Geology topics

Dana W. Kolpin

Publications and source records attributed to Dana W. Kolpin.

At least 181 records · Page 10Linked to original sources

USGS2002

Response to comment on "Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance"

We concur with the response of Eckel to our recent publication in this Journal (1). As the author notes, the topic of emerging contaminants is currently receiving extensive media coverage and scientific notice, but there are earlier reports that foreshadow this current interest. Eckel’s comment regarding the detection of pharmaceuticals and other organic wastewater contaminants (OWC) at a Superfund landfill site (2) is well taken, as other reports confirm the presence of such compounds at waste-disposal and landfill sites (3). In fact, literature from more than 20 years ago documented the occurrence of OWCs in the environment (4-7). A significant difference between these reports and our study is that we have systematically documented the frequent presence and low concentrations of a broad suite of OWCs in a wide variety of streams across the United States.

Environmental Science & Technology↗

USGS2002

Response to comment on "Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance"

We thank Ericson et al. (1) for their careful review and thoughtful comments on the synthetic hormone data presented in our recent publication summarizing the results from the USGS nationwide reconnaissance for pharmaceuticals and other organic wastewater contaminants (2). Their efforts have helped raise the awareness of the difficulties in accurately measuring these compounds at the low concentrations that occur in the environment and reinforce the need for continued research in the area of analytical methods development for synthetic hormones

Environmental Science & Technology↗

USGS2002

A reconnaissance study of herbicides and their metabolites in surface water of the midwestern united states using immunoassay and gas chromatography/mass spectrometry

Preemergent herbicides and their metabolites, particularly atrazine, deethylatrazine, and metolachlor, persisted from 1989 to 1990 in the majority of rivers and streams in the midwestern United States. In spring, after the application of herbicides, the concentrations of atrazine, alachlor, and simazine were frequently 3-10 times greater than the U.S. Environmental Protection Agency maximum contaminant level (MCL). The concentration of herbicides exceeded the MCLs both singly and in combination. Two major degradation products of atrazine (deisopropylatrazine and deethylatrazine) also were found in many of the streams. The order of persistence of the herbicides and their metabolites in surface water was atrazine > deethylatrazine > metolachlor > alachlor > deisopropylatrazine > cyanazine. Storm runoff collected at several sites exceeded the MCL multiple times during the summer months as a function of stream discharge, with increased concentrations during times of increased streamflow. It is proposed that metabolites of atrazine may be used as indicators of surface-water movement into adjacent alluvial aquifers.

Environmental Science & Technology↗

USGS2002

Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams

A recent study by the Toxic Substances Hydrology Program of the U.S. Geological Survey (USGS) shows that a broad range of chemicals found in residential, industrial, and agricultural wastewaters commonly occurs in mixtures at low concentrations downstream from areas of intense urbanization and animal production. The chemicals include human and veterinary drugs (including antibiotics), natural and synthetic hormones, detergent metabolites, plasticizers, insecticides, and fire retardants. One or more of these chemicals were found in 80 percent of the streams sampled. Half of the streams contained 7 or more of these chemicals, and about one-third of the streams contained 10 or more of these chemicals. This study is the first national-scale examination of these organic wastewater contaminants in streams and supports the USGS mission to assess the quantity and quality of the Nation's water resources. A more complete analysis of these and other emerging water-quality issues is ongoing.

Fact Sheet↗

USGS2002

Water-quality data for pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000

Water-quality data collected during 1999 and 2000 as part of the first nationwide reconnaissance of the occurrence of pharmaceuticals, hormones, and other organic wastewater contaminants (OWCs) are presented in this report. A network of 139 streams in 30 states were sampled and analyzed for 95 different OWCs using five new research methods developed by the U.S. Geological Survey. Site selection was biased toward streams more susceptible to OWC contamination because of proximity to urban areas or livestock production. At least one OWC was detected in 80% of the streams sampled, with 82 of the 95 analyzed OWCs determined in this study detected in at least one sample.

