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At least 667 records · Page 37Linked to original sources

An assessment of optical properties of dissolved organic material as quantitative source indicators in the Santa Ana River basin, Southern California

The ability to rapidly, reliably, and inexpensively characterize sources of dissolved organic material (DOM) in watersheds would allow water management agencies to more quickly identify problems in water sources, and to more efficiently allocate water resources by, for example, permitting real-time identification of high-quality water suitable for ground-water recharge, or poor-quality water in need of mitigation. This study examined the feasibility of using easily measurable intrinsic optical properties' absorbance and fluorescence spectra, as quantitative indicators of DOM sources and, thus, a predictor of water quality. The study focused on the Santa Ana River Basin, in southern California, USA, which comprises an area of dense urban development and an area of intense dairy production. Base flow in the Santa Ana Basin is primarily tertiary treated wastewater discharge. Available hydrologic data indicate that urban and agricultural runoff degrades water quality during storm events by introducing pathogens, nutrients, and other contaminants, including significant amounts of DOM. These conditions provide the basis for evaluating the use of DOM optical properties as a tracer of DOM from different sources. Sample spectra representing four principal DOM sources were identified among all samples collected in 1999 on the basis of basin hydrology, and the distribution of spectral variability within all the sample data. A linear mixing model provided quantitative estimates of relative endmember contribution to sample spectra for monthly, storm, and diurnal samples. The spectral properties of the four sources (endmembers), Pristine Water, Wastewater, Urban Water, and Dairy Water, accounted for 94 percent of the variability in optical properties observed in the study, suggesting that all important DOM sources were represented. The scale and distribution of the residual spectra, that not explained by the endmembers, suggested that the endmember spectra selected did not adequately represent Urban Water base flow. However, model assignments of sources generally agreed well with those expected, based on sampling location and hydrology. The results suggest that with a fuller characterization of the endmember spectra, analysis of optical properties will provide rapid quantitative estimates of the relative contribution of DOM sources in the Santa Ana Basin.

Scientific Investigations Report↗

Use and availability of continuous streamflow records in Wyoming

This report documents a survey that identifies local, State, and Federal uses of data from 139 continuous-record, surface-water stations, presently (1984) operated by the Wyoming District of the U. S. Geological Survey; identifies sources of funding pertaining to collections of streamflow data; and presents frequency of data availability. Uses of data from the 139 stations are categorized into seven classes: Regional Hydrology, Hydrology Systems, Legal Obligations, Planning and Design, Project Operation, Hydrologic Forecasts, and Water Quality Monitoring. Sufficient use of surface water data collected from the stations justifies the continued operation of all stations. (USGS)

Open-File Report↗

Water resources data, Massachusetts and Rhode Island, water year 1997

Water resources data for the 1997 water year for Massachusetts and Rhode Island consists of records of stage, discharge, and water quality of streams; contents of lakes and reservoirs; and ground-water levels. This report contains discharge records for 86 gaging stations, month end contents of 4 lakes and reservoirs, water quality at 18 gaging stations, and water levels for 142 observation wells. Miscellaneous hydrologic data were collected at various sites that were not a part of the systematic data-collection program and are published as miscellaneous discharge measurements. A few pertinent stations in bordering States are also included in this report. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Massachusetts and Rhode Island.

Massachusetts, Rhode Island↗

Models no not provide proof: An example of model ambiguity and application of isotopic data in a mine pit lake

