Jimmy Arthur, water production supervisor for The Colony—a suburb of Dallas, TX with a population of more than 36,000—saw a problem: Whenever diving companies would scrub his city’s water tanks clean, they’d miss the walls.
The tanks’ floors would be clean. But the walls? They were still coated with sediment—the divers’ vacuums and suction devices useless.
“You could see it in the videos of some of our elevated steel tanks. They had these nice clean floors, but the sidewalls were still dingy and dirty,” says Arthur.
The water utility pressure-washed its tanks, too. But that also did little to remove deposits from their sidewalls, he says.
It was time to take action. Arthur didn’t want the sediment from these tanks slipping into The Colony’s water supply. So starting in 2007, The Colony began using Floran, a chemical product manufactured by Las Vegas-based Blue Earth Labs, to remove the naturally occurring organic and inorganic deposits in the water system’s tanks.
The water utility has used Floran on six of its tanks, using it multiple times on some of them, and Arthur believes that the results have been impressive. “You get a much better appearance when you’re done,” he says. “You can see a night-and-day difference between using that product and just pressure-washing the tank down.”
Arthur is far from the only water district official to experiment in recent years with the way he maintains his water system’s infrastructure and treats his water supply. Municipalities across the country are exploring new techniques to monitor the amount of solids, disinfection byproducts, nitrates, and other substances in their drinking and wastewater.
The manufacturers that specialize in providing treatment solutions say that the actions taken by water utility professionals like Arthur are a positive: They offer evidence that municipalities are working harder than ever—and are more willing to invest in alternative treatment methods—to make sure that their water supplies are as pure as possible.
This doesn’t mean, though, that water utilities don’t face challenges when it comes to water treatment. New regulations and increased scrutiny from the public are making water treatment a more challenging puzzle for utilities.
Battling Waste, Regulations
Saqib Karori, project manager with Buford, GA-based AdEdge Water Technologies, says that one of the challenges municipalities and utilities face is that there is not one treatment solution that is perfect for eliminating every type of pollutant or micropollutant or chemical from water supplies.
Some substances in water are easy to treat, says Karori, such as iron and magnesium. Others, including fluoride and nitrates, are far more difficult to remove.
Sometimes the problem doesn’t even lie in removing the substances. Sometimes the real struggle for municipalities is dealing with the waste that is left behind when they eliminate substances with treatment methods like ion exchange or reverse osmosis.
Municipalities who use these two methods will be able to eliminate excess nitrates from their waste and drinking water streams. And both will allow municipalities to hit EPA’s maximum containment level goal for nitrates of 10 milligrams per liter. But in doing so, both treatments also produce a significant amount of wastewater.
Conventional ion exchange systems produce waste volumes in the range of 2–4% of the total amount of water that a municipality treats. Those municipalities that need to remove Total Dissolved Solids (TDS), as well as nitrates from their water supplies, will usually turn to reverse osmosis systems. These systems are effective, too, using membranes to remove both nitrates and dissolved solids from water supplies. Again, though, they generate too much wastewater, anywhere from 15%–25% of the total amount of water that the municipality treats.
Dealing with this wastewater is rarely an easy task. Consider California. Municipalities there aren’t allowed to discharge their waste brine from these treatment methods into sanitary sewer systems. Instead, municipalities must store this waste in a holding tank and transport it offsite for discharge.
Karori says that municipalities today, faced with ever-tougher regulations and searching for waste-intensive treatment solutions, are more willing to experiment with technologies that are unfamiliar to them. This is especially true if manufacturers can convince them that alternative treatment methods can eliminate pollutants, remove nitrates, save them money, and leave them with less wastewater with which to deal.
At AdEdge, this means that more clients are asking about the company’s absorption method of treating water supplies, says Karori.
In the absorption process, contaminants in the water stream break their bond with water molecules and chemically adhere to a filter media. AdEdge makes this happen by directing the water flow through pressure vessels that hold the filter media. The water flows at a rate that allows for enough contact time for the absorption to occur. AdEdge has developed filter media that can reduce contaminants such as arsenic, fluoride, and dissolved organic chemicals.
Not all municipalities, though, are able to move from chemical-based treatment methods to more advanced treatments such as absorption. The biggest reason, says Karori, comes down to—no surprise here—money.
