Algae is no friend to Dave Kessinger.
Kessinger is general foreman of the plumbing department at Hollywood Park racetrack in Inglewood, CA. Part of his job—a major part, actually—involves keeping the 19 million gallons of water in an onsite lake free from algae.
Guests at the track want to see clear water, not a lake turned green from an overabundance of algae. Eliminating the lake has never been an option; track officials use the water in it—which is drained into the lake after being used it to wash down the horses and then treated at a small onsite wastewater treatment plant—to irrigate the track, infield and infield grass.
Reducing the algae content, then, is the only solution.
“That water is important because the turf track is so important to our business,” Kessinger says. “Without a healthy turf track, no one wants to come back to our park. The horses don’t want to run here. So we need that clean water to irrigate.”
Kessinger relies on a host of weapons to control the algae in the lake. He installed three aerators to keep the waters of the lake moving, making it more difficult for algae to thrive and reproduce. He applies a shading chemical to prevent the rays of the sun from heating the water and providing the perfect home for quick-growing algae. And he relies on natural microbes to eat away at the nutrients necessary for algae to take hold.
It may seem as though Kessinger is spending a lot of time and money on battling algae. But such an investment is a wise one; keeping algae away is good for business.
And Kessinger is far from alone. Water-treatment officials have a greater-than-ever variety of tools to use in their fight against algae.
Everything from chemicals to microbes and from aerators to devices that emit high-decibel sound waves are helping professionals keep lakes and ponds at housing subdivisions, business parks, and municipal facilities free of algae.
With the right tools or, most often, a combination of them, controlling algae has become an easier process.
A Typical Day
Shane Brown faced a busy day. The owner of Oak Grove, MO–based Clear Water would stop by six residential ponds before lunchtime, all to make sure algae didn’t take over at any of them.
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| Left untreated, algae can completely take over a pond. |
Brown’s first stop was in his hometown of Oak Grove, where he needed to change a light bulb in a surface aerator manufactured by Air-O-Lator Corp., of Kansas City, MO. He would then travel to the nearby city of Lone Jack, where he would spray five ponds in a housing subdivision using Cutrine Plus, an algaecide manufactured by Applied Biochemists that controls existing algae and inhibits the plants’ ability to reproduce.
This is a typical morning for Brown, who spends much of his time from April through September battling algae in the lakes and ponds that provide decoration and drainage for area housing subdivisions.
“Because I work with home associations, the main thing my clients want from me is aesthetic value,” Brown says before heading off to his first appointment. “Conservationists will say that ideally you should have about 10%–20% vegetation in a pond, including algae. When you’re being contracted out for aesthetic value, though, you want even more out of there.”
Most times, Brown is dealing with filamentous algae. This is the algae that most commonly becomes a problem in ponds, forming long strands that float together in thick mats. When left untreated, filamentous algae can completely cover a pond. This, of course, won’t do in a housing subdivision.
Less frequently, Brown is called upon to control a thriving population of planktonic algae. These free-floating plants gather in the top few feet of water, where the light is bright enough to spur their growth. Planktonic algae is usually made up of green algae, blue-green algae, diatoms, and euglenoids.
Brown figures he’ll always have business. He’s run Clear Water for more than 12 years, and never during this period have customers not worried about the algae that clogs their lakes and ponds. Things have changed, though. Officials with the housing subdivisions surrounding him are advertising their onsite amenities in an effort to attract buyers to their homes. Boasting of clean lakes or ponds is fine, but not if they’re filled with unappealing filamentous algae.
“It’s always been the same concern,” Brown notes. “The biggest change is that I’m getting more commercial accounts as opposed to individuals. More home associations are coming in. If you have 200–300 homes, a park, and a four- or five-acre lake, there seems to be more money available to maintain a pond like that, spread out between 200 people.”
Brown also works with homeowners, and he tries to educate them as much as possible about the way in which chemicals and aerators work to combat algae. Too often, he says, homeowners who try to treat algae on their own make the problem worse.
“The biggest problem I see with homeowners is that they don’t first identify the species of plant,” Brown explains. “They dump in the wrong chemical, and it doesn’t do anything. That’s the most important thing in aquatic-plant management: What species of plant are you dealing with? Not all algae is the same.”
A Day At The Races
Officials at Hollywood Park are well aware of how important it is to use recycled water to irrigate their track and infield. Water is a precious resource, after all, in California. Using recycled water is one way to protect that resource.
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| By keeping water moving, aeration makes itmore difficult for algae to take hold. |
The problem was, the track’s 19-million-gallon lake often became infested with filamentous algae, which at times nearly covered its entire surface. This, of course, was unappealing to the track’s visitors.
When Kessinger started working at the track, algae had taken over the lake. The water, he says, was “filled with nasty stuff.” His hand would disappear when he held it under the surface. He’d wiggle his fingers and not see a thing.
