Navigation Links
Fracking flowback could pollute groundwater with heavy metals

ITHACA, N.Y. The chemical makeup of wastewater generated by "hydrofracking" could cause the release of tiny particles in soils that often strongly bind heavy metals and pollutants, exacerbating the environmental risks during accidental spills, Cornell University researchers have found.

Previous research has shown 10 to 40 percent of the water and chemical solution mixture injected at high pressure into deep rock strata, surges back to the surface during well development. Scientists at the College of Agriculture and Life Sciences studying the environmental impacts of this "flowback fluid" found that the same properties that make it so effective at extracting natural gas from shale can also displace tiny particles that are naturally bound to soil, causing associated pollutants such as heavy metals to leach out.

They described the mechanisms of this release and transport in a paper published in the American Chemical Society journal Environmental Science & Technology.

The particles they studied are colloids larger than the size of a molecule but smaller than what can be seen with the naked eye which cling to sand and soil due to their electric charge.

In experiments, glass columns were filled with sand and synthetic polystyrene colloids. They then flushed the column with different fluids deionized water as a control, and flowback fluid collected from a Marcellus Shale drilling site at different rates of flow and measured the amount of colloids that were mobilized.

On a bright field microscope, the polystyrene colloids were visible as red spheres between light-grey sand grains, which made their movement easy to track. The researchers also collected and analyzed the water flowing out of the column to quantify the colloid concentration leaching out.

They found that fewer than five percent of colloids were released when they flushed the columns with deionized water. That figure jumped to 32 to 36 percent when flushed with flowback fluid. Increasing the flow rate of the flowback fluid mobilized an additional 36 percent of colloids.

They believe this is because the chemical composition of the flowback fluid reduced the strength of the forces that allow colloids to remain bound to the sand, causing the colloids to actually be repelled from the sand.

"This is a first step into discovering the effects of flowback fluid on colloid transport in soils," said postdoctoral associate Cathelijne Stoof, a co-author on the paper.

The authors hope to conduct further experiments using naturally occurring colloids in more complex field soil systems, as well as different formulations of flowback fluid collected from other drilling sites.

Stoof said awareness of the phenomenon and an understanding of the mechanisms behind it can help identify risks and inform mitigation strategies.

"Sustainable development of any resource requires facts about its potential impacts, so legislators can make informed decisions about whether and where it can and cannot be allowed, and to develop guidelines in case it goes wrong," Stoof said. "In the case of spills, you want to know what happens when the fluid moves through the soil."


Contact: Melissa Osgood
Cornell University

Related biology news :

1. Another concern arises over groundwater contamination from fracking accidents
2. Hormone-disrupting activity of fracking chemicals worse than initially found
3. How to avoid water wars between fracking industry and residents
4. Acid mine drainage reduces radioactivity in fracking waste
5. UTSA, Southwest Research Institute to develop low-cost method to treat fracking water
6. First risk assessment of shale gas fracking to biodiversity
7. Many stressors associated with fracking due to perceived lack of trust, Pitt finds
8. Fracking: Challenges and opportunities
9. Fracking in Michigan: U-M researchers study potential impact on health, environment, economy
10. UMN scientists get federal grant for biotechnology development to purify fracking water
11. Fracking and Health Impact Assessments -- IOM hosts workshop April 30 and May 1
Post Your Comments:
Related Image:
Fracking flowback could pollute groundwater with heavy metals
(Date:11/19/2015)... MOUNTAIN VIEW, Calif. , Nov. 19, 2015 /PRNewswire/ ... authentication market, Frost & Sullivan recognizes BIO-key with the ... Strategy Leadership. Each year, Frost & Sullivan presents this ... comprehensive product line catering to the needs of the ... which the product line meets and expands on customer ...
(Date:11/18/2015)... 2015 --> ... market report titled  Gesture Recognition Market - Global Industry ... 2021. According to the report, the global gesture recognition market was valued ... reach US$29.1 bn by 2021, at a CAGR of ... America dominated the global gesture recognition market ...
(Date:11/17/2015)... Nov. 17, 2015  Vigilant Solutions announces today that ... Board of Directors. --> ... retiring from the partnership at TPG Capital, one of ... over $140 Billion in revenue.  He founded and led ... the TPG companies, from 1997 to 2013.  In his ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... Germany , November 30, 2015 ... Vienna, Austria to be held December ... (ECNR) in Vienna, Austria to ... wholly owned subsidiary of Vycor Medical, Inc. ("Vycor") (OTCQB: VYCO), ... NovaVision Therapy Suite at the 3rd European Congress of ...
(Date:11/27/2015)... , Nov. 27, 2015 /PRNewswire/--  Mallinckrodt plc (NYSE: ... today that it has closed the sale of its ... Guerbet (GBT- NYSE Euronext) in a transaction valued at ... manufacturing facilities and a total of approximately 1,000 employees ... St. Louis area. This entire ...
(Date:11/25/2015)... , November 26, 2015 ... Biobanking Market 2016 - 2020 report analyzes that ... integrity and quality in long-term samples, minimizing manual ... cost-effectiveness. Automation minimizes manual errors such as mislabeling ... efficiency. Further, it plays a vital role in ...
(Date:11/25/2015)... 25, 2015  Neurocrine Biosciences, Inc. (Nasdaq: NBIX ... and CEO of Neurocrine Biosciences, will be presenting at ... New York . .   ... approximately 5 minutes prior to the presentation to download ... presentation will be available on the website approximately one ...
Breaking Biology Technology: