U.S. Geological Survey ground-water investigations in Michigan
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Open-File Report↗
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Ground-water quality and geochemistry in Dayton, Stagecoach, and Churchill Valleys, western Nevada
The U.S. Geological Survey investigated the quality of ground water in the Dayton, Stagecoach, and Churchill Valleys as part of the Carson River Basin National Water-Quality Assessment (NAWQA) pilot study. Four aquifer systems have been de- lineated in the study area. Principal aquifers are unconsolidated deposits at altitudes of less than 4,900 feet above sea level and more than 50 feet below land surface. Shallow aquifers are at altitudes of less than 4,900 feet and less than 50 feet below land surface. Upland aquifers are above 4,900 feet and provide recharge to the principal aquifers. Thermal aquifers, defined as those having a water temperature greater than 30 degrees Celsius, are also present. Ground water used in Dayton, Stagecoach, and Churchill Valleys is pumped from principal aquifers in unconsolidated basin-fill deposits. Ground water in these aquifers originates as precipitation in the adjacent mountains and is recharged by the Carson River and by underflow from adjacent upstream valleys. Ground-water flow is generally parallel to the direction of surface-water flow in the Carson River. Ground water is discharged by pumping, evapo- transpiration, and underflow into the Carson River. The results of geochemical modeling indicate that as ground water moves from upland aquifers in mountainous recharge areas to principal aquifers in basin-fill deposits, the following processes probably occur: (1) plagioclase feldspar, sodium chloride, gypsum (or pyrite), potassium feldspar, and biotite dissolve; (2) calcite precipitates; (3) kaolinite forms; (4) small amounts of calcium and magnesium in the water exchange for potassium on aquifer minerals; and (5) carbon dioxide is gained or lost. The geochemical models are consistent with (1) phases identified in basin- fill sediments; (2) chemical activity of major cations and silica; (3) saturation indices of calcite and amorphous silica; (4) phase relations for aluminosilicate minerals indicated by activity diagrams; and (5) results of optical, X-ray diffraction, and scanning-electron microscopy examination of mineral grains in the aquifer sediments. Sulfur-isotopic composition of ground- water samples also supports the models. In general, the quality of ground water in the study area meets Nevada State drinking-water standards and is acceptable for most uses. In addition to analysis for major ions, samples were analyzed for 22 inorganic trace elements, 3 nutrients, and 4 radionuclides. Selenium in 1 sample is the only constituent that exceeded Nevada State primary drinking-water standards. Nevada State secondary- drinking water standards were exceeded for fluoride in 1 sample, for iron in 7 samples, and for manganese in 19 samples. Minor constituent con- centrations are generally the result of local redox conditions, and are primarily from minerals in volcanic and marine metasedimentary rocks, metal- oxide coatings on mineral grains, and organic matter.
Open-File Report↗
Vertical distribution of hydraulic characteristics and water quality in three boreholes in the Galena-Platteville Aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1990
The U.S. Geological Survey investigated contaminant migration in the Galena-Platteville aquifer at the Parson's Casket Hardware site in Belvidere, Ill. This report presents the results of the first phase of the investigation, from August through December 1990. A packer assembly was used to isolate various depth intervals in three 150-foot-deep boreholes in the dolomite aquifer. Aquifer-test data include vertical distributions of vertical hydraulic gradient, horizontal hydraulic conductivity (K), and response of water levels in observation wells to borehole pumping. Water-quality data include vertical distributions of field-measured properties and laboratory determinations of concentrations of volatile organic compounds (VOC's). vertical hydraulic gradients in the aquifer were downward. The downward gradients ranged from less than 0.01 to 0.37 foot/foot. The largest gradient was associated with an elevated-K interval at 115 to 125 feet below land surface. The hydraulic characteristics of strata within the aquifer seem to be generally consistent across the site. The strata can be subdivided into five hydraulic units with the following approximate depth ranges-and K's : (1) a 1- to 5-foot-thick weathered surface at about 35 feet below land surface, 1-200 ft/d (feet per day); (2) 35-80 feet, 0.05-0.5 ft/d; (3) 80-115 feet, 0.5 ft/d; (4) 115-125 feet, 0.5-10 ft/d; and (5) 125-150 feet, 0.5 ft/d. Water-level drawdowns were detected in one shallow bedrock observation well during pumping of some of the packed intervals in a nearby borehole, indicating that the degree of vertical connection between some intervals in the aquifer may be greater than that between others. During development pumping of one borehole, drawdowns were detected in a nearby well screened in the lower part of the overlying glacial-drift deposits, indicating hydraulic connection between the glacial drift aquifer and the bedrock aquifer. VOC's were detected throughout the upper half (about 150 feet ) of the bedrock aquifer beneath the site. The detected compounds were predominantly chlorinated ethenes and ethanes (maximum concentration was 570 ppb (parts per billion) of trichloroethylene. There was a positive correlation between concentrations of VOC's, specific conductance, and K. The distribution of VOC concentrations indicate that the low-K dolomite beds in the Galena-Platteville aquifer may impede the downward migration of the VOC's and that the high-K beds and fissures may provide pathways for the lateral migration of VOC's through the aquifer. Contaminant migration is possibly affected by ground-water flow through vertical fractures that connect shallow beds with deeper beds in the aquifer, thus explaining the detections of some VOC species at intermittent depths.
