Salty Water DischargeTim Hagemeier, MRWA Wastewater Technician & Trainer

Many of you have heard the term ‘Salty Water Discharge’ and associated it with some testing parameters that you are doing.Operations specialists have asked me: “What impact do water softeners have on the wastewater stream?”

When a typical water softener regenerates it goes through 40 to 70 gallons of water; all 40 to 70 gallons have high concentra-tions of salt in it. Salt also comes from other sources like soaps and fillers for laundry detergent. Water softeners regeneratetwo ways: by time or by demand. The time mode is done by setting how many times per week to regenerate. Demand is done

by how much water has been used and the hardness of thewater. Households that do the time mode normally over-regen-erate, which means more water and salt is added to the waste-water stream. Some studies haveshown metered softeners used60% less salt over a year. So in

theory, having everyone on a metered softener would reduce the amount of water and salt in thewastewater stream. But with that said, every wastewater system would be different. It depends onhow many households have softeners, how many are timed softeners, the hardness of water, howmuch salt is used during each generation, water pressure, and pipe size. Many softeners are set touse around 10 pounds of salt per generation.

If your system has many households with the time mode and they would switch to demand mode,you would probably see a reduction in water and salt usage. How much? Who knows? I have notcome across a wastewater system in Minnesota that did a softener change with good data on theeffect. But if you have done something like this and have information you would like to share, letme know. You can reach me by e-mail at tim.hagemeier@mrwa.com or by phone at: 320-760-5885.

“What impact do water softeners haveon the wastewater stream?”

12 MRWA TODAY w Spring 2014

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