Flow-weighted composite samples of stormwater runoff from areas of different land use in Davenport, Iowa, were collected in the summer and fall of 1992 and analyzed for selected nutrients. Annual constituent loads were estimated for the area drained by the Davenport storm-sewer network. In all cases, the regression-equation estimate of mean annual load isless than the estimate obtained by using the method of the U.S. Environmental Protection Agency. The largest mean annual loads for total nitrite nitrogen, total nitrate nitrogen, total nitrite and nitrate nitrogen, total organic nitrogen, total ammonia and organic nitrogen, total nitrogen, and total phosphorus are associated with residential land, which covers 67.2 percent of the area drained. Using concentration data from this study, it is estimated that an average storm-producing runoff during the 7-day, 10-year low-flow discharge of the Mississippi River would contribute about 4 percent of the total ammonia and organic nitrogen load in the river. Precipitation-chemistry data indicate that substantial parts of the nitrate nitrogen and ammonia nitrogen contained in the stormwater runoff could be from precipitation.
Additional publication details
USGS Numbered Series
Selected nutrients in stormwater runoff from Davenport, Iowa, 1992
Water-Resources Investigations Report
U.S. Geological Survey ;
USGS Earth Science Information Center, Open-File Reports Section [distributor],