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How is water quality measured? Who measures it?. Dr. Matt Helmers Assistant Professor and Extension Agricultural Engineer Dept . of Agricultural and Biosystems Engineering Iowa State University. What do we mean by “water quality”.
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How is water quality measured? Who measures it? Dr. Matt Helmers Assistant Professor and Extension Agricultural Engineer Dept . of Agricultural and Biosystems Engineering Iowa State University
What do we mean by “water quality” • Water quality is the measure of the suitability of water for a particular use based on physical, chemical, and biological characteristics.
Why do we measure water quality? • To ensure the water is safe for the intended use • Fishing • Swimming • Drinking • Agricultural use • Aquatic life • To make sure the quality of the water is meeting some determined criteria • To understand the impacts of land management practices or changes
How do we measure water quality? • Some aspects determined right in the stream • Flow • Temperature • pH • Dissolved oxygen • Electrical conductivity • Collection of water sample and analysis in the laboratory • Nutrients • Sediment • Bacteria • Etc.
Monitoring site on Upper Maquoketa River; northeast Iowa, above Backbone State Park (1999-2001)
Subsurface Flow – Timing of Flow If drainage main is undersized problems occur
How do we setup a monitoring scheme? • Depends on contaminant? • For nitrate grab samples on some set schedule may be appropriate • For constituents primarily transported during high-flow events more frequent sampling or automated sampling may be necessary
Monitoring sites on Upper Maquoketa River (1999-2001)northeast Iowa, 68% row-crop/significant subsurface drainage
Does pollutant of concern impact ability to detect changes? • In Upper Midwest significant portion of nitrogen inputs to the stream may have fairly defined source from the tile lines – reducing nitrate to some acceptable level from drains may be relatively quickly reflected in watershed N-levels • Phosphorus source may be both field and in-stream which may greatly impact ability to detected impacts of practices changes on watershed P-levels
Monitoring Water Quality Checklist • Identify your watershed. • Choose between the types of monitoring. • Get expert help, including training and equipment. • Choose site(s) to collect samples. • Collect, organize, and analyze data. • Report your results to agencies and the public. • Maintain quality control.
Overview • To get a general idea of water quality conditions voluntary water monitoring may be appropriate • If the goal is to document effects of practices or practice changes a more detailed monitoring protocol would be necessary since would need samples over various conditions with corresponding analysis that has a high degree of precision.
Who monitors water quality? • Academia • Federal and state agencies (e.g. U.S.G.S. and IA DNR) • Watershed groups • Volunteer groups (e.g. IOWATER)
Links for additional information • National Water Quality Monitoring Council • http://acwi.gov/monitoring/index.html • http://www.epa.gov/owow/monitoring/monintr.html • http://iaspub.epa.gov/waters10/w305b_report_control.get_report?p_state=IA&p_cycle=#impairment