Open-File Report↗
Petroleum geology of the Sichuan basin, China; report on U.S. Geological Survey and Chinese Ministry of Geology and Mineral Resources field investigations and meetings, October 1991
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Open-File Report↗
Simulation of the water-table altitude in the Biscayne Aquifer, southern Dade County, Florida, water years 1945-89
A digital model of the flow system in the highly permeable surficial Biscayne aquifer of southern Dade County, Florida, was constructed for the purposes of better understanding processes that influence the flow system and of supporting the construction of a subregional model of the transport of brackish water from a flowing artesian well. Problems that needed resolution in this endeavor included the development of methods to represent the influence of flowing surface water in seasonally inundated wetlands and the influence of a network of controlled canals developed in stages during the simulation time period (water years 1945-89). An additional problem was the general lack of natural aquifer boundaries near the boundaries of the study area. The model construction was based on a conceptual description of the Biscayne aquifer developed from the results of previous U.S. Geological Survey investigations. Modifications were made to an existing three-dimensional finite-difference simulator of ground-water flow to enable an upper layer of the grid to represent seasonally occurring overland sheetflow in a series of transient simulations of water levels from 1945 to 1989. A rewetting procedure was developed for the simulator that permitted resaturation of cells in this layer when the wet season recurred. An "equivalent hydraulic conductivity" coefficient was assigned to the overland flow layer that was analogous, subject to various approximations, to the use of the Manning equation. The surficial semiconfining peat and marl layers, levees, canals, and control structures were also represented as part of the model grid with the appropriate choices of hydraulic coefficient values. For most of the Biscayne aquifer grid cells, the value assigned to hydraulic conductivity for model calibration was 30,000 feet per day and the value assigned to porosity was 20 percent. Boundary conditions were specified near data sites having long-term records of surface-water stages or water-table altitudes, and modifications to the simulator permitted the specification of time-varying pressures at boundary grid cells. Rainfall data from a station in Homestead generally were used as an areally uniform rainfall specification throughout the modeled region. Maximum evapotranspiration rates ranged seasonally from a minimum of 0.08 inch per day in January to a maximum of 0.21 inch per day between June and October. Shallow-root and deep-root zone depths for the evapotranspiration calculation were 3 and 20 feet in the coastal ridge and were 0.10 and 5 feet in the glades regions where peat and marl covers occurred. Results of sensitivity analyses indicated that the simulations of stages and water levels were relatively unresponsive to 50 percent changes in aquifer hydraulic conductivity, porosity, and the equivalent hydraulic conductivity of overland flow. However, 20 percent changes in rainfall and maximum evapotranspiration rates produced significantly different water levels, as did interchange of coastal ridge and glades deep-root zone (extinction) depths. Water levels were simulated very well at most measurement sites. Sensitivity analyses illustrated the significant influence of the uncontrolled agricultural drainage canals on pre-1968 regional water levels and the further influence of Black Creek Canal in draining a region of high water after 1961. Other analyses indicated that the flood-control system of 1968-82 lowered peak water levels in the affected region by as much as 1.5 feet in the wet summers of 1968, 1969, and 1981, and that Levee 67 Extended channeled flows from the S-12 spillway structures and raised overland flow stages in Shark River Slough. Hypothetical scenarios of well-field pumping in the vicinity of Levee 31N indicated that the pumping induced a significant amount of recharge from the adjacent borrow canal, the degree of which depended on the distance between the canal and the well field. The computed ratio of evapotranspiration to rainfall recharge ranged from 88 to 94 percent during water years 1945-82. The ratio increased to about 97.9 percent during water years 1983-89, possibly because of changing water-management practices and deficient rainfall.
Florida↗
Selected environmental and geohydrologic reports for the Fort Wainwright and Fairbanks areas, Alaska as of July 1995
As part of its effort to help collect data and gather information for geohydrologic investigations, the U.S. Geological Survey (USGS) collects and reviews environmental and technical reports relating to geology, hydrology, and geohydrology. The USGS investigation efforts are coordinated with ongoing technical investigations by the Water Research Center of the University of Alaska Fairbanks and the U.S. Army Cold Regions Research and Engineering Laboratory. One project objective for Fort Wainwright includes maintaining a library of report references for USGS project use and for use by the U.S. Army, Alaska (USARAK), USARAK contractors, and other Federal and State agencies. This report presents an annotated bibliography of reports relating to the project study area or geohydrologic processes important to investigations in the study area.
Open-File Report↗
Introduction to greater Green River basin geology, physiography, and history of investigations
No abstract available.
