SEARCH · USGS Science

Results for “State of the Survey”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources

USGS1985

Water-resources activities of the U.S. Geological Survey in Nebraska, 1984

The State of Nebraska has a greater abundance of water than most of the surrounding States. The major water issues in the State concern the management of these water resources in regard to their availability areally across the State and temporally over the changing seasons and cycles of weather. Management also concerns the protection of the supply of water from deterioration through contamination. The U.S. Geological Survey (USGS) in Nebraska began providing data to allow for better management of the State 's water near the end of the 19th Century. Since then the USGS activities have continued and have included the monitoring of hydrologic conditions, detailed studies to describe the hydrology of specific areas, and studies to add to the basic scientific knowledge of hydrology. Projects in all these areas continue. The work has been supported through Federal funding, through support from other Federal agencies, and through cooperative programs with many State and local agencies. This report summarizes these activities which are ongoing in the State of Nebraska. (Lantz-PTT)

Open-File Report↗

USGS1977

Bird atlasing in the United States

Since the Breeding Bird Survey provides an annual quantitative sample of about 75% of the 1? blocks of latitude and longitude in every state except Alaska and Hawaii, and 47% of the 1/2? blocks (equivalent on the average to a 48 km square), no national Atlas based on merely presence or absence has been contemplated. Conventional atlases are in progress in the states of Maryland (2.5 km), Massaohusetts (5 km) and Vermont (5 km) and in parts of 3 other states. Quantitative studies including mapping have been published for North Dakota (10 km) and are in progress in Wyoming (1?). A Montana project (1?) is continuing.

Polish Ecological Studies↗

USGS1976

Hydrologic studies of the U.S. Geological Survey related to coal development on Colorado

This report summarizes the hydrologic studies related to coal development being conducted by the U.S. Geological Survey in the State of Colorado. The objective of the hydrologic data-acquisition program is to collect surface-water quality and quantity data and ground-water level records. These data are needed to define predevelopment conditions and to monitor the effects of construction and operation of coal mines and waste-disposal areas. Data-acquisition activities related to coal development in Colorado have concentrated on the Yampa River basin. A description of the hydrologic data-acquisition activities, including parameters collected and frequency of collection, precedes the summaries of the three interpretive studies currently in progress. Each study summary consists of the project title, definition of the problem being studied, objective of the study, approach of the study, and when known, the schedule for completion of the study and proposed report products resulting from the study. (Woodard-USGS)

Open-File Report↗

USGS2005

Naturally Occurring Arsenic in Ground Water, Norman, Oklahoma, 2004, and Remediation Options for Produced Water

In 2000, the U.S. Environmental Protection Agency (EPA) reviewed the arsenic drinking water standard for public water supplies. Considering the available research and statistics on the health effects of arsenic ingestion, the EPA reduced the Maximum Contaminant Level (MCL) for public drinking water from 50 micrograms per liter (?g/L) to 10 ?g/L (U.S. Environmental Protection Agency, 2001a). As a result of the more stringent standard, the EPA estimates that about 3,000 public water providers across the United States must take action to meet the new standard before it becomes effective on January 23, 2006 (U.S. Environmental Protection Agency, 2001b). The City of Norman (City) is one of several Oklahoma municipalities affected by the new arsenic standard. About 20 percent of Norman?s water is supplied by wells completed in the Central Oklahoma (Garber-Wellington) aquifer; the rest is supplied by Lake Thunderbird (fig. 1) or purchased from Oklahoma City. The Norman well field is composed of 24 active wells, and water produced from about half of the wells will not be in compliance with the new MCL (figs. 2 and 3). Chemical treatment of water with elevated arsenic is possible, but it is generally cost prohibitive. Another costly solution is simply to abandon the high-arsenic wells and replace them with new wells in low-arsenic areas. In the next phase of well construction beginning in 2005, the City plans to construct as many as 30 new wells in northeast Norman (Bryan Mitchell, City of Norman, oral commun., 2005). The new wells will replace production lost to the new arsenic standard and add new production to keep pace with rapidly growing consumer demand. Well modification to exclude arsenic-bearing water from existing wells is a more cost-effective solution, but it requires a great deal of knowledge about local aquifer properties and individual well dynamics to decide which wells are good candidates for modification. With the goal of determining if well modification can be used to bring some of Norman?s high-arsenic wells into compliance with the new arsenic standard, the EPA Office of Research and Development (ORD) initiated a three-year research project in 2003 with participation from the U.S. Geological Survey (USGS), Oklahoma State University, and the City of Norman. The primary objectives of the project are to: (1) determine where naturally occurring arsenic is entering wells by collecting water samples at different depths, (2) investigate the utility of new methods for collecting water-quality data in a pumping well, (3) better understand the stratigraphy and composition of aquifer rocks, (4) assess 10 wells for the possibility of arsenic remediation by well modification, and (5) evaluate the effectiveness of well modification in bringing marginal wells into compliance with the new arsenic MCL. The purpose of this report is to describe the occurrence of arsenic in ground water near Norman, Oklahoma, and available options for reducing arsenic concentrations in produced ground water.