Geochemical and hydrologic models of pit lakes are commonly used in environmental regulatory decisions to predict future water quality and hydrologic conditions and to understand existing pit lakes. Models may be used to quantify sulfide oxidation, predict thermal/chemical stratification and mixing, and better understand connections between pit lakes and aquifers. One concern related to the hydrologic character of pit lakes is if they are terminal (a groundwater sink with no outflow) or flowthrough (both receiving groundwater inflow and discharging to groundwater). This question was pertinent to the Liberty pit lake, a small acidic pit lake formed in a former Cu deposit in south-central Nevada where potentiometric and geochemical data potentially indicate pit-lake outflow. Potential discharge to groundwater from the pit lake was evaluated using a water-balance model, but uncertainty in hydraulic parameters led to ambiguity in the hydrologic character. Stable isotopes of water were then sampled from the pit lake and adjacent groundwater wells, which unambiguously indicated the lack of an evaporative signature in downgradient groundwater because the groundwater did not plot on a hypothetical mixing line between evaporated pit lake water and observed meteoric recharge. This methodology provided a more effective and more data-driven approach for understanding pit-lake hydrology. Although predictive models are required to quantify reasonable bounds on future conditions, many models contain substantial uncertainty and are not well suited in some environments. Datasets that provide more clear lines of evidence could be collected from existing pit lakes whenever possible to inform water-rock interaction, limnological behavior, and connectivity to adjacent groundwater.

Nevada↗

Hydrologic data for the Usquepaug-Queen River basin, Rhode Island

The Usquepaug-Queen River ground-water reservoir in Rhode Island is part of the stratified-drift aquifer along the Usquepaug-Queen River and its tributaries. The thickest, most permeable parts of the aquifer form the Usquepaug-Queen River ground-water reservoir. The 36.1-square mile study area comprises parts of Washington and Kent counties, and includes parts of the towns of Exeter, North Kingstown, Richmond, South Kingstown, and West Greenwich. The report presents geologic and hydrologic information needed for the prediction and management of hydrologic effects of proposed ground-water development. The report describes aquifer lithology, provides historical data on water-level and aquifer-storage changes, provides information on ground-water quality, and presents natural flow characteristics and water quality of streams in the Usquepaug-Queen River area. The data includes 275 ground-water sites; lithologic logs of 66 ground-water sites; water levels for 43 ground- water sites; chemical analyses of 36 ground-water sites; stream discharge measurements from the continuous-record gaging station on the Usquepaug- Queen River; discharge measurements at 10 partial- record stations in the area; chemical analyses of 17 stream sites; and the data from 14 slug tests conducted at ground-water sites.

Open-File Report↗

Statistical analyses of hydrologic system components and simulation of Edwards aquifer water-level response to rainfall using transfer-function models, San Antonio region, Texas

In 2003 the U.S. Geological Survey, in cooperation with the San Antonio Water System, did a study using historical data to statistically analyze hydrologic system components in the San Antonio region of Texas and to develop transfer-function models to simulate water levels at selected sites (wells) in the Edwards aquifer on the basis of rainfall. Water levels for two wells in the confined zone in Medina County and one well in the confined zone in Bexar County were highly correlated and showed little or no lag time between water-level responses. Water levels in these wells also were highly correlated with springflow at Comal Springs. Water-level hydrographs for 35 storms showed that an individual well can respond differently to similar amounts of rainfall. Fourteen water-level-recession hydrographs for a Medina County well showed that recession rates were variable. Transfer-function models were developed to simulate water levels at one confined-zone well and two recharge-zone wells in response to rainfall. For the confined-zone well, 50 percent of the simulated water levels are within 10 feet of the measured water levels, and 80 percent of the simulated water levels are within 15 feet of the measured water levels. For one recharge-zone well, 50 percent of the simulated water levels are within 5 feet of the measured water levels, and 90 percent of the simulated water levels are within 14 feet of the measured water levels. For the other recharge-zone well, 50 percent of the simulated water levels are within 14 feet of the measured water levels, and 90 percent of the simulated water levels are within 27 feet of the measured water levels. The transfer-function models showed that (1) the Edwards aquifer in the San Antonio region responds differently to recharge (effective rainfall) at different wells; and (2) multiple flow components are present in the aquifer. If simulated long-term system response results from a change in the hydrologic budget, then water levels would be difficult to simulate accurately.