Kessinger needed to do something. He researched different methods of eliminating and controlling algae and decided his lake needed aeration. By keeping water moving and pushing oxygen into it, aeration makes it more difficult for algae to take hold. It’s an alternative to chemicals, which can be pricey and harsh.
Kessinger purchased and installed three 3-hp AIRE-O2 aspirator aerators from Aeration Industries International in Chaska, MN. Aspirator aerators have a propeller that revolves below the surface of the water, pulling air from the atmosphere down a supply tube. The air then mixes with the water around it, preventing algae from forming or reproducing.
Kessinger saw immediate results from the machines. Within a month, the ponds had cleared.
“I can see my hand 3 inches below the surface now,” he says. “Now we can see the bottom of the lake. Before, you could never see anything. It was all just green.”
Kessinger doesn’t rely solely on his aerators. He also applies Aquashade, an aquatic dye manufactured by Applied Biochemists. The yellow and blue dyes in the product work together to block specific light rays that spur photosynthesis. He also relies on natural microbes, which eat the nutrients on which algae thrives.
The combination of all three keeps the lake clear.
“Everything seems to work well together,” Kessinger says. “It was really a process to get to this point. We were first looking at chemicals but decided that would be too expensive. The combination we have now is working well.”
The approach taken by Kessinger and Brown is far from unusual. Those battling algae are more often than not relying on a multifaceted approach to keep the planktonic and filamentous versions out of their bodies of water.
More Options
William Randall isn’t surprised that professionals such as Kessinger and Brown are taking this approach. Municipalities, housing associations, and businesses have more incentives to keep their bodies of water free from pollution, including algae.
Permit regulations contained in the National Pollutant Discharge Elimination System force the owners of lakes and ponds to contain the amount of suspended soils in these bodies of water, explains Randall, vice president of technical sales for Aeration Industries, a manufacturer of aerators and affiliated products. He says algae and duckweed are big contributors to the problem of suspended soils, noting that it makes sense for owners, mindful of the possibility of heavy fines for violating the federal regulations, to take the necessary steps to eliminate or control the aquatic plants.
At the same time, many owners are installing aerators in holding ponds, using the water filling them to spray-irrigate everything from golf courses to fields, Randall says. Too much algae in these ponds can cause serious problems, especially if the blooms plug the nozzles of the irrigation sprayers.
Finally, a growing number of municipal officials and private business owners are aware of the value and economic benefits of using recycled water for irrigating golf courses and agricultural lands, Randall points out. Recycled water, though, must be stored, and those maintaining the lakes and ponds holding it are constantly working to control their algae populations.
It’s all added up to one thing for Randall and his peers who specialize in controlling algae and aquatic plants: more business.
“We really are seeing an increase in the demand for our equipment,” Randall says. “Algae, it seems, is becoming more and more of a prevalent problem. There seems to be an increase in the nutrients that feed it. We’re seeing more phosphorous and nitrogen runoff both from point-source and nonpoint-source pollutants.”
Aeration is one of several ways to control the resulting algae. Aerators create an artificial water flow, much like what happens in nature with streams or moving bodies of water. Aeration is especially effective in combating filamentous algae. This type of algae can’t reproduce in moving water. It needs stagnant water.
Aeration, though, is useless against certain types of algae. Unicellular blue-green algae, for instance, is distributed evenly through the water column and are free swimmers. Mixing or aeration does not help control this species. In fact, aeration does more harm than good, enhancing this species’ ability to absorb nutrients.
“That’s why it is so important to identify up front what type of algae you are dealing with,” Randall says.
Aeration also is effective against a problem seen in many ponds dealing with algae issues: an overabundance of duckweed.
This aquatic plant can prove relentless, and it is often found choking wastewater lagoons. Duckweed does not thrive in moving water, however, preferring to take hold in stagnant ponds.
There are basically three types of aerators that officials can choose from to combat algae. Diffused-air versions create a moving stream of water from a compressor or a blower that pushes air from the atmosphere through a hose. Aspirated aerators, as already mentioned, rely on a propeller revolving below the water surface. Surface-sprayed aerators, also known as floating or fountain aerators, use a propeller located close to the surface and propel water into the air. This transfers oxygen to the main body of water.
Doug Cramer, chief executive officer of Air-O-Lator Corp., knows aeration and its potential impact on algae. He also knows that while one aerator may be perfect for a homeowners association, a different version might work better for a municipality trying to control the spread of algae in its wastewater lagoon.
In a paper he wrote earlier this year, Cramer outlined the benefits and negatives of the different types of aerators. Diffused-air systems, for example, are rarely practical for ponds because diffusers need 10–25 feet of water depth to allow for a large enough bubble of air to provide a maximum amount of oxygen, Cramer writes. These products are also noisy and may not be the ideal solution for a housing subdivision.
