SEARCH · USGS Science

Results for “Report of Investigation”

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 1,081 records · Page 60Linked to original sources

USGS2014

Groundwater conditions in Utah, spring of 2014

This is the fifty-first in a series of annual reports that describe groundwater conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing groundwater conditions. This report, like the others in the series, contains information on well construction, groundwater withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of groundwater. Supplementary data are included in reports of this series only for those years or areas that are important to a discussion of changing groundwater conditions and for which applicable data are available. This report includes individual discussions of selected significant areas of groundwater development in the State for calendar year 2013. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is also available online at http://www.waterrights.utah.gov/techinfo/ and http://ut.water. usgs.gov/publications/GW2014.pdf. Groundwater conditions in Utah for calendar year 2012 are reported in Burden and others (2013) and are available online at http://ut.water.usgs. gov/publications/GW2013.pdf

Utah↗

USGS1993

Ground-water conditions in Utah, spring of 1993

This is the thirtieth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1992. Water-level fluctuations and selected related data, however, are described from the spring of 1988 to the spring of 1993. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Divisions of Water Rights and Water Resources, Utah Department of Natural Resources.

Utah↗

USGS1997

Ground-water conditions in Utah, spring of 1997

This is the thirty-fourth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources, provide data to enable interested parties to keep aware of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of ground water. Supplementary data are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1996. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Divisions of Water Rights and Water Resources.

Utah↗

USGS1980

Developing a state water plan: Ground-water conditions in Utah, spring of 1980

This is the seventeenth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. Supplementary data such as graphs showing chemical quality of water and maps showing water-table configuration are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected major areas of ground-water withdrawal in the State for the calendar year 1979. Water-level fluctuations, however, are described for the period spring 1979 to spring 1980. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

Utah↗

USGS2003

The Great Lakes Water Balance: Data availability and annotated bibliography of selected references

Water balance calculations for the Great Lakes have been made for several decades and are a key component of Great Lakes water management. Despite the importance of the water balance, little has been done to inventory and describe the data available for use in water balance calculations. This report provides a catalog and brief description of major datasets that are used to calculate the Great Lakes water balance. Several additional datasets are identified that could be used to calculate parts of the water balance but currently are not being used. Individual offices and web pages that are useful for attaining these datasets are included. Four specific data gaps are also identified. An annotated bibliography of important publications dealing with the Great Lakes water balance is included. The findings of this investigation permit resource managers and scientists to access data more easily, assess shortcomings of current datasets, and identify which data are not currently being utilized in water balance calculations.

Water-Resources Investigations Report↗

USGS1985

Cost effectiveness of stream-gaging program in Michigan

This report documents the results of a study of the cost effectiveness of the stream-gaging program in Michigan. Data uses and funding sources were identified for the 129 continuous gaging stations being operated in Michigan as of 1984. One gaging station was identified as having insufficient reason to continue its operation. Several stations were identified for reactivation, should funds become available, because of insufficiencies in the data network. Alternative methods of developing streamflow information based on routing and regression analyses were investigated for 10 stations. However, no station records were reproduced with sufficient accuracy to replace conventional gaging practices. A cost-effectiveness analysis of the data-collection procedure for the ice-free season was conducted using a Kalman-filter analysis. To define missing-record characteristics, cross-correlation coefficients and coefficients of variation were computed at stations on the basis of daily mean discharge. Discharge-measurement data were used to describe the gage/discharge rating stability at each station. The results of the cost-effectiveness analysis for a 9-month ice-free season show that the current policy of visiting most stations on a fixed servicing schedule once every 6 weeks results in an average standard error of 12.1 percent for the current $718,100 budget. By adopting a flexible servicing schedule, the average standard error could be reduced to 11.1 percent. Alternatively, the budget could be reduced to $700,200 while maintaining the current level of accuracy. A minimum budget of $680,200 is needed to operate the 129-gaging-station program; a budget less than this would not permit proper service and maintenance of stations. At the minimum budget, the average standard error would be 14.4 percent. A budget of $789,900 (the maximum analyzed) would result in a decrease in the average standard error to 9.07 percent. Owing to continual changes in the composition of the network and the changes in the uncertainties of streamflow accuracy at individual stations, the cost-effectiveness analysis will need to be updated regularly if it is to be used as a management tool. Cost of these updates need to be considered in decisions concerning the feasibility of flexible servicing schedules.

