Wind-powered air system “oxygenates” water, overcoming dilemmas of stagnation and stratification that threaten people, livestock, wildlife and property values.
Still waters may not always run deep; sometimes they just go bad. Just ask anyone who has watched his pond turn into a dark, ugly odorous mass of weeds and algae.
Problems of stagnation, stratification and harmful biologicals are creating toxic water conditions in ponds and other non-free-flowing waters that are perilous to livestock, fish and other wildlife – not to mention humans. In addition, the odors and other negative ecological conditions from unhealthy water can severely undermine residential and commercial property values.
Yet, as discouraging as it is to see a pond or lake go toxic, it is encouraging that many of those who own, manage or maintain them for agricultural, recreational or household use are restoring their water to health again by installing a relatively low-cost technology – the windmill-driven aeration system.
“If you have a sick pond or dugout, you know how frustrating and expensive it is to try to treat your way out of the problem,” says Terry Miller, who owns a farm in Batavia, NY. “I got to the point where I was so tired of pouring in chemicals and raking algae that I wanted to fill in my pond and forget about it.”
Fortunately for Miller, after years of stopgap solutions that were costly and time consuming yet only vaguely effective, he began to look at aeration rather than chemicals as for a resolution to his water problems.
Also, not only are chemical treatments such as copper sulfate expensive, but research shows that ponds treated with it over years begin to show diminished results. Further, this treatment method may be eliminated by stricter environmental rules governing its use.
Inducing oxygen through circulation
Two years ago Miller started to investigate the prospects of using aeration to oxygenate his dugout while also inducing circulation in order to avoid thermal stratification of the water as well as prevent stagnation.
Miller paid special attention to a technology that employed a windmill to compress air and pump it through one or more diffusers, which were located at the bottom of a lake or pond. The action of the air permeating the water circulating at the bottom and bubbling to the top would cause the water to flow outward to the sides of the pond on top, thereby aerating through exposure to the atmosphere. As the circulation continued, the water would become more oxygenated, thermal stratification would be reduced, and the pond would become healthier. The aeration acts as a natural filtration system, burning off excess nutrients and organic matter that facilitates the growth of algae and weeds. Clean, clear water also prevents odors and pests and inhibits the spread and growth of mosquito larvae that may be floating on a pond’s surface.
“I don’t think anyone disagrees that aeration is highly beneficial to non free-flowing waters,” Miller says. “It is really a question of which technology is best for your application. In my case, since my pond had virtually become a cesspool, I figured that I needed some wind power to generate the amount of aeration necessary to clean up my dugout.”
While electric-powered aeration systems would no doubt do the job, Miller decided their operating and maintenance costs would be too expensive for him. Exploring the Internet he came upon the web site of Superior Windmill, which looked promising. He learned that farmers in the western states use this wind-driven aeration and circulation system to keep ponds clean so it is safe for cattle to drink from them.
“You don’t have to use any power to run them,” Miller says “Plus they are maintenance free.”
It turned out that Superior Windmill, headquartered in Regina (Saskatchewan), was a world leading developer of windmill aeration technology as well as a supplier of windmill and diffuser systems.
No more toxic BGAs
Gene Pavelich and his wife Glenn, who operate a mixed farm and ranch as well as a Bed & Breakfast at Kenaston, Saskatchewan (about 50 miles south of Saskatoon), had a dugout with problems similar to Miller’s. Only those problems were exacerbated by occasional droughts and the bane of many lakes and ponds – blue-green algae (BGA) blooms. BGA is often toxic enough to kill fish and also threaten stock and wildlife, not to mention those who use the water for household purposes.
Pavelich had discovered the benefits of windmill aeration years ago after installing an eight-foot high model to circulate a dugout he had excavated in the late 1980s. That windmill and related aeration accessories had performed well for years until tall trees grew up around the water’s edge, shielding the wind from the windmill blades.
As a result, the dugout became stagnant and suffered from onslaughts of toxic BGA (cyanobacteria), which almost completely covered the 180-ft. long by 60 ft. wide pond and caused noticeable discoloration of the water as well as a putrid odor.
Pavelich installed the dugout to irrigate his orchards and vegetable gardens and water his cattle during dry summer months, and the BGA gave him grave concerns about endangering the health of his cows.
“Last summer we installed a new Superior windmill and aeration system,” Pavelich says. “This one is 20 ft. tall, so it is able to catch a lot more air flow than the original windmill. The diffuser technology has also improved, and is much more efficient. Although the system accommodates two diffusers I only utilized one. A bypass valve will allow the use of one diffuser plus a water pump, which I plan to add in 2007.”
Pavelich says there were significant improvements in the color and odor of the water within three or four days of installing the new system. Within a couple of weeks there was no noticeable odor or discoloration.
“Even with only one diffuser, the water was suddenly in very good condition,” he says. “We had had fish in the dugout (pond) in years past, and the water is so healthy now that we may stock some fish again. But without the windmill aeration system, we wouldn’t be able to use the water at all.”
Pavelich says that this summer he also plans to use the windmill’s power as an off-the-grid means of pumping water to a trough for his cattle.
Getting a free ride from the wind
The Superior Windmill air compressor is a direct drive design from the turbine to the diaphragm assembly. Sealed ball bearings are installed in a heavy-duty crankshaft and connecting rods to provide reliability, smooth running and low maintenance.
Airflow is produced using molded rubber diaphragms. Air is drawn in on the down stroke via three intake valves on each diaphragm assembly. On the upstroke the compressed air is passed out the exhaust valve to the air hose via the pivot post to the 1/2″ hose going to the pond.
The air is released into the pond through an optional rubber membrane diffuser that creates a fine bubbling action in the water. The diffuser is equipped with an internal check valve to eliminate water from entering the hose when the turbine is not operating in low wind conditions.
“You can clearly see the action of the diffuser in the water,” Pavlovich says. “The water above it is full of air bubbles and the circulation is enough to make the water appear to be boiling.”
Terry Miller notes that after installing his windmill aeration system he realizes there are many applications that are well suited to the technology.
“I notice that golf courses are using them,” he says. “They may not require healthy water for livestock or wildlife, but golf courses typically want everything to be sparkling clean. And they don’t want the smell. Also, campgrounds are using them, too, for swimming and other recreation. I understand that some of these lakes and ponds have stopped pouring copper sulfate and other chemicals into them. So, the windmill aeration turns out to be a very timely solution for the environment. It’s free power, and it’s something that you can actually do right now.”
Superior Windmill, one of the world’s only manufacturers of Windmill Aeration Systems, offers models from 12 to 20 feet in height with hub and compressor preinstalled at the factory for ease of installation. Depending on the model selected, volumes of air flow produced range from 1.5 cfm @ 15 Kph (9 Mph) to 180 cfH or 3.0 cfm @ 15 Kph (9 Mph). Superior Windmill has warehouses in Canada and the U.S. and ships their units all over the world for surprisingly low shipping rates and innovative packaging.
For more information, contact:
Superior Windmill, Inc.
3426 Saskatchewan Drive
Regina, SK Canada S4T 1H1
Phone: toll free in North America 1-888-821-5533
Visit the web site: www.superiorwindmill.com
Source: Pond & Garden Lifestyle May/June & July/August 2008
About the Author
Ed Sullivan is a writer on technology based in Hermosa Beach, California