“Some of the smaller municipalities don’t have deep pockets to fund their projects,” says Karori. “They have to rely on federal and state agencies to fund their projects for them. That is a big driver of any water-treatment project. If the government funding comes in, it’s full steam ahead, let’s implement the job. If that funding isn’t there, though, it becomes more difficult for many municipalities to make changes in their treatment technologies.”
But Karori says that those municipalities that do experiment, and those that are willing to spend the upfront dollars necessary to invest in new technologies, will benefit in the long-run.
As an example of a utility that is receiving benefits from experimentation, Karori points to a project in California that he refers to as the future of water treatment. If all goes according to plan, this project will remove nitrates from the municipality’s drinking water without generating the costly waste streams that other treatment methods leave behind, he says.
In January, AdEdge was awarded a biottta—the company’s name for a biologically tailored two-stage treatment approach—nitrate removal project with the city of Delano, CA.
The city, with about 38,000 residents, sits in the San Joaquin Valley, about 30 miles north of Bakersfield. Like many municipalities, Delano is struggling to hit nitrate levels that are compliant with the California drinking water standard of 45 mg/L nitrate as NO3.
AdEdge’s biottta treatment uses natural bacteria to eliminate contaminants from groundwater. The treatment does not create the waste streams that result from ion exchange and reverse osmosis applications, says Karori.
In this project, which was still in the early planning stages as of the writing of this story, AdEdge will design and manufacture a treatment package rated for a maximum flow of 1 million gallons per day. A vertical pressure vessel will act as a bioreactor, while a second vertical pressure vessel will serve as the biofilter.
Karori says that he hopes this project will prove to other utilities that using biological treatment methods is an effective and affordable option. There is still some resistance among municipalities in using biological treatment methods, he says.
“There is still a perception that biological treatments and microbes are not acceptable,” says Karori. “But projects like this will show people that biological treatments are not only acceptable, but preferable. This project is the first in the country of its scale and technology. This is a noteworthy project.”
Other Natural Approaches
Ozonia North America, based in Leonia, NJ, is also providing alternative water treatment methods to utilities, something the company has done for more than 50 years. Ozonia specializes in ozone, ultraviolet, and advanced oxidation process (AOP) technologies, offering these treatment methods to municipalities that want to reduce the solids and pollutants in their water supplies without having to overdose these supplies with chemicals.
Of these treatment methods, AOP systems are designed for the most serious of water-treatment issues. Such systems combine three treatment technologies—ozone, ultraviolet and hydrogen peroxide—to form hydroxyl radicals. These radicals then work to eliminate organic pollutants from a utility’s water supply.
The hydroxyl radicals force the oxidation of most organic compounds until these compounds are fully mineralized as carbon dioxide and water. Ozonia says that hydroxyl radicals have higher oxidation potentials than do ozone or hydrogen peroxide. They also react at least 1 million times faster than these other treatment methods.
Christopher Huynh, senior market manager with Ozonia North America, says that municipalities today are more willing to invest in methods such as AOP to remove organic pollutants and disinfection byproducts from their water supplies.
“The market is definitely moving toward lowering disinfection byproducts,” says Huynh. “That has become very prevalent here in the United States. The market is changing from chemical-based disinfectants to non-chemical-based methods like ozone and ultraviolet. This is more of a driver in developed countries than in emerging ones, but there are also some emerging markets, like China, that use ozone and ultraviolet extensively.”
Huynh says that there are many reasons for this market shift away from chemical products and toward more natural solutions.
First, many utilities are striving to become more environmentally friendly. Others are worried about meeting stricter water regulations. Still others are working to hit more stringent restrictions on the levels of total suspended and dissolved solids that are now acceptable in both their drinking water and the waste effluent that they are discharging into bodies of water.
As Huynh says, utilities need more advanced technology to hit these new limits. “In the past, a low dose of chlorine was the solution used by the main part of the market,” he says. “People in most municipalities used chlorine 50 years ago for the bulk of their treatment needs. That is now changing. More are now switching to more advanced technology to hit these lower limits.”
Utilities’ increasing focus on ridding their water supplies of pollutants is an especially important driver of the rise of ozone and other more natural water-treatment methods, says Huynh.
