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In this paper, a field study was carried out to examine the effect of flue gas desulfurization (FGD) by‐product on water quality at an underground coal mine in central‐eastern Ohio. Flue gas desulfurization by‐product was injected into the down‐dip portions of the Roberts–Dawson mine in an attempt to seal major seeps exiting the mine and to coat exposed pyritic surfaces. Immediately following grout injection, significant increases in acidity, iron, aluminum, sulfur, and calcium were observed at most surface and ground water locations near where grouting was carried out. Following this initial flush of elements, concentrations of most constituents have decreased to near pre‐grouting levels. Data from the site and geochemical modeling suggest that an increase in water level or rerouting of drainage flow resulted in the dissolution of iron and aluminum sulfate salts and ferrihydrite. Dissolution of the FGD grout material resulted in increases in calcium and sulfate concentrations in the drainage waters. Water within the mine voids was saturated with respect to calcium sulfate and gypsum immediately following grout injection. Based on an analysis of core samples obtained from the site, acid mine drainage (AMD) was in contact with at least some portions of the grout and this resulted in grout weathering. Subsequent transport of calcium and sulfate to the underclay, perhaps by fracture flow, has resulted in the deposition of gypsum and calcium sulfate solids. [ABSTRACT FROM AUTHOR]

In southeastern Ohio, active remediation of streams affected by Acid Mine Drainage (AMD) has proven to be successful for some streams, while others have not recovered based on macroinvertebrate assessment. In this study, biofilms were collected from three Moderately Impaired, three Recovered, and two Unimpaired streams. The biodiversity was characterized by metabarcoding using two universal barcode markers (16S and 18S) along with two algal specific markers (UPA and rbcL) and high‐throughput amplicon sequencing. For each marker, the ordination of Bray–Curtis Index calculated from the total Amplicon Sequence Variants (ASVs) present in each stream showed the Unimpaired and Recovered streams clustered, while Moderately Impaired streams were more distant. Focusing on the algal ASVs, the Shannon index for the rbcL, and UPA markers showed significantly lower alpha diversity in Moderately Impaired streams compared to Unimpaired streams, but the Recovered streams were not significantly different from the other two stream categories. The two universal markers together captured all algal phyla providing an outline of the diversity, but the two algal specific markers produced a greater number of ASVs and taxonomic depth for algal taxa. Further examination of the UPA marker revealed a drastic decrease in relative abundance of diatoms in Moderately Impaired streams compared to Recovered and Unimpaired streams. Likewise, diatom genera identified in the rbcL data and indicative of stream water quality showed marked differences in relative abundance among stream categories. Although all markers were useful, the algal‐specific UPA and rbcL contributed more insights into algal community differences among stream categories. [ABSTRACT FROM AUTHOR]

Both acid mine drainage (AMD) and untreated sewage are serious water quality issues faced by poor, rural communities both within the United States and worldwide. In Appalachia, it is common for these water quality issues to coincide. The aim of this study was to investigate the interaction between AMD and untreated sewage in stream. The study area, Murray City, Ohio, was conflicted, blocking construction of a mine water treatment system to maintain sewage 'treatment' by the AMD. Data collected over 5 months from Snow Fork Creek in Murray City, Ohio, show that during low flow, high net acidity portions of a water year, the acidity is sufficient to limit fecal indicator bacteria populations below regulatory limits. During high flow, low net acidity portions of the water year, bacterial populations thrive above the regulatory limits until a point where dilution by water of good quality leads to a decrease in fecal indicator bacteria concentrations to near the regulatory limit of 126 CFU/100 mL for primary contact recreation. This study shows that AMD limits the survival of fecal indicator bacteria and suggests that traditional fecal indicator bacteria are insufficient for detecting untreated sewage in acidic streams despite both visual and olfactory evidence. [ABSTRACT FROM AUTHOR]

A research institute at Ohio University recently conducted a comprehensive study on highway culvert structures for the Ohio Department of Transportation. During the study, a number of thermoplastic pipe structures under Ohio's highways were inspected and rated. One of the thermoplastic pipe structures was a 0.61-m-diameter (24-in.-diameter) corrugated high-density polyethylene (HDPE) pipe under State Route 145 in Noble County, Ohio. What was unique about this pipe structure was that it was the oldest thermoplastic pipe culvert in service in Ohio. The pipe was installed under a shallow cover in 1981. The Ohio University team visited the culvert site in 2004 and inspected the pipe structure thoroughly. It was inspected again in June 2010. Drainage water entering the culvert was acidic, indicating the influence of a nearby surface coal-mining operation. The pipe structure had moderate amounts of deflection under the roadway, but overall it appeared to be in satisfactory condition. In 2004, a short pipe section was taken from the outlet end to determine if the pipe material had degraded over the years from constant exposure to ultraviolet light and acid mine drainage. A series of tensile strength and density tests were performed according to industry standard test methods. Test results showed that the thermoplastic pipe material experienced little aging. Finally, a course of action was recommended for the HDPE pipe structure based on a basic risk assessment analysis. [ABSTRACT FROM AUTHOR]

