Transcript Power Point: How is water quality measured? Who measures it?

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)
ISCO flow-meter and auto-sampler in insulated enclosure
Flow and sampling set-up/Gilmore City site
Subsurface Flow – Timing of Flow
If drainage main is undersized problems occur
Subsurface Flow – Timing of Flow
Surface Runoff –
Small Watersheds
with Detailed
Sampling
Surface Runoff – Small Watersheds with
Detailed Sampling
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 instream which may greatly impact ability to
detected impacts of practices changes on
watershed P-levels
Monitoring Water Quality Checklist
1.Identify your watershed.
2.Choose between the types of monitoring.
3.Get expert help, including training and
equipment.
4.Choose site(s) to collect samples.
5.Collect, organize, and analyze data.
6.Report your results to agencies and the
public.
7.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_r
eport?p_state=IA&p_cycle=#impairment