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At least 1,027 records · Page 57Linked to original sources
USGS2007

Principal Facts of Gravity data in the Northern Willamette Valley and Vicinity, Northwestern Oregon and Southwestern Washington

Gravity data were collected from 2004 through 2006 to assist in mapping subsurface geology in the northern Willamette Valley and vicinity, northwestern Oregon and southwestern Washington. Prior to this effort to improve the gravity data coverage in the study area, very little regional data were available. This report gives the principle facts for 2710 new gravity stations and 1446 preexisting gravity stations. Much of the study area is now covered with data of sufficient density to define basin boundaries and correlate with many of the larger fault systems. ,p> The study area lies between 44? 52.5 and 46? N latitude and between 122? 15 and 123? 37.5 W longitude. Although this is a continuing project and more gravity data is expected to be collected, this report is being published to show the progress of the data collection. The majority of these data are spaced at about 1.6 km (1 mile), but three closely spaced profiles were measured in the Portland area across several faults. To obtain a 1.6 km grid of data points would require about 5120 gravity stations. To date we have collected 2710 stations. Including the preexisting data points, the total number of stations is 4156, and complete regional coverage is about 80 percent at this time.

Open-File Report↗
USGS1978

Low-cost computer classification of land cover in the Portland area, Oregon, by signature extension techniques

Computer-aided techniques for interpreting multispectral data acquired by Landsat offer economies in the mapping of land cover. Even so, the actual establishment of the statistical classes, or "signatures," is one of the relatively more costly operations involved. Analysts have therefore been seeking cost-saving signature extension techniques that would accept training data acquired for one time or place and apply them to another. Opportunities to extend signatures occur in preprocessing steps and in the classification steps that follow. In the present example, land cover classes were derived by the simplest and most direct form of signature extension: Classes statistically derived from a Landsat scene for the Puget Sound area, Wash., were applied to the Portland area, Oreg., using data for the next Landsat scene acquired less than 25 seconds down orbit. Many features can be recognized on the reduced-scale version of the Portland land cover map shown in this report, although no statistical assessment of its accuracy is available. The cost of classifying 5,607 square kilometers (2,165 sq. mi.) in the Portland area was less than 8 cents per square kilometer ($0.0788, or $0.2041 per square mile). Besides saving in costs, this and other signature extension techniques may be useful in completing land use and land cover mapping in other large areas where multispectral and multitemporal Landsat data are available in digital form but other source materials are generally lacking.

Oregon, Washington↗
USGS1980

Geophysical logs of 13 drill holes, Acord Lakes Quadrangle, Utah

This report presents the geophysical logs for 13 drill holes drilled during 1979 in the Convulsion Canyon-Duncan Mountain area, Acord Lakes quadrangle, Sevier County, Utah. The drilling was done by the Utah Geological and Mineralogical Survey under contract to the U.S. Geological Survey. The sites of all of the drill holes are within the Wasatch Plateau Known Recoverable Coal Resource Area (KRCRA) and in the Richfield Ranger district of the Fishlake National Forest. The purpose of the drilling was to identify and evaluate coal resources under public lands that may be included in a future coal leasing program. The area is underlain by Cretaceous and younger rocks (table 1). The coal seams of economic interest are in the lower 200 ft of the Upper Cretaceous Blackhawk Formation, a complex sequence of intertonguing sandstone, shale and coal. Regional dip of the strata in the area is approximately 2° to the northwest. The geology and coal resources of the area were described by Spieker (1931) and Doelling (1972). Most of the drill holes were rotary drilled and the thicknesses and depths were determined from geophysical logs. In order to obtain data on the quality of the coal, the coal-bearing section in selected holes was core drilled. Table 2 gives the drilling and logging information for the 13 completed holes. All drill holes were bottomed in the Upper Cretaceous Star Point Sandstone.

