Fox River Watershed Investigation - Publication Details

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Abstract:
Data collected during the pilot phase of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program in the upper Illinois River Basin were used to describe the presence, spatial distribution, and temporal vari ability of nutrients, dissolved oxygen (DO), and fecal-indicator bacteria in selected streams during 1987-90 and to identify, where possible, factors affecting in-stream concentrations and loads of these constituents. Streams in the upper Illinois River Basin receive nutrient inputs from many different sources within the basin, including wastewater treatment plants, agricultural runoff, urban runoff, ground-water discharge, diversions from Lake Michigan, eroded soils, and transported plant material. Nutrient concentrations in the upper Illinois River Basin were larger than nutrient concentrations typically found in Midwestern streams, and most of the largest nutrient concentrations and loads were found in the urban areas of the basin. Median concentrations of total nitrogen at eight NAWQA fixed stations ranged from 2.2 to 9.7 mg/L (milligrams per liter). Most of the nitrogen in upper Illinois River Basin streams was in the form of nitrate, except at two sites where either ammonia nitrogen or organic nitrogen comprised a large part of the total nitrogen concentration. Median concentrations of total phosphorus at the fixed stations ranged from 0.06 to 0.84 mg/L. The spatial distribution of total phosphorus concentrations was similar to that of total nitrogen concentrations‹the smallest concentrations were present in the agricultural Kankakee River Basin and the largest in the urban Des Plaines River Basin. Total nitrogen concentrations were correlated with streamflow at all but one of the fixed stations. Positive correlations were found at stations in predominantly agricultural basins, and negative correlations were found at stations in urban areas. Approximately 252,000 tons of nitrogen and 94,000 tons of phosphorus are input to streams in the upper Illinois River Basin annually. Only 74,730 tons of nitrogen and 3,850 tons of phosphorus are exported from the upper Illinois River Basin each year via the Illinois River. These figures correspond to 30 and 4 percent of the nitrogen and phosphorus inputs, respectively. During low-flow conditions, the nutrient load in streams in the Des Plaines River Basin accounted for virtually all of the low-flow nitrogen load in the upper Illinois River Basin, with other streams contributing a relatively minor load. Upward trends in total nitrogen concentrations from 1978-90 were found at three of the fixed stations, and downward trends in total phosphorus concentrations were found at two stations. Median DO concentrations measured at the fixed stations during routine monthly sampling (daylight hours) ranged from 3.4 to 12.2 mg/L. During a low-flow synoptic sampling (measurements made prior to sunrise), all DO concentrations in the Fox River Basin equaled or exceeded 5.0 mg/L, the lllinois water quality standard for general-use waters. DO concentrations during the low-flow synoptic sampling at 59 percent of the sampled stream sites in the agricultural Kankakee River Basin and at 49 percent of the sites in the Des Plaines River Basin were less than 5.0 mg/L. Neither stream size nor land use appeared to affect DO concen trations at the synoptic sites significantly. Upward trends in DO concentrations were indicated at the two most downstream stations in the upper Illinois River Basin. The water quality at these two stations represents the aggregate water quality of streams draining the entire upper Illinois River Basin. The NAWQA program used both fecal coliform and Escherichia coli to indicate bacterial contamination. Fecal-coliform densities at the fixed stations ranged from 1 to 45,000 colonies per 100 milliliters. Median fecal-coliform densities were one or two orders of magnitude larger at two stations in the Des Plaines River Basin than at the other fixed stations. From 30 to 100 percent of the stream-water samples collected at stations in the Des Plaines River Basin had Escherichia coli densities greater than the Federal criteria for a single sample for infrequently used, full-body-contact water. Trend analyses for bacteria indicated significant downward trends in bacteria densities at three fixed stations: Iroquois River near Chebanse, Ill., Fox River at Algonquin, Ill., and Fox River at Dayton, Ill.

Data Record Period: 1987-1990
Data Record Notes: 1987-90 (USGS, 8 fixed sites, 70 synoptic sampling), 1978-86 (IEPA)

Potential Issues: TP>0.0725 mg/L (all 8 fixed stations), TN>2.95 mg/L (all 8 fixed stations), dramatic diurnal variation (Algonquin), supersat. (Dayton), Fecal-coliform (Dayton, Montgomery)

Screening Criteria: IEPA's WQ stds, EPA's recommended nutrient criteria for TP and TN

Data Sources: USGS

Parameters: Ammonia, total; Ammonia, un-ionized; DO; Fecal coliform; Hardness; Nitrate+Nitrite; Nitrate-N; Nitrogen, total; pH; Phosphorus, total; Temperature

Sites - IEPA Station(USGS Station): (5549500), (5552400), (5551937), DT06(5550000), DT09(5551000), DT38(5551540), DT46(5552500), DTG02(5550500)