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USGS2008

Interior River Lowland Ecoregion Summary Report

ECOREGION DESCRIPTION The Interior River Lowlands ecoregion encompasses 93,200 square kilometers (km2) across southern and western Illinois, southwest Indiana, east-central Missouri, and fractions of northwest Kentucky and southeast Iowa. The ecoregion includes the confluence areas of the Mississippi, Missouri, Ohio, Illinois, and Wabash Rivers, and their tributaries. This ecoregion was formed in non-resident, non-calcareous sedimentary rock (U.S. Environmental Protection Agency, 2006). The unstratified soil deposits present north of the White River in Indiana are evidence that pre-Wisconsinan ice once covered much of the Interior River Lowlands. The geomorphic characteristics of this area also include terraced valleys filled with alluvium as well as outwash, acolian, and lacustrine deposits. Historically, agricultural land use has been a vital economic resource for this region. The drained alluvial soils are farmed for feed grains and soybeans, whereas the valley uplands also are used for forage crops, pasture, woodlots, mixed farming, and livestock (USEPA, 2006). This ecoregion provides a key component of national energy resources as it contains the second largest coal reserve in the United States, and the largest reserve of bituminous coal (Varanka and Shaver, 2007). One of the primary reasons for change in the ecoregion is urbanization.

Open-File Report↗

USGS2006

Occurrence, distribution, loads, and yields of selected pesticides in the Little River basin, Kentucky, 2003-04

Water resources in the Little River Basin are potentially vulnerable to applications of pesticides associated with both agricultural and nonagricultural activities, because much of the basin is characterized by karst topography. Concerns about water quality resulting from pesticide use in karst areas and lack of data on concentrations of pesticides in surface water led to further investigation of water quality in the Little River Basin, which includes about 600 square miles in Christian and Trigg Counties and a portion of Caldwell County in western Kentucky. Water samples were collected in streams in the Little River Basin, Kentucky during 2003-04 as part of a study conducted in cooperation with the Kentucky Department of Agriculture. The objectives of the study were to assess the occurrence and distribution of pesticides, to evaluate the spatial and seasonal variability of pesticides, and to evaluate loads and yields of selected pesticides in the basin. A total of 91 water samples was collected at 4 fixed-network sites from March through November 2003 and from February through November 2004. An additional 20 samples were collected at 5 synoptic-network sites within the same period. Twenty-four pesticides were detected of the 127 pesticides analyzed in the stream samples. Of the 24 detected pesticides, 15 were herbicides, 7 were insecticides, and 2 were fungicides. The most commonly detected pesticides-atrazine, simazine, metolachlor, and acetochlor-were those most heavily used on crops during the study. Atrazine and simazine were detected in 100 percent of all surface-water samples, and metolachlor and acetochlor were detected in more than 45 percent. The pesticide degradate, deethylatrazine, was detected in 100 percent of the samples. Only one nonagricultural herbicide, prometon, was detected in more than 50 percent of the samples. Diazinon, the most commonly detected insecticide, was found in 25 percent of all samples and was found at all sites except Casey Creek. Metalaxyl was the most commonly detected fungicide (14 percent); most detections were in samples from the Sinking Fork subbasin. Concentrations of herbicides were highest following application in the spring (March-May). In contrast, insecticides typically were present during the summer (June-August). The most commonly detected pesticides in the Little River Basin were found at low concentrations in streams year-round. Atrazine and simazine (row-crop herbicides) had the highest measured concentrations (22 and 6.1 micrograms per liter (?g/L), respectively) and were the most heavily applied herbicides in the basin. Metolachlor also was heavily applied in the basin, but measured concentrations did not exceed 0.32 ?g/L. The insecticide, Malathion, was only detected in 4 percent of the samples, although it was heavily applied in the basin during 2003-04. Most detections of pesticides were at low concentrations in relation to drinking-water standards and guidelines established for the protection of aquatic life. Only two pesticide compounds--atrazine and simazine--exceeded the U.S. Environmental Protection Agency (USEPA) standards for drinking water. Atrazine exceeded the USEPA's maximum contaminant level (MCL) 19 times in 111 detections; simazine exceeded the established MCL 2 times in 111 detections. These exceedences occurred in the spring. Concentrations of atrazine also exceeded the established aquatic-life criterion (1.8 ?g/L) in 32 samples collected from all sites. Concentrations of deethylatrazine, an herbicide-transformation compound, tended to follow the same monthly concentration pattern as its parent compound (atrazine), but concentrations of deethylatrazine were lower than those of atrazine. Atrazine may have been present in the soil much longer at these sites, which might have allowed microbial populations to transform atrazine into deethylatrazine. A statistical comparison of concentrations of selected pesticides among four fixed-network sites

Scientific Investigations Report↗

USGS2005

Assessment of shallow ground-water quality in recently urbanized areas of Sacramento, California, 1998

