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USGS2023

Value-aligned planning objectives for restoring North Carolina aquatic resources

Rapid population growth and development in the southeastern United States have resulted in substantial impairment to freshwater aquatic ecosystems. National or regional restoration policies strive to address impaired ecosystems but can suffer from inconsistent and opaque processes. The Clean Water Act, for example, establishes reallocation mechanisms to transfer ecosystem services from sites of disturbance to compensation sites to offset aquatic resource functions that are unavoidably lost through land development. However, planning for the prioritization of compensatory mitigation areas is often hampered by unstructured decision-making processes that are narrowly framed because they are not co-produced with stakeholders affected by, or having an interest in, the impacts and mitigation. This summary report represents the collaborative efforts of the U.S. Geological Survey and the North Carolina Department of Environmental Quality, Division of Mitigation Services, to co-develop an applied decision framework following the principles of structured decision-making for prioritizing watershed catchments by their potential for realizing a range of beneficial outcomes from future mitigation projects. The framework focuses on supporting the State’s nationally recognized stream and wetlands compensatory mitigation program by clarifying a discrete decision problem and specifying agency and stakeholder values to formulate fundamental and means objectives for prioritizing restoration sites. The co-development of this decision framework resulted in a number of useful insights from the perspective of the decision maker, including recognition (1) that the problem is a multi-objective decision driven by values beyond restoring lost functionality of ecosystems (that is, biogeophysical goals), (2) that the decision comprises a linked and sequential planning-to-implementation process, and (3) that future risk associated with land-use and climate change must be considered. The outcomes of this collaboration can serve as a systematic and transparent framework to prioritize a wide range of restoration, conservation, and resource-allocation activities in similar environmental contexts across the Nation.

North Carolina↗

USGS2012

Exploring relationships among land ownership, agricultural land use, and native fish species richness in the Upper Mississippi River Basin

The general effects of agriculture on in-stream fish communities in the Upper Midwestern United States have been well studied for nearly three decades (Karr et al. 1985; Nerbonne and Vondracek 1991; Zimmerman et al. 2001; Goldstein and Meador 2005). Specific impacts include: lowered water levels, sediment loading and nutrient enrichment, loss of riparian habitat, changes to channel morphometry and physical habitat, and changes to the forage base. As part of the National Fish Habitat Action Plan (NFHAP), an initiative to protect, restore, and enhance the nation's fish and aquatic communities, the Fishers and Farmers Partnership specifically focuses on working with agricultural producers to help protect and restore aquatic resources in the Upper Mississippi River Basin (UMRB) (Fig. 1). Successful protection and/or restoration will require the partnership and local conservation agencies to effectively communicate and work with local landowners. However, roughly 43% of the agricultural lands in the UMRB are not operated by those who own the land (National Agricultural Statistics Service 2009) and this is expected to increase as heirs of farm estates now reside greater distances from their home farms than ever before (Arbuckle 2010). It has long been presumed that changes in land ownership trends, toward more absentee landowners, would have important consequences for soil erosion and other conservation practices, as larger, more corporate agriculture, is thought to maximize farm income at the expense of environmental quality (Lee 1980). Absentee landowners may be less likely to take advantage of conservation programs. For example, land operated by renters lags enrollment in the Conservation Reserve (CRP) and Wetland Reserve (WRP) programs by 64% nation-wide (Petrzelka et al. 2009). Also, it has been found that the more detached an absentee landowner becomes from their land, both geographically and culturally, their commitment to land stewardship decreases (Arbuckle 2010). The Fishers and Farmers Partnership recognizes the challenge agricultural producers face in maintaining food and fiber production for a growing world population while also trying to improve environmental quality and fish habitat. This challenge is likely exacerbated when the landowners are absentee. Thus, reaching non-owner-operated farmers and convincing them to help protect and/or restore aquatic resources may be critical to the success of the Fishers and Farmers Partnership. In this study, we explored relationships among agricultural land use, land ownership, and native fish biodiversity in the UMRB as a first step toward helping the Fishers and Farmers Partnership identify specific locations in the UMRB that may pose conservation challenges. For example, places that have experienced a loss of native fish species richness relative to historical conditions and also have high proportions of absentee landowners may provide restoration challenges. We were also interested in identifying areas that have retained high levels of species richness and are owner-operated. These areas present good opportunities to work with local landowners to protect aquatic resources. To identify such areas, we addressed two primary questions: 1) Is there a relationship between the type of agricultural land use (i.e. cropland vs pastureland) and the % of land rented or leased within the UMRB? and 2) How does the type of agricultural production and whether land is rented or leased relate to the maintenance of historical levels of native fish species richness? We predicted that areas with large amounts of land devoted to crop production will have experienced the greatest losses of native fish species richness. However, our hypothesis is that watersheds with large amounts of land rented or leased will have experienced even greater declines in native fish species richness than would be predicted from the amount of cultivated cropland alone. By testing these hypotheses, we intended to identify watersheds that would be strong candidates for protection, restoration, and enhancement of fish species richness by accounting for land use and ownership characteristics.

