Produced water from Marcellus Shale and amphibians

Science Center Objects

Research biologists at the USGS Patuxent Wildlife Research Center (PWRC) are conducting a series of scientific studies on the potential effects of wastewater from hydraulic fracturing activities on terrestrial wildlife. Findings will help in assessing proposals for managing recycling and distribution of large volumes of flowback and produced waters generated by methods of oil and gas extraction.  This work is being conducted as part of the EHMA Energy Project with the goal of investigating effects of the Energy Life Cycle on Environmental Health.    

The Challenge: Hydraulic fracturing of horizontally drilled wells to extract fossil fuels can require up to 11M liters of fresh water and generates large volumes of flowback and produced water (PW).  PW contains a chemical mixture consisting of biocides, industrial solvents, hydrocarbons, heavy metals, brine, silicates and naturally occurring radioactive materials.  Whether it be from leaks or spills from surface or underground pipe transport, storage tanks, flooding of containment ponds, or more recently proposed reusing this wastewater for irrigating crops, components of PW have been identified in natural streams, roadside ditches and vernal pools.  These are the habitats and natural resources on which wildlife depend for growth and development. To date there have been few, if any, empirical data available on whether exposure to PW affects the physiology of amphibians and reptiles, and on their ability to adapt to chemicals associated with PW.

The Science: Amphibians depend on these sources of freshwater from egg deposition through reproduction over both their aquatic and terrestrial stages of development.  In collaboration with Towson University and USGS labs, biologists at PWRC are conducting controlled study trials during which anuran and caudate species are exposed to environmental concentrations of PW obtained from Marcellus Shale Energy and Environmental Laboratory (MSEEL).  Chronic exposure to PW at low levels (~0.03%) affects wood frog survival during their early developmental stages. Under similar conditions, study trials are being conducted with forest dwelling salamanders exposed to the same PW, to investigate hatching success, larval and adult growth, behaviors and survival.  

The Future: Many amphibians and reptiles, some classified as species of concern, live within forested and agricultural lands in close proximity to major shale formations in North America.  Given projections of expanded hydraulic fracturing activities and proposals to reuse wastewater from these facilities, larger environmental mesocosm trials are planned to separate the real from the perceived risks on communities and populations of terrestrial wildlife.  These risk assessments should be based on direct chemical exposure and on indirect effects from changes in habitat and available wildlife resources. These more comprehensive findings can be applied to decision processes related to managing PW and other wastewater distribution in the future.

In collaboration with:

Adam Mumford, Isabelle Cozzarrelli, Jeanne Jeaschke - USGS Water Resources Mission Area

Aida Farag - USGS Columbia Environmental Research Center