Nature plays a major role in one Saskatchewan village’s waste water management system.
Vonda treats its waste water with two cells plus a man-made wetland, all of which are heavily populated with bulrushes and cattails, says mayor Dan Sembalerus.
Sembalerus, who was born and raised in this small community northeast of Saskatoon, said he recalls the debate surrounding expansion of the sewage treatment system in 1983.
“I remember when they were deciding what to do. There was a lot of argument at the time about the cost and whether we need to expand the treatment system,” he said.
“But it’s been functioning as planned since 1983 without a glitch. It’s turned out to be quite a boon to the town.”
Vonda had built a small, single cell facility in the 1960s, but 20 years later it couldn’t handle the volume as the population increased. Engineers said a second cell would not only increase the overall liquid capacity but would help make the effluent cleaner. As well, a third larger overflow wetland would ensure that the local environment was protected and that the water would be pristine.
After some debate at the local level, the village entered into a cost-sharing agreement with Ducks Unlimited in 1983 for the construction of shallow retention basin. This man-made wetland was created by building a dike on sloping land near the primary treatment facilities and would serve as an overflow for the second cell if needed.
The original design allows for the occasional release of water in periods of high runoff, but Sembalerus said this has never been necessary because the wetland has proven to have enough capacity.
“The Ducks wetland project functions as a third cell for us,” he said.
“The two main cells are located fairly close to town. This Ducks wetland receives water from our second treatment cell through an underground pipe. There had been some concern in past years about the quality of water in that third wetland, so we’ve had it tested many times.
“You could literally drink that water from the third wetland with no harm to yourself. I wouldn’t want to, but I could if I wanted.”
He said the heavy population of cattails and bulrushes in all three cells absorbs phosphates and nitrates in the waste water.
Sembalerus said the past few years have been wet, and the village has had to drain off the first two cells more often than its management plan allows.
“But when the effluent leaves the second cell and flows into the Ducks’ wetland, it’s pretty well 95 percent good to go anyway.”
“There’s been no harm to wildlife, and this wetland has given us a third filter before any water is ever released into the environment. But even in the wettest years, we’ve had no concern about the third cell wetland overflowing. It wasn’t even close. The wetland has a huge capacity.”
He said the plan calls for overflow to run by gravity into Buffer Lake, a low-lying salt lake into which the entire area drains naturally, if the wetland ever does reach capacity.
The system has been trouble-free, requiring no changes or modifications, he added.
“It really has been a sewage treatment system we don’t have to think about. Most people in town don’t know where it is. In fact, most people in town don’t even know anymore that it exists.”
Ducks Unlimited provided cost-sharing deals for Saskatchewan communities such as Vonda, Prud’Home and Humboldt and others, building wetlands that create duck nesting habitat in conjunction with wastewater treatment systems.
Sembalerus said Lakshman Lakshman, a scientist at the Saskatchewan Research Council in the 1970s, did much of the research into the use of bulrushes and cattails.
His studies proved that aquatic plants have the capacity to extract nitrates and phosphorous from water.
That same conclusion has been reached hundreds of times around the globe in recent decades and put into practice in thousands of sewage treatment projects.
Researchers at the leading edge of waste water treatment technology say the North American livestock industry is lagging far behind the rest of the world in putting this natural treatment method to work.