Illinois, Indiana, Iowa, Michigan, Minnesota, Miss↗

USGS2013

Restoring the Great Lakes: DOI stories of success and partnership in implementing the Great Lakes Restoration Initiative

The Great Lakes are a monumentally unique national treasure containing nearly ninety-five percent of the United States' fresh surface water. Formed by receding glaciers, the Great Lakes support a thriving, resilient ecosystem rich with fish, wildlife, and abundant natural resources. The Great Lakes also support an array of commercial uses, including shipping, and provide a source of recreation, drinking water, and other critical services that drive the economy of the region and the Nation. Regrettably, activities such as clear cutting of mature forests, over-harvesting of fish populations, industrial pollution, invasive species, and agricultural runoffs have degraded these treasured lakes over the decades creating long-term impacts to the surrounding watershed. Fortunately, the people who live, work, and recreate in the region recognize the critical importance of a healthy Great Lakes ecosystem, and have come together to support comprehensive restoration. To stimulate and promote the goal of a healthy Great Lakes region, President Obama and Congress created the Great Lakes Restoration Initiative (GLRI) in 2009. This program provides the seed money to clean up legacy pollution, restore habitats, protect wildlife, combat invasive species, and address agricultural runoff in the Great Lakes watershed. At the same time GLRI promotes public outreach, education, accountability, and partnerships.

The Great Lakes↗

USGS2000

Design of a shallow ground-water network to monitor agricultural chemicals, Lake Wales Ridge, central Florida

Extensive agricultural land use and dynamic hydraulic connections between the land surface and ground-water resources render many of Florida's aquifers vulnerable to chemical contamination. In these areas, there is a need to monitor shallow ground water for agricultural chemicals to evaluate potential migration of the chemicals to the subsurface and to deeper aquifers, and to assess the effects of agricultural practices on ground-water quality. Historically, efforts to monitor water-table aquifers have been minimal compared with monitoring deeper aquifers used for municipal drinking-water supply. The Florida Department of Agriculture and Consumer Services has proposed the establishment of long-term, water-quality networks to monitor shallow ground water in agricultural areas of Florida. These networks will bridge the current information gap between local-scale short-duration field studies, which are required for pesticide licensing, and statewide monitoring of deeper ground-water resources. Laboratory (experimental) and short-term field evaluations of the transport of agricultural chemicals to the subsurface contain some degree of uncertainty due to widespread variations in environmental conditions. The proposed regional-scale shallow ground-water networks will serve as "early warning" networks to avoid contamination of ground-water resources. The objectives of these shallow ground-water networks are to provide information for early detection of pesticides and nitrate in the subsurface, and for evaluating temporal trends in concentrations in relation to changes in land use and agricultural practices. Information on trends is important to the U.S. Environmental Protection Agency, State agencies, and agricultural managers, and is an integral part of Florida's Pesticide Management Plan, which evaluates the effectiveness of implementing "best management practices" to minimize environmental impacts. Lake Wales Ridge in Polk and Highlands Counties has been identified by the Florida Department of Agriculture and Consumer Services as a pilot study area for implementing a regional shallow ground-water network. Information gained from designing the Lake Wales Ridge Network will be used to develop plans as similar networks are considered for other areas of Florida. Lake Wales Ridge is heavily utilized for citrus production, but the well-drained, clean sands underlying the region, coupled with a hydraulic connection with deeper karst formations, render the area extremely vulnerable to the transport and migration of agricultural chemicals within the subsurface. The network design for Lake Wales Ridge was developed on the basis of the objectives of monitoring, factors affecting aquifer vulnerability, probability (statistical) sampling theory, and specifications regarding well construction, sampling, and laboratory analysis. The network will provide estimates of regional pesticide and nitrate concentrations in targeted ground water, monitor for trends over time, and will provide baseline, regional-scale information. The areas targeted for sampling were citrus groves located on soils classified as vulnerable to leaching of agricultural chemicals, and ground water in close proximity to the water table. The duration of monitoring is planned to be long term. Chemicals targeted for monitoring include selected nutrients, trace elements, and pesticides used for citrus management. Standardization of field sampling and laboratory methods, and construction of a computerized data-base repository will be important for long-term utility of the data. The proposed network design consists of existing and newly drilled wells. Existing wells were evaluated as candidates for the network based on location and well-construction specifications for water-quality monitoring. Using probability selection techniques, new well locations were selected in areas that lacked adequate existing wells. Implementation of the network will occur in phases. Quarterly sampling of 13 Phase I wells commenced in April 1999. An additional 11 Phase II wells were added to the network in April 2000. Proposed locations have been identified for 8 Phase III wells. Future topics for study include a regional water-quality analysis, a network design evaluation, and consideration of local-scale studies needed to support regional monitoring efforts. An analysis of historical water-quality data for Lake Wales Ridge, including Phase I wells, is needed for the purpose of examining trends, providing a preliminary description of spatial and short-term variability in water quality, and evaluating the proposed network design for cost effectively meeting program objectives. Local-scale, process-oriented studies are needed to provide important information for evaluating regional water-quality data. Coordination between individuals conducting such local-scale studies and those interpreting regional sampling results will be considered as a component of the network design, and will require coordination between multiple agencies.