Open-File Report↗

USGS2001

It's not just how high; it's how clean: Sampling the spring 2001 flood in the Upper Mississippi River Basin

Floods can cause water-quality problems because of the large amounts of contaminants (sediment, nutrients, pesticides, and bacteria) that can be transported by floodwaters. during the flood on the Upper Mississippi River in 2001, water-quality and water-quality data were collected during near-record streamflow. This is the first time that samples for determining organic wastewater contaminants (pharmaceuticals, hormones, and industrial/household use compounds) and pesticide degradates have been collected during a flood of this magnitude.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2000

Importance of the Mississippi River Basin for investigating agricultural–chemical contamination of the hydrologic cycle

This special issue is devoted to recent and ongoing research relating to the fate and transport of agricultural chemicals in the Mississippi River Basin by the US Geological Survey Toxic Substances Hydrology (Toxics) Program. The Mississippi River Basin drains approximately 3 200 000 km 2 representing 41% of the United States. This is the largest river in the United States and the third largest in the world. The Mississippi River discharges an average of 19 920 m 3 /s of water into the Gulf of Mexico. The river is an extensively used resource, supplying drinking water to 70 cities in the United States. The Mississippi River Basin has undergone dramatic land use and cultural changes over the last 150 years. Approximately 70 million people now live within the basin, representing approximately 27% of the nation's population. This basin has also become one of the most productive agricultural regions in the world in terms of both crops and livestock grown. Approximately 65% of the nation's harvested cropland is grown in this basin, with more than 100 000 metric tons (t) of pesticides and approximately 6 500 000 t of commercial nitrogen fertilizers applied to cropland within the basin annually. The drainage of more than 20 000 000 ha within the basin has been enhanced by means of tile lines and ditches to lower the water table to make the cropland more productive. While removing the water from the soil as intended, this practice also leads to more rapid transport of contaminants to the river, and ultimately the Gulf of Mexico. Furthermore, the extensive chemical use in the Mississippi River Basin has led to the transport of pesticides and nitrate into the region’s streams, aquifers, and atmosphere. An estimated 1 000 000 t of nitrate-N is transported from the Mississippi River Basin into the Gulf of Mexico annually. The peak annual load of herbicides to the Gulf of Mexico has been documented at 1920 t. The fundamental goal of the papers presented in this volume is to provide a scientific basis for decisions necessary to promote sound and efficient agricultural practices and protect the quality of the nation's water resources.

Science of the Total Environment↗

USGS2000

Water-quantity and water-quality aspects of a 500-year flood - Nishnabotna River, southwest Iowa, June 1998

Flooding that occurred in southwest Iowa during June 15–17, 1998, was the worst flood ever recorded on the Nishnabotna River, exceeding the theoretical 500-year flood calculated from peak-flow records (1922 to present). This flood was a direct consequence of severe thunderstorm activity that caused more than 4 inches of rain to fall over a large part of the Nishnabotna River Basin. In fact, a new official State record for 24-hour total rainfall (13.18 inches) was set by this storm. The peak streamflow of the Nishnabotna River near Hamburg, Iowa, was 65,100 cubic feet per second, about 20 percent more than any previous recorded peak streamflow at this site. To determine the concentrations of selected contaminants that might be present in this record flooding, water-quality samples were collected within hours of the flood peak. The results from these samples documented the presence of numerous herbicide compounds (11 parent compounds and 12 herbicide degradates). The highest herbicide concentration was 5.06 micrograms per liter (µg/L) for atrazine, followed by metolachlor (1.16 µg/L), metolachlor ESA (1.04 µg/L), acetochlor OA (0.99 µg/L), and acetochlor ESA (0.95 µg/L). The total herbicide concentration (summation of the 23 herbicide compounds detected) was 15.6 µg/L. The timing of the severe thunderstorm activity and flooding, which occurred shortly after chemical application associated with planting of crops, was the principal reason for the large number and concentrations of herbicide compounds found in the flood water. At the time the water-quality samples were collected, the Nishnabotna River was transporting about 6,000 pounds of suspended sediment, 18 pounds of nitrogen, 3 pounds of phosphorus, and 0.02 pound of atrazine each second. These loads were about 10 to 150 times greater than those during a previous runoff event, and about 260 to 4,600 times greater than those during a previous base-flow condition. This sampling demonstrates the importance of collecting both water-quantity and water-quality data during flood events to estimate contaminant loads. Potential environmental effects of a flood can only be understood when both components are measured.