Evidence for anthropogenic impact on shallow ground-water quality beneath recently developed urban areas of Sacramento, California, has been observed in the sampling results from 19 monitoring wells in 1998. Eight volatile organic compounds (VOCs), four pesticides, and one pesticide transformation product were detected in low concentrations, and nitrate, as nitrogen, was detected in elevated concentrations; all of these concentrations were below National and State primary and secondary maximum contaminant levels. VOC results from this study are more consistent with the results from urban areas nationwide than from agricultural areas in the Central Valley, indicating that shallow ground-water quality has been impacted by urbanization. VOCs detected may be attributed to either the chlorination of drinking water, such as trichloromethane (chloroform) detected in 16 samples, or to the use of gasoline additives, such as methyl tert-butyl ether (MTBE), detected in 2 samples. Pesticides detected may be attributed to use on household lawns and gardens and rights-of-way, such as atrazine detected in three samples, or to past agricultural practices, and potentially to ground-water/surface-water interactions, such as bentazon detected in one sample from a well adjacent to the Sacramento River and downstream from where bentazon historically was used on rice. Concentrations of nitrate may be attributed to natural sources, animal waste, old septic tanks, and fertilizers used on lawns and gardens or previously used on agricultural crops. Seven sample concentrations of nitrate, as nitrogen, exceeded 3.0 milligrams per liter, a level that may indicate impact from human activities. Ground-water recharge from rainfall or surface-water runoff also may contribute to the concentrations of VOCs and pesticides observed in ground water. Most VOCs and pesticides detected in ground-water samples also were detected in air and surface-water samples collected at sites within or adjacent to the recently developed urban areas. Five arsenic sample concentrations exceeded the U.S. Environmental Protection Agency (USEPA) primary maximum contaminant level (MCL) of 10 milligrams per liter adopted in 2001. Measurements that exceeded USEPA or California Department of Health Services recommended secondary maximum contaminant levels include manganese, iron, chloride, total dissolved solids, and specific conductance. These exceedances are probably a result of natural processes. Variations in stable isotope ratios of hydrogen (2H/1H) and oxygen (18O/16O) may indicate different sources or a mixing of recharge waters to the urban ground water. These variations also may indicate recharge directly from surface water in one well adjacent to the Sacramento River. Tritium concentrations indicate that most shallow ground water has been recharged since the mid-1950s, and tritium/helium-3 age dates suggest that recharge has occurred in the last 2 to 30 years in some areas. In areas where water table depths exceed 20 meters and wells are deeper, ground-water recharge may have occurred prior to 1950, but low concentrations of pesticides and VOCs detected in these deeper wells indicate a mixing of younger and older waters. Overall, the recently urbanized areas can be divided into two groups. One group contains wells where few VOCs and pesticides were detected, nitrate mostly was not detected, and National and State maximum contaminant levels, including the USEPA MCL for arsenic, were exceeded; these wells are adjacent to rivers and generally are characterized by younger water, shallow (1 to 4 meters) water table, chemically reducing conditions, finer grained sediments, and higher organics in the soils. In contrast, the other group contains wells where more VOCs, pesticides, and elevated nitrate concentrations were detected; these wells are farther from rivers and are generally characterized by a mixture of young and old waters, intermediate to deep (7 to 35 meters) wate

Scientific Investigations Report↗

USGS2025

The US EPA’s National Nutrient Inventory: Critical shifts in US nutrient pollution sources from 1987 to 2017

Efforts to constrain the negative environmental impacts of excess nitrogen (N) and phosphorus (P) are costly and challenging, due in part to inconsistent reporting of nutrient sources at temporal and spatial scales relevant for local decision making. To meet this challenge, the U.S. Environmental Protection Agency’s National Nutrient Inventory provides estimates of major agricultural, urban, atmospheric, and natural nutrient fluxes for the contiguous United States at county and HUC12 scales annually from 1987 (from 1950 for agriculture) to 2017. Since the late 1980s, total N emissions and atmospheric N deposition have declined 22% and 15%, respectively, despite increased agricultural emissions. Over the same period, municipal wastewater N and P loads remained largely stable, despite population increases, through wastewater treatment upgrades and the phaseout of phosphorus-containing detergents. Improved agricultural efficiency allowed for dramatic increases in agricultural production and crop harvest since 1987 (∼25% for N and P), with little change in surplus nutrients left on fields. Overall, a combination of innovative technologies and management has stemmed or even decreased major sources of nutrient pollution to the environment over the last several decades, representing an important shift that, if continued, may contribute to improved air, land, and water quality and human health.

contiguous United States↗

USGS2006

Concentrations of nutrients, pesticides, and suspended sediment in the karst terrane of the Sinking Creek basin, Kentucky, 2004