Michigan↗

USGS2012

Comparison of index velocity measurements made with a horizontal acoustic Doppler current profiler

The State of Illinois' annual withdrawal from Lake Michigan is limited by a U.S. Supreme Court decree, and the U.S. Geological Survey (USGS) is responsible for monitoring flows in the Chicago Sanitary and Ship Canal (CSSC) near Lemont, Illinois as a part of the Lake Michigan Diversion Accounting overseen by the U.S. Army Corps of Engineers, Chicago District. Every 5 years, a technical review committee consisting of practicing engineers and academics is convened to review the U.S. Geological Survey's streamgage practices in the CSSC near Lemont, Illinois. The sixth technical review committee raised a number of questions concerning the flows and streamgage practices in the CSSC near Lemont and this report provides answers to many of those questions. In addition, it is the purpose of this report to examine the index velocity meters in use at Lemont and determine whether the acoustic velocity meter (AVM), which is now the primary index velocity meter, can be replaced by the horizontal acoustic Doppler current profiler (H-ADCP), which is currently the backup meter. Application of the AVM and H-ADCP to index velocity measurements in the CSSC near Lemont, Illinois, has produced good ratings to date. The site is well suited to index velocity measurements in spite of the large range of velocities and highly unsteady flows at the site. Flow variability arises from a range of sources: operation of the waterway through control structures, lockage-generated disturbances, commercial and recreational traffic, industrial withdrawals and discharges, natural inflows, seiches, and storm events. The influences of these factors on the index velocity measurements at Lemont is examined in detail in this report. Results of detailed data comparisons and flow analyses show that use of bank-mounted instrumentation such as the AVM and H-ADCP appears to be the best option for index velocity measurement in the CSSC near Lemont. Comparison of the rating curves for the AVM and H-ADCP demonstrates that the H-ADCP is a suitable replacement for the AVM as the primary index velocity meter in the CSSC near Lemont. A key component to Lake Michigan Diversion Accounting is the USGS gaging station on the CSSC near Lemont, Illinois. The importance of this gaging station in monitoring withdrawals from Lake Michigan has made it one of the most highly scrutinized gaging stations in the country. Any changes in streamgaging practices at this gaging station requires detailed analysis to ensure the change will not adversely affect the ability of the USGS to accurately monitor flows. This report provides a detailed analysis of the flow structure and index velocity measurements in the CSSC near Lemont, Illinois, to ensure that decisions regarding the future of this streamgage are made with the best possible understanding of the site and the characteristics of the flow.

Illinois↗

USGS2012

Creation of digital contours that approach the characteristics of cartographic contours

The capability to easily create digital contours using commercial off-the-shelf (COTS) software has existed for decades. Out-of-the-box raw contours are suitable for many scientific applications without pre- or post-processing; however, cartographic applications typically require additional improvements. For example, raw contours generally require smoothing before placement on a map. Cartographic contours must also conform to certain spatial/logical rules; for example, contours may not cross waterbodies. The objective was to create contours that match as closely as possible the cartographic contours produced by manual methods on the 1:24,000-scale, 7.5-minute Topographic Map series. This report outlines the basic approach, describes a variety of problems that were encountered, and discusses solutions. Many of the challenges described herein were the result of imperfect input raster elevation data and the requirement to have the contours integrated with hydrographic features from the National Hydrography Dataset (NHD).

