West Virginia waters have become affected by fossil fuel operations.
A recent study by Rutgers into the West Virginia waters downstream from fossil fuel extraction facilities, including gas, oil and fracking from shale, have concluded that the operations have lead to a change in the natural microbial fauna of the water. The study, which was published in Science of the Total Environment, showed that wastewater, including briny water that contained petroleum and other pollutants, affected the biodiversity, number, and functions of microbes downstream. The microbes exhibited signs of changes in respiration, nutrient cycling and also showed signs of stress.
There were also signs of antibiotic resistance in sediments downstream from the operations, but no significant hotspots were found. It was also indicated that microbial changes in these sediments may have implications for the treatment and beneficial recycling of wastewater.
“My hope is that the study could be used to start making hypotheses about the impacts of wastewater,” said Nicole Fahrenfeld, lead author of the study and assistant professor in Rutgers’ Department of Civil and Environmental Engineering. “I do think we’re at the beginning of seeing what the impacts could be. I want to learn about the real risks and focus our efforts on what matters in the environment.”
Underground reservoirs containing oil or natural gas usually also contain water, some of which is natural, and some of which is injected to boost production. When fracking, a fracturing fluid and solid material are pumped into such reservoirs under high pressure to make the rock more porous. During the extraction process, water from the reservoir is then pumped to the surface, usually as a mixture of the injected fluids, along with briny water from the reservoir. It can contain dissolved salt, petroleum and other organic compounds, suspended solids, trace elements, bacteria, naturally occurring radioactive materials and anything injected into wells, says the US Geological Survey (USGS).
This water can be injected into deep wells or evaporated, but some of it is recycled and discharged. The new study suggests that such recycling efforts may not be enough to properly treat the waste water. The samples analyzed in the study were taken from Wolf Creek in West Virginia in June 2014, including from an unnamed tributary that runs through an underground injection control facility. The facility includes a disposal well, which injects wastewater deep under the surface, brine storage tanks, and two settling ponds hat were used to temporarily store wastewater before injection.
“We have this really nice dataset with all the genes and all the microbes that were at the site,” Fahrenfeld said. “We hope to apply some of these techniques to other environmental systems.”