Utah↗
USGS1998

Chemical analyses of hot springs, pools, geysers, and surface waters from Yellowstone National Park, Wyoming, and vicinity, 1974-1975

This report presents all analytical determinations for samples collected from Yellowstone National Park and vicinity during 1974 and 1975. Water temperature, pH, Eh, and dissolved O2 were determined on-site. Total alkalinity and F were determined on the day of sample collection. Flame atomic-absorption spectrometry was used to determine concentrations of Li, Na, K, Ca, and Mg. Ultraviolet/visible spectrophotometry was used to determine concentrations of Fe(II), Fe(III), As(III), and As(V). Direct-current plasma-optical-emission spectrometry was used to determine the concentrations of B, Ba, Cd, Cs, Cu, Mn, Ni, Pb, Rb, Sr, and Zn. Two samples collected from Yellowstone Park in June 1974 were used as reference samples for testing the plasma analytical method. Results of these tests demonstrate acceptable precision for all detectable elements. Charge imbalance calculations revealed a small number of samples that may have been subject to measurement errors in pH or alkalinity. These data represent some of the most complete analyses of Yellowstone waters available.

Wyoming↗
USGS1987

Water quality of Lake Tuscaloosa and streamflow and water quality of selected tributaries to Lake Tuscaloosa, Alabama, 1982-86

Lake Tuscaloosa, created in 1969 by the impoundment of North River, provides the primary water supply for Tuscaloosa, Alabama , and surrounding areas. This report describes the percent contribution of major tributaries to the mean inflow to the lake; water quality; and changes in water quality in the lake and selected tributaries. During base flow, about 60% of the total flow into Lake Tuscaloosa is contributed by Binion and Carroll Creeks, which drain only 22% of the Lake Tuscaloosa basin. Binion and Carroll Creek basins are underlain primarily by sand and gravel deposits of the Coker Formation. Mean inflow to the lake was 1,150 cu ft/sec during 1983, a wet year, and 450 cu ft/sec during 1985, a relatively dry year. More than 80% of the total inflow during both years was contributed by North River and Binion, Cripple, and Carroll Creeks. About 59% was contributed by North River during those years. Except for pH, sulfate, and dissolved and total recoverable iron and manganese, the water quality of the tributaries is generally within drinking water limits and acceptable for most uses. The water quality of Lake Tuscaloosa is generally within drinking water limits and acceptable for most uses. The maximum and median concentrations of sulfate increased every year at the dam from 1979 to 1985 (7.2 to 18 mg/L and 6.2 to 14 mg/L, respectively). The dissolved solids concentrations for water at the dam have varied (1979-86) from 27 to 43 mg/L; the sulfate, 5.2 to 18 mg/L; and the dissolved iron, 10 to 250 micrograms/L--all within the recommended drinking water limits. However, concentrations of dissolved manganese and total recoverable iron and manganese at the dam commonly exceeded the recommended drinking water limits. In November 1985, after the summer warmup and increase in biological activity, the water quality at five depth profiles sites on Lake Tuscaloosa was acceptable for most uses, generally. However, a dissolved oxygen concentration of 1 mg/L or less was observed within 5 to 10 ft of the bottom for several depth profiles. At depths > 35 to 40 ft (out of a total depth of about 50 to 100 ft) the dissolved oxygen concentration was < 5 mg/L at several sites. By mid-January 1986, the temperature and dissolved oxygen depth profiles were virtually constant from top to bottom of the lake at all five sites; this indicated that lake turnover was complete. However, significant variation existed in pH depth profiles. (Author 's abstract)

Water-Resources Investigations Report↗
USGS2008

Assessment of undiscovered oil and gas resources of the West Siberian Basin Province, Russia, 2008

The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the West Siberian Basin Province in Russia as part of the USGS Circum-Arctic Resource Appraisal program. This province is the largest petroleum basin in the world and has an areal extent of about 2.2 million square kilometers. It is a large rift-sag feature bounded to the west by the Ural fold belt, to the north by the Novaya Zemlya fold belt and North Siberian Sill, to the south by the Turgay Depression and Altay-Sayan fold belt, and to the east by the Yenisey Ridge, Turukhan-Igarka uplift, Yenisey-Khatanga Basin, and Taimyr High. The West Siberian Basin Province has a total discovered oil and gas volume of more than 360 billion barrels of oil equivalent (Ulmishek, 2000). Exploration has led to the discovery of tens of giant oil and gas fields, including the Urengoy gas field with more than 3500 trillion cubic feet of gas reserves and Samotlar oil field with reserves of nearly 28 billion barrels of oil (Ulmishek, 2003). This report summarizes the results of a reassessment of the undiscovered oil and gas potential of that part of the province north of the Arctic Circle; a previous assessment that included the entire province was completed in 2000 (Ulmishek, 2000). The total petroleum system (TPS) and assessment units (AU) defined by the USGS for the assessments in 2000 were adopted for this assessment. However, only those parts of the Aus lying wholly or partially north of the Arctic Circle were assessed for this study.