Florida↗

USGS2024

Change in growth and prey utilization for a native salmonid following invasion by an omnivorous minnow in an oligotrophic reservoir

Aquatic invasive species can affect food web structure, native fish growth, and production, depending on the traits of the invasive species and the pre-invasion conditions of the ecosystem. Thermal tolerances and behavioral traits can further influence differential exploitation of resources shared between native and invasive species. An unauthorized introduction of redside shiner ( Richardsonius balteatus ) into reservoirs in the Upper Skagit River, Washington, USA caused concern of potential competition, decreased production, and recruitment of rainbow trout ( Oncorhynchus mykiss ). We combined bioenergetics modeling and stable isotope analysis with field data to quantify consumption demand of native and invasive fishes and related consumption to the availability of key zooplankton prey. Per capita consumption on Daphnia by redside shiner was low; however, their high abundance imposed considerable demand on prey resources in Ross Lake. Although monthly consumption demand by the fish community was less than 50% of the monthly production and biomass of Daphnia in Ross Lake, the current Daphnia densities and growth of rainbow trout were considerably lower than before the invasion. These reductions correspond to lower annual consumption of Daphnia . Our study provides insight on mechanisms that influence food web impacts of an invasive omnivore in cold-water reservoirs.

Washington↗

USGS1986

An evaluation of water-quality data from Hydrologic Accounting Unit 051100, Green River Basin, Kentucky

Streamflow and water quality data collected by the U.S. Geological Survey (USGS) and the Kentucky Natural Resources and Environmental Protection Cabinet from 37 sites in the Green River basin were compared to data from the USGS National Stream Quality Accounting Network (NASQAN) Station, Green River near Beech Grove, Kentucky. This comparison was used to determine variability of water quality data throughout the basin, and to determine if water quality data from the NASQAN station were representative of water quality data upstream. Water quality concentrations, yields, and trends were studied. Water quality data from the NASQAN station were fairly representative conditions throughout the basin for specific conductance, pH, phosphorus and nitrogen, but were not representative for chloride, sulfate, iron, and water temperature. Water quality characteristics which were not representative can generally be attributed to impacts of specific land uses such as coal mining or oil production. Mean concentrations of suspended sediment were similar, but extreme concentrations varied throughout the basin. There were no temporal trends detected in instantaneous streamflow, sulfate, or total iron concentrations. Specific conductance was increasing at three stations and decreasing at one, chloride was increasing at two stations and decreasing at one, phosphorus was increasing at two stations, dissolved iron was increasing at one station and decreasing at one, pH was increasing at three stations and decreasing at two, suspended sediment was increasing at one station and decreasing at one, and water temperature was decreasing at two stations. The NASQAN station had increasing trends in chloride, phosphorus, pH, and suspended sediment, and a decreasing trend in water temperature with time. (Author 's abstract)

