Michael B. Griffith

The effects of mountaintop mines and valley fills on the physicochemical quality of stream ecosystems in the central Appalachians: a review.

This review assesses the state of the science on the effects of mountaintop mines and valley fills (MTM-VF) on the physicochemical characteristics of streams in the central Appalachian coalfields of West Virginia, Kentucky, Virginia and Tennessee, USA. We focus on the impacts of mountaintop removal coal mining, which involves removing all - or some portion - of the top of a mountain or ridge to expose and mine one or more coal seams. Excess overburden is disposed in constructed fills in small valleys adjacent to the mining site. MTM-VF leachate persistently increases the downstream concentrations of major ions. Conductivity is a coarse measure of these ions, which are dominated by a distinct mixture of SO(4)(2-), HCO(3)(-), Ca(2+) and Mg(2+), that reflects their source, the oxidation of pyrite to form acid followed by neutralization of the acidity by carbonate minerals within the valley fills. This results in neutral to alkaline pHs, a range at which many metals are relatively insoluble. Other compounds within coal or overburden are solubilized and occur at elevated albeit lower concentrations, including K(+), Na(+), Cl(-), Se and Mn. In terms of physical characteristics, the valley fills act like headwater aquifers, baseflows increase in streams below valley fills and water temperatures exhibit reduced seasonal variation. Peak discharges may be increased in response to intense precipitation events, because of compaction of base surfaces of the MTM-VF areas, but newer approaches to reclamation reduce this compaction and may ameliorate these peak flows. Although the sedimentation pond is intended to capture fine particles that wash downstream from the valley fill, some studies found increased fine sediments in streams downstream from valley fills. However, a proportion of these fines may be eroded from stream banks rather than the valley fills. This is probably a result of the alterations in stream flows.

Relationships among exceedences of metals criteria, the results of ambient bioassays, and community metrics in mining-impacted streams.

If bioassessments are to help diagnose the specific environmental stressors affecting streams, a better understanding is needed of the relationships between community metrics and ambient criteria or ambient bioassays. However, this relationship is not simple, because metrics assess responses at the community level of biological organization, while ambient criteria and ambient bioassays assess or are based on responses at the individual level. For metals, the relationship is further complicated by the influence of other chemical variables, such as hardness, on their bioavailability and toxicity. In 1993 and 1994, U.S. Environmental Protection Agency (U.S. EPA) conducted a Regional Environmental Monitoring and Assessment Program (REMAP) survey on wadeable streams in Colorados (USA) Southern Rockies Ecoregion. In this ecoregion, mining over the past century has resulted in metals contamination of streams. The surveys collected data on fish and macroinvertebrate assemblages, physical habitat, and sediment and water chemistry and toxicity. These data provide a framework for assessing diagnostic community metrics for specific environmental stressors. We characterized streams as metals-affected based on exceedence of hardness-adjusted criteria for cadmium, copper, lead, and zinc in water; on water toxicity tests (48-h Pimephales promelas and Ceriodaphnia dubia survival); on exceedence of sediment threshold effect levels (TELs); or on sediment toxicity tests (7-d Hyalella azteca survival and growth). Macroinvertebrate and fish metrics were compared among affected and unaffected sites to identify metrics sensitive to metals. Several macroinvertebrate metrics, particularly richness metrics, were less in affected streams, while other metrics were not. This is a function of the sensitivity of the individual metrics to metals effects. Fish metrics were less sensitive to metals because of the low diversity of fish in these streams.

Toxicological perspective on the osmoregulation and ionoregulation physiology of major ions by freshwater animals: Teleost fish, crustacea, aquatic insects, and Mollusca

Anthropogenic sources increase freshwater salinity and produce differences in constituent ions compared with natural waters. Moreover, ions differ in physiological roles and concentrations in intracellular and extracellular fluids. Four freshwater taxa groups are compared, to investigate similarities and differences in ion transport processes and what ion transport mechanisms suggest about the toxicity of these or other ions in freshwater. Although differences exist, many ion transporters are functionally similar and may belong to evolutionarily conserved protein families. For example, the Na+/H+-exchanger in teleost fish differs from the H+/2Na+ (or Ca2+)-exchanger in crustaceans. In osmoregulation, Na+ and Cl− predominate. Stenohaline freshwater animals hyperregulate until they are no longer able to maintain hypertonic extracellular Na+ and Cl− concentrations with increasing salinity and become isotonic. Toxic effects of K+ are related to ionoregulation and volume regulation. The ionic balance between intracellular and extracellular fluids is maintained by Na+/K+-adenosine triphosphatase (ATPase), but details are lacking on apical K+ transporters. Elevated H+ affects the maintenance of internal Na+ by Na+/H+ exchange; elevated HCO3− inhibits Cl− uptake. The uptake of Mg2+ occurs by the gills or intestine, but details are lacking on Mg2+ transporters. In unionid gills, SO42− is actively transported, but most epithelia are generally impermeant to SO42−. Transporters of Ca2+ maintain homeostasis of dissolved Ca2+. More integration of physiology with toxicology is needed to fully understand freshwater ion effects.