West Siberian Basin Province↗
USGS1981

Geologic structure, hydrology, and water quality of the Laramie-Fox Hills aquifer in the Denver basin, Colorado

The Denver ground-water basin underlies a 6,700-square-mile area extending from Greeley in the north to Colorado Springs in the south, and from the Front Range in the west to near Limon in the east. The four major bedrock aquifers that occur in the basin are the Laramie-Fox Hills aquifer (the deepest aquifer), the Arapahoe aquifer, the Denver aquifer, and the Dawson aquifer (the uppermost aquifer). The Laramie-Fox Hills aquifer, which is the subject of this report, underlies the entire area of the basin in east-central Colorado (index map, fig. 1) and is an important source of water for residents in the northern Denver suburban area and in the rural areas of eastern Jefferson, Arapahoe, and Elbert Counties, Adams County, and southern Weld and El Paso Counties. About 90 percent of the estimated 1,700 wells completed in the aquifer supply water to residents and livestock. The remaining wells supply water for commercial and industrial use and limited irrigation of commercial crops.

Colorado↗
USGS2014

Wildland fire ash: Production, composition and eco-hydro-geomorphic effects

Fire transforms fuels (i.e. biomass, necromass, soil organic matter) into materials with different chemical and physical properties. One of these materials is ash, which is the particulate residue remaining or deposited on the ground that consists of mineral materials and charred organic components. The quantity and characteristics of ash produced during a wildland fire depend mainly on (1) the total burned fuel (i.e. fuel load), (2) fuel type and (3) its combustion completeness. For a given fuel load and type, a higher combustion completeness will reduce the ash organic carbon content, increasing the relative mineral content, and hence reducing total mass of ash produced. The homogeneity and thickness of the ash layer can vary substantially in space and time and reported average thicknesses range from close to 0 to 50 mm. Ash is a highly mobile material that, after its deposition, may be incorporated into the soil profile, redistributed or removed from a burned site within days or weeks by wind and water erosion to surface depressions, footslopes, streams, lakes, reservoirs and, potentially, into marine deposits. Research on the composition, properties and effects of ash on the burned ecosystem has been conducted on material collected in the field after wildland and prescribed fires as well as on material produced in the laboratory. At low combustion completeness (typically T < 450 °C), ash is organic-rich, with organic carbon as the main component. At high combustion completeness (T > 450 °C), most organic carbon is volatized and the remaining mineral ash has elevated pH when in solution. It is composed mainly of calcium, magnesium, sodium, potassium, silicon and phosphorous in the form of inorganic carbonates, whereas at T > 580 °C the most common forms are oxides. Ash produced under lower combustion completeness is usually darker, coarser, and less dense and has a higher saturated hydraulic conductivity than ash with higher combustion completeness, although physical reactions with CO 2 and when moistened produce further changes in ash characteristics. As a new material present after a wildland fire, ash can have profound effects on ecosystems. It affects biogeochemical cycles, including the C cycle, not only within the burned area, but also globally. Ash incorporated into the soil increases temporarily soil pH and nutrient pools and changes physical properties such as albedo, soil texture and hydraulic properties including water repellency. Ash modifies soil hydrologic behavior by creating a two-layer system: the soil and the ash layer, which can function in different ways depending on (1) ash depth and type, (2) soil type and (3) rainfall characteristics. Key parameters are the ash's water holding capacity, hydraulic conductivity and its potential to clog soil pores. Runoff from burned areas carries soluble nutrients contained in ash, which can lead to problems for potable water supplies. Ash deposition also stimulates soil microbial activity and vegetation growth. Further work is needed to (1) standardize methods for investigating ash and its effects on the ecosystem, (2) characterize ash properties for specific ecosystems and wildland fire types, (3) determine the effects of ash on human and ecosystem health, especially when transported by wind or water, (4) investigate ash's controls on water and soil losses at slope and catchment scales, (5) examine its role in the C cycle, and (6) study its redistribution and fate in the environment.

