Water softeners are a hard problem

Salts and chlorides are not good for the groundwater basin

There is more to water softeners than just soft water. Water softeners reduce the “hardness” of the water, which can have several benefits for consumers: smaller amounts of soap and detergents (non-synthetic) are necessary for laundry and cleaning processes; reduced staining, spotting, scaling; bathing and showering feelings; increased fabric life; and energy saving in water heating due to less scaling.

How does a water softener work?
A typical water softener softens water by ion exchange, which involves the exchange of the hardness minerals, chiefly calcium and magnesium, for sodium or potassium minerals.

The exchange takes place by passing water containing hardness minerals over ion exchange resins in a tank. As the calcium and magnesium contact the resin in their travel through the resin tank, they displace sodium or potassium ions. The displaced sodium or potassium ions pass downward through the resin “bed” and out the softener drain; thus, the softener delivers “soft” water.

The Problem
The discharge of salt brines from the regeneration of water softeners into the wastewater collection system has a negative impact on the quality of water in our groundwater basin, recycled water and wastewater effluent. Higher salinity increases the treatment costs and reduces the potential for reuse of wastewater for non-potable irrigation and industrial purposes. It can also impair a wastewater treatment agency’s ability to comply with discharge standards for total dissolved solids (TDS) which is a measure of the total concentration of dissolved minerals in water, including concentrations such as sodium, calcium, magnesium, potassium, and anions such as chloride, sulfate, and many others.

A typical wastewater treatment facility removes very little of these mineral concentrations from the waste stream and are passed on to the environment.

Sodium really has no redeeming value in the environment outside of saltwater or brackish water ecosystems. It has been declared as the biggest contaminate affecting water supplies in California, the nation and the world. Water with salinity levels above 1,000 mg/l is of questionable use for irrigation and industrial customers. As salinity increases, laundry detergents work less efficiently, plumbing fixtures and home appliances wear out faster and industry incurs higher treatment costs for boilers, cooling towers and manufacturing processes, and farmers experience reduced crop yields.

Results of Noncompliance
Every wastewater treatment facility in the state must meet strict limits issued by the state and federal agencies on the amount of TDS and mineral concentrations before reclaimed wastewater can be introduced back into the environment. If a wastewater treatment facility is found to be in violation of its discharge limits by these agencies significant fines may result. Presently, the City of San Juan Bautista’s wastewater treatment facility is experiencing difficulty in meeting its TDS, sodium, and chloride discharge limits. As a result, the city is being fined $3,000 per month by the Central Coast Regional Water Quality Board. One of many contributing factors to this problem is salt brine from water softening units.

In fact, the City Council in Hollister recently passed an ordinance banning the installation of any new, self-regulating water softeners that use salt and/or potassium. This action will assist the city and its water managers on their recycled water efforts and meeting discharge requirements.

Our groundwater basin is a precious natural resource that provides critical water supply, especially during times of drought like we are currently experiencing. We must protect it for future generations!

Possible Solutions
If you find that a softener is necessary, then a possible solution is to switch to potassium chloride from sodium chloride in your softener. This substitution will indeed solve the sodium problem. The downside of potassium chloride it will add to any chloride problem and costs more than sodium chloride.

Another possible solution, which may not solve but can greatly reduce the problem, is to use less salt. Most softener owners use at least twice as much salt to soften water as is necessary. By adjusting your softener to use the proper amount of salt per regeneration required to soften your water may greatly reduce the amount of sodium or chloride being used and subsequently discharged to the sewer.

Lastly, it has been found that many softeners are set to recharge or backwash too frequently. Again by adjusting the backwash cycle to the appropriate time period between each backwash can significantly reduce the amount of sodium or chloride being discharged into the sewer system. Instead of a daily or every other day recharge cycle, a five-day cycle may be used to achieve the proper softening level.

If you find you aren’t using your water softener or it’s time to replace it, consider the incentives being offered by the Water Resources Association of San Benito County (WRASBC). If you demolish your self-regulating water softener that uses salt and/or potassium without replacing it the WRASBC has a $300 rebate for you. If you transition from a self-regulating water softener that uses salt and/or potassium to an offsite exchange service, the WRASBC offers a $250 rebate. To receive this rebate a participant must sign at least a one year contract with the exchange service.

Exchange tank softeners work in a manner similar to automatic water softeners, but feature a removable mineral tank that is replaced with a fresh mineral tank when the sodium or the resin is depleted. The depleted tanks are regenerated by water conditioning services at off-site facilities that are permitted to treat and discharge salty wastes, and thus do not put chloride into our local groundwater basin.

Conclusion
The solution to the salinity problem in water supplies is going to be a very long, difficult and costly process. But everyone can help by using the least amount of sodium possible or finding more environmentally friendly ways to soften water. For more information on the WRASBC’s water softener rebate program call (831) 637-4378.

 

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Shawn Novack

Shawn Novack is the Director of the Water Resources Association of San Benito County. The Association represents the City of Hollister, the City of San Juan Bautista, the Sunnyslope County Water District and the San Benito County Water District for all their water conservation and water resource protection programs. Shawn has been in the field of water conservation for 18 years. He has a certification as a Water Conservation Practioner from the American Water Works Association California/Nevada Chapter. He also is a Certified Landscape Irrigation Auditor through the Irrigation Association in Virginia. Before getting into the water industry, Shawn worked as a technical writer for the Naval Research Center in Monterey.