| | Study Purpose
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Snowfluent tests on municipal wastewater by the Ontario Ministry of the Environment and Energy, and Delta Engineering Ltd. showed significant reductions in nutrient and pathogen concentrations (Huber and Palmateer, 1985). They showed that raw municipal wastewater from Collingwood, Ontario could meet standards for release to surface water courses after one treatment with Snowfluent. Installations at Westport, a village near Ottawa, Canada and a ski resort in the Carrabassett Valley, Maine have shown that Snowfluent is a cost-competitive treatment system for municipal wastewater.
The Alberta pork industry is poised for significant expansion as processing plants are developed or expanded. However, expansion on the primary side is being limited by municipalities, who are reluctant to grant development permits for new barns based on complaints from neighbours regarding manure odours. Very often, since manure odour cannot be related directly to public health issues, water quality effects from manure storage and spreading are raised as the critical issue for reviewing development plans. The Snowfluent technology had not previously been tested on liquid manure. Alberta Agriculture, Food & Rural Development (AAFRD) proposed a pilot test on liquid manure with the help of the Alberta Research Council (ARC), Vegreville. Reductions in ambient odour were important in attracting AAFRD's research interest, in addition to the system's water treatment potential. The Alberta Pork Producers Development Corporation took the lead in funding the pilot tests. In order to accommodate a series of pilot-scale tests in western Canada, Delta Engineering Ltd. constructed a portable Snowfluent plant which was used for the hog manure trials.
The AFC/Snowfluent liquid manure trial had three questions to answer:
- what degree of treatment is achieved using Snowfluent® to treat liquid hog manure?
- how is treatment achieved during snowmaking, in the snow pack and at snowmelt?
- what are the levels of airborne bacteria (bioaerosols) in the air during snowmaking, and do these levels present any health risk to operators and neighbours?
Methodology
A test plot was initially constructed on the Matejka farm near Red Deer, Alberta. Excessively warm weather forced the snowmaking operation to be moved to the Giebelhaus hog farm, south of Vegreville, Alberta. The test plot was approximately 15 m by 15 m and was bordered with standard square bales. Both the plot and the bales were then covered with an impermeable liner, and an outlet installed at the downslope end to facilitate meltwater sampling and flow monitoring.
Snowmaking began on February 26, but was confined to nighttime hours due to above normal daytime temperatures. Over the course of two nights, the plot was covered with approximately three metres of Snowfluent snow. Throughout the course of the snowmaking process, samples were taken of the raw liquid manure and the freshly made snow. In addition, the air around the operation was also sampled for airborne bacteria (bioaerosols).
Samples of the meltwater were taken throughout the thaw period, which occurred approximately from the last week of March until the last week of April. After runoff was over, the residue remaining on the liner was sampled from a number of 1 m2 quadrats, weighed, and analyzed for nutrients and contaminants.
A more detailed description of the methodology is contained in Appendix A. |
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