Earth-Science Reviews↗
USGS1955

Sixth progress report on the cooperative investigation of springs and streamflow in the Tecolote Tunnel area of Santa Barbara County, California

This report is the sixth in a continuing series of progress reports giving the results of discharge measurements obtained at more than 120 selected sites in the "Tecolote Tunnel Area" of the Santa Ynez Mountains. The area derives its name from the tunnel now being completed by the Bureau of Reclamation for the purpose of diverting the flood waters of the Santa Ynez River stored in Cachuma Reservoir into urban and agricultural areas in and near the city of Santa barbara. The observational area for purposes of this investigation extends from Refugio Pass on the west to San Marcos Pass and the Painted Cave area on the east. The tunnel alignment is rouhly north and south through the center of this area.

California↗
USGS1990

Results of test drilling and hydrologic monitoring in the Indian Bathtub area, Owyhee County, southwestern Idaho, January 1989 through September 1990

This report presents data collected during the period January 1989 through September 1990 from eight test holes and selected thermal-water wells and springs in the Indian Bathtub area, southwestern Idaho. The data include completion, lithologic, and gamma logs for eight test holes, hydrographs of water levels in the test holes and ten other wells, hydrographs of discharges at four springs, and chemical and isotopic analyses of water from six of the test holes. These data were collected as part of a continuing study to determine the cause or causes of decreased discharge at Indian Bathtub Spring and other thermal springs along Hot Creek.

Idaho↗
USGS2017

Design and methods of the Midwest Stream Quality Assessment (MSQA), 2013

During 2013, the U.S. Geological Survey (USGS) National Water-Quality Assessment Project (NAWQA), in collaboration with the USGS Columbia Environmental Research Center, the U.S. Environmental Protection Agency (EPA) National Rivers and Streams Assessment (NRSA), and the EPA Office of Pesticide Programs assessed stream quality across the Midwestern United States. This Midwest Stream Quality Assessment (MSQA) simultaneously characterized watershed and stream-reach water-quality stressors along with instream biological conditions, to better understand regional stressor-effects relations. The MSQA design focused on effects from the widespread agriculture in the region and urban development because of their importance as ecological stressors of particular concern to Midwest region resource managers. A combined random stratified selection and a targeted selection based on land-use data were used to identify and select sites representing gradients in agricultural intensity across the region. During a 14-week period from May through August 2013, 100 sites were selected and sampled 12 times for contaminants, nutrients, and sediment. This 14-week water-quality “index” period culminated with an ecological survey of habitat, periphyton, benthic macroinvertebrates, and fish at all sites. Sediment was collected during the ecological survey for analysis of sediment chemistry and toxicity testing. Of the 100 sites, 50 were selected for the MSQA random stratified group from 154 NRSA sites planned for the region, and the other 50 MSQA sites were selected as targeted sites to more evenly cover agricultural and urban stressor gradients in the study area. Of the 50 targeted sites, 12 were in urbanized watersheds and 21 represented “good” biological conditions or “least disturbed” conditions. The remaining 17 targeted sites were selected to improve coverage of the agricultural intensity gradient or because of historical data collection to provide temporal context for the study. This report provides a detailed description of the MSQA study components, including surveys of ecological conditions, routine water sampling, deployment of passive polar organic compound integrative samplers, and stream sediment sampling at all sites. Component studies that were completed to provide finer scale temporal data or more extensive analysis at selected sites, included continuous water-quality monitoring, daily pesticide sampling, laboratory and in-stream water toxicity testing efforts, and deployment of passive suspended-sediment samplers.

Illinois, Indiana, Iowa, Kansas, Kentucky, Michiga↗
USGS2012

Monitoring of stream restoration habitat on the main stem of the Methow River, Washington, during the pre-treatment phase (October 2008-May 2012) with a progress report for activities from March 2011 to November 2011