Water samples were collected in streams and springs in the karst terrane of the Sinking Creek Basin in 2004 as part of study in cooperation with the Kentucky Department of Agriculture. A total of 48 water samples were collected at 7 sites (4 springs, 2 streams, and 1 karst window) from April through November 2004. The karst terrane of the Sinking Creek Basin (also known as Boiling Spring Basin) encompasses about 125 square miles in Breckinridge County and portions of Meade and Hardin Counties in Kentucky. Fourteen pesticides were detected of the 52 pesticides analyzed in the stream and spring samples. Of the 14 detected pesticides, 12 were herbicides and 2 were insecticides. The most commonly detected pesticides?atrazine, simazine, metolachlor, and acetochlor?were those most heavily used on crops during the study. Atrazine was detected in 100 percent of all samples; simazine, metolachlor, and acetochlor were detected in more than 35 percent of all samples. The pesticide-transformation compound, deethylatrazine, was detected in 98 percent of the samples. Only one nonagricultural herbicide, prometon, was detected in more than 30 percent of the samples. Malathion, the most commonly detected insecticide, was found in 4 percent of the samples, which was followed by carbofuran (2 percent). Most of the pesticides were present in low concentrations; however, atrazine was found in springs exceeding the U.S. Environmental Protection Agency?s (USEPA) standards for drinking water. Atrazine exceeded the USEPA?s maximum contaminant level 2 times in 48 detections. Concentrations of nitrate greater than 10 milligrams per liter (mg/L) were not found in water samples from any of the sites. Concentrations of nitrite plus nitrate ranged from 0.21 to 3.9 mg/L at the seven sites. The median concentration of nitrite plus nitrate for all sites sampled was 1.5 mg/L. Concentrations of nitrite plus nitrate generally were higher in the springs than in the main stem of Sinking Creek. Forty-two percent of the concentrations of total phosphorus at all seven sites exceeded the USEPA?s recommended maximum concentration of 0.1 mg/L. The median concentration of total phosphorus for all sites sampled was 0.09 mg/L. The highest median concentrations of total phosphorus were found in the springs. Median concentrations of orthophosphate followed the same pattern as concentrations of total phosphorus in the springs. Concentrations of orthophosphate ranged from <0.006 to 0.192 mg/L. Concentrations of suspended sediment generally were low throughout the basin; the median concentration of suspended sediment for all sites sampled was 23 mg/L. The highest concentration of suspended sediment (1,486 mg/L) was measured following a storm event at Sinking Creek near Lodiburg, Ky.

Open-File Report↗

USGS1997

Evaluation of agricultural best-management practices in the Conestoga River headwaters, Pennsylvania: Hydrology of a small carbonate site near Ephrata, Pennsylvania, prior to implementation of nutrient management

The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture and Pennsylvania Department of Environmental Protection, investigated the effects of agricultural best-management practices on water quality in the Conestoga River headwaters watershed. This report describes environmental factors and the surface-water and ground-water quality of one 47.5-acre field site, Field-Site 2, from October 1984 through September 1986, prior to implementation of nutrient management. The site is partially terraced agricultural cropland underlain by carbonate rock. Twenty-seven acres are terraced, pipe-drained, and are under no-till cultivation. The remaining acreage is under minimum-till cultivation. Corn is the primary crop. The average annual rate of fertilization at the site was 480 pounds per acre of nitrogen and 110 pounds per acre of phosphorus. An unconfined limestone and dolomitic aquifer underlies the site, Depth to bedrock ranges from 5 to 30 feet below land surface. Estimated specific yields range from 0.05 to 0.10, specific capacities of wells range from less than 1 to about 20 gallons per minute per foot of drawdown, and estimates of transmissivities range from 10 to 10,000 square feet per day. Average ground-water recharge was estimated to be about 23 inches per year. The specific capacity and transmissivity data indicate that two aquifer regimes are present at the site. Wells drilled into dolomites in the eastern part of the site have larger specific capacities (averaging 20 gallons per minute per foot of drawdown) relative to specific capacities (averaging less than 1 gallon per minute per foot of drawdown) of wells drilled into limestones in the western part of the site. Median concentrations of soil-soluble nitrate and soluble phosphorus in the top 4 feet of silt- or silty-clay-loam soil ranged from 177 to 329 and 8.5 to 35 pounds per acre, respectively. Measured runoff from the pipe-drained terraces ranged from 10 to 48,000 cubic feet and was 1.7 and 0.8 percent, respectively, of the 1985 and 1986 annual precipitation. An estimated 90,700 cubic feet of surface runoff carried 87 pounds to total nitrogen and 37 pounds of total phosphorus, or less that 0.65 percent of the amount of either nutrient applied during the study period. Rainfall on the snow-covered, frozen ground produced more that half of the runoff and nitrogen and phosphorus loads measured in pipe-drained runoff. Graphical and regression analyses of surface runoff suggest that (1) mean-storm concentrations of total nitrogen species and total phosphorus decreased with increasing time between a runoff event and the last previous nutrient application, and (2) mean total-phosphorus concentrations approached a baseline value (estimated at 2 to 5 milligrams per liter for total-phosphorus concentrations) after several months without nutrient applications. Dissolved nitrate concentrations in ground water in wells unaffected by an on-site ammonia spill ranged from 7.4 to 100 milligrams per liter. Average annual additions and removals of nitrogen were estimated. Nitrogen was added to the site by applications of manure and commercial fertilizer nitrogen, as well as by precipitation and ground water entering across the western site boundary. These sources of nitrogen accounted for 95, 3, 1, and 1 percent, respectively, of estimated additions. Nitrogen was removed from the site in harvested crops, by ground-water discharge, by volatilization, and in surface runoff, which accounted for 42, 28, 29, and less than 1 percent, respectively, of estimated removals.