Scientific Investigations Report↗

USGS2014

Methods for estimating drought streamflow probabilities for Virginia streams

Maximum likelihood logistic regression model equations used to estimate drought flow probabilities for Virginia streams are presented for 259 hydrologic basins in Virginia. Winter streamflows were used to estimate the likelihood of streamflows during the subsequent drought-prone summer months. The maximum likelihood logistic regression models identify probable streamflows from 5 to 8 months in advance. More than 5 million streamflow daily values collected over the period of record (January 1, 1900 through May 16, 2012) were compiled and analyzed over a minimum 10-year (maximum 112-year) period of record. The analysis yielded the 46,704 equations with statistically significant fit statistics and parameter ranges published in two tables in this report. These model equations produce summer month (July, August, and September) drought flow threshold probabilities as a function of streamflows during the previous winter months (November, December, January, and February). Example calculations are provided, demonstrating how to use the equations to estimate probable streamflows as much as 8 months in advance.

Virginia↗

USGS2018

An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data

An exploratory discrete Bayesian network (BN) was developed to assess the potential of this type of model for estimating the magnitudes and uncertainties of an arbitrary subset of unmeasured water-quality parameters given the measured complement of parameters historically measured at a U.S. Geological Survey streamgage. Water-quality data for 27 water-quality parameters from 596 discrete measurements at U.S. Geological Survey streamgage 03374100 White River at Hazleton, Indiana, were used to develop this BN. Data for each of the water-quality parameters were discretized into five intervals based on the quintiles of the measured values. The 596 discrete measurements were randomly partitioned into a training set with 80 percent of the data and a testing set with 20 percent of the data to identify, estimate, and assess the training and testing accuracy of the Bayesian network. A BN with 28 nodes was formed from the 27 water-quality parameters and the month of sample collection. Based on data in the training set, a network with 53 directed edges and month as the target node was identified by minimizing the negative log-likelihood function for all nodes treated, in turn, as the target variable. The edge structure determines the number and magnitude of elements in conditional probability tables associated with all nodes. The effectiveness of the BN was assessed on the basis of correct classification rates to one of the five discrete intervals, which were computed separately for the training and testing datasets and for two conditioning variable sets. The selected sets of conditioning variables represent two of many possible sets of measured parameters on which to base estimates of unmeasured parameters. The first set includes only the month of sample collection ( month ), and an expanded set includes month and six other continuously measurable parameters, referred to as the ContMeasSet , all of which were obtained from the discrete data. Results indicated that the training dataset had average correct classification rates of 41.7- and 61.2-percent rates conditioned on the month and ContMeasSet sets, respectively. The testing dataset had somewhat lower average correct classification rates of 40.8 and 56.5 percent for the two conditioning variable sets. When conditioned on month only, the average correct classification rate for the testing dataset was only slightly lower than the average correct classification rate in the training dataset, indicating little model overfitting. When using the ContMeasSet , however, the average decrease in accuracy between training and testing sets was 4.9 percent. The training and testing datasets and both sets of conditioning variables, however, indicate that the BN would substantially outperform a random assignment model, which would be expected to have a 20-percent correct classification rate. In addition, the edge structure of the BN depicts how information can flow through the network, which may help prioritize parameters for measurement to facilitate estimation of unmeasured parameters. Finally, extension of a static BN, like the one developed in this report, to a dynamic BN may provide a basis for using high-frequency or continuous water-quality data to extend information in time between discrete water-quality samples, and this integration could mitigate some of the limitations of high-frequency and discrete water-quality sampling methods.

Indiana↗

USGS2020

Groundwater quality in relation to drinking water health standards and hydrogeologic and geochemical characteristics for 47 domestic wells in Potter County, Pennsylvania, 2017