Introduction The U.S. Geological Survey (USGS) received a request from the Bureau of Reclamation (Reclamation) to provide monitoring and an evaluation of the effectiveness of habitat actions that Reclamation plans to implement in the Upper Columbia River basin, which includes the Methow River. This monitoring and evaluation program is to partially fulfill Reclamations part of the 2008 Biological Opinion for the Federal Columbia River Power System that includes a Reasonable and Prudent Alternative (RPA) to protect listed salmon and steelhead across their life cycle. The target species in the Methow River for this monitoring and restoration effort include Upper Columbia River (UCR) spring Chinook salmon ( Oncorhynchus tshawytscha ), UCR steelhead ( O. mykiss ), and bull trout ( Salvelinus confluentus ), which are listed as threatened or endangered under the Endangered Species Act. This report covers UCR activities performed by USGS personnel from March 2011 to November 2011. It involves collecting and analyzing data collected during pre-implementation (2008&ndash;2012) there will be a follow-up after actions are completed (2012&ndash;2014). The goal of Reclamation is to maximize the potential of habitat and improve proposed limiting factors affecting the middle Methow River subwatershed (Reclamation, 2010). The Middle Methow (M2) reach (river kilometer mile [rkm] 843.065 to 843.080) of the Methow River was selected as the treatment reach for this study based on possible stream restoration plans by Reclamation (fig. 1). The upper Methow River (rkm 843.094 and 843.080), Chewuch River, and the Methow River downstream of the Twisp River (rkm 843.065) are being sampled as reference and control reaches in this study (fig. 2). This report covers the third year in the pre-evaluation of the M2 reach and its side channels. Restoration of the M2 reach is scheduled for 2012, which is planned to be followed by a multi-year intensive post-evaluation period. The intent of the summary of information provided in this report is to fulfill the objectives and tasks submitted in a statement of work to Reclamation in November 2010 (Connolly and Martens, 2011). The study design provides data by which to assess potential fish response to a Reclamation habitat restoration effort focused to improve juvenile salmonid rearing habitat in the M2, which runs between the towns of Winthrop and Twisp, Washington (fig. 1). The pre-treatment phase of the study is designed so that specific questions about the response of target fish species (spring Chinook salmon, steelhead, and bull trout) to the restoration actions can be addressed. Effectiveness is being determined by measuring fish productivity and habitat connectivity of the restoration reach and adjoining reaches, and their tributaries. The study includes sampling efforts directed to understand the relationships between stream habitat and the abundance of various fish species and to assess the response of the fish community. To complement these measurements, we will use models to predict response to treatment, and we will update the model with empirically derived data as these data become available. This modeling effort is expected to inform us of data gaps, sensitivity of key variables, and ability to detect response based on variability of the data. The approach and actions taken or planned by Reclamation to modify off-channel habitat are largely untested as to their effectiveness to improve target fish species&rsquo; productivity and survival needs. Those documented strategies that identify both physical parameters and biological relationships and benefits have been identified (Reclamation, 2008). To assess biological performance, we plan to compare age structure, growth, and age at smolting between those fish that stay in natal areas versus those fish that move. To assess retention in, and movement from or into, the restoration reach, we have used a combination of within-reach and out-of-reach sampling. We are using passive integrated transponder (PIT) tags, a network of instream PIT tag interrogation systems, and smolt traps to assess differences in biological performance and the magnitude of retention in, and movement from and into, the restoration reach.

Washington↗
USGS2019

Coal geology and assessment of resources and reserves in the Little Snake River Coal Field and Red Desert Assessment Area, Greater Green River Basin, Wyoming

