Electricity costs for a water treatment system are minimal. It costs about $4-$6 a year to operate a water treatment system. Most users will, however, experience more water usage than before they had a water treatment system. Typically water usage is about 3% higher than before a water softener was installed.In fact, a 2016 study by Trupanion found that pets that drink hard water are at greater risk for urinary infections than those who drink soft water.