Water-Resources Investigations Report↗

USGS2004

Hydraulic tests in highly permeable aquifers

A semianalytical solution is presented for a mathematical model describing the flow of groundwater in response to a slug or pumping test in a highly permeable, confined aquifer. This solution, which is appropriate for wells of any degree of penetration and incorporates inertial mechanisms at both the test and observation wells, can be used to gain new insights into hydraulic tests in highly permeable settings. The oscillatory character of slug‐ and pumping‐induced responses will vary considerably across a site, even in an essentially homogeneous formation, when wells of different radii, depths, and screen lengths are used. Thus variations in the oscillatory character of responses do not necessarily indicate variations in hydraulic conductivity (K). Existing models for slug tests in partially penetrating wells in high‐K aquifers neglect the storage properties of the media. That assumption, however, appears reasonable for a wide range of common conditions. Unlike in less permeable formations, drawdown at an observation well in a high‐K aquifer will be affected by head losses in the pumping well. Those losses, which affect the form of the pumping‐induced oscillations, can be difficult to characterize. Thus analyses of observation‐well drawdown should utilize data from the period after the oscillations have dissipated whenever possible. Although inertial mechanisms can have a large impact on early‐time drawdown, that impact decreases rapidly with duration of pumping and distance to the observation well. Conventional methods that do not consider inertial mechanisms should therefore be viable options for the analysis of drawdown data at moderate to large times.

Water Resources Research↗

USGS1981

Stream-temperature patterns of the Muddy Creek basin, Anne Arundel County, Maryland

Using a water-balance equation based on a 4.25-year gaging-station record on North Fork Muddy Creek, the following mean annual values were obtained for the Muddy Creek basin: precipitation, 49.0 inches; evapotranspiration, 28.0 inches; runoff, 18.5 inches; and underflow, 2.5 inches. Average freshwater outflow from the Muddy Creek basin to the Rhode River estuary was 12.2 cfs during the period October 1, 1971, to December 31, 1975. Harmonic equations were used to describe seasonal maximum and minimum stream-temperature patterns at 12 sites in the basin. These equations were fitted to continuous water-temperature data obtained periodically at each site between November 1970 and June 1978. The harmonic equations explain at least 78 percent of the variance in maximum stream temperatures and 81 percent of the variance in minimum temperatures. Standard errors of estimate averaged 2.3C (Celsius) for daily maximum water temperatures and 2.1C for daily minimum temperatures. Mean annual water temperatures developed for a 5.4-year base period ranged from 11.9C at Muddy Creek to 13.1C at Many Fork Branch. The largest variations in stream temperatures were detected at thermograph sites below ponded reaches and where forest coverage was sparse or missing. At most sites the largest variations in daily water temperatures were recorded in April whereas the smallest were in September and October. The low thermal inertia of streams in the Muddy Creek basin tends to amplify the impact of surface energy-exchange processes on short-period stream-temperature patterns. Thus, in response to meteorologic events, wide ranging stream-temperature perturbations of as much as 6C have been documented in the basin. (USGS)

Water-Resources Investigations Report↗

USGS2015

Accelerating advances in continental domain hydrologic modeling

In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

Water Resources Research↗

USGS2006

Global synthesis of groundwater recharge in semiarid and arid regions

Global synthesis of the findings from ∼140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40–374 000 km 2 ) range from 0·2 to 35 mm year −1 , representing 0·1–5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to ∼720 m year −1 , results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Niño Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Niños (1977–1998) relative to periods dominated by La Niñas (1941–1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year −1 during the Sahel drought (1970–1986) to 150 mm year −1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (≥10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in the SW US. The impact of LU change was much greater than climate variability in Niger (Africa), where replacement of savanna by crops increased recharge by about an order of magnitude even during severe droughts. Sensitivity of recharge to LU/LC changes suggests that recharge may be controlled through management of LU. In irrigated areas, recharge varies from 10 to 485 mm year −1 , representing 1–25% of irrigation plus precipitation. However, irrigation pumpage in groundwater-fed irrigated areas greatly exceeds recharge rates, resulting in groundwater mining. Increased recharge related to cultivation has mobilized salts that accumulated in the unsaturated zone over millennia, resulting in widespread groundwater and surface water contamination, particularly in Australia. The synthesis of recharge rates provided in this study contains valuable information for developing sustainable groundwater resource programmes within the context of climate variability and LU/LC change.