Texas↗

Surface variable‐based machine learning for scalable arsenic prediction in undersampled areas

In the United States, private wells are not federally regulated, and many households do not test for Arsenic (As). Chronic exposure is linked with multiple health outcomes, and risk can change sharply over short distances and with well depth. Coarse maps or sparse sampling often miss exceedances. Most existing models operate at ∼1 km resolution and use groundwater chemistry or detailed geologic logs, which limits their use in undersampled areas where improved guidance is most needed. We overcome these limitations by developing a machine learning model for Minnesota, USA, that predicts As exposure risk using only surficial variables from remote sensing and global data sets. Variables related to surface water hydrology and geomorphology are selected based on mechanistic links that control redox conditions and As mobilization. Local training was essential, and surficial geology variables that are more sensitive to local conditions were needed to maximize model accuracy. The resulting complete model was sufficiently sensitive to generate accurate and detailed risk maps and depth profiles of As concentrations above the 10 μg/L maximum contaminant level. Accuracy depended on local training data density. We identified a training data density of 0.07 wells/km 2 as a practical target for stable county-level performance. Maps of exceedance probabilities highlight priority areas for testing that are particularly important in rural communities that have received less sampling. These results support public health action by guiding where to install wells and where to test them, how much new sampling is needed, and where treatment outreach is most urgent.

Minnesota↗

Hydrologic data for the Great and Denbow heaths in eastern Maine, October 1981 through October 1982

Hydrologic data collected on the Great and Denbow Heaths, Maine, include precipitation, pan evaporation, air temperatures, streamflow, and ground water levels. These data were collected for a peat bog hydrology study conducted in cooperation with the Maine Geological Survey. The data network consisted of climate information from three rain gages, an evaporation pan and two maximum-minimum thermometers; surface water information from two continuous gaging stations and 19 partial record sites; groundwater information from an observation well equipped with a continuous recorder and 106 piezometers. Methods used for the collection and analyses of data included standard Survey techniques modified for the unique hydrologic environment of the study area. (Author 's abstract)

Open-File Report↗

Hydrologic conditions in the South Coast aquifer, Puerto Rico, 2010–15

In 1958, the U.S. Geological Survey began documenting hydrologic conditions, including groundwater levels, groundwater withdrawals for agricultural irrigation and public water supply, and water quality, in the South Coast aquifer, Puerto Rico. This information has improved the understanding of the water resources of the region. The hydrologic data indicate that (1) groundwater levels declined as much as 40 feet in the Salinas area and 11 feet in the Guayama area during 2012–14; (2) groundwater withdrawals for agricultural irrigation increased from 6.0 to 10.5 million gallons per day, or 75 percent, from 2010 to 2012; and (3) total groundwater withdrawals decreased from 29.3 to 23.8 million gallons per day from 2010 to 2014. The quantity and quality of water in the aquifer is primarily affected by variations in aquifer recharge as a result of changing rainfall or modes of irrigation; however, the spatial patterns and magnitude of water withdrawals for all uses have a secondary impact on the quantity and quality of water in the aquifer. National Oceanic and Atmospheric Administration data from climatological stations indicate that the 30-year normal precipitation for the period 1991–2010 in the South Coastal and Southern Slopes climatological regions was about 37.74 and 61.61 inches, respectively; the 30-year moving average precipitation for the period 1985–2014 was 37.94 and 61.80 inches, respectively, for these regions. The mean annual precipitation during 2012–14 was 13 percent below the 30-year moving average for the South Coastal climatological region and 7.7 percent below for the Southern Slopes climatological region. When rainfall is below the 30-year moving average, recharge is diminished and groundwater levels decline. Annual precipitation in the South Coast aquifer, which includes a large part of the South Coastal and Southern Slopes climatological regions, was 39.42, 37.25, and 34.89 inches per year for 2012, 2013, and 2014, respectively. Water level declines reduce the thickness of freshwater in the unconfined parts of the South Coast aquifer. Additionally, the pumping-induced migration of poor-quality water from deep or seaward areas of the aquifer can contribute to reductions in the thickness of freshwater in the aquifer. The reduction in the freshwater saturated thickness of the aquifer in areas near Ponce, Juana Díaz, Salinas, and Guayama is of particular concern because the total saturated thickness of the aquifer is thinner in these areas. Total dissolved solids concentration in groundwater samples indicates a small positive trend in Ponce, Santa Isabel, Salinas, and Guayama. Diminished aquifer recharge during 2012 to 2015 and, to a lesser extent, increased groundwater withdrawals have resulted in a reduction in the freshwater saturated thickness of the aquifer. The reduction in freshwater saturated thickness of the aquifer may affect freshwater resources available for agriculture and public water supply. A prolonged time period with reduced aquifer recharge may have substantial implications for groundwater levels and fresh groundwater availability.

