As you may already know, freshwater organisms cannot tolerate high levels of dissolved solids such as chloride. Approximately 60% of the salt that we use and flush is the chloride ion. Scientists tested a variety of organisms and determined that a long-term exposure to chloride concentration of 395 mg/l is dangerous for the living organisms in the stream -- a concentration equal to about half of a tablespoon of salt in five gallons of water. The wastewater that reaches our facility contains these higher concentrations, created from various sources such as water softening systems, industrial sources and winter ice control.
Why should we Change?
While it only costs 20 cents to add a pound of salt to water, it costs five dollars to remove it. MMSD undertook a study which showed it could cost from $300-million to $2.3-billion to remove the required amount of chloride.
Rather than adding costly treatment in order to continue protecting our freshwater life, we have other options. Together, we can take small but helpful steps in order to reduce the amount of salt put into water by examining our current water practices. By understanding where this salt comes from, we can all identify and form habit that help maintain healthy waterways without sacrificing our well-being.
What Can We Do?
Look to Your Water Softener
Optimize water softeners ( our household softening study found that, on average, this can reduce salt use by 27%). Local water quality professionals provide this service.
Replace older or inefficient softeners - when replacing a softener with high efficiency softeners, the same study found 48% savings on the amount of salt used. Some existing models can be particularly wasteful on salt and water use for example Timer Based Models.