Hydrological Processes↗

USGS2000

Breeding season ecology: Chapter 6 in Status, ecology and conservation of the Southwestern Willow Flycatcher (RMRS-GTR-60)

The willow flycatcher ( Empidonax traillii ) breeds across much of the conterminous United States and in portions of extreme southern Canada. As might be expected in such a wide-ranging species, willow fly- catchers in different portions of the range exhibit differences in appearance, song, and ecological characteristics. The intent of this chapter is to provide information on the breeding-season ecology of the southwestern subspecies, E.t. extimus . However, most ecological studies to date have dealt with other willow flycatcher subspecies. Relatively few studies have been published on E.t. extimus , and much of what is currently known is presented in unpublished literature (e.g., agency and consulting firm reports); these sources are relied upon heavily in this chapter. This chapter does not address habitat characteristics in depth, other than for nest sites (refer to A Survey of Current Breeding Habitats for additional details). Although southwestern willow flycatchers are frequent victims of nest parasitism by brown-headed cowbirds ( Molothrus ater ), this chapter will not address the topic of parasitism and its effect on breeding ecology (refer to The Ecology of Brown-headed Cowbirds and their Effects on Southwestern Willow Flycatchers for details). Readers interested in more details of willow flycatcher biology and ecology are encouraged to read McCabe’s (1991) treatise, which is based on over a decade of willow flycatchers research in Wisconsin and includes comparisons with other populations and subspecies.

General Technical Report↗

USGS2007

Factors affecting coastal wetland loss and restoration

Opening paragraph: Tidal and nontidal wetlands in the Chesapeake Bay watershed provide vital hydrologic, water-quality, and ecological functions. Situated at the interface of land and water, these valuable habitats are vulnerable to alteration and loss by human activities including direct conversion to non-wetland habitat by dredge-and-fill activities from land development, and to the effects of excessive nutrients, altered hydrology and runoff, contaminants, prescribed fire management, and invasive species. Processes such as sea-level rise and climate change also impact wetlands. Although local, State, and Federal regulations provide for protection of wetland resources, the conversion and loss of wetland habitats continue in the Bay watershed. Given the critical values of wetlands, the Chesapeake 2000 Agreement has a goal to achieve a net gain in wetlands by restoring 25,000 acres of tidal and nontidal wetlands by 2010. The USGS has synthesized findings on three topics: (1) sea-level rise and wetland loss, (2) wetland restoration, and (3) factors affecting wetland diversity.

Book chapter↗

USGS2003

The use of sea ice habitat by female polar bears in the Beaufort Sea

Polar bears ( Ursus maritimus ) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We used stepwise procedures to create resource selection models of habitat use for radio-collared female polar bears in the Beaufort Sea. Sea ice characteristics and ocean depths at known polar bear locations were compared to the same features at randomly selected locations. Models generated for each of four seasons confirmed complexities of habitat use by polar bears and their response to numerous factors. Bears preferred shallow water areas where ice concentrations were > 80 % and different ice types intersected. Variation among seasons was reflected mainly in differential selection of ice stages, floe sizes, and their interactions. Water depth, total ice concentration and distance to the nearest interface between different ice types were significant terms in models for most seasons. Variation in ice stage and form also appeared in three models, and several interaction effects were identified. Habitat selection by polar bears is likely related to prey abundance and availability. Use of habitats in shallow water possibly reflects higher productivity in those areas. Habitat use in close proximity to ice edges is probably related to greater access of prey in those habitats.