Pennsylvania↗

USGS2009

Pesticides in ground water in selected agricultural land-use areas and hydrogeologic settings in Pennsylvania, 2003-07

This report was prepared by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Agriculture (PDA) as part of the Pennsylvania Pesticides and Ground Water Strategy (PPGWS). Monitoring data and extensive quality-assurance data on the occurrence of pesticides in ground water during 2003–07 are presented and evaluated; decreases in the land area used for agriculture and corresponding changes in the use of pesticides also are documented. In the Pennsylvania ground waters assessed since 2003, concentrations of pesticides did not exceed any maximum contaminant or health advisory levels established by the U.S. Environmental Protection Agency; PPGWS actions are invoked by the PDA at fractions of these levels and were needed only in areas designated by the PDA for special ground-water protection. Previous investigations through 1998 of pesticides in Pennsylvania ground water identified land use, as a surrogate for pesticide use, and rock type of the aquifer combined with physiography as key hydrogeologic setting variables for understanding aquifer vulnerability to contamination and the common occurrence of atrazine and metolachlor in ground water. Of 20 major hydrogeologic settings in a framework established in 1999 for pesticide monitoring in Pennsylvania, 9 were identified as priorities for data collection in order to change the monitoring status from "inadequate" to "adequate" for the PPGWS. Agricultural and forested land-use areas are decreasing because of urban and suburban growth. In the nine hydrogeologic settings evaluated using 1992 and 2001 data, decreases of up to 12 percent for agricultural land and 10 percent for forested land corresponded to increases of up to 11 percent for urban land. Changes in agricultural pesticide use were computed from crop data. For example, from 1996 to 2004–05, atrazine use declined by about 15 percent to 1,314,000 lb/yr (pounds per year) and metolachlor use increased by about 20 percent to 895,000 lb/yr; these compounds are the two most-used agricultural pesticides statewide. In 2003–07, a baseline assessment of pesticides was conducted in five of nine hydrogeologic settings with inadequate monitoring data—the Blue Ridge crystalline and Triassic Lowland siliciclastic, Eastern Lake surficial, Devonian-Silurian carbonate, Great Valley siliciclastic, and Northeastern Glaciated surficial settings. Between 20 and 30 wells in each setting were monitored. Of the 126 wells sampled, 96 well-water samples were analyzed for at least 52 pesticide compounds at the USGS National Water Quality Laboratory (NWQL) using a method with a minimum reporting level (MRL) at or above 0.002 µg/L (micrograms per liter). Of the 96 well waters analyzed by NWQL, 43 had measureable concentrations of one or more pesticides. Atrazine and (or) deethylatrazine (CIAT), a degradation product of atrazine, were reported at or above the MRL in 39 of the 43 well waters. Neither atrazine nor CIAT were reported at concentrations exceeding 0.10 µg/L; all measured concentrations in these five settings were below PPGWS action levels. Metolachlor was present in 7 of the 43 well waters with measureable concentrations of 1 or more pesticides; however, concentrations were below the MRL. The other 30 samples (10 of 20 wells in the Blue Ridge crystalline and Triassic Lowland siliciclastic setting and all 20 wells in the Eastern Lake surficial setting) were analyzed for at least 19 pesticide compounds at the Pennsylvania Department of Environmental Protection Laboratory (PADEPL); the PADEPL reported no concentrations of pesticides at or above an MRL of 0.10 µg/L. Statistical tests using the NWQL analytical results showed correlations between pesticide occurrence and two indicators of water-quality degradation—the occurrence of total coliform bacteria and nitrate concentration. A 2 × 2 contingency-table test indicated a relation between presence or absence of atrazine or metolachlor and presence or absence of bacteria only for the 10 wells representing the Blue Ridge crystalline and Triassic Lowland siliciclastic setting. Results of Spearman’s rank test showed strong positive correlations in the Devonian-Silurian carbonate setting between 1) the number of pesticides above the MRLs and nitrate concentration, and 2) concentrations of atrazine and nitrate. Atrazine concentration and nitrate concentration also showed a statistically significant positive correlation in the Great Valley siliciclastic setting. An additional component of baseline monitoring was to evaluate changes in pesticide concentration in water from wells representing hydrogeologic settings most vulnerable to contamination from pesticides. In 2003, 16 wells originally sampled in the 1990s were resampled—4 each in the Appalachian Mountain carbonate, Triassic Lowland siliciclastic, Great Valley carbonate, and Piedmont carbonate settings. Nine of these wells, where pesticide concentrations from 1993 and 2003 were analyzed at the NWQL, were chosen for a paired-sample analysis using concentrations of atrazine and metolachlor. A statistically significant decrease in atrazine concentration was identified using the Wilcoxon signed-rank test (p = 0.004); significant temporal changes in metolachlor concentrations were not observed (p = 0.625). Monitoring in three areas of special ground-water protection, where selected pesticide concentrations in well water were at or above the PPGWS action levels, was done at wells BE 1370 (Berks County, Oley Township), BA 437 (Blair County, North Woodbury Township), and LN 1842 (Lancaster County, Earl Township). Co-occurrence of pesticide-degradation products with parent compounds was documented for the first time in ground-water samples collected from these three wells. Degradation products of atrazine, cyanazine, acetochlor, alachlor, and metolachlor were commonly at larger concentrations than the parent compound in the same water sample. Pesticide occurrence in water from wells neighboring the hot-spot wells was highly variable; however, the same sets of pesticide compounds that were present in wells BA 437, BE 1370, and LN 1842 were present to some degree in water from neighboring wells. To evaluate temporal changes in concentration, nonparametric statistical tests were used to determine overall and seasonal monotonic trends. Concentrations of alachlor, atrazine, metolachlor, and nitrate were examined using the 5-year (2003–07) and the long-term data from wells BA 437 and LN 1842 (1996–2007 and 1995–2007, respectively), and the long-term data for well BE 1370 (1998–2007); results showed either downward trends or no trends. Trends in acetochlor concentrations were tested only at well LN 1842 using the 5-year data; no trends were observed. Homogeneity of trend tests indicated statistically significant downward concentration trends in the long-term data were due to seasonal trends as follows: BA 437—alachlor and atrazine (summer); BE 1370—atrazine and metolachlor (winter) and alachlor (winter and spring); LN 1842—alachlor (summer and fall) and atrazine (spring and fall).

