Troubled Water?

Selecting the right water treatment technology for your customers’ needs.

By Jennifer Strawn

It’s no secret consumers today have high expectations and are looking to you to provide their home or business with quality water.

People also want to know what may be lurking in their water—and if there is any contamination, how to remove it. It puts a lot on a contractor’s plate.

“The first step is understand your customers’ needs and water treatment goals,” says Todd Krause with Northwest Water Systems Inc. in Port Orchard, Washington. “In the end, why are we here? We’re here to serve and help people, so we can’t adequately serve and help them unless we know what their needs are.”

Defining what success looks like to your customer is the key to actually being successful. Some people expect their water to be perfect and others may want it to simply be better. Some people are willing to spend whatever it takes, and some have a budget.

“You can treat water to varying degrees,” says Gabe Ergler with Cascadian Water in Cle Elum, Washington. “As long as you explain to the customer what the water will look like and feel like when you’re done treating it, you’re on your way to success.”

Let your customers know what you can test for and what you can’t. They should also understand it’s hard to predict how water will react, and their water can change over time.

For example, a new well may not initially have a strong sulfur smell. But six months later, it could. In other wells, the opposite may happen. This is why some contractors encourage homeowners with new installations to use their water for six months before treating it.

“Don’t be so quick to treat the water,” advises Shawn Lyons with Lyons Well Drilling in Stockton, Illinois. “Sulfurs can drop and rise, nitrates can go sporadic, and everything is constantly changing.”

A good baseline water test should be completed before treatment. That can include pH, calcium, magnesium, iron, manganese, bacteria,  nitrates/nitrites, total dissolved solids, phosphates, and silica.

Iron-related bacteria is an important test for Shawn Lyons because it has as many forms as the common cold. The results help him determine if an iron filter would work or if the system needs to be chemically treated.

“It’s constantly changing and adapting to its environment,” he says. “When I do an iron-specific test, I look to see if it’s iron bacteria or is it something else? Is it aerobic or anaerobic? Does it have slime?”

Also, pH, phosphates, and silica are often overlooked but are vitally important to treatment success.

“They are especially important when you come across more difficult treatment situations, especially for iron, manganese, and arsenic,” Krause of Northwest Water Systems adds.

For example, if you have silica and high pH, it will form a silicate polymer that inhibits floc formation. The results are pin floc that are too small to filter out.

“At a pH under 5, water softeners simply won’t work,” says Larry Lyons of Lyons Well Drilling. “Sometimes you need to do a little pretreatment to get the pH to where it needs to be.”

Always test for pH at the point of use. If you take the sample to a lab, the pH will change by the time it gets there. If you check that same sample the next day, it will be a different number yet again.

The results of the water quality tests and your customers’ water usage and treatment goals will help you determine the right technology for the job.

Ion exchange

Ion exchange works by replacing positively charged calcium and magnesium ions with positively charged sodium ions as the water flows through a tank full of small polystyrene or zeolite mineral media.

When the calcium and magnesium ions take up all of the sodium ions, a regeneration cycle recharges the resin with sodium, and the remaining brine, calcium, and magnesium is flushed through a drain pipe.

Ion exchange can also be successful in removing watersoluble iron and manganese, but it requires frequent regeneration.

There’s also a risk of fouling if the iron oxidizes. Resins can be cleaned, but it can be expensive and reduce the capacity of the resin.

“In general, if there’s a lower level of iron and (the homeowners’) water use isn’t excessive, ion exchange is a good option,” Krause says. “It’s definitely cheaper, simpler, and less prone to problems.”

Ion exchange can also be used to remove nitrates with anion resins regenerated with salt or potassium chloride. If you’re using a standard anion resin, and it is run past the point of exhaustion, the resin will “dump” nitrates into the water. This is less common with nitrate-selective resins.

The potential for “dumping” is another reason Krause doesn’t recommend ion exchange for arsenic removal.

“You may end up getting more arsenic out of it than is being put in,” Krause says. “That’s obviously not good.”

Some states also have placed bans and restrictions on water softener discharge into city sewers and septic systems. Larry Lyons expects it to become a bigger issue in the near future—whether it’s discharge from a softener or another treatment solution.

“It doesn’t matter what technology you use,” he says. “If you’re filtering it out, you’re still going to end up with that contaminant in your possession. You’ve got to deal with that.”

Salt-free softeners

Salt-free cartridges could be an option in areas where there are bans or restrictions on water softener discharge.

Salt-free systems are available from several manufacturers, including Cascadian Water. These systems often use polyphosphate, such as Cascadian Water’s PolyHalt, that bonds with positively charged calcium and magnesium to form a new complex that prevents minerals from behaving as if not treated.