Fact Sheet↗

USGS1997

Water resources data, Washington, water year 1996

The Water Resources Division of the U.S. Geological Survey, in cooperation with State, local, and other Federal agencies, obtains a large amount of data pertaining to the water resources of Washington each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make these data readily available to interested parties outside the Geological Survey, the data are published annually in this report series entitled "Water Resources Data Washington." This report includes records on both surface and ground water in the State. Specifically, it contains: (1) Discharge records for 225 stream-gaging stations, 29 partial-record or miscellaneous streamflow stations, and 3 crest-stage partial-record streamflow station; (2) stage only records for 2 gaging stations; (3) stage and (or) content records for 34 lakes and reservoirs; (4) water-quality records for 68 stream, canal and drain sites; (5) water-level records for 4 observation wells; and (6) water quality record for 1 observation well. Records included for stream stages and for ground-water levels are only a small fraction of those obtained during the water year. This series of annual reports for Washington began with the 1961 water year with a report that contained only data relating to the quantities of surface water. For the 1964 water year, a similar report was introduced that contained only data relating to water quality. Beginning with the 1975 water year, the report format was changed to present, in one volume, data on quantities of surface water, quality of surface and ground water, and ground-water levels.

Washington↗

USGS1981

Geologic mapping of Kentucky: A history and evaluation of the Kentucky Geological Survey--U.S. Geological Survey Mapping Program, 1960-1978

In 1960, the U.S. Geological Survey and the Kentucky Geological Survey began a program to map the State geologically at a scale of 1:24,000 and to publish the maps as 707 U.S. Geological Survey Geologic Quadrangle Maps. Fieldwork was completed by the spring of 1977, and all maps were published by December 1978. Geologic mapping of the State was proposed by the Kentucky Society of Professional Engineers in 1959. Wallace W. Hagan, Director and State Geologist of the Kentucky Geological Survey, and Preston McGrain, Assistant State Geologist, promoted support for the proposal among organizations such as Chambers of Commerce, industrial associations, professional societies, and among members of the State government. It was also arranged for the U.S. Geological Survey to supply mapping personnel and to publish the maps; the cost would be shared equally by the two organizations. Members of the U.S. Geological Survey assigned to the program were organized as the Branch of Kentucky Geology. Branch headquarters, including an editorial staff, was at Lexington, Ky., but actual mapping was conducted from 18 field offices distributed throughout the State. The Publications Division of the U.S. Geological Survey established a cartographic office at Lexington to prepare the maps for publication. About 260 people, including more than 200 professionals, were assigned to the Branch of Kentucky Geology by the U.S. Geological Survey at one time or another. The most geologists assigned any one year was 61. To complete the mapping and ancillary studies, 661 professional man-years were required, compared with an original estimate of 600 man-years. A wide variety of field methods were used, but most geologists relied on the surveying altimeter to obtain elevations. Surface data were supplemented by drill-hole records, and several dozen shallow diamond-drill holes were drilled to aid the mapping. Geologists generally scribed their own maps, with a consequent saving of publication costs. Paleontologists and stratigraphers of the U.S. Geological Survey cooperated closely with the program. Paleontologic studies were concentrated in the Ordovician of central Kentucky, the Pennsylvanian of eastern and western Kentucky, and the Mesozoic and Cenozoic of westernmost Kentucky. In addition to financial support, the Kentucky Geological Survey provided economic data, stratigraphic support, and drillhole records to the field offices. Geologists of the State Survey made subsurface structural interpretations, constructed bedrock topography maps, and mapped several quadrangles. Some of the problems encountered were the inadequacy of much of the existing stratigraphic nomenclature, the uneven quality of some of the mapping, and the effects of relative isolation on the professional development of some of the geologists. The program cost a total of $20,927,500. In terms of 1960 dollars, it cost $16,035,000; this compares with an original estimate of $12,000,000. Although it is difficult to place a monetary value on the geologic mapping, the program has contributed to newly discovered mineral wealth, jobs, and money saved by government and industry. The maps are used widely in the exploration for coal, oil and gas, fluorspar, limestone, and clay. The maps are also used in planning highways and locations of dams, in evaluating foundation and excavation conditions, in preparing environmental impact statements, and in land-use planning.