Puerto Rico↗

Economic worth of hydrologic data in project design: An application to regional energy development

The linkage between the benefits to a regional economy from a water-dependent industry and the statistical uncertainty of the water supply that is needed in the production process is analyzed using a Bayesian scheme of expected-expected benefits of hydrologic data. In this analysis, expected benefits are calculated using anticipated streamflow data and these benefits are averaged over all possible data values. The increase in these average expected benefits is subsequently compared to the costs of obtaining the data and benefits foregone by delaying the project to collect the data. Thus, the value of collecting the data may be determined. A Leontief type production function is assumed for an oil shale retorting plant. The economic impact of hydrologic uncertainty is investigated by examining potential changes in plant output along with changes in regional incomes which are calculated by means of a regional input-output model. Alternatives for reducing the uncertainty included establishing water discharge measuring stations, transferring streamflow information from one site to another via regionalization, and a combination of both. Given a specific alternative, the optimum time period for data collection was found. Regionalization considered statistical properties of network designs based on simulated regression analysis.

Open-File Report↗

Comparison of hydrologic data from Monroe County, Michigan, 1991-2001

In the summer of 2001, there were renewed concerns about the effects of quarry dewatering on nearby domestic ground-water supplies in Monroe County, Michigan. Reports of domestic wells “going dry” are not uncommon historically in Monroe County. Such reports have been linked to droughts, nearby irrigation, quarrying, and other large ground-water uses since as early as 1900 (Sherzer, 1900). Concerns about ground-water availability during the short, but extreme, drought of 1988 prompted the County and the State of Michigan to cooperate with the USGS (U.S. Geological Survey) on a county water resources assessment during the early 1990s (Nicholas and others, 1996). Aquifers in Monroe County generally yield sufficient water for domestic supplies. High transmissivities and low storage in fractured carbonate aquifers and poor water quality at depth (Nicholas and others, 1996), however, make domestic supplies very susceptible to the effects of drought and large withdrawals. Therefore, there are legitimate concerns about sustainable groundwater supplies in the County. Additionally, significant increases in ground-water uses in Monroe County during the past decade coincide with very dry years during the late 1990s. Although ground-water-level data were collected by Monroe County during the last decade, there are not comparable data sets available for many water uses. Therefore, determining whether concerns about domestic wells going dry can be linked to ground-water withdrawals or climate is problematic. In response to recent concerns, the USGS and MDEQ (Michigan Department of Environmental Quality) entered into a cooperative agreement in October 2001 to conduct a study regarding the availability of ground water in Monroe County. The major goal of this study is to determine how widespread are the impacts of quarry dewatering operations. This report summarizes the initial phase of the study which consists of a comparison of hydrologic data from 1991 to 2001. The 1991 data are reported by the USGS in the report by Nicholas and others (1996). Later data come from a variety of sources including USGS, MDEQ, Monroe County, National Oceanic and Atmospheric Administration, U.S. Army Corps of Engineers, and ground-water users. All non-USGS data in this report are given as reported; data verification was not a part of this initial phase. The types of data chosen for comparison in this report include water levels of Lake Erie, precipitation at Monroe, streamflow in the River Raisin at Manchester, ground-water use, ground-water levels, and ground-water quality. The authors acknowledge the cooperation and provision of data and information by several agencies. Ground-water use for irrigation was provided by Ron Van Til of MDEQ. Quarry discharges were provided by Jennifer Rogers of MDEQ. Ground-water-level data for 1993 to 2001 were provided by the Monroe County Health Department. The authors also acknowledge Carlos Hernandez, Chris Hoard, Tom Morgan, Tom Sabin, and Dave Westjohn for collecting streamflow, ground-water, and ground-water-quality data in autumn, 2001. Sharon Baltusis and Jaye Lunsford assisted in the compilation and presentation of hydrologic data in this report.

