Document Type

Conference Proceeding

Publication Date


Conference Title

Presented at a workshop "Environmental Water Quality - sampling for nutrients" Department of Agriculture, Bunbury, August 27th, 1993.


Water quality, nutrient runoff, monitoring


Agriculture | Environmental Monitoring | Natural Resources Management and Policy | Water Resource Management


Making accurate and precise estimations of pollutant loadings is becoming more important as our waterways suffer from increased inputs of pollutants and as statutory requirements to meet target loads are established. The most studied pollutant in waterways in WA is phosphorus (P) since it is reported to be the stimulus for algal growth. Many reports publish nutrient load data without any discussion of potential errors in sampling, chemical analysis or load calculations, or any discussion of the assumptions made and conclusions drawn from those calculations. The result can be the adoption of incorrect sampling, analytical and calculation procedures, leading ultimately to incorrect conclusions. This may lead to an untimely delay in the implementation of appropriate management strategies to reduce nutrient loads. These notes identify some potential sources of error in sampling, chemical analysis and load calculations. A major assumption in all discussions in these notes is that all flow data are 100% accurate and that all estimates of bias or accuracy do not include errors associated with flow measurements