Potential for Municipal Sewage Sludge Application on Agricultural Lands in Southern Quebec

Abstract

Abstract In the present study, sludge composition from 112 municipalities in southern Quebec, Canada, were studied in order to examine the potential of alternative, environmentally sound sludge disposal, such as land application. Twenty-four municipalities with complete data set produced 24,000 dry tons of sludge per year. Of this amount, 47% (11,000 dry tons) could potentially be used for agricultural land application, according to Quebec standards. The other municipalities could not use their sludge for agricultural land application because of heavy metal contamination. The available areas of agricultural lands in southern Quebec are limited to about 149,454 ha. Considering that only 15% of this surface is adequate for sludge application and that a large part is already applied with manure, only 86,683 ha could be used for sludge application. Geographical Information System modeling in a smaller portion of this region showed that another 38% of land must be removed for other reasons, e.g., buffer zones around water bodies and roads. This left a surface area of approximately 54,000 ha or 5.4% of all agricultural land available for sewage sludge application in this region. Land application of sewage sludge may be possible but not without some limitations in some regions of southern Quebec. Other factors, such as pathogens contamination, climatic constraints and economic costs for the transportation and storage of sludge, must also be considered.