Pennsylvania↗

USGS2018

The Midwest Stream Quality Assessment—Influences of human activities on streams

Healthy streams and the fish and other organisms that live in them contribute to our quality of life. Extensive modification of the landscape in the Midwestern United States, however, has profoundly affected the condition of streams. Row crops and pavement have replaced grasslands and woodlands, streams have been straightened, and wetlands and fields have been drained. Runoff from agricultural and urban land brings sediment and chemicals to streams. What is the chemical, physical, and biological condition of Midwestern streams? Which physical and chemical stressors are adversely affecting biological communities, what are their origins, and how might we lessen or avoid their adverse effects? In 2013, the U.S. Geological Survey (USGS) conducted the Midwest Stream Quality Assessment to evaluate how human activities affect the biological condition of Midwestern streams. In collaboration with the U.S. Environmental Protection Agency National Rivers and Streams Assessment, the USGS sampled 100 streams, chosen to be representative of the different types of watersheds in the region. Biological condition was evaluated based on the number and diversity of fish, algae, and invertebrates in the streams. Changes to the physical habitat and chemical characteristics of the streams—“stressors”—were assessed, and their relation to landscape factors and biological condition was explored by using mathematical models. The data and models help us to better understand how the human activities on the landscape are affecting streams in the region.

Fact Sheet↗

USGS2014

Influence of grazing and land use on stream-channel characteristics among small dairy farms in the Eastern United States

Rotational grazing (RG) is a livestock management practice that rotates grazing cattle on a scale of hours to days among small pastures termed paddocks. It may beneficially affect stream channels, relative to other livestock management practices. Such effects and other beneficial effects on hydrology are important to RG's potential to provide a highly multifunctional mode of livestock farming. Previous comparisons of effects of RG and confinement dairy (CD) on adjoining streams have been restricted in scale and scope. We examined 11 stream-channel characteristics on a representative sample of 37 small dairy farms that used either RG or CD production methods. Our objectives were: (1) to compare channel characteristics on RG and CD farms, as these production methods are implemented in practice, in New York, Pennsylvania and Wisconsin, USA; and (2) to examine land use on these farms that may affect stream-channel characteristics. To help interpret channel characteristic findings, we examined on-farm land use in riparian areas 50 m in width along both sides of stream reaches and whole-farm land use. In all states, stream-channel characteristics on RG and CD farms did not differ. Whole-farm land use differed significantly between farm types; CD farms allocated more land to annual row crops, whereas RG farms allocated more land to pasture and grassland. However, land cover in 50 m riparian areas was not different between farm types within states; in particular, many RG and CD farms had continuously grazed pastures in riparian areas, typically occupied by juvenile and non-lactating cows, which may have contributed sediment and nutrients to streams. This similarity in riparian management practices may explain the observed similarity of farm types with respect to stream-channel characteristics. To realize the potential benefits of RG on streams, best management practices that affect stream-channel characteristics, such as protection of riparian areas, may improve aggregate effects of RG on stream quality and also enhance other environment, economic and social benefits of RG.

Renewable Agriculture and Food Systems↗

USGS1997

Water resources of Bannock Creek basin, southeastern Idaho

The potential for development of water resources in the Bannock Creek Basin is limited by water supply. Bannock Creek Basin covers 475 square miles in southeastern Idaho. Shoshone-Bannock tribal lands on the Fort Hall Indian Reservation occupy the northern part of the basin; the remainder of the basin is privately owned. Only a small amount of information on the hydrologic and water-quality characteristics of Bannock Creek Basin is available, and two previous estimates of water yield from the basin ranged widely from 45,000 to 132,500 acre-feet per year. The Shoshone-Bannock Tribes need an accurate determination of water yield and baseline water-quality characteristics to plan and implement a sustainable level of water use in the basin. Geologic setting, quantities of precipitation, evapotranspiration, surface-water runoff, recharge, and ground-water underflow were used to determine water yield in the basin. Water yield is the annual amount of surface and ground water available in excess of evapotranspiration by crops and native vegetation. Water yield from Bannock Creek Basin was affected by completion of irrigation projects in 1964. Average 1965-89 water yield from five subbasins in Bannock Creek Basin determined from water budgets was 60,600 acre-feet per year. Water yield from the Fort Hall Indian Reservation part of Bannock Creek Basin was estimated to be 37,700 acre-feet per year. Water from wells, springs, and streams is a calcium bicarbonate type. Concentrations of dissolved nitrite plus nitrate as nitrogen and fluoride were less than Maximum Contaminant Levels for public drinking-water supplies established by the U.S. Environmental Protection Agency. Large concentrations of chloride and nitrogen in water from several wells, springs, and streams likely are due to waste from septic tanks or stock animals. Estimated suspended-sediment load near the mouth of Bannock Creek was 13,300 tons from December 1988 through July 1989. Suspended-sediment discharge was greatest during periods of high streamflow.

Idaho↗

USGS2009

Stem demography and post-fire recruitment of a resprouting serotinous conifer

The contribution of resprouts and seedling recruitment to post-fire regeneration of the South African fynbos conifer Widdringtonia nodiflora was compared eight months after wildfires in 1990. Stems on all trees were killed by fire but resprouting success was > 90 % at all but one site. A demographic study of burned skeletons revealed that prior to these fires, nearly all plants were multi-stemmed (4–9 stems/plant) and multi-aged, indicating continuous sprout production between fires. All stems were killed by these 1990 fires and at most sites > 90 % of the stems were burned to ground level. All diameter stems were susceptible to such incineration as, at most sites, there was no difference in average diameter of stems burned to ground level and those left standing. Individual genets usually had all ramets incinerated to ground level or all ramets charred, but intact, suggesting certain micro-sites burned hotter, whereas other sites were somewhat protected. Although not true of the 1990 fires, there was evidence that occasionally Widdring-tonia stems may survive fire. At one site, four of the 16 plants sampled had a burned stem twice as old as the oldest burned stem on the other 12 plants at the site, suggesting some stems had survived the previous fire (ca. 1970) and this conclusion was supported by fire-scars on these four stems that dated to ca. 1970. Based on the highly significant correlation between stem diameter and cone density left standing after the 1990 fires, we calculated that for most sites > 80 % of the initial cone crop was incinerated by fire. This is important because we observed a strong relationship between size of the canopy cone crop surviving fire and post-fire seedling recruitment. Under these conditions we hypothesize that sprouting confers a selective advantage to genets when fires cause heavy losses of seed. The infrequent occurrence of sprouting in the Cupressaceae suggests the hypothesis that resprouting is an apomorphic or derived trait in Widdringtonia. Data from this study suggests resprouting provides a selective advantage under severe fynbos fires, which are not only 'stand-replacing fires,’but also are intense enough to incinerate cone-bearing stems.

Journal of Vegetation Science↗

USGS1996

The Beaver Creek story

Beaver Creek watershed in West Tennessee includes about 95,000 acres of the Nation's most productive farmland and most highly erodible soils. In 1989 the U.S. Geological Survey, in cooperation with the Tennessee Department of Agriculture, began a study to evaluate the effect of agricultural activities on water quality in the watershed and for best management practices designed to reduce agricultural nonpoint-source pollution. Agrichemical monitoring included testing the soils, ground water, and streams at four farm sites ranging from 27 to 420 acres. Monitoring stations were operated downstream to gain a better understanding of the water chemistry as runoff moved from small ditches into larger streams to the outlet of the Beaver Creek watershed. Prior to the implementation of best management practices at one of the farm study sites, some storms produced an average suspended-sediment concentration of 70,000 milligrams per liter. After the implementation of BMP's, however, the average value never exceeded 7,000 milligrams per liter. No-till crop production was the most effective best management practice for conserving soil on the farm fields tested. A natural bottomland hardwood wetland and a constructed wetland were evaluated as instream resource-management systems. The wetlands improved water quality downstream by acting as a filter and removing a significant amount of nonpoint-source pollution from the agricultural runoff. The constructed wetland reduced the sediment, pesticide, and nutrient load by approximately 50 percent over a 4-month period. The results of the Beaver Creek watershed study have increased the understanding of the effects of agriculture on water resources. Study results also demonstrated that BMP's do protect and improve water quality.

Open-File Report↗

USGS1983

Evaluating environmental and economic consequences of alternative pest management strategies: results of modeling workshops

The U.S. Environmental Protection Agency (EPA) needs a comprehensive method to evaluate the human health and environmental effects of alternative agricultural pest management strategies. This project explored the utility of Adaptive Environmental Assessment (AEA) techniques for meeting this need. The project objectives were to produce models for environmental impact analysis, improve communications, identify research needs and data requirements, and demonstrate a process for resolving conflicts. The project was structured around the construction (in an initial 2 1/2-day workshop) and examination (in a second 2 1/2-day workshop) of a simulation model of a corn agroecosystem. The model conceptualized at the first workshop simulates the effect of corn agrecosystem decisions on crop production, economic returns, and environmental indicators. The model is composed of five interacting submodels: 1) a Production Strategies submodel which makes decisions concerning tillage, planting, fertilizer and pesticide applications, and harvest; 2) a Hydrology/Chemical Transport submodel which represents soil hydrology, erosion, and concentrations of fertilizers and pesticides in the soil, runoff, surface waters, and percolation; 3) a Vegetation submodel which simulates growth of agricultural crops (corns and soybeans) and weeds; 4) a Pests submodel which calculates pest population levels and resulting crop damage; and 5) an Environmental Effects submodel which calculates indicators of potential fish kills, human health effects, and wildlife habitat. The most persistent data gaps encountered in quantifying the model were coefficients to relate environmental consequences to alternative pest management strategies. While the model developed in the project is not yet accurate enough to be used for real-world decisions about the use of pesticides on corn, it does contain the basic structure upon which such a model could be built. More importantly at this stage of development, the project has shown that very complex systems can be modeled in short periods of time and that the process of building such models increases understanding among disciplinary specialists and between diverse institutional interests. This process can be useful to EPA as the agency cooperates with other institutions to meet its responsibilities in less costly ways. Activities at the second 2 1/2-day workshop included a review of the model, incorporation of necessary corrections, simulation of policy scenarios, and examination of techniques to address remaining institutional conflicts. Participants were divided into three groups representing environmental, production or industry, and regulatory interests. Each group developed scenarios that would be most appealing to their particular interest and the scenarios were simulated by the agroecosystem computer model. Negotiators from each of the interest groups decided whether a hypothetical herbicide should be relabeled and if certain restrictions should be imposed on its use. Other participants functioned as experts and consultants on caucus teams. A solution to the hypothetical problem was successfully negotiated. Workshop participants and project staff agreed that the model and processes developed during the project should be used in training students, extension specialists, farmers, researchers, and chemical producers in collaborative problem solving methods. More productive research can be planned, and more realistic models of complex systems can be built in this way. More importantly, greater trust of decisionmakers in computer models, better understanding by technical experts about disciplines other than their own, and improved cooperation between institutional interests can be achieved. This trust, understanding, and cooperation are critical ingredients in solving problems that are too complex to be resolved by independent disciplinary activity and unilateral decision authority.