Conference Paper↗

USGS1985

Evaluation of the Mission, Santee, and Tijuana hydrologic subareas for reclaimed-water use, San Diego County, California

A study was made to determine the suitability of three small hydrologic subareas in San Diego County, California, for reuse of treated municipal wastewater (reclaimed water). Groundwater quality has been impacted by agricultural water use, changes in natural recharge patterns, seawater intrusion, and groundwater movement from surrounding marine sediments. Groundwater levels near land surface may limit artificial recharge of reclaimed water or may require pumping of groundwater from the aquifer prior to recharge with reclaimed water. Reclaimed water may be used for irrigated water in upland areas. (USGS)

Water-Resources Investigations Report↗

USGS2010

Some basic considerations in the design of hydrologic data networks

Two preeminent considerations of data network design are the random nature of the hydrologic phenomena and the uses that will be made of the data. Information distilled from the data is usually measured in a parametric statistical sense, although the data user is more concerned with the integrated measure of information - what impact does the lack of perfect hydrologic information have on the ensuing decisions? Two facets of the network, the efficiency of the data collection and the effectiveness of the resulting information, must be integrated to achieve a complete network design.

Water Resources Research↗

USGS1978

Present and potential sediment yields in the Yampa River Basin, Colorado and Wyoming

Average annual suspended- and total-sediment loads in streamflow were determined by the flow-duration sediment-transport-curve method at 18 sites in the Yampa River basin, Colorado and Wyoming. These computations indicate that about 2.0 million tons of sediment are carried by the Yampa River at Deerlodge Park during an average year. Significant areal differences in the sediment yield from various parts of the basin also were determined. The lower Little Snake River subbasin contributes about 60 percent of the total basin sediment yield, although it represents less than 35 percent of the area and supplies less than 3 percent of the streamflow. In contrast, the upland (eastern) one-third of the basin contributes only about 14 percent of the sediment yield but 76 percent of the streamflow. Projected economic development of the basin, especially surface mining of coal, will impact the physical environment. Depending upon the amount and location of land disturbed, an estimated 10 ,000 to 30,000 tons per year of additional sediment will be contributed to the main-stem Yampa River. (Woodard-USGS)

Water-Resources Investigations Report↗

USGS2014

1.13 – Emerging contaminants

Since the Industrial Revolution, a diversity of large-scale chemical innovations has impacted aquatic systems in urban environments. Beginning in the 1990s, there has been a growing scientific interest and public awareness of the effects of the chemicals used in domestic, commercial, industrial, and agricultural applications, referred to in this article as ‘emerging contaminants’ (ECs), on ecosystem and human health. The growing global population and its increasing demands on water supplies in conjunction with climate-induced changes in hydrologic regimes place stress on freshwater resources, resulting in a greater reliance on reuse of reclaimed municipal wastewater treatment plant (WWTP) effluents to meet human and environmental needs. WWTP effluents are a major source of ECs, and it is important to have an understanding of the chemical composition of the reclaimed water, because many ECs are biologically active and the effects of chronic exposure to low concentration complex mixtures are unknown. Several classes of ECs that have been shown to be widespread in the aquatic environment are discussed in this chapter, including surfactants, complexing agents, fragrances, antimicrobials, industrial chemicals, pharmaceuticals, natural and synthetic estrogens, and disinfection byproducts. All of these compounds are biologically active via a variety of modes of action, and can occur in aquatic systems at concentrations ranging from <0.001 to >100 μg l −1 .

Book chapter↗

USGS2016

Wastewater disposal from unconventional oil and gas development degrades stream quality at a West Virginia injection facility

The development of unconventional oil and gas (UOG) resources has rapidly increased in recent years; however, the environmental impacts and risks are poorly understood. A single well can generate millions of liters of wastewater, representing a mixture of formation brine and injected hydraulic fracturing fluids. One of the most common methods for wastewater disposal is underground injection; we are assessing potential risks of this method through an intensive, interdisciplinary study at an injection disposal facility in West Virginia. In June 2014, waters collected downstream from the site had elevated specific conductance (416 μS/cm) and Na, Cl, Ba, Br, Sr, and Li concentrations, compared to upstream, background waters (conductivity, 74 μS/cm). Elevated TDS, a marker of UOG wastewater, provided an early indication of impacts in the stream. Wastewater inputs are also evident by changes in 87Sr/86Sr in streamwater adjacent to the disposal facility. Sediments downstream from the facility were enriched in Ra and had high bioavailable Fe(III) concentrations relative to upstream sediments. Microbial communities in downstream sediments had lower diversity and shifts in composition. Although the hydrologic pathways were not able to be assessed, these data provide evidence demonstrating that activities at the disposal facility are impacting a nearby stream and altering the biogeochemistry of nearby ecosystems.

Environmental Science & Technology↗