the growth, concerns were expressed from both an environmental and health aspect.
As Graph 1 indicates, salt consumption nearly doubled in 14 years, from 1984 to 1999. As the amount of salt usage in water softeners increased, so did the amount of sodium chloride that was discharged from homes using softeners.
Further, as concerns began to surface regarding the amount of sodium intake by people with hypertension conditions, softened water containing sodium became a point of increased interest.
To put the issue into perspective, the question must be asked "Where does the salt used for water softener regeneration go?" In reality all of the salt goes into the environment, with the majority of it going into the sewer in the form of brine discharge.
A much smaller percentage goes into septic tanks, cesspools and dry wells. In any case, all of the salt goes to a waste discharge system of one kind or another.
An alternative solution
To reduce the amount of salt discharged to the environment, water softener manufacturers have begun to address issues in the area of salt efficiency.
However, new water softener technology isn’t the only solution for areas where brine discharge is of special concern.
The use of potassium chloride in water softeners instead of sodium chloride can diminish the perceived environmental impact of brine discharge because potassium chloride is considered a healthy nutrient for both humans and plants.
Putting this into perspective, potassium chloride is the main source of potash fertilizer in the world. Potassium chloride accounts for 94 percent of all forms of potash used domestically as reported by Agriculture Canada for 1995/1996.
The total domestic consumption was 314,000 tons of potassium chloride out of 333,253 total tons of potash, and 4,829,045 tons of all fertilizer. Further, the amount exported was 13,076,0771 tons from a total of 13,082,442 or 99.5 percent.
The total potash consumption worldwide in 1996 was 20,550,000 tons, clearly indicating the environmental advantages to the environment from using potassium chloride as a regenerant.
It is important to note that potassium is an important nutrient we all need for good health. But, the human body doesn’t produce potassium, so we must get it from our diet.
Water softened with potassium chloride can provide as much as 11 percent of the minimum daily requirement for potassium. This number is based on the widely recommended consumption rate of eight glasses of water per day and on the assumption that the water contains 15 grains of hardness.
An additional benefit of potassium chloride is the impact on sodium in drinking water. Studies have found that softening water with potassium chloride does not add sodium to drinking water, and will also remove up to 90 percent of the existing sodium from the water.
The significance of this discovery must not be lost on consumers with restricted sodium diets. If the same eight glasses with 15 grain hard water referenced above were softened with salt and consumed by a person on a restricted sodium diet, they would receive 240 milligrams of sodium — up to half a daily level on a low sodium diet.
Potassium instead of sodium is added when softening with potassium and any background sodium would also be removed — two significant benefits for restricted diet situations.
1. Fallon, Irving, Water Conditioning and Purification Magazine, Feb., 1989, "Sodium Removal in Potable Water, Potassium Chloride Offers Solution."
Jerry Poe is technical director of North American Salt Company, Overland Park, KS, a full-line salt manufacturer for applications including agriculture, water softeners, consumer ice melters, industrial applications and food.
Nathan Herman is a marketing specialist at North American Salt Company.