Cramer says aspirating systems are efficient but that they have some limitations. For example, they have a limited ability to provide oxygen-enriched water much deeper than 3 to 4 feet below the surface of lakes or ponds because of the increased pressure caused by the weight of the water against the discharge outlet. This can be alleviated if the aerator comes with some kind of mechanical means, such as a blower, to augment the discharge outlet.
According to Cramer, floating sprayers provide two benefits: They are efficient and they are decorative. However, they are only effective aerators if they are pumping a high enough volume of water into the atmosphere. Floating sprayers that do not pump a large enough volume into the air will have no appreciable or even measurable amount of aeration in a lake or pond, Cramer writes.
Aqua Control, based in Spring Valley, IL, provides several floating display aerators offering both aesthetic and practical benefits.
The company’s Arch, for example, is a display aerator that produces eight heavy and high-arching streams. The Arum features a heavy vertical stream surrounded by 12 low-arching streams that travel about one-third the height of the center stream. The company also manufactures the Torrent, an aerator not intended for display but simply built to aerate water. This machine creates a high-volume white boil of highly aerated water.
Renna Pelszynski, Aqua Control’s general manager, says the display aerators are a good option for residential homeowners, condominium associations, and other clients who need not only clean, clear water but also aerators that provide some visual bang.
“The fountains look pretty, but the aerators benefit the ponds,” Pelszynski says. “It helps reduce the algae. It does not get rid of it the entire way. But that’s the difference between us and someone who provides display fountains. The fountains are there just for looks. Our
display aerators also aerate the water.”
Other Options
Municipal officials, homeowners, and homeowners associations can choose other methods than aeration to combat algae.
SonicSolutions, for instance, in West Hatfield, MA, creates an algae-control device that floats just below the surface of ponds or pools and emits an ultrasonic wave that disrupts the cell walls of algae. The device works 24 hours a day, is environmentally safe, and requires little maintenance.
Best of all, it requires no chemicals.
“We see a wide range of people using this,” says Joann Sanborn, who handles sales for SonicSolutions. “We have everything from golf-course ponds to stormwater and fire ponds to surface-water reservoirs and wastewater lagoons. Almost any water site where you have some retention time and have algae growing, our system would work.”
Sanborn points to state and federal regulatory bodies as inspiring municipalities and housing officials to look toward alternatives to chemicals.
“Regulatory folks are requiring people to exercise more caution on chemicals and how much can be used on these sites,” Sanborn says. “They are limiting the amount of chemicals that can be used to treat these sites. The chemicals can flow into your groundwater, and you don’t want that.”
Sanborn also says that algae is becoming a more frequent nemesis.
“For some reason, and I don’t know why, my perception is that water sites are having significantly increased problems with controlling algae today than they did just five years ago,” she notes. “That’s my perception and I could be 100% wrong, but it seems to me that people are having all sorts of troubles trying to control algae that they didn’t have in the past.”
Water-treatment pros can also look to Norwalk, CT-based SolarBee. Its solar-powered water circulator pumps water from a fixed depth just above the thermocline and distributes it across the lake surface while providing turbulence and aeration. This action allows the good algae and microbes to outcompete the harmful blue-green algae for dominance of the lake. The good algae and microbes are then eaten by zooplankton. The results are clear water, a vigorous food chain, and plenty of oxygen within the lake. It can draw water from more than 100 feet or as little as 1½ feet below the surface, and can also be installed in water depths as shallow as 3 feet.
There are other options, too, including Aquashade, which uses dye to prevent sunlight from heating up lakes and ponds, and natural microbes that eat the nutrients on which algae survives.
A Full Toolbox
Nels Lindgren, director of grounds for the Loch Lloyd Country Club in Loch Lloyd, MO, knows enough about algae to know that he can’t beat it by relying on just one product.
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| Aspirator aerators draw air from the atmosphere down a supply tube. |
Lindgren uses biological compounds, bacteria that eat the nutrient load on the bottoms of the country club’s lakes and ponds. But those alone are not 100% effective. Lindgren also uses aerators from Air-O-Lator Corp. to supplement his use of biologicals.
“Algae is tough,” Lindgren says. “There is not any one thing that is going to take care of everything. You have to use multiple methods that work together to create a clean lake.”
Lindgren also uses Aquashade, taking a true combination approach to keeping his water bodies clear.
By now, Lindgren’s algae battle plan is second nature. He turns his aerators on early in the season, as soon as he sees his first algae blooms. This helps, but it doesn’t completely erase the problem. Lindgren then applies Lake Relief, a biological compound sold by the Denmark-based Novozymes. To finish the process, Lindgren adds his Aquashade dye to the course’s lakes and ponds.
“It is something you have to keep on top of,” Lindgren says. “As lakes get older, more of a nutrient load builds up in them. You kill the algae and it falls to the bottom and becomes new nutrient that feeds the beast again. But like anything else, the earlier you start on it, the better it works.”
Dan Rafter is a technical writer based in Chesterton, IN.
OW - September/October 2006 |
