Regulation of Water Pollution from Hydraulic Fracturing in Horizontally-Drilled Wells in the Marcellus Shale Region, USA

Hydraulic fracturing is an industrial process used to extract fossil fuel reserves that lie deep underground. With the introduction of horizontal drilling, new commercial sources of energy have become available. Wells are drilled and injected with large quantities of water mixed with specially selected chemicals at high pressures that allow petroleum reserves to flow to the surface. While the increased economic activities and the outputs of domestic energy are welcomed, there is growing concern over negative environmental impacts from horizontal drilling in shale formations. The potential for water contamination, land destruction, air pollution, and geologic disruption has raised concerns about the merits of production activities used during extraction. This paper looks at the impacts of horizontal drilling using hydraulic fracturing on water supplies and takes a comprehensive look at legislative and regulatory approaches to mitigate environmental risks in the Marcellus shale region. The overview identifies shortcomings associated with regulatory controls by local and state governments and offers two policy suggestions to better protect waters of the region

Temporal phylogeography of Yersinia pestis in Madagascar : Insights into the long-term maintenance of plague

Data Availability: All relevant data are within the paper and its Supporting Information files except for the sequence read archives for 31 newly sequenced strains that are available at NCBI under the accession numbers: SRR4175414-SRR4175444. The direct link to this data is: https://www.ncbi.nlm.nih.gov/sra/?term=SRP086709. Funding: Funding for this study was provided by the US Department of Homeland Security’s Science and Technology Directorate award number HSHQDC-10-C-00139 to PK; the Cowden Endowment at Northern Arizona University; and Wellcome fellowships 081705 and 095171 to ST. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Preparation and characterization of antibacterial cobalt-exchanged natural zeolite/poly(vinyl alcohol) hydrogels

In the present study, potential application of the local clinoptilolite-rich natural zeolite in formulation of antibacterial hydrogels was investigated. The zeolite powder exchanged with cobalt(II) ions was used in preparation of the zeolite/poly(vinyl alcohol) hydrogel films in different amounts. The films were physically crosslinked by the freezing-thawing method and characterized for their crystallinity, surface and cross sectional morphology, chemical composition, thermal behaviour, mechanical properties, swelling and dissolution behaviours, and antibacterial activities against a Gram-negative bacteria. The films with 0.48 wt% and higher cobalt-exchanged zeolite contents showed antibacterial activity. Addition of the zeolite powder in the formulations did not cause significant changes in the other properties of the films.Turkish Republic Prime Ministry State Planning Organization (DPT-2006 K120690

Regulation of Water Pollution from Hydraulic Fracturing in Horizontally-Drilled Wells in the Marcellus Shale Region, USA

Hydraulic fracturing is an industrial process used to extract fossil fuel reserves that lie deep underground. With the introduction of horizontal drilling, new commercial sources of energy have become available. Wells are drilled and injected with large quantities of water mixed with specially selected chemicals at high pressures that allow petroleum reserves to flow to the surface. While the increased economic activities and the outputs of domestic energy are welcomed, there is growing concern over negative environmental impacts from horizontal drilling in shale formations. The potential for water contamination, land destruction, air pollution, and geologic disruption has raised concerns about the merits of production activities used during extraction. This paper looks at the impacts of horizontal drilling using hydraulic fracturing on water supplies and takes a comprehensive look at legislative and regulatory approaches to mitigate environmental risks in the Marcellus shale region. The overview identifies shortcomings associated with regulatory controls by local and state governments and offers two policy suggestions to better protect waters of the region

Burkholderia pseudomallei, the causative agent of melioidosis, is rare but ecologically established and widely dispersed in the environment in Puerto Rico.

BackgroundBurkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. The global burden and distribution of melioidosis is poorly understood, including in the Caribbean. B. pseudomallei was previously isolated from humans and soil in eastern Puerto Rico but the abundance and distribution of B. pseudomallei in Puerto Rico as a whole has not been thoroughly investigated.Methodology/principal findingsWe collected 600 environmental samples (500 soil and 100 water) from 60 sites around Puerto Rico. We identified B. pseudomallei by isolating it via culturing and/or using PCR to detect its DNA within complex DNA extracts. Only three adjacent soil samples from one site were positive for B. pseudomallei with PCR; we obtained 55 isolates from two of these samples. The 55 B. pseudomallei isolates exhibited fine-scale variation in the core genome and contained four novel genomic islands. Phylogenetic analyses grouped Puerto Rico B. pseudomallei isolates into a monophyletic clade containing other Caribbean isolates, which was nested inside a larger clade containing all isolates from Central/South America. Other Burkholderia species were commonly observed in Puerto Rico; we cultured 129 isolates from multiple soil and water samples collected at numerous sites around Puerto Rico, including representatives of B. anthina, B. cenocepacia, B. cepacia, B. contaminans, B. glumae, B. seminalis, B. stagnalis, B. ubonensis, and several unidentified novel Burkholderia spp.Conclusions/significanceB. pseudomallei was only detected in three soil samples collected at one site in north central Puerto Rico with only two of those samples yielding isolates. All previous human and environmental B. pseudomallei isolates were obtained from eastern Puerto Rico. These findings suggest B. pseudomallei is ecologically established and widely dispersed in the environment in Puerto Rico but rare. Phylogeographic patterns suggest the source of B. pseudomallei populations in Puerto Rico and elsewhere in the Caribbean may have been Central or South America

Maximum clade credibility phylogeny, reconstructed in BEAST, with mean divergence times for whole genome sequences from 32 Malagasy <i>Yersinia pestis</i> strains and reference strain CO92.