Colorado, Utah, Wyoming↗
Data compilation, synthesis, and calculations used for organic-carbon storage and inventory estimates for mineral soils of the Mississippi River Basin
U.S. Geological Survey investigations of environmental controls on carbon cycling in soils and sediments of the Mississippi River Basin (MRB), an area of 3.3 x 106 square kilometers (km2), have produced an assessment tool for estimating the storage and inventory of soil organic carbon (SOC) by using soil-characterization data from Federal, State, academic, and literature sources. The methodology is based on the linkage of site-specific SOC data (pedon data) to the soil-association map units of the U.S. Department of Agriculture State Soil Geographic (STATSGO) and Soil Survey Geographic (SSURGO) digital soil databases in a geographic information system. The collective pedon database assembled from individual sources presently contains 7,321 pedon records representing 2,581 soil series. SOC storage, in kilograms per square meter (kg/m2), is calculated for each pedon at standard depth intervals from 0 to 10, 10 to 20, 20 to 50, and 50 to 100 centimeters. The site-specific storage estimates are then regionalized to produce national-scale (STATSGO) and county-scale (SSURGO) maps of SOC to a specified depth. Based on this methodology, the mean SOC storage for the top meter of mineral soil in the MRB is approximately 10 kg/m2, and the total inventory is approximately 32.3 Pg (1 petagram = 109 metric tons). This inventory is from 2.5 to 3 percent of the estimated global mineral SOC pool.
Professional Paper↗
Determining Volcanic Risk in Auckland (DEVORA) Research Programme—A transdisciplinary approach to address the challenge of distributed volcanism in an urban environment
The Determining Volcanic Risk in Auckland (DEVORA) Research Programme was launched in 2008 to address the challenges associated with monogenetic volcanism in an urban setting and to enhance volcanic risk management in Tāmaki Makaurau Auckland in Aotearoa New Zealand. It is a multi-agency, increasingly transdisciplinary (defined here as research that transcends traditional disciplinary boundaries by integrating diverse types of knowledge, perspectives, and methods from academic and non-academic participants to create novel solutions to complex problems), and collaborative research program jointly led by Waipapa Taumata Rau University of Auckland and Earth Sciences New Zealand (ESNZ; formerly GNS Science), with core funding from Natural Hazards Commission Toka Tū Ake (NHC; formerly the Earthquake Commission, EQC) and Te Kaunihera o Tāmaki Makaurau Auckland Council (AC). The primary research focus of DEVORA is to investigate the geologic history, volcanic hazards, and risk posed by the basaltic intraplate Auckland Volcanic Field. Disruption from ash fall and gas from other Aotearoa New Zealand volcanoes is also considered. DEVORA’s work to explore exposure and vulnerability in Tāmaki Makaurau Auckland is also useful for assessing risks from other non-volcanic natural hazards, such as seismic and tsunami hazards. The greater Tāmaki Makaurau Auckland region has an ethnically and socio-economically diverse population of approximately 1.7 million, representing about one-third of the Aotearoa New Zealand population, and hosts critical infrastructure of national significance. The size and nature of the populace, consequential economic base, and important infrastructure within Tāmaki Makaurau Auckland mean that the effects of a volcanic eruption would be felt nationally, including through the disruption of air travel to Aotearoa New Zealand. The hazards from such an eruption could potentially affect hundreds of thousands of people, businesses, and lifelines (critical infrastructure). A considerable challenge for emergency and risk managers is the monogenetic nature of the volcanic field. It is not known where or when the next eruption will occur, how much warning we may get before an eruption, nor how an eruption and its effects might unfold. In this contribution, we highlight the concept and collaborative intent of the DEVORA Programme and show how it has evolved over the 16 years since its inception. We describe how DEVORA has unified more than 100 researchers (including more than 50 graduate students) and numerous stakeholders to address key issues facing Tāmaki Makaurau Auckland and describe how research findings are being implemented into policy and communicated to stakeholder agencies and the public. We also illustrate the broader influence of the DEVORA Programme and provide some learnings that might benefit others embarking on similar integrated projects, especially those focused on distributed volcanism in and near populated areas.