Michigan↗

Streamflow and selected precipitation data for Yucca Mountain and vicinity, Nye County, Nevada, water years 1983-85

Streamflow and precipitation data collected at and near Yucca Mountain, Nevada, during water years 1983-85, are presented. The data were collected and compiled as part of the studies the U.S. Geological Survey is making, in cooperation with the U.S. Department of Energy, to characterize surface water hydrology in the Yucca Mountain area. Streamflow data include daily mean discharges and peak discharges at 4 complete-record gaging stations and peak discharges at 10 crest-stage, partial-record stations and 12 miscellaneous sites. Precipitation data include cumulative totals at 12 stations maintained by the U.S. Geological Survey and daily totals at 17 stations maintained by the Weather Service Nuclear Support Office, National Oceanic and Atmospheric Administration.

Open-File Report↗

Streamflow and selected precipitation data for Yucca Mountain region, southern Nevada and eastern California, water years 1986-90

Streamflow and precipitation data collected at and near Yucca Mountain, Nevada, during water years 1986-90 are presented in this report. The data were collected and compiled as part of the studies by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, to characterize surface-water hydrology in the Yucca Mountain area. Streamflow data include daily-mean discharges and peak discharges at 5 continuous-record gaging stations, and peak discharges at 10 crest-stage, partial-record stations and 2 miscellaneous sites. Precipitation data include cumulative totals at 20 stations maintained by the U.S. Geological Survey and daily totals at 15 stations maintained by the Weather Service Nuclear Support Office, National Oceanic and Atmospheric Administration.

California, Nevada↗

Hydrologic Unit Map-1978, state of South Dakota

This map and accompanying table show Hydrologic Unites that are basically hydrographic in nature. The Cataloging Unites shown supplant the Cataloging Units previously depicted n the 1974 State Hydrologic Unit Map. The boundaries as shown have been adapted from the 1974 State Hydrologic Unit Map, "The Catalog of Information on Water Data" (1972), "Water Resources Regions and Subregions for the National Assessment of Water and Related Land Resources" by the U.S. Water Resources Council (1970), "River Basin of the United States" by the U.S. Soil Conservation Service (1963, 1970), "River Basin Maps Showing Hydrologic Stations" by the Inter-Agency Committee on Water Resources, Subcommittee on Hydrology (1961), and State planning maps. The Political Subdivision has been adopted from "Counties and County Equivalents of the States if the United States" presented in Federal Information Processing Standards Publication 6-2, issued by the National Bureau of Standards (1973) in which each county or county equivalent is identified by a 2-character State code and a 3-character county code. The Regions, Subregions and Accounting Units are aggregates of the Cataloging Unites. The Regions and Sub regions are currently (1978) used by the U.S> Water Resources Council for comprehensive planning, including the National Assessment, and as a standard geographical framework for more detailed water and related land-resources planning. The Accounting Units are those currently (1978) in use by the U.S. Geological Survey for managing the National Water Data Network. This map was revised to include a boundary realinement between Cataloging Units 10140103 and 10160009.