As part of a regional effort to characterize groundwater in rural areas of Pennsylvania, water samples from 47 domestic wells in Potter County were collected from May through September 2017. The sampled wells had depths ranging from 33 to 600 feet in sandstone, shale, or siltstone aquifers. Groundwater samples were analyzed for physicochemical properties that could be evaluated in relation to drinking-water health standards, geology, land use, and other environmental factors. Laboratory analyses included concentrations of major ions, nutrients, bacteria, trace elements, volatile organic compounds (VOCs), ethylene and propylene glycol, alcohols, gross-alpha/beta-particle activity, uranium, radon-222, and dissolved gases. A subset of samples was analyzed for radium isotopes (radium-226 and -228) and for the isotopic composition of methane. Results of this 2017 study show that groundwater quality generally met most drinking-water standards that apply to public water supplies. However, a percentage of samples exceeded maximum contaminant levels (MCLs) for total coliform bacteria (69.6 percent), Escherichia coli (30.4 percent), arsenic, and barium; and secondary maximum contaminant levels (SMCLs) for field pH, manganese, sodium, iron, total dissolved solids, aluminum, and chloride. All of the analyzed VOCs were below limits of detection and associated drinking water criteria. Radon-222 activities exceeded the proposed drinking-water standard of 300 picocuries per liter in 80.9 percent of the samples. The field pH of the groundwater ranged from 4.6 to 9.0. Generally, the lower pH samples had greater potential for elevated concentrations of dissolved metals, including beryllium, copper, lead, nickel, and zinc, whereas the higher pH samples had greater potential for elevated concentrations of total dissolved solids, sodium, fluoride, boron, and uranium. Near-neutral samples (pH 6.5 to 7.5) had greater hardness and alkalinity concentrations than other samples with pH values outside this range. Calcium/bicarbonate waters were the predominant hydrochemical type for the sampled aquifers, with mixed water types for many samples, including variable contributions from calcium, magnesium, and sodium combined with bicarbonate, sulfate, chloride, and nitrate. Water from 45 wells had concentrations of methane greater than the 0.0002 milligrams per liter (mg/L) detection limit. One sample had the maximum value of 11 mg/L, which exceeds the Pennsylvania action level of 7 mg/L. Additionally, three other samples had concentrations of methane greater than 4 mg/L. Outgassing of such levels of methane from the water to air within a confined space can result in a potential hazard. The elevated concentrations of methane generally were associated with suboxic groundwater (dissolved oxygen less than 0.5 mg/L) that had near-neutral to alkaline pH with relatively elevated concentrations of iron, manganese, ammonia, lithium, fluoride, and boron. Other constituents, including barium, sodium, chloride, and bromide, commonly were elevated, but not limited to, those well-water samples with elevated methane. Low levels of ethane (as much as 1.2 mg/L) were present in eight samples with the highest methane concentrations. Five samples were analyzed for methane isotopes. The isotopic and hydrocarbon compositions in these five samples suggest the methane may be of microbial origin or a mixture of thermogenic and microbial gas, but differed from the compositions reported for mud-gas logging samples collected during drilling of gas wells. The concentrations of sodium (median 8.2 mg/L), chloride (median 7.64 mg/L), and bromide (median 0.02 mg/L) for the 47 groundwater samples collected for this study ranged widely and were positively correlated with one another and with specific conductance and associated measures of ionic strength. Sixty percent of the Potter County well-water samples had chloride concentrations less than 10 mg/L. Samples with higher chloride concentrations had variable bromide concentrations and corresponding chloride/bromide ratios that are consistent with sources such as road-deicing salt and septic effluent (low bromide) or brine (high bromide). Brines are naturally present in deeper parts of the regional groundwater system and, in some cases, may be mobilized by gas drilling. It is also possible that valley wells were drilled close to or into the brine-freshwater interface, so brine signatures do not necessarily indicate contamination due to drilling. The chloride, bromide, and other constituents in road-deicing salt or brine solutions tend to be diluted by mixing with fresh groundwater in shallow aquifers used for water supply. Although 1 of 8 groundwater samples with the highest methane concentrations (greater than 0.2 mg/L) had concentrations of chloride and bromide with corresponding chloride/bromide ratios that indicated mixing with road-deicing salt, the other 7 of 8 samples with elevated methane had concentrations of chloride and bromide with corresponding chloride/bromide ratios that indicated mixing with a small amount of brine (0.02 percent or less) similar in composition to those reported for gas and oil well brines in Pennsylvania. In several eastern Pennsylvania counties where gas drilling is absent, groundwater with comparable chloride/bromide ratios and chloride concentrations have been reported. Approximately 50 percent of Potter County well-water samples, including two samples with the fourth (72.9 mg/L) and fifth (47.0 mg/L) highest chloride concentrations, have chloride/bromide ratios that indicate predominantly anthropogenic sources of chloride, such as road-deicing salt or septic effluent.