Auckland↗
Logs and Geologic Data from a Paleoseismic Investigation of the Susitna Glacier fault, Central Alaska Range, Alaska
This report contains field and laboratory data from a paleoseismic study of the Susitna Glacier fault, Alaska. The initial M 7.2 subevent of the November 3, 2002, M 7.9 Denali fault earthquake sequence produced a 48-km-long set of complex fault scarps, folds, and aligned landslides on the previously unknown, north-dipping Susitna Glacier thrust fault along the southern margin of the Alaska Range in central Alaska. Most of the 2002 folds and fault scarps are 1-3 m high, implying dip-slip thrust offsets (assuming a near-surface fault dip of approximately 20 degrees)of 3-5 m. Locally, some of the 2002 ruptures were superimposed on preexisting scarps that have as much as 5-10 m of vertical separation and are evidence of previous surface-rupturing earthquakes on the Susitna Glacier fault. In 2003-2005, we focused follow-up studies on several of the large scarps at the 'Wet fan' site in the central part of the 2002 rupture to determine the pre-2002 history of large surface-rupturing earthquakes on the fault. We chose this site for several reasons: (1) the presence of pre-2002 thrust- and normal-fault scarps on a gently sloping, post-glacial alluvial fan; (2) nearby natural exposures of underlying fan sediments revealed fine-grained fluvial silts with peat layers and volcanic ash beds useful for chronological control; and (3) a lack of permafrost to a depth of more than 1 m. Our studies included detailed mapping, fault-scarp profiling, and logging of three hand-excavated trenches. We were forced to restrict our excavations to 1- to 2-m-high splay faults and folds because the primary 2002 ruptures mostly were superimposed on such large scarps that it was impossible to hand dig through the hanging wall to expose the fault plane. Additional complications are the pervasive effects of cryogenic processes (mainly solifluction) that can mask or mimic tectonic deformation. The purpose of this report is to present photomosaics, trench logs, scarp profiles, and fault slip, radiocarbon, tephrochronologic, and unit description data obtained during this investigation. We do not attempt to use the data presented herein to construct a paleoseismic history of the Susitna Glacier fault; that history will be the subject of a future report. When completed, our results will be used to compare the Susitna Glacier fault paleoseismic record with results of similar studies on the nearby Denali fault to determine if the simultaneous rupture of these two faults during the 2002 Denali fault earthquake sequence is typical or atypical of their long-term interaction.
Scientific Investigations Map↗
Reconnaissance of surface-water and ground-water quality at the Lincoln Boyhood National Memorial near Lincoln City, Indiana, 2001-02
In cooperation with the National Park Service, the U.S. Geological Survey investigated water quality of key water bodies at the Lincoln Boyhood National Memorial near Lincoln City in southwestern Indiana. The key water bodies were a stock pond, representing possible nonpoint agricultural effects on water quality; an ephemeral stream, representing the water quality of drainage from forested areas of the park; parking-lot runoff, representing water quality related to roads and parking lots; an unnamed ditch below the parking lot, representing the water quality of drainage from the parking lot and from an adjacent railroad track; and Lincoln Spring, a historical ground-water source representing ground-water conditions near a former diesel-fuel-spill site along a rail line. Water samples were analyzed for pH, temperature, specific conductance, and dissolved oxygen and for concentrations of selected major ions and trace metals, nutrients, organic constituents, and Escherichia coli bacteria. Surface-water-quality data of water samples from the park represent baseline conditions for the area in relation to the data available from previous studies of area streams. Specific-conductance values and concentrations of most major ions and various nutrients in surface-water samples from the park were smaller than those reported for samples collected in other USGS studies in areas adjacent to the park. Water-quality-management issues identified by this investigation include potentially impaired water quality from parking-lot runoff, unknown effects on surface-water quality from adjacent railroads, and the potential impairment of water quality in Lincoln Spring from human influences. Parking-lot runoff is a source of calcium, alkalinity, iron, lead, and organic carbon in the water samples from the unnamed ditch. Detection of small concentrations of petroleum hydrocarbons in water from Lincoln Spring could indicate residual contamination from a 1995 diesel-fuel spill and cleanup. The concentration of nitrite plus nitrate in water from Lincoln Spring was 16.5 milligrams per liter as nitrogen, greater than the State of Indiana standard for nitrate in drinking water (10 milligrams per liter as nitrogen). Lead concentrations in samples from the stock pond, parking-lot runoff, and the unnamed ditch exceeded the Indiana chronic aquatic criteria.
Indiana↗
Evaluation of the relation between evapotranspiration and normalized difference vegetation index for downscaling the simplified surface energy balance model
The Simplified Surface Energy Balance (SSEB) model uses satellite imagery to estimate actual evapotranspiration (ET a ) at 1-kilometer resolution. SSEB ET a is useful for estimating irrigation water use; however, resolution limitations restrict its use to regional scale applications. The U.S. Geological Survey investigated the downscaling potential of SSEB ET a from 1 kilometer to 250 meters by correlating ET a with the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer instrument (MODIS). Correlations were studied in three arid to semiarid irrigated landscapes of the Western United States (Escalante Valley near Enterprise, Utah; Palo Verde Valley near Blythe, California; and part of the Columbia Plateau near Quincy, Washington) during several periods from 2002 to 2008. Irrigation season ET a -NDVI correlations were lower than expected, ranging from R 2 of 0.20 to 0.61 because of an eastward 2–3 kilometer shift in ET a data. The shift is due to a similar shift identified in the land-surface temperature (LST) data from the MODIS Terra satellite, which is used in the SSEB model. Further study is needed to delineate the Terra LST shift, its effect on SSEB ET a , and the relation between ET a and NDVI.
