| Abstract: | Hydrologic data were collected in the Big Spring Basin located in Clayton County, Iowa, during the 1991 water year. The data were collected to pro- vide information on variation and movement of agricultural chemicals in the hydrologic cycle in the basin. Precipitation, surface-water, and ground-water data were collected. Calcium and sulfate were the predominant ions in the rain, and the median concentrations of nitrate and ammonia as nitrogen were 0.36 and 0.49 mg/L (milligrams per liter), respectively. Discharge, specific conductance, pH, and water temperature were monitored continuously, and monthly water-quality samples were collected at Big Spring and at a site on Roberts Creek. Nitrite plus nitrate as nitrogen concentrations in water from Roberts Creek ranged from 1.8 to 22 mg/l, and herbicide concentrations ranged from less than 0.10 to 43 micrograms per liter. Alachlor was detected in 42 percent; atrazine in 92 percent; and cyanazine and metolachlor in 35 percent of the samples from Roberts Creek. Total suspended-sediment load discharged in Roberts Creek was about 160,000 tons. Water from Big Spring, the ground-water discharge point, contained concentrations of nitrite plus nitrate that ranged from 4.2 to 17 mg/L. Total measured suspended sediment discharged from Big Spring was about 17,000 tons. Alachlor was detected in 26 percent; atrazine in 100 percent; cyanazine in 26 percent, and metolachlor in 9 percent of the samples from Big Spring. The maximum atrazine concentration was 16 micrograms per liter. |
| Genre: | USGS Numbered Series |
| ProdID: | 19596 |
| Citation Author: | Kalkhoff, S. J.; Kuzniar, R. L. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | - |
| Citation Editor: | |
| Citation End Page: | |
| Citation Issue: | |
| Citation Keywords: | |
| Citation Language: | ENGLISH |
| Citation Larger Work Title: | |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | vi, 87 p. :ill., maps ;28 cm. |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | U.S. Geological Survey ;
USGS Earth Science Information Center, Open-File Reports Section [distributor], |
| Citation Series: | Open-File Report |
| Citation Series Code: | OFR |
| Citation Series Number: | 94-56 |
| Citation Search Results Text: | Hydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1991; 1994; OFR; 94-56; Kalkhoff, S. J.; Kuzniar, R. L. |
| Citation Start Page: | |
| Citation Volume: | |
| Citation Year: | 1994 |
| Type: | citation/reference |
| Text: | Hydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1991; 1994; OFR; 94-56; Kalkhoff, S. J.; Kuzniar, R. L. |
| URL (THUMBNAIL): | http://pubs.usgs.gov/of/1994/0056/report-thumb.jpg |
| URL (DOCUMENT): | http://pubs.usgs.gov/of/1994/0056/report.pdf |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
| Publisher: | U.S. Geological Survey ;
USGS Earth Science Information Center, Open-File Reports Section [distributor], |