Iowa, Missouri↗

USGS1999

Distribution of major herbicides in ground water of the United States

Information on the concentrations and spatial distributions of pesticides and their transformation products, or degradates, in the hydrologic system is essential for managing pesticide use in both agricultural and nonagricultural settings to protect water resources. This report examines the occurrence of selected herbicides and their degradates in ground water, primarily on the basis of results from two large-scale, multistate investigations by the U.S. Geological Survey—the National Water-Quality Assessment (NAWQA) Program and the Midwest Pesticide Study (MWPS). The NAWQA pesticide data were derived from 2,227 sites (wells and springs) sampled in 20 major hydrologic basins across the United States from 1993 to 1995; the MWPS data were obtained from the sampling of 303 wells in a 12-state area of the northern midcontinent from 1991 to 1994. Data are presented for seven high-use herbicides: five of current interest to the U.S. Environmental Protection Agency for designing Pesticide Management Plans (atrazine, cyanazine, simazine, alachlor and metolachlor), a largely nonagricultural herbicide (prometon), and an agricultural herbicide first registered in 1994 for use in the United States (acetochlor). Six of the herbicides (all except acetochlor) were detected by the U.S. Geological Survey studies in shallow ground water—that is, ground water recharged within the past 10 years—in a variety of agricultural and nonagricultural settings, as well as in several aquifers that are sources of drinking-water supply. Acetochlor was not detected by the MWPS in the summer of 1994, but was detected in shallow ground water during the NAWQA Program by early 1995, and during another U.S. Geological Survey study in Iowa during the summers of 1995 and 1996. The acetochlor observations suggest that, in agreement with results from previous field studies, some pesticides may be detected in shallow ground water within 1 year following their application. In accord with the results from other largescale multistate studies of pesticides in ground water, more than 98 percent of the detections during the NAWQA and MWPS investigations were at concentrations of less than 1 microgram per liter. Consequently, water quality criteria for drinking water—that is, standards established to protect human health—were exceeded at fewer than 0.1 percent of the sites sampled by NAWQA (all of these exceedances involving atrazine alone) and at none of those sampled in 1992 by the MWPS. These criteria, however, may not accurately reflect the overall health risks associated with pesticide detections in water resources because they have been established only for a relatively small number of pesticides and they do not account for the additive or synergistic effects of mixtures, impacts on the health of aquatic ecosystems, or the effects of pesticide degradates. Among the sites sampled during the NAWQA and MWPS investigations, 19.7 and 13.8 percent, respectively, had detections of two or more of the herbicides of interest. Furthermore, for most of the herbicides for which degradates were examined, detection frequencies for major degradates were typically higher than for their respective parent compounds, particularly for the herbicides that are less persistent in aerobic soil. Frequencies of detection at or above 0.01 microgram per liter in shallow ground water beneath agricultural areas during the NAWQA study were significantly correlated with agricultural use in those areas for atrazine, cyanazine, alachlor, and metolachlor (P<0.05; Spearman rank correlations), but not for simazine (P>0.05). In urban areas, overall frequencies of detection of these five herbicides in shallow ground water were positively correlated with their total nonagricultural use nationwide (P=0.026; simple linear correlation). Multivariate statistical analysis indicated that frequencies of detection in shallow ground water beneath agricultural areas were positively correlated with half-lives for transformation in aerobic soil and agricultural use of the compounds (P≤0.0001 for both parameters). Although frequencies of detection were not significantly correlated with their subsurface mobility (K oc ; P=0.19) or the median well depths of the sampled networks (P=0.72), the range of K oc values among the five herbicides and the range of well depths were limited.

