Description: Trends in nitrogen and phosphorus concentrations and loads in the Cedar River from the 1960’s to 2024 will be described in relation to   the 20 and 45 percent reduction goals based on the 1980-96 baseline average. Changes in nitrate, total nitrogen, and total phosphorus since the implementation of nutrient reduction practices in 2013 will be discussed.

Author: Stephen Kalkhoff (U.S. Geological Survey)*

Author Bio: Steve Kalkhoff is an emeritus hydrologist with the U.S. Geological Survey in Iowa City. Steve collected, analyzed, and reported on water quality conditions in surface and groundwater in Iowa for more than 30 years. Steve managed the Eastern Iowa Basins study unit of the National NAWQA program for 15 years from its inception in 1994 through two intensive data collection phases. For the past decade, Steve was the project lead of the cooperative project with the City of Cedar Rapids to map alluvial deposits, document ground-water quality, and monitor nutrients and pesticides in the Cedar River. Steve is the senior author of several journal articles and USGS reports and junior author on numerous other water quality reports.