Pennsylvania↗

USGS2023

Documentation of linear regression models for computing water-quality constituent concentrations using continuous real-time water-quality data for the North Fork Ninnescah River and Cheney Reservoir, Kansas, 2014–21

Cheney Reservoir, in south-central Kansas, was constructed to provide a reliable municipal water supply for the city of Wichita, Kansas, and to provide downstream flood control, wildlife habitat, and recreation. Cheney Reservoir will continue to be important for municipal water supply use as needs increase with ongoing population growth and urban development. Advanced notification of changing water-quality conditions near water-treatment facility intakes and in source waters allows water-treatment facilities and resource planning officials to proactively monitor changing conditions. The U.S. Geological Survey (USGS), in cooperation with the City of Wichita, collected water-quality data at the North Fork Ninnescah River above Cheney Reservoir (USGS station 07144780) and Cheney Reservoir near Cheney, Kans. (USGS station 07144790), monitoring sites to update and develop regression models relating continuous water-quality constituents, streamflow, reservoir storage, and seasonal components to discretely sampled water-quality constituent concentrations of interest. Linear regression analysis was used to update and develop models for alkalinity, major ions, nutrients (nitrogen and phosphorus species), total and dissolved organic carbon, total suspended solids, suspended sediment, fecal indicator bacteria, and atrazine at the North Fork Ninnescah River site and total dissolved solids, major ions, hardness as calcium carbonate, nutrients (nitrogen and phosphorus species), chlorophyll a , and suspended sediment at the Cheney Reservoir site. New and updated models for both sites are applicable to the period of YSI EXO water-quality monitor and sensor deployment (November 14, 2015, through September 30, 2021, at the North Fork Ninnescah River site; October 1, 2014, through September 30, 2021, at the Cheney Reservoir site). Models and resulting water-quality information included in this report can be used in real time, potentially as guidance for water-treatment processes, and can be used to characterize changes in water-quality conditions over time in Cheney Reservoir and its contributing drainage basin provided that the deployed equipment, sensors, and location do not change.

Kansas↗

USGS2026

Southeastern Utah Federal lands science needs survey

Evidence-based scientific information can help support defensible decision making in the management of public lands. This report sought to identify current (2024–25) Federal agency research needs in southeastern Utah and to synthesize common management challenges and questions across jurisdictional boundaries. We implemented a science needs assessment focused on lands managed by the Bureau of Land Management (BLM), U.S. Department of Agriculture Forest Service (FS), and National Park Service (NPS) in southeastern Utah—the area delineated by BLM’s Canyon Country District Office, portions of the FS Manti-La Sal National Forest, and Southeast Utah Group NPS units. U.S. Geological Survey (USGS) researchers met with and surveyed BLM, NPS, and FS staff in 2024 and 2025 to understand their science needs and preferred modes of information delivery. The USGS’s approach may be unrepresentative in terms of which topic areas were addressed, but the responses nevertheless highlight challenges and high-priority research areas that could contribute positively to agency decision making. Common management challenges and areas where additional research could be beneficial to land managers include the effects of climate change, recreation effects and visitor behavior, hydrology and hydrologic changes due to anthropogenic pressures, and the capacity for inventory and monitoring across essentially all resource types. Research on site-specific restoration techniques and their outcomes was also a common theme. In this report we discuss ways in which researchers can increase the extent to which their work could be actionable for resource managers and provide suggestions for potential priority research areas for the study region.