Kentucky↗

USGS1946

The quartz crystal deposits of western Arkansas

Extensive geological investigations of domestic deposits of quartz crystals were undertaken by the Geological Survey of the United States Department of the Interior in the fall of 1942 in response to the urgent demand for crystals for war purposes. The work was continued throughout 1943 and took survey geologists into some 20 states in which over 1,400 deposits or reports of deposits were examined. Of the numerous highly varied occurrences of quartz examined, only the deposits in western Arkansas, in the Piedmont and Blue Ridge provinces of Virginia, North Carolina and Georgia and the placer quartz of Mokelumne Hill, California, were of sufficient promise to warrant detailed work. Production in 1943 from these areas totaled slightly less than 4 tons of oscillator quartz, over 85 per cent of which came from Arkansas.The Arkansas deposits occur throughout the thick, deformed Paleozoic shales, sandstones, and cherts exposed along the central belt of the Ouachita Mountains. Steeply dipping fractures closely related to the major folds control the deposition of most quartz.Clear quartz is confined largely to the terminal parts of primary crystals, which have developed without disturbance or interference, are commonly elongate parallel to their C axes and are bounded by relatively simple forms. Deposition of silica during and subsequent to the fracturing of crystals resulted in the formation of complex crystals which are characterized by extensive optical twinning and lineage structures, and commonly are bounded by aggregates of the simpler crystal forms. The principal defects in all types of crystals are twinning, smokiness, cavities, solid inclusions and fractures.The Arkansas quartz deposits include veins, sheeted zones and stock-works. They are largely cavity fillings, apparently deposited by rising, attenuated, hydrothermal solutions, at relatively low temperatures and pressures. Minerals associated with the quartz, which constitutes 90 per cent or more of the cavity fillings, include dickite and carbonaceous material, calcite, adularia, and chlorite. The constituents of the cavity fillings could have been derived principally from magmatic sources or more probably from underlying rocks, with small additions from the rocks enclosing the cavities. The complex vein fabrics apparently resulting from intermittent regional deformation during the deposition of the quartz, and certain structural relations of the deposits, indicate that they were formed in the final stages of the Ouachita orogeny, probably in mid-Pennsylvanian time.

Arkansas↗

USGS1978

Geothermal resource assessment of the United States

Geothermal resource assessment is the broadly based appraisal of the quantities of heat that might be extracted from the earth and used economically at some reasonable future time. In the United States, the Geological Survey is responsible for preparing geothermal assessments based on the best available data and interpretations. Updates are required every few years owing to increasing knowledge, enlarging data base, improving technology, and changing economics. Because geothermal understanding is incomplete and rapidly evolving, the USGS complements its assessments with a broad program of geothermal research that includes (1) study of geothermal processes on crustal and local scales, (2) regional evaluations, (3) intensive study of type systems before and during exploitation (4) improvement of exploration techniques, and (5) investigation of geoenvironmental constraints. ?? 1978 Birkha??user Verlag.

Pure and Applied Geophysics PAGEOPH↗

USGS2000

Chemical and physical properties affecting strontium distribution coefficients of surficial-sediment samples at the Idaho National Engineering and Environmental Laboratory, Idaho

The U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy, conducted a study to determine strontium distribution coefficients (K d s) of surficial sediments at the Idaho National Engineering and Environmental Laboratory (INEEL). Batch experiments using synthesized aqueous solutions were used to determine K d s, which describe the distribution of a solute between the solution and solid phase, of 20 surficial-sediment samples from the INEEL. The K d s for the 20 surficial-sediment samples ranged from 36 to 275 ml/g. Many properties of both the synthesized aqueous solutions and sediments used in the experiments also were determined. Solution properties determined were initial and equilibrium concentrations of calcium, magnesium, and strontium, pH and specific conductance, and initial concentrations of potassium and sodium. Sediment properties determined were grain-size distribution, bulk mineralogy, whole-rock major-oxide and strontium and barium concentrations, and Brunauer-Emmett-Teller (BET) surface area. Solution and sediment properties were correlated with strontium K d s of the 20 surficial sediments using Pearson correlation coefficients. Solution properties with the strongest correlations with strontium K d s were equilibrium pH and equilibrium calcium concentration correlation coefficients, 0.6598 and –0.6518, respectively. Sediment properties with the strongest correlations with strontium K d s were manganese oxide (MnO), BET surface area, and the >4.75-mm-grain-size fraction correlation coefficients, 0.7054, 0.7022, and –0.6660, respectively. Effects of solution properties on strontium K d s were interpreted as being due to competition among similarly charged and sized cations in solution for strontium-sorption sites; effects of sediment properties on strontium K d s were interpreted as being surface-area related. Multivariate analyses of these solution and sediment properties resulted in r 2 values of 0.8071 when all five properties were used and 0.8043 when three properties, equilibrium pH, MnO, and BET surface area, were used.

Idaho↗

USGS2019

Plant richness and composition in hardwood forest understories vary along an acidic deposition and soil-chemical gradient in the northeastern United States

Aims A century of atmospheric deposition of sulfur and nitrogen has acidified soils and undermined the health and recruitment of foundational tree species in the northeastern US. However, effects of acidic deposition on the forest understory plant communities of this region are poorly documented. We investigated how forest understory plant species composition and richness varied across gradients of acidic deposition and soil acidity in the Adirondack Mountains of New York State. Methods We surveyed understory vegetation and soils in hardwood forests on 20 small watersheds and built models of community composition and richness as functions of soil chemistry, nitrogen and sulfur deposition, and other environmental variables. Results Community composition varied significantly with gradients of acidic deposition, soil acidity, and base cation availability (63% variance explained). Several species increased with soil acidity while others decreased. Understory plant richness decreased significantly with increasing soil acidity ( r = 0.60). The best multivariate regression model to predict richness ( p < 0.001, adjusted -R 2 = 0.60) reflected positive effects of pH and carbon-to-nitrogen ratio (C:N). Conclusions The relationship we found between understory plant communities and a soil-chemical gradient, suggests that soil acidification can reduce diversity and alter the composition of these communities in northern hardwood forests exposed to acidic deposition.

New York↗

USGS2026

Indirect mineral import reliance and provenance

Mineral commodity supply chain analyses rely on international trade data reported by individual countries as quantities of a mineral commodity form imported from (or exported to) a partner. However, export quantities frequently exceed a country’s domestic production, or occur when no production data are reported, suggesting that the trade partner is merely an intermediary in a transshipment. These discrepancies can result in misleading conclusions regarding supply chain vulnerabilities and dependencies. We present a two-stage methodology to reconcile gaps between reported material sources and actual producers. First, we construct trade networks for specific mineral forms, treating production as a type of import to distinguish producing nations from entrepôts. By tracing flows through these networks, we attribute a target country’s imports to original producers via both direct (in a single trade link) and indirect (transferring through intermediaries) pathways. Second, these production-attributed flows are incorporated into multi-stage supply chains to determine the upstream provenance of feedstock for domestic refining and processing. This approach provides a more representative picture of trade reliance. For example, while the United States (U.S.) Geological Survey reports no imports of unwrought antimony metal from Russia in 2022 (U.S. Geological Survey (2025). Mineral Commodity Summaries 2025. 10.3133/mcs2025), our analysis reveals that over 16% of U.S. imports can be traced back to Russian mining through intermediate processing in countries such as China, India, and Vietnam. Additionally, our analysis of the aluminum supply chain shows that while the U.S. is reported as 52% net import reliant on aluminum materials in 2022, it is 100% reliant on foreign bauxite, 7% of which arrived indirectly. This unreported reliance, which is predominantly tied to bauxite mined in Brazil (43%) and Jamaica (28%), highlights our methods ability to capture the supply chain’s dependence on foreign feedstock that may be missing in single-stage trade data.

Mineral Economics↗

USGS2020

Paired air-water annual temperature patterns reveal hydrogeological controls on stream thermal regimes at watershed to continental scales

Despite decades of research into air and stream temperature dynamics, paired air-water annual temperature signals have been underutilized to characterize watershed processes. Annual stream temperature dynamics are useful in classifying fundamental thermal regimes and can enhance process-based interpretation of stream temperature controls, including deep and shallow groundwater discharge, when paired with air signals. In this study, we investigated multi-scale variability in annual paired air-water temperature patterns using sine-wave linear regressions of multi-year daily temperature data from streams of various sizes. A total of 311 sites from two spatially intensive regional datasets (Shenandoah National Park and Olympic Experimental State Forest) and a spatially extensive national dataset spanning the contiguous United States (U.S. Geological Survey gages) were evaluated. We calculated three annual air-water thermal metrics (mean ratio, phase lag, and amplitude ratio) to deduce the influence of groundwater and other watershed processes on stream thermal regimes at multiple spatial scales. Site-specific values of the three annual air-water thermal metrics ranged from 0.69 to 5.29 (mean ratio), −9 to 40 days (phase lag), and 0.29 to 1.12 (amplitude ratio). Regional patterns in the annual thermal metrics revealed persistent yet spatially variable influences of shallow groundwater discharge and high levels of thermal variability within watersheds, indicating the importance of local hydrogeological controls on stream temperature. Furthermore, annual thermal metric patterns from the regional datasets were generally concordant with the national dataset suggesting the utility of these annual thermal metrics for analysis at multiple scales. Analysis of the national dataset showed that previously defined thermal regimes based on water temperature alone could be further refined using air-water metrics and these metrics were related to physiographic watershed characteristics such as contributing area, elevation, and slope. This research demonstrates the importance of spatial scale and heterogeneity for inferring hydrological process in streams and provides guidance for the interpretation of annual air-water temperature metrics that can be efficiently applied to the growing database of multi-year temperature records. Results from this research can aid in the prediction of future thermal habitat suitability for coldwater-adapted species at ecologically and management-relevant spatial scales with readily available data.

Continental United States↗

USGS2014

What predicts support for antler point restrictions?

Although considerable research has focused on satisfaction with recreation experiences, limited work has examined factors related to regulatory support. In 2005, an antler point restriction (APR) regulation was introduced for hunting white-tailed deer ( Odocoileus virginianus ) in Minnesota’s Itasca State Park. Hunter surveys were conducted following the 2005, 2006, 2007, and 2009 seasons. We modeled how (a) satisfaction with the deer seen, (b) type of deer pursued, (c) agency trust, and (d) years of deer-hunting experience, influenced support for the APR, and compared the model over the four survey years. Type of deer pursued and agency trust were the strongest predictors of APR support, followed by satisfaction with deer seen, and years of hunting experience. Hunters who targeted big bucks, had more trust in the agency, and expressed more satisfaction with deer seen in the field, were more supportive of the APR. Hunters who had more deer-hunting experience were less supportive.

Human Dimensions of Wildlife: An International Jou↗

USGS2019

Hydroclimatology of the Mississippi River Basin

Model estimated monthly water balance (WB) components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff [ R ]) for 848 United States (U.S.) Geological Survey 8-digit hydrologic units located in the Mississippi River Basin (MRB) are used to examine the temporal and spatial variability of the MRB WB for water years 1901 through 2014. Results indicate the MRB can be divided into nine subregions with similar temporal variability in R . The WB analyses indicated ~79% of total water-year MRB runoff is generated by four of the nine subregions and most of the R in the basin is derived from surplus ( S ) water during the months of December through May. Furthermore, the analyses showed temporal variability in S is largely controlled by the occurrence of negative atmospheric pressure anomalies over the western U.S. and positive atmospheric pressure anomalies over the eastern U.S. coast. This combination of atmospheric pressure anomalies results in an anomalous flow of moist air from the Gulf of Mexico into the MRB. In the context of paleo-climate reconstructions of the Palmer Drought Severity Index, since about 1900 the MRB has experienced wetter conditions than were experienced during the previous 500 years.