Chapter 23 USEPA biomonitoring and bioindicator concepts needed to evaluate the biological integrity of aquatic systems

Abstract This chapter presents the current uses, concepts and anticipated future directions of biomonitoring and bioindicators in the regulatory and research programs of the United States Environmental Protection Agency (USEPA). The chapter provides a historical look on how biomonitoring and bioindicators evolved in the USEPA or its predecessor agencies from the 1960s – 1980s, then describes two current key biomonitoring and bioindicator programmes, the USEPA Office of Research and Developments Environmental Monitoring and Assessment Programme (EMAP) and USEPAs Office of Waters Biocriteria Programme. The remainder of the chapter is organized hierarchically beginning with concepts and monitoring approaches using fish, macroinvertebrates, and periphyton assemblages, and functional ecosystem measures. The assemblage approaches are followed by current research and regulatory use of whole organism toxicity testing assessments for measuring contamination in aquatic environments and remediation assessment. The chapter includes existing and proposed activities in the use of real-time biomonitoring to assess biological exposures to contaminants and other environmental changes. A new approach that uses small and large adult whole fish tissue as a bioindicator for assessing potential contaminant exposures to wildlife is presented, followed by a description of new research in molecular approaches to biomonitoring and bioindicators through measures of gene expression, use of microarrays and measures of genetic diversity.

Using extirpation to evaluate ionic tolerance of freshwater fish

Field data of fish occurrences and specific conductivity were used to estimate the tolerance of freshwater fish to elevated ion concentrations and to compare the differences between species- and genus-level analyses for individual effects. We derived extirpation concentrations at the 95th percentile (XC95) of a weighted cumulative frequency distribution for fish species inhabiting streams of the central and southern Appalachians by customizing methods used previously with macroinvertebrate genera. Weighting factors were calculated based on the number of sites in basins where each species occurred, reducing overweighting observations of species restricted to fewer basins. Comparing the species- and genus-level fish XC95 values, XC95s for fish genera were near the XC95s for the most salt-tolerant species in the genus. Therefore, a genus-level effect threshold is not reliably predictive of species-level extirpation, unless the genus is monospecific in the assessed assemblage. Of the 101 fish species XC95 values, 5% were <509 and 10% were <565 µS/cm. The lowest XC95 for a species was 322 µS/cm, which is >300 µS/cm, the exposure estimated to extirpate 5% of macroinvertebrate genera in the central Appalachians. Above 509 µS/cm, 41 of the 101 species are expected to decline in occurrence. Environ Toxicol Chem 2018;37:871-883. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Proof of concept for the use of macroinvertebrates as indicators of polychlorinated biphenyls (PCB) contamination in Lake Hartwell

The US Environmental Protection Agency (USEPA) develops methods and tools for evaluating risk management strategies for sediments contaminated with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other legacy pollutants. Monitored natural recovery is a risk management alternative that relies on existing physical, chemical, and biological processes to contain, destroy, and/or reduce the bioavailability or toxicity of in-place contaminants. These naturally occurring processes are monitored to ensure that management and recovery are progressing as expected. One approach frequently used to evaluate the recovery of contaminated sediments and associated biota is the assessment of contaminant tissue levels, or body burden concentrations, in top trophic level fish. In the present study, aquatic invertebrates were examined as an indicator of recent exposure to PCBs. The approach aimed to determine whether invertebrates collected using artificial substrates (i.e., Hester-Dendy samplers) could be used to discriminate among contaminated sites through the analyses of PCBs in whole homogenates of macroinvertebrates. Macroinvertebrates were sorted, preserved, and analyzed for total PCBs (t-PCBs), by summing 107 PCB congeners. Macroinvertebrate body burden concentrations showed similar trends to sediment t-PCB concentrations at the sites sampled. The results indicate that macroinvertebrates can be used to assess sediment contamination among sites that have different PCB contamination levels.

