The gas extraction method known of as hydraulic fracturing (fracking) could pollute groundwater even more severely than has been estimated in the past.
Scientists reported that when waste fluids from fracking are spilled or deliberately applied to land they most likely pick up tint particles in the soil that attract heavy metals and other chemicals that can harm the health of both humans and animals, an American Chemical Society news release reported.
Fracking involves injecting large volumes of fluids underground to push up gas and oil. The method has increased energy production in the U.S., but it is believed to be extremely bad for the environment and had caused a great deal of controversy. One issue in fracking is flowback, which is the fluids that surge out of fracked wells during the extraction process. This liquid contains "water, lubricants, solvents and other substances from the original fracking fluid," the news release reported. These liquids have been spilled on certain occasions and in some cases are legally applied to the land.
Researchers have linked fracking to groundwater contamination, but tiny pieces of mineral and clay called colloids have never really been taken into account. Colloids are dangerous because they attract heavy metals and environmental toxins.
To see what would happen if colloids were released into soil after a fracking spill, researchers flushed flowback fluids through sand that had a known amount of colloids. When they increased the flow rate the fluids picked up an additional 36 percent of colloids.
"This indicates that infiltration of flowback fluid could turn soils into an additional source of groundwater contaminants such as heavy metals, radionuclides and microbial pathogens," the researchers said in the news release.
"The authors acknowledge funding from HATCH funding of the U.S. Department of Agriculture, the National Science Foundation, the Chinese Scholarship Council, and the National Natural Science Foundation of China," the news release reported.