Scientific Investigations Report↗
Availability and distribution of low flow in Anahola Stream, Kauaʻi, Hawaiʻi
Anahola Stream is a perennial stream in northeast Kauaʻi, Hawaiʻi, that supports agricultural, domestic, and cultural uses within its drainage basin. Beginning in the late 19th century, Anahola streamflow was diverted by Makee Sugar Company at altitudes of 840 feet (upper intake) and 280 feet (lower intake) for irrigating sugarcane in the Keālia area. When sugarcane cultivation in the Keālia area ceased in 1988, part of the Makee Sugar Company’s surface-water collection system (Makee diversion system) in the Anahola drainage basin was abandoned. In an effort to better manage available surface-water resources, the State of Hawaiʻi Department of Hawaiian Home Lands is considering using the existing ditches in the Anahola Stream drainage basin to provide irrigation water for Native Hawaiian farmers in the area. To provide information needed for successful management of the surface-water resources, the U.S. Geological Survey investigated the availability and distribution of natural low flow in Anahola Stream and also collected low-flow data in Goldfish Stream, a stream that discharges into Kaneha Reservoir, which served as a major collection point for the Makee diversion system. Biological surveys of Anahola Stream were conducted as part of a study to determine the distribution of native and nonnative aquatic stream fauna. Results of the biological surveys indicated the presence of the following native aquatic species in Anahola Stream: ʻoʻopu ʻakupa (Sandwich Island sleeper) and ʻoʻopu naniha (Tear-drop goby) in the lower stream reaches surveyed; and ʻoʻopu nākea (Pacific river goby), ʻoʻopu nōpili (Stimpson’s goby), and ʻōpae kalaʻole (Mountain shrimp) in the middle and upper stream reaches surveyed. Nonnative aquatic species were found in all of the surveyed stream reaches along Anahola Stream. The availability and distribution of natural low flow were determined using a combination of discharge measurements made from February 2011 to May 2012 at low-flow partial-record and seepage-run stations established at locations of interest along study-area streams. Upstream of the upper intake, the estimated natural (undiverted) median flow in Anahola Stream is 2.7 million gallons per day, and the flow is expected to be greater than or equal to 0.97 million gallons per day 95 percent of the time. About 0.7 mile upstream of the lower intake and downstream from the confluence with Keaʻoʻopu Stream, the estimated natural (undiverted) median flow in Anahola Stream is 6.3 million gallons per day, and the flow is expected to be greater than or equal to 2.7 million gallons per day 95 percent of the time. In Goldfish Stream, about 0.4 mile upstream from the point of discharge into Kaneha Reservoir, the estimated natural median flow is 0.54 million gallons per day, and the flow is expected to be greater than or equal to 0.23 million gallons per day 95 percent of the time. The discharge estimates are representative of low-flow conditions in the study-area streams, and they are applicable to the base period (water years 1961–2011) over which they have been computed. The distribution of natural low flow in Anahola Stream was characterized through data collected during wet- and dry-season seepage runs. Seepage-run results show that Anahola Stream was generally a gaining stream under natural low-flow conditions. During the wet-season seepage run, Anahola Stream at the station located upstream of tributary Kaʻalula Stream had more than five times the flow that was measured upstream from the upper intake. The estimated total gain (including tributary inflow) in the 6.1-mile seepage-run reach was 6.97 million gallons per day; about 42 percent of that gain was groundwater discharge to the main channel of Anahola Stream. During the dry-season seepage run, about 34 percent of the estimated total gain of 3.93 million gallons per day in the same seepage-run reach was groundwater discharge to the main channel of Anahola Stream. A 15-percent seepage loss was estimated in a 0.3-mile reach downstream from the confluence of Anahola and Keaʻoʻopu Streams. The report summarizes scenarios that describe (1) surface-water availability under regulated conditions of Anahola Stream if the upper and lower intakes are restored in the future; and (2) amount of flow available for agricultural use at the upper intake under a variety of potential instream-flow standards that may be established by the State of Hawaiʻi for the protection of instream uses.