<p>A maximum clade credibility phylogeny based upon SNPs identified among the 31 Malagasy <i>Y</i>. <i>pestis</i> strains sequenced here and the previously sequenced Malagasy strain IP275 and reference strain CO92. Malagasy strain branches are labeled with the SNP nodes from <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.g001" target="_blank">Fig 1</a>, the strain IDs from <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.s004" target="_blank">S1 Table</a>, and the year of isolation of the strain. Colors of the clades and/or branches indicate identified subgroups and correspond to the subgroup color designations in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.g001" target="_blank">Fig 1</a>. A timeline indicates the estimated mean divergence times for the various branch points. Estimated mean divergence times for various nodes of interest are also indicated on the phylogeny. Yellow circles indicate the posterior probabilities for each of the clades, where larger circles indicate higher confidence.</p

Divergence time estimates for nodes of interest.

<p>Divergence time estimates for nodes of interest.</p

Geographic distribution of 45 Malagasy <i>Yersinia pestis</i> samples from 2009 to 2012.

<p>The geographic distribution of identified subgroups is presented in separate panels for each year, with symbols and colors as in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.g002" target="_blank">Fig 2</a>.</p

SNP and MLVA phylogenies depicting 18 major phylogenetic subgroups identified among 773 Malagasy <i>Yersinia pestis</i> samples.

<p>(A) SNP phylogeny based on 212 informative SNPs identifying 100 individual nodes (circles and stars) among 770 Malagasy <i>Y</i>. <i>pestis</i> samples (only the lineage could be identified for the remaining 3 samples, and not the specific node). Stars indicate terminal nodes defined by a sequenced strain. Circles indicate intermediary nodes (i.e., collapsed branch points) along the lineages containing groups of samples. Branch points that did not contain any samples are labeled in black italics. A dashed arrow indicates a branch leading to a single, previously identified, terminal node not represented among the samples in this analysis. Lineages (lower case letters) and nodes within lineages (numbers within circles and stars) were named as in [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.ref017" target="_blank">17</a>–<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.ref019" target="_blank">19</a>], with new letters and numbers assigned to newly identified lineages and nodes, respectively. Basal nodes d and k are represented by pie charts, indicating the presence of multiple MLVA identified subgroups within these nodes. Color shading indicates the 18 identified phylogenetic subgroups and, to the extent possible, corresponds to the subgroup colors used in reference [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.ref019" target="_blank">19</a>]. Solid pale green and striped pale green, respectively, indicate the new SNP lineage (w) and remaining subset of samples within basal node d that were split in this analysis from a single previously identified subgroup. The number of SNPs on branches with >1 SNP are indicated in red. The single SNP differentiating between Groups I and II is indicated by a perpendicular red line on the branch between nodes d and k. (B) MLVA phylogenies of 10 and 38 Malagasy <i>Y</i>. <i>pestis</i> samples from basal SNP nodes d and k, respectively. The MLVA phylogenies consist of neighbor-joining dendrograms constructed in MEGA6 [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.ref035" target="_blank">35</a>] using mean character based distance matrices. Bootstrap values ≥50 (generated in PAUP 4.0b10 (D. Swofford, Sinauer Associates, Inc., Sunderland, MA) based upon 1,000 simulations) supporting MLVA phylogeny branches are indicated. One and four additional phylogenetic subgroups consistent with previous analyses [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.ref019" target="_blank">19</a>] were identified within the MLVA phylogenies of nodes d and k, respectively. In addition, 1 and 3 samples within nodes d and k, respectively, did not fall into any identified phylogenetic subgroup and were labeled with a “+” or an “*”, and classified as II.NONE and I.NONE, respectively.</p

Geographic distribution of 355 Malagasy <i>Yersinia pestis</i> samples from 1995 to 2000.

<p>The map of Madagascar in the upper left indicates elevation, all of the geographic points in this study (small black points), and the portion of Madagascar represented in the other panels (rectangle). The geographic distribution of identified subgroups is presented in separate panels for each year. Circles in the panels represent the locations of the fokontany (i.e., villages) or commune centroids (when the fokontany was unknown) where samples were collected. In some cases where separate circles were too close together to be visibly distinguished at this scale, a single circle indicating the overlapping circles was substituted. This occurred primarily for fokontany within communes Mahajanga and Mahabibo within district Mahajanga I, and for fokontany within the various arrondissements (i.e., administrative divisions) within district Antananarivo Renivohitra, but also occasionally occurred at other locations. Colors of the mapped circles indicate identified subgroups and correspond to the subgroup color designations in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005887#pntd.0005887.g001" target="_blank">Fig 1</a>. Divisions within circles indicate that multiple subgroups were found at that location in that year. Unaffiliated Group I and II samples (i.e., I.NONE and II.NONE) are indicated by a “*” and a “+”, respectively.</p