Water-Resources Investigations Report↗

USGS1999

Occurrence of acetochlor and acetochlor metabolites in alluvial aquifers in Iowa

No abstract available.

Iowa↗

USGS1998

Degradation of chloroacetanilide herbicides: The prevalence of sulfonic and oxanilic acid metabolites in Iowa groundwaters and surface waters

Water samples were collected from 88 municipal wells throughout Iowa during the summer and were collected monthly at 12 stream sites in eastern Iowa from March to December 1996 to study the occurrence of the sulfonic and oxanilic metabolites of acetochlor, alachlor, and metolachlor. The sulfonic and oxanilic metabolites were present in almost 75% of the groundwater samples and were generally present from 3 to 45 times more frequently than their parent compounds. In groundwater, the median value of the summed concentrations of acetochlor, alachlor, and metolachlor was less than 0.05 μg/L, and the median value of the summed concentrations of the six metabolites was 1.2 μg/L. All surface water samples contained at least one detectable metabolite compound. Individual metabolites were detected from 2 to over 100 times more frequently than the parent compounds. In surface water, the median value of the summed concentrations of the three parent compounds was 0.13 μg/L, and the median value of the summed concentrations of the six metabolites was 6.4 μg/L. These data demonstrate the importance of analyzing both parent compounds and metabolites to more fully understand the environmental fate and transport of herbicides in the hydrologic system.

Iowa↗

USGS1998

Occurrence of pesticides in shallow groundwater of the United States: initial results from the National Water-Quality Assessment program

The first phase of intensive data collection for the National Water-Quality Assessment (NAWQA) was completed during 1993−1995 in 20 major hydrologic basins of the United States. Groundwater land-use studies, designed to sample recently recharged groundwater (generally within 10 years) beneath specific land-use and hydrogeologic settings, are a major component of the groundwater quality as sessment for NAWQA. Pesticide results from the 41 land-use studies conducted during 1993−1995 indicate that pesticides were commonly detected in shallow groundwater, having been found at 54.4% of the 1034 sites sampled in agricultural and urban settings across the United States. Pesticide concentrations were generally low, with over 95% of the detections at concentrations less than 1 μg/L. Of the 46 pesticide compounds examined, 39 were detected. The compounds detected most frequently were atrazine (38.2%), deethylatrazine (34.2%), simazine (18.0%), metolachlor (14.6%), and prometon (13.9%). Statistically significant relations were observed between frequencies of detection and the use, mobility, and persistence of these compounds. Pesticides were commonly detected in both agricultural (56.4%; 813 sites) and urban (46.6%; 221 sites) settings. Frequent detections of pesticides in urban areas indicate that, as is the case with agricultural pesticide use in agricultural areas, urban and suburban pesticide use significantly contribute to pesticide occurrence in shallow groundwater. Although pesticides were detected in groundwater sampled in urban areas and all nine of the agricultural land-use categories examined, significant variations in occurrence were observed among these categories. Maximum contaminant levels (MCLs) established by the U.S. Environmental Protection Agency for drinking water were exceeded for only one pesticide (atrazine, 3 μg/L) at a single location. However, MCLs have been established for only 25 of the 46 pesticide compounds examined, do not cover pesticide degradates, and, at present, do not take into account additive or synergistic effects of combinations of pesticide compounds or potential effects on nearby aquatic ecosystems.

Environmental Science & Technology↗

USGS1998

Herbicides in ground water of the Midwest: A regional study of shallow aquifers, 1991-94

The intensive herbicide use associated with the 'Corn Belt' marks the Midwestern United States as a region where herbicide contamination of ground water could be a problem. To better understand the regional occurrence of herbicides in shallow aquifers of the Midwest, a sampling network of 303 wells across 12 States was developed. The results documented relatively widespread, low-level concentrations of herbicides in the shallow aquifers sampled. The most frequently detected compounds, however, were the transformation products of these herbicides. A relation was determined between herbicide occurrence and the general age of the ground water sampled. Water that recharged ground water within the past 40 years was much more likely to contain herbicides than water recharged earlier.