Hawai'i↗
Estimates of future inundation of salt marshes in response to sea-level rise in and around Acadia National Park, Maine
Salt marshes are ecosystems that provide many important ecological functions in the Gulf of Maine. The U.S. Geological Survey investigated salt marshes in and around Acadia National Park from Penobscot Bay to the Schoodic Peninsula to map the potential for landward migration of marshes using a static inundation model of a sea-level rise scenario of 60 centimeters (cm; 2 feet). The resulting inundation contours can be used by resource managers to proactively adapt to sea-level rise by identifying and targeting low-lying coastal areas adjacent to salt marshes for conservation or further investigation, and to identify risks to infrastructure in the coastal zone. For this study, the mapping of static inundation was based on digital elevation models derived from light detection and ranging (LiDAR) topographic data collected in October 2010. Land-surveyed control points were used to evaluate the accuracy of the LiDAR data in the study area, yielding a root mean square error of 11.3 cm. An independent accuracy assessment of the LiDAR data specific to salt-marsh land surfaces indicated a root mean square error of 13.3 cm and 95-percent confidence interval of ± 26.0 cm. LiDAR-derived digital elevation models and digital color aerial photography, taken during low tide conditions in 2008, with a pixel resolution of 0.5 meters, were used to identify the highest elevation of the land surface at each salt marsh in the study area. Inundation contours for 60-cm of sea-level rise were delineated above the highest marsh elevation for each marsh. Confidence interval contours (95-percent,± 26.0 cm) were delineated above and below the 60-cm inundation contours, and artificial structures, such as roads and bridges, that may present barriers to salt-marsh migration were mapped. This study delineated 114 salt marshes totaling 340 hectares (ha), ranging in size from 0.11 ha (marshes less than 0.2 ha were mapped only if they were on Acadia National Park property) to 52 ha, with a median size of 1.0 ha. Inundation contours were mapped at 110 salt marshes. Approximately 350 ha of low-lying upland areas adjacent to these marshes will be inundated with 60 cm of sea-level rise. Many of these areas are currently freshwater wetlands. There are potential barriers to marsh migration at 27 of the 114 marshes. Although only 23 percent of the salt marshes in the study are on ANP property, about half of the upland areas that will be inundated are within ANP; most of the predicted inundated uplands (approximately 170 ha) include freshwater wetlands in the Northeast Creek and Bass Harbor Marsh areas. Most of the salt marshes analyzed do not have a significant amount of upland area available for migration. Seventy-five percent of the salt marshes have 20 meters or less of adjacent upland that would be inundated along most of their edges. All inundation contours, salt marsh locations, potential barriers, and survey data are stored in geospatial files for use in a geographic information system and are a part of this report.
Maine↗
Development of ion-exchange collectors for monitoring atmospheric deposition of inorganic pollutants in Alaska parklands
Between 2010 and 2014, the U.S. Geological Survey completed a series of laboratory and field experiments designed to develop methodology to support the National Park Service’s long-term atmospheric pollutant monitoring efforts in parklands of Arctic Alaska. The goals of this research were to develop passive sampling methods that could be used for long-term monitoring of inorganic pollutants in remote areas of arctic parklands and characterize relations between wet and dry deposition of atmospheric pollutants to that of concentrations accumulated by mosses, specifically the stair-step, splendid feather moss, Hylocomium splendens. Mosses and lichens have been used by National Park Service managers as atmospheric pollutant biomonitors since about 1990; however, additional research is needed to better characterize the dynamics of moss bioaccumulation for various classes of atmospheric pollutants. To meet these research goals, the U.S. Geological Survey investigated the use of passive ionexchange collectors (IECs) that were adapted from the design of Fenn and others (2004). Using a modified IEC configuration, mulitple experiments were completed that included the following: (a) preliminary laboratory and development testing of IECs, (b) pilot-scale validation field studies during 2012 with IECs at sites with instrumental monitoring stations, and (c) deployment of IECs in 2014 at sites in Alaska having known or suspected regional sources of atmospheric pollutants where samples of Hylocomium splendens moss also could be collected for comparison. The targeted substances primarily included ammonium, nitrate, and sulfate ions, and certain toxicologically important trace metals, including cadmium, cobalt, copper, nickel, lead, and zinc. Deposition of atmospheric pollutants is comparatively low throughout most of Alaska; consequently, modifications of the original IEC design were needed. The most notable modification was conversion from a single-stage mixed-bed column to a two-stage arrangement. With the modified IEC design, ammonium, nitrate, and sulfate ions were determined with a precision of between 5 and 10 percent relative standard deviation for the low loads that happen in remote areas of Alaska. Results from 2012 field studies demonstrated that the targeted ions were stable and fully retained on the IEC during field deployment and could be fully recovered by extraction in the laboratory. Importantly, measurements of annual loads determined by combining snowpack and IEC sampling at sites near National Atmospheric Deposition Program monitoring stations was comparable to results obtained by the National Atmospheric Deposition Program. Field studies completed in 2014 included snowpack and IEC samples to measure depositional loads; the results were compared to concentrations of similar substances in co-located moss samples. Analyses of constituents in snow and IECs included ammonium, nitrate, and sulfate ions; and a suite of trace metals. Constituent measurements in Hylocomium splendens moss included total nitrogen, phosphorous, and sulfur, and trace metals. To recover ammonium ions and metal ions from the upper cation-exchange column, a two-step extraction procedure was developed from laboratory spiking experiments. The 2014 studies determined that concentrations of certain metals, nitrogen, and sulfur in tissues of Hylocomium splendens moss reflected differences in presumptive deposition from local atmospheric sources. Moss tissues collected from two sites farthest from urban locales had the lowest levels of total nitrogen and sulfur, whereas tissues collected from three of the urban sites had the greatest concentrations of many of the trace metals. Moss tissue concentrations of three trace metals (cobalt, chromium, and nickel) were strongly (positively) Spearman’s rank correlated ( p <0.05) with annual depositional loads of those metals. In addition, moss sulfur concentrations were positively rank correlated with annual depositional loads of sulfate ( p <0.07). Exploratory models indicated linear uptake of the three metals by Hylocomium splendens moss and nonlinear uptake of sulfur from sulfate. Our results provided useful preliminary models for several of the targeted substances; however, our ability to characterize relations between concentrations in moss and loadings for many of the metals was precluded by several factors. The few test sites, small concentration gradients, and generally low concentrations hampered model developments. In addition, the weather was unusually warm throughout Alaska during the winter of 2013–14, which caused intermittent melting of the snowpack at some of the test sites; consequently, our measurements of overwinter loads based on snowpack samples (obtained in late March) probably underestimated the actual loads. Regardless of these potential limitations, these studies have established a foundation to support further studies that can improve our understanding of how mosses accumulate inorganic substances and ultimately how mosses might be used as biomonitors of atmospheric pollutants; moreover, the successful development and validation of the IECs during this research documents how the methodology can be used for future monitoring efforts in remote regions of Alaska and elsewhere.