Report↗

USGS2020

Development of a novel framework for modeling field-scale conservation effects of depressional wetlands in agricultural landscapes

The intermixed cropland, grassland, and wetland ecosystems of the upper mid-western United States combine to provide a suite of valuable ecological services. Grassland and wetland losses in the upper midwestern United States have been extensive, but government-funded conservation programs have protected and restored hundreds of thousands of acres of wetland and grassland habitat in the region. The value of restored wetlands in agricultural fields is complex, and the USDA Natural Resource Conservation Service, Conservation Effects Assessment Project (CEAP) has been lacking the methodology to include these conservation practices in their analyses. Our aim is to develop a reproducible methodology for simulating wetlands within the CEAP cropland modeling framework used to evaluate other agricultural conservation practices. Furthermore, we evaluate the effect of using upland conservation practices on the functioning of restored wetlands. By simulating the addition of a depressional wetland that effectively removes 6% of the field from crop production, we obtained a 15% reduction in annual runoff and a 29% and 28% reduction in mean annual nitrogen (N) and phosphorus (P) losses, respectively. The presence of the depressional wetland in the field is estimated to also reduce edge-of-field losses of sediments by 20% and sediment-bound N and P by 19% and 23%, respectively. Additionally, adding a grass filter strip around the wetland greatly decreased sediment inputs to the wetland, increasing the effective life of the wetland, in terms of its ability to perform valued services, by decades to centuries. Our method for modeling depressional wetlands embedded in cropped fields provides a means to quantify the effects of wetland conservation practices on field-level losses for regional assessments, such as the CEAP.

Journal of Soil and Water Conservation↗

USGS2008

Pesticide Occurrence and Distribution in the Lower Clackamas River Basin, Oregon, 2000-2005

Pesticide occurrence and distribution in the lower Clackamas River basin was evaluated in 2000?2005, when 119 water samples were analyzed for a suite of 86?198 dissolved pesticides. Sampling included the lower-basin tributaries and the Clackamas River mainstem, along with paired samples of pre- and post-treatment drinking water (source and finished water) from one of four drinking water-treatment plants that draw water from the lower river. Most of the sampling in the tributaries occurred during storms, whereas most of the source and finished water samples from the study drinking-water treatment plant were obtained at regular intervals, and targeted one storm event in 2005. In all, 63 pesticide compounds were detected, including 33 herbicides, 15 insecticides, 6 fungicides, and 9 pesticide degradation products. Atrazine and simazine were detected in about half of samples, and atrazine and one of its degradates (deethylatrazine) were detected together in 30 percent of samples. Other high-use herbicides such as glyphosate, triclopyr, 2,4-D, and metolachlor also were frequently detected, particularly in the lower-basin tributaries. Pesticides were detected in all eight of the lower-basin tributaries sampled, and were also frequently detected in the lower Clackamas River. Although pesticides were detected in all of the lower basin tributaries, the highest pesticide loads (amounts) were found in Deep and Rock Creeks. These medium-sized streams drain a mix of agricultural land (row crops and nurseries), pastureland, and rural residential areas. The highest pesticide loads were found in Rock Creek at 172nd Avenue and in two Deep Creek tributaries, North Fork Deep and Noyer Creeks, where 15?18 pesticides were detected. Pesticide yields (loads per unit area) were highest in Cow and Carli Creeks, two small streams that drain the highly urban and industrial northwestern part of the lower basin. Other sites having relatively high pesticide yields included middle Rock Creek and upper Noyer Creek, which drain basins having nurseries, pasture, and rural residential land. Some concentrations of insecticides (diazinon, chlorpyrifos, azinphos-methyl, and p,p?-DDE) exceeded U.S. Environmental Protection Agency (USEPA) aquatic-life benchmarks in Carli, Sieben, Rock, Noyer, Doane, and North Fork Deep Creeks. One azinphos-methyl concentration in Doane Creek (0.21 micrograms per liter [?g/L]) exceeded Federal and State of Oregon benchmarks for the protection of fish and benthic invertebrates. Concentrations of several other pesticide compounds exceeded non-USEPA benchmarks. Twenty-six pesticides or degradates were detected in the Clackamas River mainstem, typically at much lower concentrations than those detected in the lower-basin tributaries. At least 1 pesticide was detected in 65 percent of 34 samples collected from the Clackamas River, with an average of 2?3 pesticides per sample. Pesticides were detected in 9 (or 60 percent) of the 15 finished water samples collected from the study water-treatment plant during 2003?2005. These included 10 herbicides, 1 insecticide, 1 fungicide, 1 insect repellent, and 2 pesticide degradates. The herbicides diuron and simazine were the most frequently detected (four times each during the study), at concentrations far below human-health benchmarks?USEPA Maximum Contaminant Levels or U.S. Geological Survey human Health-Based Screening Levels (HBSLs). The highest pesticide concentration in finished drinking water was 0.18 ?g/L of diuron, which was 11 times lower than its low HBSL benchmark. Although 0?2 pesticides were detected in most finished water samples, 9 and 6 pesticides were detected in 2 storm-associated samples from May and September 2005, respectively. Three of the unregulated compounds detected in finished drinking water (diazinon-oxon, deethylatrazine [CIAT], and N, N-diethyl-m-toluamide [DEET]) do not have human-health benchmarks available for comparison. Although most of the 51 curren

