Dugouts and the Prairie Farm Rehabilitation Administration (PFRA)

by Glen Brandt and Kelly Fischer, PFRA, Regina, Saskatchewan

Dugouts designed to trap runoff have been a major source of drinking water for thousands of prairie farmers and small communities throughout this century. Prairie Farm Rehabilitation Administration (PFRA) has supported the construction of "dugouts" since 1935.

Since that time, dugout design has been standardized to include 1.5 to 1 side slopes, 4 to 1 end slopes, and optimum size and depth requirements. The slope was triggered by safety concerns and the size by the need to store more water.

In the past couple of years, PFRA has begun to re-evaluate dugout design and financial support criteria. A driving force be hind the re-evaluation are concerns about water quality and conservation.

To better understand the magnitude of water quality and treatment problems inherent to small surface water reservoirs and farm dugouts, PFRA, the Saskatchewan Research Council (SRC), Napier University (Edinburgh, Scotland), and the Faculty of Medicine at the University of Alberta, have initiated a study to focus on these concerns. This work has now entered into its second year and the researchers have found:

• Runoff from the surrounding farm land and the growth of algae and weeds in the dugouts are the main contributors to the high levels of dissolved organics. High evaporation rates concentrate the dissolved organics in the dugouts intensifying the problem.
• The high levels of dissolved organic carbon in these reservoirs form disinfection byproducts when the water is chlorinated, in turn higher levels of chlorine are required to safely disinfect the water. Concentrations of the disinfection by-products can be such that the treated water is unsuitable for human consumption.

The researchers are now concentrating their efforts on ways of removing some of the dissolved organics before the water is disinfected. In addition to improved removal methods, dugout management to limit the introduction of dissolved organics will become increasingly more important as part of an overall strategy to supply safe drinking water.

PFRA is aiming to work with provincial agencies, research organizations, and private companies in an expanding effort to provide the rural prairies with good quality water of sufficient quantity.