By Darrell Corkal, PFRA, Saskatoon; Rob May, PFRA, Watrous; and Larry Eggleton, ADD Board 37
When rural residents are confronted with using dugout water for domestic purposes, they can be faced with a water source two to five times worse than Buffalo Pound Lake or the South Saskatchewan River.Considering that cities such as Regina and Saskatoon have elaborate water treatment plants with highly trained technicians, chemists and engineers, what are rural residents supposed to do with dugout water once it comes into the house? Even costly in-home systems still do not seem able to remove the slough-like smell and yellow colour of dugout water. ADD Board 37 and researchers are hoping to address some of these issues by comparing a number of treatment systems. The Water Treatment Demonstration Trailer is a joint project between the ADD Board, PFRA and the Saskatchewan Research Council. Funded by the Canada-Saskatchewan Agriculture Green Plan, PFRA and SRC, the trailer has four different treatment systems for dugout surface water.
The trailer is being moved to several sites within ADD Board 37. To date, it has been set up on three different dugouts.
The treatment systems inside the trailer use a number of different processes to improve water quality. Sand filtration, granular activated carbon filtration, biologically-assisted carbon filtration, nanofiltration and reverse osmosis membranes are all being analyzed in their ability to treat dugout water to a level safe for drinking.
Dugout water has very high levels of nutrients and organic matter, which is not surprising. Animal waste, fertilizer, grasses, crops and even soil contribute to the organic load, and dugouts act as a trap for these nutrients, which settle in the dugout and become concentrated over the years.
When water high in organics is chlorinated, carcinogenic disinfection by-products are created. If the levels are high, they can exceed the limits recommended for drinking water. It is recognized, however, that chlorine disinfection is the most common means of disinfection, and disinfection is necessary for all surface water treatment systems to protect the user from bacteria, viruses and parasites.
The water treatment trailer will help us understand some limitations of the treatment systems studied. Promising results have been seen with membrane filters, such as a nanofilter or a biological treatment process, that literally biodegrade the organics in the filter. Common in-home systems using sand filtration and carbon filtration would be improved if the carbon is regularly replaced.
Anyone hoping for high quality water for washing or drinking from a poor surface water source will have to consider the costs. Effective treatment trains can cost as much as $5,000 to $7,000, and will require regular operation and maintenance procedures that cannot be neglected without the system failing.
Should anyone have questions regarding this project, or for a tour of the trailer, please call Larry Eggleton, Raymore (ADD Board 37) at 524-4436 or Rob May, Watrous (PFRA) at 946-3303.