Geology topics

D. Kolpin

Publications and source records attributed to D. Kolpin.

4 recordsLinked to original sources

USGS2007

Impacts of waste from concentrated animal feeding operations on water quality

Waste from agricultural livestock operations has been a long-standing concern with respect to contamination of water resources, particularly in terms of nutrient pollution. However, the recent growth of concentrated animal feeding operations (CAFOs) presents a greater risk to water quality because of both the increased volume of waste and to contaminants that may be present (e.g., antibiotics and other veterinary drugs) that may have both environmental and public health importance. Based on available data, generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens, and pharmaceuticals present in the waste. Impacts on surface water sources and wildlife have been documented in many agricultural areas in the United States. Potential impacts on human and environmental health from long-term inadvertent exposure to water contaminated with pharmaceuticals and other compounds are a growing public concern. This workgroup, which is part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards-Searching for Solutions, identified needs for rigorous ecosystem monitoring in the vicinity of CAFOs and for improved characterization of major toxicants affecting the environment and human health. Last, there is a need to promote and enforce best practices to minimize inputs of nutrients and toxicants from CAFOs into freshwater and marine ecosystems.

Environmental Health Perspectives↗

USGS2004

Determination of pharmaceutical compounds in surface- and ground-water samples by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry

Commonly used prescription and over-the-counter pharmaceuticals are possibly present in surface- and ground-water samples at ambient concentrations less than 1 μg/L. In this report, the performance characteristics of a combined solid-phase extraction isolation and high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC–ESI-MS) analytical procedure for routine determination of the presence and concentration of human-health pharmaceuticals are described. This method was developed and used in a recent national reconnaissance of pharmaceuticals in USA surface waters. The selection of pharmaceuticals evaluated for this method was based on usage estimates, resulting in a method that contains compounds from diverse chemical classes, which presents challenges and compromises when applied as a single routine analysis. The method performed well for the majority of the 22 pharmaceuticals evaluated, with recoveries greater than 60% for 12 pharmaceuticals. The recoveries of angiotensin-converting enzyme inhibitors, a histamine (H2) receptor antagonist, and antihypoglycemic compound classes were less than 50%, but were retained in the method to provide information describing the potential presence of these compounds in environmental samples and to indicate evidence of possible matrix enhancing effects. Long-term recoveries, evaluated from reagent-water fortifications processed over 2 years, were similar to initial method performance. Method detection limits averaged 0.022 μg/L, sufficient for expected ambient concentrations. Compound-dependent matrix effects on HPLC/ESI-MS analysis, including enhancement and suppression of ionization, were observed as a 20–30% increase in measured concentrations for three compounds and greater than 50% increase for two compounds. Changing internal standard and more frequent ESI source maintenance minimized matrix effects. Application of the method in the national survey demonstrates that several pharmaceuticals are routinely detected at 0.010–0.100 μg/L concentrations.

Journal of Chromatography A↗

USGS1999

Nitrate in groundwater of the midwestern United States: A regional investigation on relations to land use and soil properties

The intense application of nitrogen-fertilizer to cropland in the midwestern United States has created concern about nitrate contamination of the region's aquifers. Since 1991, the US Geological Survey has used a network of 303 wells to investigate the regional distribution of nitrate in near-surface aquifers of the midwestern United States. Detailed land use and soil data were compiled within a 2 km radius of 100 unconsolidated wells in the regional network to determine relations to nitrate concentrations in groundwater. For land use, the amount of irrigated land was directly related to nitrate concentrations in groundwater. For soils, the general water table depth and soil factors associated with rates of water movement were directly related to nitrate concentrations in groundwater.

IAHS-AISH Publication↗

USGS1992

Hydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1990

Hydrologic data were collected in the Big Spring basin located in Clayton County, Iowa, during the 1990 water year. The data were collected by the U.S. Geological Survey in cooperation with the Iowa Department of Natural Resources, Geological Survey Bureau, to provide information on variation and movement of agricultural chemicals in the hydrologic cycle in the basin. Precipitation, surface-water, and ground-water data were collected. Rainfall recorded during water year 1990 at a monitoring site on Roberts Creek totaled 43.67 inches. The greatest monthly rainfall (14.45 inches) occurred in August. Calcium and sulfate were the predominant ions in the rain, and the median concentrations of nitrate and ammonia as nitrogen were 0.35 and 0.48 milligrams per liter, respectively. Stream discharge, specific conductance, pH, and water temperature were monitored continuously, and monthly water-quality samples were collected at three sites in the basin. The predominant ions in samples from Roberts Creek at the point where it leaves the basin were calcium, magnesium, and bicarbonate. Nitrite plus nitrate as nitrogen concentrations in 42 samples ranged from less than 0.10 to 18 milligrams per liter. Pesticide concentrations in 34 samples ranged from less than 0.10 to 12 micrograms per liter. Alachlor was detected in 56 percent of the samples; atrazine in 100 percent; cyanazine in 68 percent; and metolachlor in 47 percent. At Big Spring, the ground-water discharge point, the daily mean specific conductance ranged from 378 to 796 microsiemens per centimeter at 25 degrees Celsius, the daily median pH ranged from 6.5 to 7.2, and the daily mean water temperature ranged from 5.5 to 11.5 degrees Celsius. Calcium, magnesium, and bicarbonate generally were the predominant ions in solution. Concentrations of nitrite plus nitrate as nitrogen in 32 samples ranged from 3.4 to 16 milligrams per liter. Alachlor was detected in 22 percent of the samples; atrazine in 100 percent; cyanazine in 44 percent, and metplachlor in 6 percent. The maximum atrazine concentration was 4.5 micrograms per liter. During a low-flow seepage study, May 29 and 30,1990, the measured discharge lost by streams in the basin was 8.56 cubic feet per second, the measured dissolved nitrogen load lost was 0.29 ton per day, and the measured atrazine load lost was 0.028 pound per day. The total measured discharge and total dissolved nitrogen load leaving the basin in streams were 3.63 cubic feet per second and about 0.04 ton per day, respectively.

Iowa↗