Utah↗

USGS1985

Acoustic velocity meter systems

Acoustic velocity meter (AVM) systems operate on the principles that the point-to-point upstream traveltime of an acoustic pulse is longer than the downstream traveltime and that this difference in traveltime can be accurately measured by electronic devices. An AVM system is capable of recording water velocity (and discharge) under a wide range of conditions, but some constraints apply: 1. Accuracy is reduced and performance is degraded if the acoustic path is not a continuous straight line. The path can be bent by reflection if it is too close to a stream boundary or by refraction if it passes through density gradients resulting from variations in either water temperature or salinity. For paths of less than 100 m, a temperature gradient of 0.1' per meter causes signal bending less than 0.6 meter at midchannel, and satisfactory velocity results can be obtained. Reflection from stream boundaries can cause signal cancellation if boundaries are too close to signal path. 2. Signal strength is attenuated by particles or bubbles that absorb, spread, or scatter sound. The concentration of particles or bubbles that can be tolerated is a function of the path length and frequency of the acoustic signal. 3. Changes in streamline orientation can affect system accuracy if the variability is random. 4. Errors relating to signal resolution are much larger for a single threshold detection scheme than for multiple threshold schemes. This report provides methods for computing the effect of various conditions on the accuracy of a record obtained from an AVM. The equipment must be adapted to the site. Field reconnaissance and preinstallation analysis to detect possible problems are critical for proper installation and operation of an AVM system.

Techniques of Water-Resources Investigations↗

USGS2000

Guidelines and standard procedures for continuous water-quality monitors: Site selection, field operation, calibration, record computation, and reporting

The U.S. Geological Survey uses continuous water-quality monitors to assess variations in the quality of the Nation's surface water. A common system configuration for data collection is the four-parameter water-quality monitoring system, which collects temperature, specific conductance, dissolved oxygen, and pH data, although systems can be configured to measure other properties such as turbidity or chlorophyll. The sensors that are used to measure these water properties require careful field observation, cleaning, and calibration procedures, as well as thorough procedures for the computation and publication of final records. Data from sensors can be used in conjunction with collected samples and chemical analyses to estimate chemical loads. This report provides guidelines for site-selection considerations, sensor test methods, field procedures, error correction, data computation, and review and publication processes. These procedures have evolved over the past three decades, and the process continues to evolve with newer technologies.

Water-Resources Investigations Report↗

USGS2004

Water and Streambed Sediment Quality, and Ecotoxicology of a Stream along the Blue Ridge Parkway, Adjacent to a Closed Landfill, near Roanoke, Virginia: 1999

