By GLENN GARNETT
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One of our proudest boasts as Canadians is that we possess the world’s largest supply of fresh water.
But unless your cottage is perched at the edge of a glacier on Baffin Island, the quality of your drinking water is something to worry about. Last year’s tragedy at Walkerton, Ont., in which seven died and hundreds more were made ill by dangerous levels of E. coli in the town’s drinking water, has brought the issue of safe drinking water to the forefront in this country.
For over 20 years now, Trojan Technologies has been developing water disinfection systems that employ ultra-violet (UV) light. While Trojan today specializes in industrial process water disinfection and treating municipal wastewater, with products at work in more than 25 countries around the world, the London, Ontario-based company first produced UV systems for the cottage market in the late ‘70s.
Bruce Lang, team leader, residential, commercial applications for Trojan, says this early select circle of satisfied customers clamoured for replacement lamps when the company’s original system was phased out in 1991 until this production, too, was halted in 1999. Today’s systems for cottages and homes are more refined and powerful, boasting more sophisticated features such as elapsed time metres and self-diagnostics.
The science behind UV treatment of water to fight bacteria, viruses, molds, algae and other microorganisms is fairly simple, says Lang. "If it has DNA, UV light will inactivate it," he says,. "Basically, UV affects bacteria and viruses by altering their DNA so they are not capable of reproduction. The way E. coli affects you is they get into your intestine and multiply. One E. coli in your large intestine, incapable of reproducing, does not affect you."
E.coli has become one of the world’s most dangerous strains of bacteria, infecting more than 80,000 people across the continent every year, most of them - like Walkerton - among the very young and old.
"E. coli, in fact, is very easy to kill with UV," says Lang, pointing out that with today’s technology, you can get a "five-log reduction" - that’s 99.999% - in living bacteria. That means if you had 100,000 bugs, only one would live to reproduce. Lang says in most situations of infection, you might get only five to ten in a sampling - you’d have to be very unlucky, indeed, to wash down the one that got away.
Some waterborne stuff, like blue-green algae, need a huge dose of UV to keep it in check. This usually isn’t a problem for cottagers, although UV systems are used by some to reduce the algae content in backyard ponds.
Over the past year a number of scientific studies on both sides of the border have dramatically demonstrated the effectiveness of UV in dealing with E. coli, cryptosporidium and giardia. The latter is better known to cottagers as "beaver fever". They breed in surface water and infection can greatly increase your reading time at the cottage (see our article on Composting Toilets in the Sept.-Oct. 2000 issue).
Ironically, while the results of these studies headlined medical journals last year, the tragedy of Walkerton was unfolding, leading to an unexpected and nearly overwhelming demand for Trojan’s UV products. Lang describes the period as "crazy" and says at one point delivery periods were backed up to three months.
While a UV system does a remarkable job, there are limits to what it can do. For starters, it does not change the taste or makeup of your water. A filtering system ,such as reverse osmosis (RO), will strain out stuff like salt, herbicides, gasoline and other crud that finds its way into your well or the water intake line off your dock.
Another factor in the effectiveness of UV is its ability to penetrate your water. If the water coming out of your faucet has the appearance of weak tea, you could have high concentration of tannin and that will absorb some of the UV light. That also goes for suspended solids and if that’s a problem with your water, a sediment filtration system is a must, upstream from your UV system. Carbon filtering is required to reduce undesired taste and odour.
UV is strictly for disinfection but in most situations, says Lang, that’s adequate. "It’s a good idea to use a UV system in conjunction with an RO system - but it doesn’t need to be.
"What we do is offer a service to customers to test their water to ensure the UV system is used properly," he says.
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The lamp life of the Trojan UV Max system is 9,000 hours - about one year. But if you’re a fair-weather cottager, the unit can be shut off and the lamp can last you into a second and possibly third year. UV Max systems are rated from 25-65 watts of energy (similar to a 60-watt light bulb), which reflects the maximum power at lamp start-up. Over time, the continuous energy consumption tends to be 75-80% of the rated power.
Prices for a Trojan UV system will vary, depending on where and how you buy. If you’re real handy, you can pick up a UV Max "C" product at Home Depot for around $400, while a Walkerton customer recently had an eight gallon per minute system installed, including a filter, for just under $800.
There is wisdom in getting a pro to do it, Lang suggests.
"If you get a local dealer, like Noel’s Plumbing in Bracebridge, to handle the job, they’re well informed about the conditions of lake and well water in the area and understand what they’re working with," Lang says. They’ll also be better able to suggest complementary filtering systems.
"Bottom line is, you can put a UV system in and have peace of mind for less than $1,000," he says.
For more information about Trojan’s UV systems, check out their website at www.trojanuvmax.com