Alaska↗
Estimated hydrogeologic, spatial, and temporal distribution of self-supplied domestic groundwater withdrawals for aquifers of the Virginia Coastal Plain
Water use from private-domestic wells accounts for nearly 40 percent of total groundwater withdrawals in the Virginia Coastal Plain Physiographic Province (henceforth called the Virginia Coastal Plain). However, because self-supplied domestic water use generally falls below the Virginia Department of Environmental Quality (VDEQ) reporting and management threshold of 300,000 gallons per month, quantifying these withdrawals is challenging. This report builds upon the foundation of previous U.S. Geological Survey investigations by providing revised techniques to improve estimates of the aquifer source, spatial distribution, and monthly magnitude of these groundwater withdrawals. The aquifer sources of private-domestic wells in the Virginia Coastal Plain were estimated by cross-referencing 8,264 well records from the VDEQ and the Virginia Department of Health to a digital model of the Virginia Coastal Plain hydrogeologic framework. This analysis highlights the regional importance of the Yorktown-Eastover, Potomac, and surficial aquifers. Collectively, these three aquifers account for 80 percent of self-supplied domestic groundwater withdrawals. The population using self-supplied domestic water was estimated using census blocks, well-use ratios, building footprints, and land-use and land-cover data to produce a high-resolution, disaggregated, raster-based dataset. This approach improves upon previous models at the census-block or road-network scale by reducing the low-density spread of the self-supplied domestic population across undeveloped areas and concentrating the population and its corresponding water use in the areas where it is most likely to occur. Results show that an estimated 475,332 people comprise the 2020 self-supplied domestic population of the Virginia Coastal Plain, an increase of 5.7 percent since 2010, and the greatest concentrations of self-supplied domestic population surround large cities. Estimates could be further refined with the addition of current and complete spatial data on public water-system service areas. The quantity of water used by the self-supplied domestic population was estimated by modifying published state per-capita water-use coefficients with the corresponding monthly variability assessed from Virginia Coastal Plain public water-system withdrawal data. This analysis estimates an average increase of 12 percent from June through August and an average decrease of 8 percent from December through March from the baseline annual average of 80 gallons per day per capita, which generally matches similar studies in the eastern United States. The application of these revised methodologies for the estimation of private-domestic wells and the self-supplied domestic population improves understanding of domestic groundwater use in the Virginia Coastal Plain across hydrogeologic, spatial, and temporal scales. These revisions help better inform water-resource managers and decision makers and support higher resolution groundwater modeling. Furthermore, these methods are transferrable to other areas where self-supplied domestic water withdrawals are important to the overall water budget.
Virginia↗
Hydrogeology and simulation of ground-water flow in the aquifers underlying Belvidere, Illinois
The U.S. Geological Survey investigated the ground-water-flow system and distribution of contaminants in the vicinity of Belvidere, Illinois, during 1992?2000. The study included the compilation, collection, and analyses of hydrogeologic and water-quality data and simulation of the ground-water-flow system. Hydrogeologic data include lithologic, stratigraphic, geophysical, hydraulic-property, water-level, ground-water withdrawal, and streamflow data. Water-quality data include analyses of water samples primarily for volatile organic compounds (VOC?s) and selectively for tritium and inorganic constituents. Data were collected from about 250 wells and 21 surfacewater sites. These data were used (1) to describe the hydrogeologic framework of the ground-waterflow system, preferential pathways and directions of ground-water movement and contaminant distribution, ground-water/surface-water relations, and the water budget and (2) to develop and calibrate the ground-water-flow model. The glacial drift (sand and gravel with some clay) and Galena-Platteville (fractured dolomite) aquifers and the sandstone aquifers of the Cambrian-Ordovician aquifer system compose the ground-water-flow system underlying Belvidere and vicinity. The Glenwood confining unit separates the Galena-Platteville aquifer from the underlying sandstone aquifers. The Galena- Platteville aquifer and confining unit may be absent in parts of the Troy Bedrock Valley, about 1.5 miles west of Belvidere. Throughout the study area, the Kishwaukee River and its tributaries seem to be gaining flow from shallow ground-water discharge. Potentiometric levels in the glacial drift and Galena-Platteville aquifers range from about 900 feet above sea level in the upland areas to 740 feet along the