Ozonia is headquartered in Switzerland, where there has long been a movement for treatment methods that rely less on chemicals, says Huynh. Ozone has long been a key part of water-treatment methods in the country because it is so effective in eliminating pollutants.
No one treatment method will work with every utility, says Huynh. That’s why most manufacturers today offer utilities a choice from several different treatment types. Ozonia, for example, offers traditional ozone treatment, of course. But the company also gives utilities the option of using an ozone-plus-peroxide or ozone-plus-ultraviolet combination to remove pollutants.
Huynh says that ozone is a simple treatment process for utilities to use, and that, in addition to its effectiveness, is its main selling point. Ozone treatments need only electricity to work.
If these treatment methods are environmentally friendly, effective, and efficient, what is preventing even more utilities from embracing ozone, ultraviolet, and other non-chemical treatments? Huynh, like Karori, pointed to budget woes.
“This is a very cost-driven market,” he says. “Municipalities that focus on cost will look at the capital costs of a chlorine solution versus ozone or an ultraviolet solution. The upfront costs for chlorine are lower. What they might not know, though, is that over time the entire lifecycle costs of ultraviolet or ozone are less expensive. The upkeep required for chlorine treatments is higher when you look at the longer-term.”
Huynh, though, says that he expects more municipalities to accept ozone and other alternative water treatments as they see how successful they are in other installations across the country.
“It can take a long time for municipalities to accept a new technology,” he adds. “But once we show them the background data, they are far more open.”
Tackling the Infrastructure
Dane Madsen, chief executive officer of Las Vegas-based Blue Earth Labs, takes a different approach to treating drinking water and wastewater. Two of the company’s products—Clearitas and Floran—remove the naturally occurring organic and inorganic deposits that encourage municipalities to use too much chlorine. Using too much chlorine leads to disinfection byproducts.
But Blue Earth Labs’ products don’t treat water. Instead, they treat the infrastructure through which drinking and wastewater travel. By using Blue Earth Labs’ products to clean their water utility’s filters or to keep biofilm from adhering to the insides of their water tanks, municipal officials are taking an important step to providing clean water, says Madsen.
When filters and tanks are clean, they operate more efficiently. They can then do a better job of making sure that water supplies are free of pollutants and other solids, he explains.
Madsen says that too many water officials overlook the importance of maintaining their infrastructure, something that they should consider an essential part of the water-treatment process. “Infrastructure problems have been ignored for years by utilities,” says Madsen. “No one gets re-elected by saying that the pipes are good and that the water is great. They get re-elected by building a new park or parking lots. Politicians are controlling the utilities in many places. They often don’t have a good handle on what the struggle is about.”
This extends to paying for repairs or maintenance. He says that politicians often lack the political will to raise water rates as a way of paying for pipe and infrastructure maintenance or repair.
That’s why it’s important for utility officials to do what they can to lengthen the lifespans of their existing water infrastructure, says Madsen.
“Every time we come over the Grand Canyon when flying into Vegas, you can see that there is nothing more powerful than what water can do,” he states. “As water attacks infrastructure, it starts tearing it apart. Our basic thought is that if you clean the infrastructure you have fewer problems with it.”
Clean pipes, filters that aren’t clogged and tanks that are free of biofilm are a key to effectively treating both drinking and wastewater, says Madsen.
“It’s pretty basic for us: If you clean the infrastructure, it lasts longer, and you have fewer problems,” he explains. “You don’t have the biofilms growing in the pipes that provide a harbor for bacteria both pathogenic and non-pathogenic. My dad and grandfather always drilled it into me about changing the oil in your car. Oil is cheaper than metal. But municipalities are not big on cleaning their infrastructure. They are big on having to replace it.”
Because of the work it does, water infrastructure degrades on a consistent basis, adds Madsen. Filters, as they do their jobs, accumulate solids and organics. Over time, this degrades the performance of these filters. Utility officials often try to solve the problem by replacing the sand and anthracite of their filtering system.
This is an expensive solution, though. He estimates that it costs utilities about $50 a foot to replace these components, when you factor in costs such as labor, freight, and disposal. Some filters can cover 30 cubic feet.
“That is real money,” he says.