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Acid mine drainage is a serious environmental problem throughout mining regions of the US and around the world. In Appalachia, reuse of steel slag from steel production as a source of alkalinity for treatment of acid mine drainage has become a common practice. In these systems, dubbed steel slag leach beds, relatively clean surface water is percolated through a bed of steel slag to add large amounts of alkalinity to the water before mixing it with acidic, metalliferous mine water. These beds do not operate consistently and their failure mechanisms are poorly understood. Using the experience of Raccoon Creek watershed in southern Ohio, the alkalinity distribution of the discharge of six steel slag leach beds is compared. Two of these beds are still functional, one has been abandoned and three are operating poorly. The difference in alkalinity distribution between these beds suggests that a carbonate-dominated alkalinity system is an indicator of a poorly performing steel slag leach bed, while a more even distribution between hydroxide, carbonate and bicarbonate may point to more ideal operating conditions. In eight laboratory column experiments, this evidence was then expanded upon by testing different mixed media substrates (differing mixes of steel slag, wood chips and river gravel) to see which provided the most ideal alkalinity distributions. The columns that had steel slag mixed either with wood chips or wood chips and river gravel outperformed the column with slag only in terms of alkalinity distribution, perhaps due to microbial processes or increased hydraulic conductivity without significant added calcium or carbon that could drive calcium carbonate precipitation within the beds and causing them to fail. [ABSTRACT FROM AUTHOR]

Sandy Run (Vinton County, southeastern Ohio, USA) is a stream receiving acid mine drainage (AMD) from an abandoned coal mine complex. This stream has been dammed to form Lake Hope. The heavy metal composition of waters (benthic and pore), sediments, and macroinvertebrates in the lake reservoir sediments were analyzed. Lake waters contained Mn as the heavy metal present in higher concentrations followed by Fe, Al, and Zn. Depletion of Fe and Al occurred from precipitation of less soluble Fe and Al oxides and hydroxides along Sandy Run before entering the lake, producing a high Mn water input into the reservoir. Concentrations of heavy metals in the sediments increased toward the dam area. Sequential extraction of metals in the sediments showed that the highest fractions of metals corresponded to the detrital fraction or eroded material from the watershed and metals associated with iron and manganese hydroxides. Heavy metals in the organic sediment fraction were low. Heavy metals from the AMD source, as well as sediments rich in heavy metals eroded from the watershed, were transported to the downstream dam area and stored at the bottom, producing the observed chemistry. Heavy metals in benthic waters also were sourced from the diffusion of ions from sediments and lake waters as variation in pH and redox conditions determined the flux at the sediment-water interface. Metal concentrations were measured within two deposit feeders, oligochaetes and chironomids, and compared to trends in physical metal concentration across the lake. For the four heavy metals with higher concentration in both benthic animals, the concentrations followed the trend: Fe > Al > Mn > Zn, which were similar to the bioavailable metals in the sediments rather than the pore or the benthic water where Mn was the most abundant heavy metal. Ingestion of sediment, not exposure to pore or benthic waters, appeared to be the main transfer mechanism for metals into the biota. Trends and patterns in animal metal concentrations across the lake were probably a complex process controlled by metabolic needs and metallic regulation and tolerance. Even when Mn was the highest concentration heavy metal in the pore waters, it was the lowest to bioconcentrate in the organisms. In comparison, Cd, the lowest concentration metal in the sediments, presented one of the highest bioaccumulation factors. [ABSTRACT FROM AUTHOR]

The spatial variability in chemical composition of water and sediments along Snow Fork, a stream draining 70 km2 of southeastern Ohio, was investigated under low-flow conditions. The stream is affected by acid mine drainage (AMD) beginning at Essex Mine, an abandoned mine opening, and extending 23 km downstream to the confluence with Monday Creek. Volumetric discharge and changes in stream water and sediment metal concentrations were examined to identify chemical interactions and processes controlling the transport and fate of metal contaminants. The stream loses water to the groundwater system in some sections. The water loss probably occurs through fractures connecting the stream to underlying underground coal mines. Mass balance (loading) and mineral saturation index calculations were used to identify metal sources and sinks. Dissolved metal loading increases downstream along the length of Snow Fork, despite the precipitation of metals as hydroxides in the streambed, indicating multiple groundwater sources of AMD along the flow path. Relatively high dissolved metal concentrations and low sediment metal concentrations occur where the pH is low, indicating that local sediment-water interaction dominates mass transfer between sediments and water. Calculated mineral saturation indexes indicate that aluminum and iron hydroxides precipitate in some stream segments and dissolve in others. X-ray diffractograms of sediments show two distinct mineral groups. Amorphous or weakly crystalline minerals dominate one group found near the stream headwaters near the underground mine. Crystalline mineral phases dominate the sediments downstream. These diffractograms contain the primary peaks for quartz, kaolinite and illite all of which constitute the local sandstones, shales or underclay. Peaks of amorphous phases of iron and manganese, if present, are obscured. The implications of these findings are that the transport of metals in sediments may be as important as dissolved metal transport in estimating the overall stream load, particularly if downstream sources of AMD may remobilize metals from soluble precipitates. [ABSTRACT FROM AUTHOR]