Scientific Investigations Report↗

USGS2004

Studies by the U.S. Geological Survey on sources, transport, and fate of agricultural chemicals

The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is assessing the sources, transport, and fate of chemicals applied to crops in agricultural basins across the Nation (referred to as "study units," see map). Chemicals selected for study include nutrients (nitrogen and phosphorus) and about 50 commonly used pesticides and their transformation products, including triazine and acetanilide herbicides such as atrazine and metolachlor, and organophosphorus insecticides such as chlorpyrifos and diazinon. The basins in the studies represent a range of agricultural settings—with varying crop types and agricultural practices related to tillage, irrigation, artificial drainage, and chemical use—as well as a range of landscapes with different geology, soils, topography, climate, and hydrology. Consistent methodology and analysis allow comparisons among the different basins. This study design leads to an improved understanding of the many factors that can affect the movement of water and chemicals in different agricultural settings (see "Complex factors," next page). Information from these studies will help with decision-making related to chemical use, conservation, and other farming practices that are used to reduce runoff of agricultural chemicals and sediment from fields. This information also will benefit the U.S. Environmental Protection Agency, the Department of Agriculture, local and regional water managers, and agricultural chemical manufacturers who are involved in managing chemical use and pesticide registration.

Fact Sheet↗

USGS2005

Reach-scale effects of riparian forest cover on urban stream ecosystems

We compared habitat and biota between paired open and forested reaches within five small streams (basin area 10?20 km2) in suburban catchments (9%?49% urban land cover) in the Piedmont of Georgia, USA. Stream reaches with open canopies were narrower than forested reaches (4.1 versus 5.0 m, respectively). There were no differences in habitat diversity (variation in velocity, depth, or bed particle size) between open and forested reaches. However, absence of local forest cover corresponded to decreased large wood and increased algal chlorophyll a standing crop biomass. These differences in basal food resources translated into higher densities of fishes in open (9.0 individuals?m?2) versus forested (4.9 individuals?m?2) reaches, primarily attributed to higher densities of the herbivore Campostoma oligolepis. Densities of terrestrial invertebrate inputs were higher in open reaches; however, trends suggested higher biomass of terrestrial inputs in forested reaches and a corresponding higher density of terrestrial prey consumed by water column feeding fishes. Reach-scale biotic integrity (macroinvertebrates, salamanders, and fishes) was largely unaffected by differences in canopy cover. In urbanizing areas where catchment land cover drives habitat and biotic quality, management practices that rely exclusively on forested riparian areas for stream protection are unlikely to be effective at maintaining ecosystem integrity.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2008

Reducing sedimentation of depressional wetlands in agricultural landscapes

Depressional wetlands in agricultural landscapes are easily degraded by sediments and contaminants accumulated from their watersheds. Several best management practices can reduce transport of sediments into wetlands, including the establishment of vegetative buffers. We summarize the sources, transport dynamics, and effect of sediments, nutrients, and contaminants that threaten wetlands and the current knowledge of design and usefulness of grass buffers for protecting isolated wetlands. Buffer effectiveness is dependent on several factors, including vegetation structure, buffer width, attributes of the surrounding watershed (i.e., area, vegetative cover, slope and topography, soil type and structure, soil moisture, amount of herbicides and pesticides applied), and intensity and duration of rain events. To reduce dissolved contaminants from runoff, the water must infiltrate the soil where microbes or other processes can break down or sequester contaminants. But increasing infiltration also diminishes total water volume entering a wetland, which presents threats to wetland hydrology in semi-arid regions. Buffer effectiveness may be enhanced significantly by implementing other best management practices (e.g., conservation tillage, balancing input with nutrient requirements for livestock and crops, precision application of chemicals) in the surrounding watershed to diminish soil erosion and associated contaminant runoff. Buffers require regular maintenance to remove sediment build-up and replace damaged or over-mature vegetation. Further research is needed to establish guidelines for effective buffer width and structure, and such efforts should entail a coordinated, regional, multi-scale, multidisciplinary approach to evaluate buffer effectiveness and impacts. Direct measures in "real-world" systems and field validations of buffer-effectiveness models are crucial next steps in evaluating how grass buffers will impact the abiotic and biotic variables attributes that characterize small, isolated wetlands. ?? 2008 The Society of Wetland Scientists.

Wetlands↗