Transcript Document

Water Quality Seminar Series
Jointly sponsored by
Institute of Natural Resource Sustainability (INRS)
and
Dept. of Natural Resources and Environmental Sciences (NRES)
April 28, 2009
Noon – 1 PM
Illinois Natural Resources Building
(Illinois State Geological Survey)
Room 101 (SE corner)
615 E. Peabody
(Coffee and cookies will be provided)
Surface water quality in Illinois: What have we
learned, and what do we need to study further?
by
Mark B. David
Department of Natural Resources and Environmental Sciences
University of Illinois
I will present a summary of surface water quality research in Illinois that I have been
involved in, illustrating what we now know, but also discussing areas where I think we
need additional study. Water quality in Illinois is affected by two anthropogenic factors,
agriculture and sewage effluent additions. Together, they lead to high nitrogen and
phosphorus concentrations in nearly all Illinois streams. Tile drains facilitate the
movement of nitrate from agricultural fields, as well as nearly anything else applied to a
field under certain conditions. Surface runoff and tiles both contribute phosphorus, as
does direct inputs of sewage effluent from nearly 13 million people. Given our flashy tiles,
streams, and rivers with high flows in late winter and spring, we contribute a large
percentage of the Mississippi River nitrogen and phosphorus load heading to the Gulf of
Mexico that is a major cause of hypoxia. Despite the high riverine nutrient
concentrations, however, local effects are not always very clear, or apparent at all. I will
discuss what new areas of research are needed to better understand the role of nutrients
in our streams and how agricultural production does or could affect them.