EYE ON THE ENVIRONMENT | CONDITIONS FOR WATER CONDITIONING WHEN SOFTENERS ARE HARD ON THE ENVIRONMENT
by David Goldstein
Nearly everyone in Ventura County subscribes to trash collection service, requiring three separate trucks to stop at their house each week, but thousands of people also subscribe to another environmental service requiring an additional truck. Like trash service, water softening is considered essential in some areas, but unlike trash collection service, most residents have a choice whether to subscribe to a water softening tank exchange program.
Alternatives to tank exchange include owning a softener, whole house water filtration, appliance-specific water filtration, other technologies, or using unmodified tap water. In parts of Ventura County served by state water through the Metropolitan Water District, water hardness ranges up to 5.2 grains per gallon (gpg), not a level generally considered to require softening. For example, sustainabilitymattersdaily.com recommends water softening only for hardness levels over 25-50 gpg.
Thousand Oaks, Simi Valley and Moorpark receive water from the state water project, sometimes with a blend of harder water. Using unmodified tap water in these areas, or even using a water conditioning alternative to a softener, will still result in a buildup of hard water deposits on faucets, dishwashers, coffee pots, and water heaters. However, the build-up will likely be so slow that the eventual cause of faucet or appliance replacement will probably be something other than hard water deposits.
In parts of the county using exclusively local water, including Fillmore, Santa Paula, Ojai and Ventura, water hardness is higher. Ojai’s water averages 17 gpg; Fillmore’s is 27 to 52; and Santa Paula’s is 30 to 32.
Camarillo, ranging from 6 to 18, will soon change due to a major new water source. Ventura, ranging from 17 to 53, plans two new water sources. Oxnard averages 28, and Port Hueneme ranges from 6 to 31.
Local water hardness can be found online by doing an internet search for “Water Consumer Confidence Report” and specifying any water provider in California. Reports show data from the previous year, and some water purveyors measure hardness by combining the numbers for magnesium and calcium carbonate, while others, such as Casitas Municipal Water District, measure just the calcium carbonate. Divide by 17.1 to convert “parts per million” to “grains per gallon.” Some use different blends or multiple providers for various locations in their jurisdiction, so residents should check water hardness levels for their own case.
The most common alternatives to tank exchange services are water softening systems maintained by customers and salt-free systems for water conditioning. At the risk of pointing out the environmental impacts of water softening, one subpage of the Culligan website touts the environmental advantages of the salt-free systems. As noted on the website, salt-free water conditioners eliminate the need to purchase, transport, consume and discharge salt and eliminate the need to use water for flushing filter media.
Flushing salt from the resin of exchange tanks was enough of an environmental issue to cause another local company to move its treatment facility. Harris Water moved out of Ventura, which limits salty discharge to sewer systems because the wastewater treatment facility discharges to an estuary. Harris Water moved to Oxnard, which sends discharge directly into the ocean.
Salt-based systems also have more environmental impacts. In areas where saline levels are high and treated wastewater flows to rivers, the addition of more salty water into the ecosystem is so serious, new water softeners are banned. Where not banned, adding salt still reduces the value of treated wastewater, making it less desirable for watering landscaping and non-food crops. Salty water harms plants.
Even an exchange-based water softening system adds salt to a home’s wastewater, making home greywater recovery systems untenable. On a related note, those with water softeners or exchange tanks often require a carbon filter or reverse osmosis system for their kitchen faucets, if not for health concerns related to consumption of salt, then to improve water taste. Reverse osmosis has environmental costs of its own, wasting between half a gallon and several gallons of water for every gallon forced through a membrane.
Some water softening systems use potassium instead of sodium, but these systems still discharge salt harmful to some plants. Fruit trees, for example, are damaged by chlorides, whether it is sodium chloride or potassium chloride.
A 2011 University of Arizona study found template assisted crystallization, capacitive deionization, and even electromagnetic treatment and electrically induced precipitation reduced scale formation significantly. Moreover, the scale formed was “soft” scale and easily brushed off. Other studies have cast doubt on the latter two technologies.
Each household must decide how to balance the environmental impact of water treatment methods with the risk of excessive scale build-up.
On the web:
David Goldstein, Environmental Resource Analyst with the Ventura County Public Works Agency, may be reached at 805-658-4312 or firstname.lastname@example.org.