Shale Gas Well Drilling and Wastewater Treatment Impacts on Surface Water Quality in Pennsylvania

by Shannon Julius

Shale gas development can affect surface water quality by means of runoff from well construction and discharge from wastewater treatment facilities. Olmstead et al. (2013) conducted a large-scale statistical study of the extent to which these two activities affect surface water quality downstream. This study is different than most current literature related to the regional water impacts of shale gas development in that it focuses on impacts to surface water bodies as opposed to groundwater bodies. Researchers consulted online databases to retrieve locations of shale gas wells and wastewater treatment facilities within Pennsylvania. These were spatially related to downstream water quality monitors using Geographic Information Systems (GIS). Concentrations of chloride (Cl–) and total suspended solids (TSS) were used as indicators of water quality because both are associated with shale gas development and are measured by water quality monitors. Shale gas wastewater typically has a high concentration of Cl–, which can directly damage aquatic ecosystems and is not easily removed once dissolved in water. TSS, which harm water quality by increasing temperature and reducing clarity, can potentially come from the construction of well pads, pipelines, and roads associated with well drilling, especially when precipitation creates sediment runoff. Results of the study suggest that wastewater treatment facilities are responsible for raised concentrations of Cl– downstream and that the presence of gas wells are correlated with raised concentrations of TSS downstream. Continue reading

Try Not to Live Too Close to a Fracked Well

by Emil Morhardt

If you happen to live within 1 km of a hydraulically fractured well in Pennsylvania, and you get your water supply from a well, you stand about twice as large a chance of having skin and upper respiratory problems than if you live 2 km or farther away; you have over 3 health symptoms, on average—people further away have only 1.6. Looked at another way,13% of people living near fracking operations have upper respiratory problems, versus 3% living farther away; and 39% of the same group of people have upper respiratory problems versus 18% living further away. That is the disturbing result of an epidemiological study of almost 500 people in an area of natural gas drilling in the Marcellus Shale, just published in a journal of the National Institute of Environmental Health Sciences (Rabinowitz et al. 2014). Continue reading

Impacts of Shale Gas Development on Regional Water Quality

by Shannon Julius

Drilling into shale is a difficult task, as gases are under high pressure and can easily damage the well’s integrity if drilling is done incorrectly. Such damage allows natural gases, particularly methane, to “migrate” through cement seals and into groundwater, which happens with approximately 1–3% of wells in Pennsylvania. The high toxicity of fracturing fluid raises the concern of fluid migration accompanying methane migration, and research has yet to determine the extent to which fracturing fluid can affect groundwater. However, it is highly likely that most of the unrecovered fracturing fluid is absorbed by the shale formation. The remaining fracturing fluid is recovered as Continue reading

Unexpectedly High Methane Concentrations over Shale Gas Fields

by Emil Morhardt

Methane, the main constituent of natural gas (both that from gas wells and from farm operations) is a powerful greenhouse gas, around 30 times more potent than CO2 over the hundred years after it is emitted. It is on the rise, and the culprit might be shale gas development, which utilizes hydraulic fracturing (fracking). Caulton et al. (2014) used an airplane to sample the air above a 2,800-square-kilometer area of the Marcellus shale formation gas fields in Pennsylvania. It was rich in methane, with between 2 and 15 grams heading skyward over each square kilometer every second, the upper limit of which is quite a lot higher than the 5 grams estimated from what was previously known about wellhead methane emissions; the authors suspected that the transient nature of gas leakage might be the reason, making very difficult to come up with an average over time from ground-level measurements. Since they were in an airplane, however, they could circle around areas of high concentrations and pinpoint the source. It turns out that…

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