Mississippi River Basin↗

USGS2020

The water-year water balance of the Colorado River Basin

Model‐estimated monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff ( R )) for 146 United States (U.S.) Geological Survey 8‐digit hydrologic units located in the Colorado River Basin (CRB) are used to examine the temporal and spatial variability of the CRB water balance for water years 1901 through 2014 (a water year is the period from October 1 of one year through September 30 of the following year). Results indicate that the CRB can be divided into six subregions with similar temporal variability in monthly R . The water balance analyses indicated that approximately 75% of total water‐year R is generated by just one CRB subregion and that most of the R in the basin is derived from surplus ( S ) water generated during the months of October through April. Furthermore, the analyses show that temporal variability in S is largely controlled by the occurrence of negative atmospheric pressure anomalies over the northwestern conterminous U.S. (CONUS) and positive atmospheric pressure anomalies over the southeastern CONUS. This combination of atmospheric pressure anomalies results in an anomalous flow of moist air from the North Pacific Ocean into the CRB, particularly the Upper CRB. Additionally, the occurrence of extreme dry and wet periods in the CRB appears to be related to variability of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation.

Arizona, California, Colorado, Nevada, New Mexico,↗

USGS1991

The southeastern Illinois earthquake of 10 June 1987: The later aftershocks

The 10 June 1987 southeastern Illinois earthquake (mbLg = 5.2) was the seventh in a series of moderate magnitude (≧ 4.5) MMI VII shocks to occur in the Wabash Valley seismic zone of southeastern Illinois and southwestern Indiana since 1891. Located about 200 km east of St. Louis, Missouri, the shock caused minor damage in the epicentral area, had a contiguous felt area of about 433,000 km2, and had a total felt area over 1 million km2. Within 47 hours after the main shock, a cooperative effort between the U.S. Geological Survey and Memphis State University installed a 15-station aftershock monitoring network (later expanded to 21 instruments) that recorded more than 100 aftershocks in the following 4-day period. Results from the 56 aftershocks that were well located indicate a compact, cylindrically shaped aftershock volume about 1.7 km long, 0.8 km wide, and with a vertical distribution between about 9 and 12 km in depth. Composite focal mechanism solutions of the aftershocks suggest that the predominant mode of faulting is reverse slip, but some strike-slip type motion occurred similar to the mechanism for the main shock as determined from teleseismic data. The maximum principal compressive stress (P axes) is oriented easterly to east-southeasterly and is subhorizontal in plunge. These results, combined with historical observations and the recent discovery of earthquake-induced liquefaction features in the area, imply that the seismic potential of the zone may be greater than generally perceived.

Illinois↗

USGS1997

Logistic model of nitrate in streams of the upper-midwestern United States

Nitrate in surface water can have adverse effects on aquatic life and, in drinking-water supplies, can be a risk to human health. As part of a regional study, nitrates as N (NO3-N) was analyzed in water samples collected from streams throughout 10 Midwestern states during synoptic surveys in 1989, 1990, and 1994. Data from the period immediately following crop planting at 124 sites were analyzed during logistic regression to relate discrete categories of NO3-N concentrations to characteristics of the basins upstream from the sites. The NO3-N data were divided into three categories representing probable background concentrations (<3 mg L-1), elevated concentrations (3-10 mg L-1), and concentrations that exceeded the U.S. Environmental Protection Agency maximum contaminant level (MCL) for drinking water (>10 mg L-1). Nitrate-N concentrations were positively correlated to streamflow, upstream area planted in corn (Zea mays L.), and upstream N- fertilizers application rates. Elevated NO3-N concentrations were associated with poorly drained soils and were weakly correlated with population density. Nitrate-N and streamflow data collected during 1989 and 1990 were used to calibrate the model, and data collected during 1994 were used for verification. The model correctly estimated NO3-N concentration categories for 79% of the samples in the calibration data set and 60% of the samples in the verification data set. The model was used to indicate where NO3-N concentrations might be elevated or exceed the NO3-N MCL in streams throughout the study area. The potential for elevated NO3-N concentrations was predicted to be greatest for streams in Illinois, Indiana, Iowa, and western Ohio.

Journal of Environmental Quality↗

USGS1928

Forty-ninth annual report of the Director of the Geological Survey

The appropriations made directly for the work of the Geological Survey for the fiscal year 1928 included 10 items, amounting to $1,807,880. In addition $109,000 was appropriated for printing the reports of the Geological Survey, and $11,000 for miscellaneous printing and binding, and an allotment of $15,763.95 for miscellaneous supplies was made from appropriations for the Interior Department. A detailed statement of the amounts appropriated and expended is given at the end of this report. The balance on August 30, including a budget reserve of $850, was $28,301.48. The total amount of funds made available for disbursement by the Geological Survey, together with State funds directly disbursed for work administered by the Federal officials, was $2,909,170.

Annual Report↗