It won’t remove the minerals from the water like ion exchange or oxidation/filtration. Instead, it changes the condition of these minerals so they do not behave the same as before treatment. For instance, they won’t form scale or soap scum.

These cartridges can also be used to treat up to 6 ppm of soluble iron and manganese because positively charged iron and manganese will also bind to the polyphosphates. This prevents oxidation which causes the red, brown, or black staining.

They can be cost effective and low maintenance, but they may not be for everyone.

“If your customer has had a water softener in the past, and expects their water to feel slippery, they’re going to be disappointed because treatment for hardness with polyphosphate does not make the water feel slippery,” Ergler of Cascadian Water says. “That’s why it’s important to understand a customer’s expectations and to explain what to expect with proposed treatment.”

Also, because the treatment doesn’t remove the minerals, untreated and treated water will test the same, which may make it more difficult for you to demonstrate successful treatment after installation.

“We have to offer good science and help our customers understand that, as groundwater professionals, we know their water better than anyone else.”

Oxidation/filtration and coagulation/filtration

Oxidation/filtration is a process where soluble forms of iron and manganese are oxidized into their insoluble form before they’re removed through filtration.

Oxidation can be accomplished through aeration by adding dissolved chemical oxidants such as chlorine, chlorine dioxide, and potassium permanganate, or by adsorption with greensand media and activated carbon.

Although less common, ozone, applied as hydrogen peroxide or with an ozone generator, can also be used in some instances. When used in the right application, it works almost instantly with no smell before or after treatment.

For arsenic removal, soluble iron and arsenite are oxidized. The arsenate then adsorbs onto the iron hydroxide precipitates that are filtered out.

Alternatively, iron or aluminum can be added for coagulation, making it easier to filter out the arsenic. Iron coagulates hydrolyze to form ferric hydroxide with a net positive charge. Arsenate is negatively charged, so it adsorbs to the positively charged ferric hydroxide particles.

Oxidation/filtration is good when you have high levels of iron or manganese because softeners have their limits on how much iron and manganese they can remove.

Water use also matters.

“If you have a large yard you want to irrigate with treated water, you’re going to go through literally tons of salt to soften the water,” Krause says.

So, if your customer plans to use the water for irrigation and wants to remove iron to keep his or her sidewalks and hardscaping from turning brown, then oxidation/filtration may be the best technology.

Adsorption technologies

Adsorption technologies work by breaking contaminants’ attraction with water molecules so they chemically adhere to a filter media. Pressurized vessels containing the filter media allow for enough contact time for adsorption to occur.

A number of materials can be used in this process, including aluminum oxide or iron hydroxide, activated carbon, or man-made materials. Simply put, the media adsorbs the contaminants until it’s full and can’t absorb any more.

Adsorption is a common treatment for arsenic and some—like iron hydroxide media—won’t be released back into the environment via regeneration.

“I like adsorption technologies because it requires very little work on the part of the homeowner,” Krause says. “You’re typically treating indoor water, sometimes just your drinking water, not even your toilet and shower water. It may not be terribly efficient, but because you are treating such a small volume of water, it’s not terribly expensive.”

Reverse osmosis

Reverse osmosis works by forcing water across a semipermeable membrane. Contaminants left behind are flushed down the drain.

Reverse osmosis can be used to treat saltwater intrusion, nitrates, pesticides, sulfates, fluoride, arsenic, and more.

Near Lyons Well Drilling, a number of wells have high nitrates. Drilling a new well won’t solve the problem, so they’ve installed reverse osmosis filters.

“That filter does the job and works wonderful,” Larry Lyons says. “But it’s under the sink, so it’s just at that one tap or it’s plumbed to just a couple of faucets.”

But, like water softeners, disposing of the backwash can be an issue depending on your location and the contaminants you’re treating.

Finding good help

With so many different water treatment technologies available, it’s important to know where to go for help. Good manufacturers and suppliers with strong tech support teams can help you match up your water quality with the treatment specifications to find the right product.

It’s especially important if you aren’t doing water treatment full time. You don’t have to know everything, but the person helping you with your customers should.

“A good manufacturer or supplier isn’t going to want to sell you something that’s not going to work in that particular application,” Ergler says. “We want the treatment to be successful and we want the customer to be happy.”

“Unfortunately, there are a lot of snake oil salesmen out there selling all kinds of systems to homeowners,” Shawn Lyons adds. “That’s why we have to offer good science and help our customers understand that, as groundwater professionals, we know their water better than anyone else.”


Jennifer Strawn was the associate editor of Water Well Journal from 2004 to 2007. She is currently in the internal communications department at Nationwide in Columbus, Ohio. She can be reached at strawnj2@gmail.com.