South Dakota↗

Survey of hydrologic models and hydrologic data needs for tracking flow in the Rio Grande, north-central New Mexico, 2010

The six Middle Rio Grande Pueblos have prior and paramount rights to deliveries of water from the Rio Grande for their use. When the pueblos or the Bureau of Indian Affairs Designated Engineer identifies a need for additional flow on the Rio Grande, the Designated Engineer is tasked with deciding the timing and amount of releases of prior and paramount water from storage at El Vado Reservoir to meet the needs of the pueblos. Over the last three decades, numerous models have been developed by Federal, State, and local agencies in New Mexico to simulate, understand, and (or) manage flows in the Middle Rio Grande upstream from Elephant Butte Reservoir. In 2008, the Coalition of Six Middle Rio Grande Basin Pueblos entered into a cooperative agreement with the U.S. Geological Survey to conduct a comprehensive survey of these hydrologic models and their capacity to quantify and track various components of flow. The survey of hydrologic models provided in this report will help water-resource managers at the pueblos, as well as the Designated Engineer, make informed water-resource-management decisions that affect the prior and paramount water use. Analysis of 4 publicly available surface-water models and 13 publicly available groundwater models shows that, although elements from many models can be helpful in tracking flow in the Rio Grande, numerous data gaps and modeling needs indicate that accurate, consistent, and timely tracking of flow on the Rio Grande could be improved. Deficient or poorly constrained hydrologic variables are sources of uncertainty in hydrologic models that can be reduced with the acquisition of more refined data. Data gaps need to be filled to allow hydrologic models to be run on a real-time basis and thus ensure predictable water deliveries to meet needs for irrigation, domestic, stock, and other water uses. Timeliness of flow-data reporting is necessary to facilitate real-time model simulation, but even daily data are sometimes difficult to obtain because the data come from multiple sources. Each surface-water model produces results that could be helpful in quantifying the flow of the Rio Grande, specifically by helping to track water as it moves down the channel of the Rio Grande and by improving the understanding of river hydraulics for the specified reaches. The ability of each surface-water model to track flow on the Rio Grande varies according to the purpose for which each model was designed. The purpose of Upper Rio Grande Water Operations Model (URGWOM) - to simulate water storage and delivery operations in the Rio Grande - is more applicable to tracking flow on the Rio Grande than are any of the other surface-water models surveyed. Specifically, the strengths of URGWOM in relation to modeling flow are the details and attention given to the accounting of Rio Grande flow and San Juan-Chama flow at a daily time step. The most significant difficulty in using any of the surveyed surface-water models for the purpose of predicting the need for requested water releases is that none of the surface-water models surveyed consider water accounting on a real-time basis. Groundwater models that provide detailed simulations of shallow groundwater flow in the vicinity of the Rio Grande can provide large-scale estimates of flow between the Rio Grande and shallow aquifers, which can be an important component of the Rio Grande water budget as a whole. The groundwater models surveyed for this report cannot, however, be expected to provide simulations of flow at time scales of less than the simulated time step (1 month to 1 year in most cases). Of those of the currently used groundwater models, the purpose of model 13 - to simulate the shallow riparian groundwater environment - is the most appropriate for examining local-scale surface-water/groundwater interactions. The basin-scale models, however, are also important in understanding the large-scale water balances between the aquifers and the surface water. In the case of the Upper and Middle Rio Grande Valley, models 6, 10, and 12 are the most accurate and current groundwater models available.

Colorado;New Mexico↗

A limnological study of 43 selected Maine lakes

Federal and State legislation require the trophic clas sification of lakes and ponds in the State of Maine as part of a lake management program. In 1974, the State of Maine Department of Environmental Protection (DEP) adopted a pre liminary set of procedures for establishing an index of lake trophic status. Also in 1974, this three-year study of selected Maine lakes was initiated to evaluate and improve this trophic classification system. Analyses of project results led to the following rec-commendations for modifications in Maine's lake-management program. Lake trophic state should be established using a mean annual value of twice monthly observations of chlorophyll a in epilimnetic waters during the open-water season. Actual Trophic State Index (TSI) values for lakes are calculated using the formula: TSI = 77.7 - 27.3 (log annual mean chlorophyll a, in mg/L). In lakes with colors less than or equal to TO platinum-cobalt units, mean annual Secchi disk transparencies may be used for calculation of lake TSI using the formula: TSI = 40.0 + 33.0 (log annual10mean Secchi disk, in meters). Supplemental information recommended for inclusion in the lake management program should include: morphological, hydrologic, and geologic data; baseline profile water-quality surveys; and benthic invertebrate, vegetation, and cultural surveys. Another recommendation is to change DEP's method of calculating the mean annual runoff for a lake drainage basin to an empirical formula based on drainage area characteristics. This resulted in more accurate estimations of mean annual hydraulic retention times for lakes. Many of these parameters recommended for inclusion in the lake management program will allow comparisons with future surveys to determine the impacts of cultural development on Maine lakes.