The U.S. Geological Survey is studying regional-scale assessments of resources and reserves of primary coal beds in the major coal bed basins in the United States to help formulate policy for Federal, State, and local energy and land use. This report summarizes the geology and coal resources and reserves in the Little Snake River coal field and Red Desert assessment area in the Greater Green River Basin, southwestern Wyoming. These areas are contiguous and referred to as the “assessment area” in this report. The assessment area covers about 2,300 square miles of the eastern section of the 15,400-square-mile Greater Green River Basin. This area was prioritized for assessment because no comprehensive resource assessment had previously been completed in the area; abundant, previously unavailable drill hole data from cooperators and stakeholders became available; and there are active coal mines in the Greater Green River Basin area producing from some of the same formations as those found in the assessment area. Coal-bearing Eocene, Paleocene, and Upper Cretaceous formations have a composite thickness of more than 11,000 feet in the assessment area. Stratigraphic sequences that contain multiple coal beds within a formation or member are referred to as coal zones in this report. Paleogene coal beds are found within coal zones in the Eocene Wasatch Formation and the Paleocene Fort Union Formation. Cretaceous coal beds are within coal zones in the Lance, Almond, and Allen Ridge Formations. A total of 4,214 drill holes and measured sections were used to construct a geologic database for this assessment. From these data, 7 coal zones containing 55 individual coal beds were identified. Not all 55 coal beds were assessed; only those beds that were at least 3 feet thick and had at least a 2-square-mile areal extent were considered. Using a geology-based assessment methodology, the U.S. Geological Survey estimated original, available, and recoverable coal resources for 33 coal beds that met those criteria. An original resource of 73.2 billion short tons of coal was calculated for the 33 coal beds that met the criteria in the assessment area. To be considered extractable by surface mining methods, coal beds had to be equal to or greater than 3 feet thick and less than 300 feet deep. Of the 73.2 billion short tons (BST), 19.3 BST were determined to be recoverable resources, of which approximately 2.1 BST were considered as recoverable resources by surface mining methods at a stripping ratio of 10:1 or less. (defined as recoverable resources for this assessment, based on economic modeling and regional mining analogs). Recoverable resources for underground mining methods (coal 8 to 15 feet thick and between 300 and 3,000 feet deep) totaled 17.2 BST. Out of the 19.3 BST assessed as recoverable coal resources, approximately 167 million short tons (MST) were considered to be reserves. Within the 7 coal zones, the Wasatch coal zone contains an original resource of about 6.8 BST billion short tons of coal, of which 2.6 BST are considered a recoverable resource and approximately 26.7 MST are considered reserves. The Overland coal zone, in the Fort Union Formation, contains an original resource of approximately 23 BST of coal, of which 8.4 BST are considered a recoverable resource and approximately 74 MST are considered reserves. The China Butte coal zone, in the Fort Union Formation, contains an original resource of 36.2 BST of coal, of which 6.3 BST are considered a recoverable resource and approximately 5.5 MST are considered reserves. The Almond coal zone, in the Almond Formation, contains an original resource of 7.0 BST, of which approximately 2.0 BST are considered a recoverable resource and 61 MST are considered reserves. Resources were not calculated for the coal zones within the Niland Tongue of the Wasatch Formation or the Cretaceous Lance and Allen Ridge Formations because the coal beds in those zones are relatively thin, discontinuous, and have a limited areal extent.

Wyoming↗
USGS1982

Geophysical logs of four drill holes, Acord Lakes and Emery West quadrangles, Sevier County, Utah

This report presents the geophysical logs for four drill holes drilled during 1981 in the Skumpah Creek area (Acord Lakes quadrangle) and The Pines area (Emery West quadrangle), Sevier County, Utah. Figures 1 and 2 show drill-hole locations, and figures 3-7 are the geophysical logs. The drilling was done by a private drilling company under contract to the U.S. Geological Survey. The sites of all the drill holes are within the Wasatch Plateau Known Recoverable Coal Resource Area (KRCRA). Three of the sites are in the Richfield Ranger District of the Fishlake National Forest and one site is in the Ferron Ranger District of the Manti-LaSal National Forest. The purpose of the drilling was to identify and evaluate coal resources under public lands that may be included in a future coal leasing program. The area is underlain by Cretaceous and younger rocks (table 1). The coal seams of economic interest are in the lower 200 ft of the Upper Cretaceous Blackhawk Formation, a complex sequence of intertonguing sandstone, shale, and coal. Regional dip of the strata in the area is approximately 2° to the northwest. The geology and coal resources of the area were described by Spieker (1931), Doelling (1972), and Smith (1981). The drill holes were rotary drilled and the thicknesses and depths were determined from geophysical logs. In order to obtain data on the quality of the coal, the coal-bearing section in one hole was core drilled. Table 2 gives the drilling and logging information for the four completed holes. All drill holes were bottomed in the Upper Cretaceous Star Point Sandstone.