A study was done of the effects of a closed landfill on the quality of water and streambed sediment and the benthic macroinvertebrate community of an unnamed stream and its tributary that flow through Blue Ridge Parkway lands in west-central Virginia. The primary water source for the tributary is a 4-inch polyvinyl chloride (PVC) pipe that protrudes from the slope at the base of the embankment bordering the landfill. An unusual expanse of precipitate was observed in the stream near the PVC pipe. Stream discharge was measured and water and streambed sediment samples were collected at a nearby reference site and at three sites downstream of the landfill in April and September 1999. Water samples were analyzed for major ions, nitrate, total and dissolved metals, total dissolved solids, total organic carbon, and volatile and semivolatile organic compounds, including organochlorine pesticides and polychlorinated biphenyls (PCBs). Streambed sediment samples were analyzed for total metals, total organic carbon, percent moisture, and volatile and semivolatile organic compounds, including organochlorine pesticides and PCBs. The benthic macroinvertebrate community within the stream channel also was sampled at the four chemical sampling sites and at one additional site in April and September. Each of the five sites was assessed for physical habitat quality. Water collected periodically at the PVC pipe discharge between November 1998 and November 1999 was used to conduct 48-hour acute and 7-day chronic toxicity tests using selected laboratory test organisms. Two 10-day chronic toxicity tests of streambed sediments collected near the discharge pipe also were conducted. Analyses showed that organic and inorganic constituents in water from beneath the landfill were discharged into the sampled tributary. In April, 79 percent of inorganic constituents detected in water had their highest concentrations at the site closest to the landfill; at the same site, 59 percent of inorganic constituents detected in streambed sediments were at their lowest concentration. The low dissolved-oxygen concentration and relatively low pH in ground water from beneath the landfill probably had a direct effect on the solubility of metals and other constituents, resulting in the high concentration of inorganic constituents in water, low concentration in sediment, and the development of the precipitate. Most constituents in water in April were progressively lower in concentration from the landfill site downstream. The highest concentrations for 59 percent of constituents detected in sediment were at the farthest downstream site, suggesting that the inorganic constituents came out of solution as the stream water was exposed to the atmosphere. In September, 52 percent of inorganic constituents detected in water were at their highest concentrations at the site nearest the landfill. Of inorganic constituents detected in streambed sediments in September, 60 percent were at their highest concentrations near the landfill. A storm that occurred a few days prior to the September sampling probably affected the preceding steady-state conditions and the distribution of constituents in sediment along the stream. Concentrations of many inorganic constituents in water remained elevated at the farthest downstream site in comparison to the reference site in April and September, indicating that concentrations did not return to background concentrations. In April and September, most of the 17 organic compounds detected in water, including volatile organic and semivolatile organic compounds, were collected in samples near the landfill, and most concentrations were below their respective reporting limits. Probably because of their volatility, few organic compounds were detected at sites downstream of that site. A total of 17 discrete organic compounds were detected in sediment samples in either April or September, including trichloroethene and tetrachloroethene along with their degrad

Water-Resources Investigations Report↗

USGS1976

Flood-prone areas of Jacksonville, Duval County, Florida

Floods in the consolidated city of Jacksonville, Duval County, Florida, are caused directly by rainfall which, when combined with storm driven tides, causes rivers or other bodies of water to flood the low lying parts of the county. This map report supplies information on areas subject to floods of 100-year frequency; the information will permit evaluation of alternative uses of such areas. The extent of the 100-year flood is shown on the large-scale map accompanying the report. Also included is an index map showing sections of Duval County where more detailed information on the 100-year flood can be obtained. The major flood of record in the county occurred in 1964 when Hurricane Dora crossed the area. (Woodard-USGS)

Florida↗

USGS1983

Water resources of Hanson and Davison Counties, South Dakota

Five glacial and four bedrock aquifers were delineated in Hanson and Davison Counties. The glacial aquifers, outwash deposits confined by as much as 275 feet of glacial till, are the Floyd, Plum Creek, Ethan, Warren, and Alexandria. The bedrock aquifers are the Niobrara, Codell, Dakota, and Sioux Quartzite Wash, and may be as much as 80, 350, 700, and 500 feet below land surface, respectively. The glacial aquifers averaged 13 to 40 feet in thickness and contain about 670,000 acre-feet of water in storage. Recharge to the Floyd and Plum Creek aquifers is from the Sioux Quartzite Wash aquifer and from fractures in the Sioux Quartzite. Recharge to the Ethan and Warren aquifers is from the Niobrara aquifer. Reported yield to wells from the Floyd and Plum Creek aquifers was as much as 1,000 gallons per minute. Predominant chemical constituents in water from the glacial aquifers are sulfate, calcium, and sodium. The bedrock aquifers averaged 40 to 110 feet in the thickness and contain about 11.3 million acre-feet of water in storage. The direction of water movement in the aquifers is to the northeast. The average reported yield from wells in the bedrock aquifers ranged from 1 to 75 gallons per minute. Reported yield from wells in the Niobrara aquifer was as much as 1,000 gallons per minute. Predominant chemical constituents in water from the Niobrara and Codell aquifers were sulfate, sodium, and calcium. Predominant chemical constituents in water from the Dakota and Sioux Quartzite wash were sulfate and calcium.

South Dakota↗