Maine↗

Assessment of hydrologic conditions in potential coal-lease tracts in the Warrior coal field, Alabama

Assessing the hydrology of potential Federal coal-lease tracts, because of their dissemination and limited data, requires some predictive capability. Four tracts assessed were located in the outcrop of three coal groups and of other relatively impermeable rocks in the Pottsville Formation. Physical settings of the tracts and most other areas in the Warrior coal field are similar. This results in similar ground-water and surface-water characteristics, in similar impacts resulting from surface coal mining, and in maximizing the transfer-ability of data. Assessments of the tracts reflected the small storage of water in underlying rocks and corresponding low yields to wells and to the base flow of streams. Ground water and surface water in undisturbed areas are generally of good quality. Some subbasins in the tracts have already been impacted by mining. Estimates of streamflow characteristics and the availability and quality of ground water in the tracts were made using available methodology , or assessments based on local and regional data. Estimates of the degree mineralization of surface-water were made using methodology developed from other coal hydrology work. Climatic, physiographic, hydrologic, and land-use data were analyzed by regressions to derive relations for assessing water quality in streams draining mined and unmined areas. In this approach, an equation was derived to estimate specific conductance. Additional equations, based on relations between specific conductance and other constituents, allow estimates of mine drainage indicators such as hardness, dissolved solids, and sulfate. Hydrologic assessments of the tracts, based on limited verification data, proved to be reasonably accurate. (USGS)

Open-File Report↗

Water quality, hydrology, and invertebrate communities of three remnant wetlands in Missouri, 1995-97

This report presents the results of a study conducted by the U.S. Geological Survey in cooperation with the Missouri Department of Natural Resources from December 1995 through May 1997 to describe the water quality, hydrologic, and invertebrate characteristics of three remnant wetlands. These data may be used to help develop selected water-quality standards for wetlands in Missouri. Wetlands monitored in this study include Spile Lake, Vernon County; Little Bean Marsh, Platte County; and Forker Oxbow, Linn County, Missouri. Extremes in physicochemical properties in these wetlands were greatly affected by thermal stratification, hydrologic fluctuations, biological activity, and ice formation. The wetlands had dissolved-oxygen concentrations below the 5-milligrams-per-liter State water-quality standard from 40 to 60 percent of a selected 1-year period, corresponding to periods of thermal stratification. Hydrologic fluctuations were common as the water-surface elevation changes in these systems ranged up to 12 feet during the course of the study. Photosynthesis and respiration are likely causes of diurnal fluctuations in pH and dissolved oxygen throughout the study period, but particularly in the summer months. Periods of ice formation were short lived in the wetlands, but corresponded with maximum values of specific conductance and dissolved oxygen in all three systems. Analyses of invertebrate results using the Jaccard Coefficient of Community Similarity indicated mixed results. Woody snag sample results showed little similarities between sites, while sweep net sample results indicated similarities existed. Most of the families detected at these sites are considered organic tolerant as indicated by the Hilsenhoff Biotic Index. Analysis of the dominant taxon indicates that one or two invertebrate families that are tolerant to organic enrichment generally dominate the wetlands. The hydrologic, water quality, and invertebrate information analyzed in this study indicate that while there are similarities among wetlands, these are unique systems. The statistical comparisons between water-quality constituents in wetlands and streams indicate dissimilarities are common. Including the presence of thermal stratification in these wetlands, the exclusions and modifications in State standards that are applied to lakes and reservoirs also may be applicable.

Missouri↗