Utilities that use filter-cleaning products to keep organics and solids from accumulating on their filters, though, can lengthen the working life of their filters. They can also put off as long as possible the need for a costly replacement of sand and anthracite, says Madsen.
Water tanks are another area of concern for utilities, he continues. These, too, steadily attract organic matter. Water flows into the tanks, organics fall out, and biofilm propagates.
Madsen describes tanks as acting like large petri dishes: When a summer day hits 90°F, the biofilm in these petri dishes grows rapidly. When municipalities send chlorine through their water, it, too, enters tanks, where it interacts with the organics already in them. This results in disinfection byproducts in the tanks.
“The disinfection byproduct in a tank can be pretty scary, especially with tanks that were designed 40 or 50 years ago,” says Madsen. “Back then, we didn’t understand what a disinfection byproduct was.”
Again, municipalities can protect their tanks and their water supply by using products to eat away at the biofilm on the surface of water tanks.
Madsen says that his company’s products attack the layers of biofilm that can gunk up a water tank. This then allows municipalities to use smaller amounts of chlorine to finish off the biofilm.
“You put less chlorine in, it reduces the disinfection byproducts that you get,” he says. “We’d love to say that our products destroy disinfection byproducts. But, no, we just remove the cause of them. That’s pretty important, too, though.”
Madsen says that about 100 utilities use his company’s products every day. This is more evidence that a growing number of utility managers are focusing on alternatives to treating their water supplies. They are no longer simply dumping ever-greater amounts of chlorine into their systems.
The Importance of Monitoring
Greg Manning, water account manager in the process instrumentation department of Springhouse, PA-based Siemens Industry Inc., sees the trend, too: Municipalities and the utilities serving them are becoming ever more focused on removing pollutants from their drinking water, reducing the amount of chlorine they use to treat their water supplies, and making sure that their treatment facilities are operating as efficiently as possible.
Utility managers have long been concerned with water treatment, of course. They are tasked with maintaining a clean water supply, and residents aren’t shy about complaining when they notice an odd odor or flavor in their drinking water.
But Manning says that the focus of these officials has shifted. Today, a growing number of utility managers are taking a holistic approach to water treatment.
They’re also spending more time on monitoring and analyzing water as it moves through their drinking or waste treatment systems as part of an overall treatment process, he says.
Siemens Industry can help with the monitoring part of the water delivery and treatment process. Siemens Industry manufactures and sells the instrumentation that municipalities can use to gain more information about the flow of water into their systems, the levels of water in certain tanks, and the pressure or temperature throughout their treatment processes. Siemens Industry sells a range of sensors to original equipment manufacturers that serve the municipal water industry.
Manning says that municipalities are willing to look at a variety of treatment methods because customers today demand it. There’s also the financial aspect. Municipalities and utilities aren’t immune to tighter budgets. They’re also not immune to understaffing, with many utilities requiring individual staffers, thanks to cuts, to take on more work than in the past.
By getting creative with water treatment, utilities and municipalities can reduce their operating costs at a time when cost reductions are more important.
“Utilities are becoming more ingenious about what they need to do,” says Manning. “It’s no longer just about throwing more chemicals at a problem. Now they are relying on biological phosphorous removal. They are getting the right bugs to eat the right bugs. They are looking at nitrification and denitrification. They are no longer trying to evaporate it off, or throwing more chlorine at something. They are looking at new solutions.”
He says that municipalities today are under a microscope when it comes to their water. And this isn’t the case only for drinking water. Municipalities must hit more stringent limits for the treated wastewater that they are discharging into rivers, streams, and lakes.
“Municipalities’ understanding of the entire water system is becoming greater and greater,” says Manning.
He points to the small communities in Minnesota about one hour and 30 minutes outside of Minneapolis. Many of these small towns rely heavily on irrigation ditches to treat their wastewater.
This works for these towns when they’re small, when they’re not home to factories or much industry, says Manning. But once this changes, once these towns grow, they need to take a more proactive approach to treating wastewater.
“You put in some factories, and letting water purify itself by evaporating out of ditches or by seeping into the ground isn’t as attractive anymore,” he says. “Municipalities have always been aware of the limits they have to hit when it comes to their treated water. The big change now, though, is that they are becoming more aware of the entire ecosystem, of how their actions impact everything else.