Kishwaukee River. Estimated horizontal hydraulic conductivity of the glacial drift aquifer ranges from about 0.13 to 280 feet per day. The Galena-Platteville aquifer is a dual-porosity unit with the greatest percentage of flow through fractures and bedding-plane partings. Estimated horizontal hydraulic conductivity ranges from about 0.005 to 2,500 feet per day. Estimated horizontal hydraulic conductivity of the St. Peter aquifer (the uppermost sandstone aquifer of the Cambrian-Ordovician aquifer system ranges from about 4.7 to 17.5 feet per day. Volatile organic compounds have been detected in all aquifers underlying Belvidere. Trichloroethene and tetrachloroethene are the principal VOC?s detected at concentrations above regulatory levels, with the largest number of detections and highest concentrations in the glacial drift aquifer. VOC?s generally are not detected in the glacial drift aquifer farther than 1,000 feet from known or potential source areas (industrial or disposal sites), because most source areas are near the Kishwaukee River, where shallow ground water discharges. Across most of the study area, the Glenwood confining unit seems to restrict downward movement of VOC?s into the underlying St. Peter aquifer; in the immediate vicinity of Belvidere, downward movement also seems restricted by lateral movement toward the municipal wells through permeable intervals in the 2 Hydrogeology and Simulation of Ground-Water Flow in the Aquifers Underlying Belvidere, Illinois Galena-Platteville aquifer. Fractures and (or) unused wells that may penetrate the confining unit seem to provide local pathways for limited movement of VOC?s to the sandstone aquifers. At least two municipal wells seem to intercept the bedding-plane partings at about 525 and 485 feet above sea level. Water levels in the lower one-third of the Galena-Platteville aquifer rapidly respond to withdrawals at these wells. The ground-water-flow system underlying Belvidere was simulated to test the conceptual model of the system. The three-dimensional, steady-state model represents the glacial drift, Galena-Platteville, and sandstone aquifers sep
Water-Resources Investigations Report↗
Ground-water recharge and flowpaths near the edge of the Decorah-Platteville-Glenwood confining unit, Rochester, Minnesota
The primary source of ground water for the city of Rochester, Olmsted County, southeastern Minnesota is the St. Peter-Prairie du Chien-Jordan aquifer. Based on results of a previous U.S. Geological Survey investigation in the Rochester area, relatively high rates of areal recharge to the St. Peter-Prairie du Chien-Jordan aquifer occur along the edge of the overlying Decorah-Platteville-Glenwood confining unit. The primary source of water to the zone of increased recharge along the edge of the confining unit is the upper carbonate aquifer. Ground-water recharge rates to the St. Peter-Prairie du Chien-Jordan aquifer during all of 1998 ranged from 1.9 to 25.5 in./yr (inches per year). Recharge rates were greatest near the edge of the Decorah-Platteville-Glenwood confining unit and least where the confining unit is thick and is overlain by the upper carbonate aquifer (mean of 2.0 in./yr). Recharge rates downslope from the edge of the confining unit were greatest to the St. Peter on the slope entering the main South Fork Zumbro River Valley. Results of groundwater age dating using chlorofluorocarbons (CFCs) indicated recharge dates ranging from (1) the mid-1950’s to the early 1990’s for the St. Peter, (2) the late 1960’s to approximately 1990 for the Prairie du Chien, and (3) the early to mid-1950’s for the Jordan. Cross-sectional model simulations indicated that most of the areal recharge entering the aquifer system through the upper carbonate aquifer discharges from springs and seeps. Of the 2.28 ft3/s (cubic feet per second) of areal recharge that enters the upper carbonate aquifer, 2.23 ft3/s is discharged from the aquifer by springs and seeps. Results indicate that areal recharge to the upper Prairie du Chien moves primarily westward and discharges to Bear Creek. Areal recharge rates derived from hydrograph analysis, CFC age-dating, and cross-sectional model analysis were much greater to the St. Peter downslope from the edge of the Decorah-Platteville-Glenwood confining unit (25.5, 35.3, and 23.75 in./yr, respectively) than occurs to the Prairie du Chien in any hydrogeologic setting. The model-simulated discharge from springs and seeps in the lower part of the upper carbonate aquifer represents a potential source of water of 33 in./yr to the St. Peter unit, similar to the estimated areal recharge rates derived from hydrograph analysis and CFC age-dating. The water withdrawn by pumped wells or discharged to Bear Creek is derived predominantly from areal recharge near the edge of the Decorah-Platteville-Glenwood confining unit (0.47 ft 3 /s), rather than from water that has leaked downward through the Decorah unit (0.03 ft 3 /s). Model simulated discharge through springs and seeps in the lower part of the upper carbonate aquifer (0.21 ft 3 /s) represents a potential source of water to the St. Peter-Prairie du Chien-Jordan aquifer.
Minnesota↗