Midwest↗

USGS1997

Pesticides and volatile organic compounds in shallow urban groundwater of the United States

The widespread use of pesticides and volatile organic compounds (VOCs) over the past half century has led to their detection in many hydrologic systems in the United States. However, few systematic investigations of occurrences have been carried out over multistate regions using a consistent study design. Nine urban studies of shallow groundwater have been conducted to date as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Pesticide compounds were detected in 48.6% of the 208 urban wells sampled. Sixteen different pesticide compounds were detected in samples from these wells. Prometon was by far the most frequently detected pesticide compound, being found in 8 of the 9 urban studies. VOCs were detected in 53.4% of the 208 urban wells sampled, with 36 different VOC compounds being found. Measured VOC concentrations exceeded current U.S. Environmental Protection Agency drinking water regulations in 19 wells. Methyl tert -butyl ether (MTBE), a common fuel oxygenate, was the most frequently detected VOC for this study.

Book chapter↗

USGS1996

Analysis of nitrate in near-surface aquifers in the midcontinental United States: An application of the inverse hyperbolic sine Tobit model

A nonnormal and heteroscedastic Tobit model is used to determine the primary factors that affect nitrate concentrations in near-surface aquifers, using data from the U.S. Geological Survey collected in 1991. Both normality and homoscedasticity of errors are rejected, justifying the use of a nonnormal and heteroscedastic model. The following factors are found to have significant impacts on nitrate concentrations in groundwater: well screen interval, depth to top of aquifers, percentages of urban residential, forest land, and pasture within 3.2 km, dissolved oxygen concentration level, and presence of a chemical facility and feedlot. The effects of explanatory variables on nitrate concentration are explored further by calculating elasticities. Dissolved oxygen concentration level has more notable effects on nitrate concentrations in groundwater than other variables.

Water Resources Research↗

USGS1996

Using a geographic information system and scanning technology to create high-resolution land-use data sets

A geographic information system (GIS) procedure was developed to compile low-altitude aerial photography, digitized data, and land-use data from U.S. Department of Agriculture Consolidated Farm Service Agency (CFSA) offices into a high-resolution (approximately 5 meters) land-use GIS data set. The aerial photography consisted of 35-mm slides which were scanned into tagged information file format (TIFF) images. These TIFF images were then imported into the GIS where they were registered into a geographically referenced coordinate system. Boundaries between land use were delineated from these GIS data sets using on-screen digitizing techniques. Crop types were determined using information obtained from the U.S. Department of Agriculture CFSA offices. Crop information not supplied by the CFSA was attributed by manual classification procedures. Automated methods to provide delineation of the field boundaries and land-use classification were investigated. It was determined that using these data sources, automated methods were less efficient and accurate than manual methods of delineating field boundaries and classifying land use.

Water-Resources Investigations Report↗

USGS1995

Postflood occurrence of selected agricultural chemicals and volatile organic compounds in near-surface unconsolidated aquifers in the upper Mississippi River basin, 1993

