Nutrient Management Strategy - Government of Manitoba

Page 5Item 3: Managing Nutrient SourcesSome jurisdictions have already developed, orare in the process of developing a watershed (ordrainage basin) based approach to nutrientmanagement. The watershed approach involvesfirst identifying all of the inputs to the riversystem within a basin or watershed, followed bythe development and implementation of strategiesaimed at reducing these inputs. The watershed orbasin management approach is often multidisciplinaryand requires the cooperation of allstakeholders within the watershed. The approachis in keeping with the overall movement towards amore holistic, ecosystem-based approach toenvironmental management.Nutrient sources that are discrete observabledischarges are called point sources, while sourcesthat are more diffuse and more difficult to quantifyare called non-point sources.Control of Nutrient Loading from PointSourcesPoint sources of nutrients in southernManitoba include wastewater treatment lagoondischarges, sewage and wastewater treatment plantdischarges, urban storm water drains, andchannelled run-off associated with large livestockoperations. Issues and actions to consider in thecontrol of nutrient inputs from point sourcesinclude:A. All point sources of nutrients have to beidentified and any information/data aboutnutrient loading from these point sources hasto be gathered. This information can then beanalyzed/modelled along with existing streamnutrient and flow data to ensure compliancewith the nutrient objectives of the stream.B. In cases where non-compliance occurs,nutrient control measures such as tertiarytreatment (e.g. constructed wetlands) ornutrient reduction technology (e.g. alumapplications) may have to be considered.C. In the case of streams that have multiple pointsources, the sources will be encouraged tocoordinate their discharges in such a way as toensure that stream nutrient objectives are notexceeded and water use is not compromisedduring discharge periods.D. Point source discharges may have to berelocated to minimize negative impacts to thewaterway and to water uses along thewaterway.E. Education awareness campaigns may need tobe initiated that are aimed at reducing nutrientinputs in domestic and industrial wastewater.Control of Nutrient Loading from Non-pointSourcesNon-point source loading refers to nutrientloading from land surface run-off across awatershed or catchment basin. Non-point sourcesof nutrients in southern Manitoba include surfacewater runoff from urban areas, fertilized fields,pastures, and livestock holding areas. Run-offfrom non-fertilized lands can also be considered anon-point source of nutrients simply because ofthe naturally high soil fertility in some parts ofsouthern Manitoba. Other non-point sources ofnutrients include atmospheric deposition andgroundwater seepage.In general, nutrient inputs to a waterway fromnon-point sources tend to be extremely variable,intermittent, and difficult to predict and control.This makes assessing their contribution to theeutrophication of a given waterway much moredifficult to ascertain. Some management practicesthat help to control non-point source loading ofnutrients to waterways include:A. Control of runoff waters and soil erosion fromagricultural and urban areas through improvedmethods of landscaping.B. Use of precision farming practices to limit theamount of excess chemical fertilizers andmanure applied to cultivated land.C. Preservation or re-establishment of riparianvegetation along waterways.D. Restricted access of cattle and other livestockto waterways.For Additional Information, Visit Manitoba Conservation’s Website for Current Issues - Latest Newswww.gov.mb.ca/environ/