The hydraulic fracturing process requires water and chemicals to be pumped beneath the earth’s surface at high pressures to “free” natural gas that is trapped in tight rock formations. When the fluid comes back up to the surface, it is known as produced water. Produced water can contain a number of chemicals including, but not limited to, ions, heavy metals, inorganic solids, and trace radionuclides. When produced water is accidentally spilled or otherwise discharged, it can harm the environment, especially aquatic life.
Past studies on aquatic life in areas with shale gas development have shown that produced water can inhibit the ability of certain fish to develop and swim normally. Researchers believe that at least part of the produced water’s toxicity can be explained by its high salt content.
A recent study, however, found that exposure to low levels of produced water over an extended period of time minimally impacted aquatic life. In that study, researchers at The University of Alberta, Edmonton; Newcastle University School of Natural and Environmental Sciences; Athabasca University, and the National Institute for Nanotechnology, Edmonton, studied the effects of exposure of young rainbow trout to flowback and produced water from hydraulic fracturing for 28 days.
The researchers concluded that sub-lethal levels of flowback and produced water introduced over the course of 28 days had minimal effects on the rainbow trout. Although changes were observed in the gills of the trout, it was determined not to be due to the salt in the flowback and produced water. Salt channels studied appeared to work normally.
The researchers suggested it is likely that leaked flowback and produced water from hydraulic fracturing had little long-term effect on the rainbow trout. However, it is unclear if spills and discharges are likely to occur at the low volume observed in the study or at higher volumes. In other words, research should be continued to account for high-volume events, such as major spills. With Pennsylvania’s numerous streams and rivers, it is critical to continue to safeguard wildlife and aquatic life from potential harm.