Utah↗
USGS2017

Effects of changes in pumping on regional groundwater-flow paths, 2005 and 2010, and areas contributing recharge to discharging wells, 1990–2010, in the vicinity of North Penn Area 7 Superfund site, Montgomery County, Pennsylvania

A previously developed regional groundwater flow model was used to simulate the effects of changes in pumping rates on groundwater-flow paths and extent of recharge discharging to wells for a contaminated fractured bedrock aquifer in southeastern Pennsylvania. Groundwater in the vicinity of the North Penn Area 7 Superfund site, Montgomery County, Pennsylvania, was found to be contaminated with organic compounds, such as trichloroethylene (TCE), in 1979. At the time contamination was discovered, groundwater from the underlying fractured bedrock (shale) aquifer was the main source of supply for public drinking water and industrial use. As part of technical support to the U.S. Environmental Protection Agency (EPA) during the Remedial Investigation of the North Penn Area 7 Superfund site from 2000 to 2005, the U.S. Geological Survey (USGS) developed a model of regional groundwater flow to describe changes in groundwater flow and contaminant directions as a result of changes in pumping. Subsequently, large decreases in TCE concentrations (as much as 400 micrograms per liter) were measured in groundwater samples collected by the EPA from selected wells in 2010 compared to 2005‒06 concentrations. To provide insight on the fate of potentially contaminated groundwater during the period of generally decreasing pumping rates from 1990 to 2010, steady-state simulations were run using the previously developed groundwater-flow model for two conditions prior to extensive remediation, 1990 and 2000, two conditions subsequent to some remediation 2005 and 2010, and a No Pumping case, representing pre-development or cessation of pumping conditions. The model was used to (1) quantify the amount of recharge, including potentially contaminated recharge from sources near the land surface, that discharged to wells or streams and (2) delineate the areas contributing recharge that discharged to wells or streams for the five conditions. In all simulations, groundwater divides differed from surface-water divides, partly because of differences in stream elevations and because of geologic structure and pumping. In the 1990 and 2000 simulations, all recharge in and near the vicinity of North Penn Area 7 discharged to wells, but in the 2005 and 2010 simulations some recharge in this area discharged to streams, indicating possible discharge of contaminated groundwater from North Penn Area 7 sources to streams. As the amount of groundwater withdrawals by wells has declined since 1990, the area contributing recharge to wells in the vicinity of North Penn Area 7 has decreased. To determine the effect of changes in pumping on flow paths and possible flow-path-related contributions to the observed changes in spatial distribution of contaminants in groundwater from 2005 to 2010, the USGS conducted simulations using the previously developed regional groundwater-flow model using reported pumping and estimated recharge rates for 2005 and 2010. Flow paths from recharge at known contaminant source areas to discharge locations at wells or streams were simulated under steady-state conditions for the two periods. Simulated groundwater-flow paths shifted only slightly from 2005 to 2010 as a result of changes in pumping rates. These slight changes in groundwater-flow paths from known sources of contamination are not coincident with the spatial distribution of observed changes in TCE concentrations from 2005 to 2010, indicating that the decreases of TCE concentrations may be a result of other processes, such as source removal or degradation. Results of the simulations and the absence of increases in TCE-degradation-product concentrations indicate that the decreases of TCE concentrations observed in 2010 may be at least partly related to contaminant-source removal by soil excavation completed in 2005, although additional data would be needed to confirm this preliminary explanation.

Pennsylvania↗
USGS2019

Climate adaptation Science Centers—Annual report for 2018

2018 marked the 10-year anniversary of the establishment of the U.S. Geological Survey (USGS) National Climate Change and Wildlife Science Center! With the passage of the fiscal year 2018 budget on March 23, 2018, our program name was changed from the National Climate Change and Wildlife Science Center to the National Climate Adaptation Science Center (NCASC). The eight regional Department of the Interior (DOI) Climate Science Centers were renamed Climate Adaptation Science Centers (CASCs). The name changes more clearly align the national and regional centers and emphasize their focus on meeting natural resource adaptation needs. Although the program has a new name, our mission has not changed. We are still hard at work delivering science to help fish, wildlife, water, land, and people adapt to a changing climate. During the past 10 years, the NCASC and the eight regional CASCs funded over 425 science projects and built a network of research partners, resource management stakeholders, interdisciplinary staff, fellows, and early career researchers. In celebration of our work and accomplishments over the last 10 years, the NCASC began a monthly web post series on “10 Things You May Not Know” about topics our science has focused on, including drought, glaciers, and wildfire. Additionally, CASCs that had completed their initial hosting agreement with the USGS underwent a formal review and recompetition process. New hosting agreements were awarded to the Southwest and North Central CASCs in 2018. Read the 2018 annual report to learn more about the CASCs' great science, partnerships, capacity building, and more from 2018.

Open-File Report↗