The historic stream flooding and intense rainfall across the upper Mississippi River Basin during summer 1993 had an immediate effect on near-surface unconsolidated aquifers by raising the water levels closer to the land surface . The objective of this study was to determine if this flooding also had immediate effects on groundwater quality . Water samples were collected during September and October 1993 from 110 wells completed in near-surface unconsolidated aquifers and were analyzed for herbicides, herbicide metabolites, inorganic nutrients, and volatile organic compounds. The results of these samples were compared with those obtained during summer 1991 or 1992. The difference was not statistically significant in the frequency of herbicide detection, total herbicide concentration, nitrate concentration, or the frequency of volatile organic compound detection between water samples collected in 1991 and 1992 and those collected in 1993 when all 110 wells were considered collectively . However, water samples from the Missouri River alluvial aquifer had a fourfold increase in the frequency of herbicide detection . There also appears to be a relation between increases in total herbicide concentration and the occurrence of stream flooding near a well. Water samples from wells that had at least a 20-percent increase in dissolved-oxygen concentration had the greatest frequency of substantial changes in total herbicide concentration and substantial increases in nitrate concentration . Increased dissolved-oxygen concentration could indicate areas where recharge has increased as a result of extensive stream flooding and intense rainfall . An inverse relation was determined between well depth and changes (increase or decrease) in total herbicide concentration . Water in shallow wells more quickly reflect changes in water quality in response to changes in recharge. Significantly more urban residential and industrial land use was within a 30-meter radius of the well for wells in which volatile organic compounds were detected. Because water moves more slowly along ground-water flow paths compared with surface-water runoff, additional information is required to determine long-term effects of the 1993 flood on ground-water quality.

upper Mississippi River basin↗

USGS1994

Herbicides and nitrate in near-surface aquifers in the midcontinental United States, 1991

The occurrence and distribution of selected herbicides, atrazine metabolites, and nitrate were determined for near-surface aquifers (within 50 feet of land surface) in the corn- and soybean-producing region of the midcontinental United States. The study region included all or parts of Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. Water samples were collected during the spring and summer of 1991 from 303 wells completed in near-surface unconsolidated and near-surface bedrock aquifers. At least one herbicide or atrazine metabolite was detected in 24 percent of 579 water samples analyzed for herbicides, based on a reporting limit of 0.05 microgram per liter. However, no herbicide concentration exceeded the U.S. Environmental Protection Agency's maximum contaminant levels or health advisory levels for drinking water. The most frequently detected herbicide compound was desethylatrazine, an atrazine metabolite (18.1 percent), followed by atrazine (17.4 percent); deisopropylatrazine, an atrazine metabolite (5.7 percent); prometon (5.0 percent); metolachlor (2.7 percent); alachlor (1.7 percent); simazine (1.0 percent); metribuzin (1.0 percent); and cyanazine (0.7 percent). The herbicides ametryn, prometryn, propazine, and terbutryn were not detected during this study. Nitrate concentrations equal to or greater than 3.0 milligrams per liter (excess nitrate) were detected in 29 percent of the 599 nitrate analyses, and ammonium concentrations equal to or greater than 0.01 milligram per liter were detected in 78 percent of the 584 ammonium analyses. Nitrate concentrations equal to or greater than the U.S. Environmental Protection Agency's maximum contaminant level for drinking water of 10 milligrams per liter were found in 6 percent of the samples. The frequency of herbicide detection was, in part, affected by the analytical method's reporting limit. Results from this study show that the frequency of atrazine detection increases as the reporting limit decreases. Herbicide metabolite concentrations are critical to understanding the detection of herbicide residues. The frequency of detection of atrazine residue (atrazine + desethylatrazine + deisopropylatrazine) was 22.1 percent, which was more than the frequency of detection of atrazine alone (17.4 percent). Prometon was detected more frequently than every other herbicide except atrazine. The prometon appears to be derived from areas of nonagricultural land use, such as golf courses and residential areas. Herbicides and excess nitrate were both rarely detected in the eastern part of the study region, even though this is an area of intense herbicide and nitrogen-fertilizer use. Hydrogeologic factors, land use, agricultural practices, local features, and water chemistry were analyzed for possible relation to herbicide and excess-nitrate detections. Herbicides and excess nitrate were detected more frequently in near-surface unconsolidated aquifers than in nearsurface bedrock aquifers. The depth to the top of the aquifer was inversely related to the frequency of detection of herbicides and excess nitrate. The proximity of streams to sampled wells also affected the frequency of herbicide detection. Significant seasonal differences were determined for the frequency of herbicide detection, but not for the frequency of excess nitrate.

Illinois, Indiana, Iowa, Kansas, Michigan, Minneso↗