Letter to the Editor in Chief Concerning the Article "Status of Fish and Macroinvertebrate Communities in a Watershed Experiencing High Rates of Fossil Fuel Extraction: Tenmile Creek, a Major Monongahela River Tributary" by Kimmel and Argent, 2012

We recently read Kimmel and Argent’s article “Status of fish and macroinvertebrate communities in a watershed experiencing high rates of fossil fuel extraction: Tenmile Creek, a major Monongahela River tributary,” which was published online on February 12, 2012, in Water, Air, and Soil Pollution. After discussions with the authors, some clarifications would be helpful regarding statements that refer to the recent EPA document, “A field-based aquatic life benchmark for conductivity in Central Appalachian streams” (USEPA 2011a), subsequently referred to as the Benchmark Report. These include statements that the background conductivity is higher than the benchmark value and that sensitive genera and diverse communities are present despite high specific conductance (hereafter conductivity). These statements unintentionally cast doubt on the relevance of the results in the Benchmark Report to the Western Allegheny Plateau (ecoregion 70 after Woods et al. 1996) in Pennsylvania.We address first, the background conductivity throughout the watershed, second, the sensitivity and diversity of the sampled communities and finally the relevance of the conductivity benchmark. Kimmel and Argent suggest that, “levels approximating 400 μS/cm represent natural background for the basin,” by assuming that Tenmile Creek represents natural conditions. We believe that natural conductivity background for streams in the region is lower and much lower in headwaters. The 25th centile of randomly sampled sites is a conventional estimate of background (USEPA 2011a). Based on 97 randomly sampled sites mostly collected in summer months from four EPA studies in ecoregion 70, the 25th centile of conductivity was 170 μS/cm (Mid-Atlantic Highland Assessment [MAHA], n028; Mid-Atlantic Integrated Assessment [MAIA], n030; Wadeable Stream Assessment [WSA], n020; and National Rivers and Streams Assessment [NRSA], n019) (USEPA 2010, 2011b, 2012a, b). Using the same dataset from Ecoregion 70 but limited to sites in Pennsylvania (Fig. S1), the 25th centile of 33 randomly sampled sites was 270 μS/cm. Conductivity is less than 200 μS/cm in some headwater streams in Tenmile Creek watershed (Table S1). Thus, we believe that the background level in this watershed is lower, and that Kimmel and Argent described current baseflow for the larger streams in Tenmile and SF Tenmile Creeks. At least two factors contribute to higher conductivity reported by Kimmel and Argent: multiple inputs of dissolved minerals to the larger streams they sampled via existing Water Air Soil Pollut (2012) 223:4659–4662 DOI 10.1007/s11270-012-1196-3

Using Geomorphology to Assess and Manage the Risks Associated with Clean Sediments in the Little Miami River Watershed (Southwestern OH)

We are evaluating the use of stream geomorphology and related measurements in the assessment and management of channel risks associated with stream impairment associated with clean sediments. The relationships between various geomorphological variables have been used by Rosgen and others to classify streams into groups that can be related to sediment transport or to bed and bank stability. These methods may be used to predict and evaluate the sensitivity of stream reaches to altered hydrologic regimes that subsequently result in bank destabilization and excessive sediment transport. Factors, such as increased erosion and stream channel destabilization, can result in impairment by excessive clean sediment. This project is intended to determine (1) the most effective, timely and cost-efficient methods for collecting channel morphology data, and (2) which variables may be used as indicators of increased risk of impairment from suspended and bedded sediments. Previous research in the Little Miami River (Southwestern Ohio) established thirty-five sites where data was collected for several years using the U.S. EPA Environmental Monitoring and Assessment Program protocols. Eight of these sites were selected for intensive surveying to determine the level of effort required to obtain representative data for stream classification. Slope and sinuosity measurements from the surveys resulted in the same Rosgen stream classification as that determined from measurements from aerial photographs and topographic maps. This indicates that these types of data may be used in place of extensive surveying at least in Southwestern Ohio. Other measurements such as pebble counts, entrenchment and stream profile still require field visits. The extent to which a qualitative rating system can be used is also being evaluated. The most important parameters for determining the stability of stream geomorphology and near-stream erosion risks appear to be slope, bed and bank material stability, incision and vegetative cover/type in the riparian zone.