Environmental Impact Shale Gas: Regulatory Insights Ian Duncan University of Texas at Austin
Four Questions 1. Is water consumption for hydraulic fracturing a problem? 1. Has hydraulic fracturing contaminated drinking water? 2. Has gas production led to dangerous levels of atmospheric Emissions? 3. Are the regulatory frameworks in place in the US adequate to minimize the risk of environmental damages?
Coal seam methane versus shale gas: Produced water order of magnitude less for gas shale CSM lower depth/pressure than gas shale, therefor less risk of blowouts CSM uses fewer dangerous chemicals in fracturing? There are differences but very many similarities
IS WATER CONSUMPTION FOR HYDRAULIC FRACTURING OF SHALE GAS IN THE US A PROBLEM?
What are Academics Saying About Water Consumption for Shale Gas in the US? staggering (Platt et al., 2011... Texas A&M) vast (Rahm, 2011)
What are the Facts? Consumption is very small regionally, compared to other uses (typically less than a % or two) Usage in most cases is sustainable After shale gas exploitation is over there will be no lasting imprint of its water usage
Water Consumption in PA for Gas Shale Extraction The Projected Average Peak Consumptive Water Use Demand from Shale Gas Operations at Full Build-Out ~ ( 30 MGD) Which is Equal to the Daily Consumptive Water Use from One Nuclear Power Plant Hoffman, 2011
There are Water Issues Locally, water withdrawals can be a problems, especially during droughts In dry areas of the country water withdrawals can be problematic However these problems are being avoided by: Using municipal waste water Using brackish water
Regulatory Lessons Encourage water reuse and recycle of returned fracturing waters Promote water river withdrawals during floods linked to long term storage Promote use of municipal waste water and brackish water
WHAT DO OPPONENTS SAY ABOUT CONTAMINATION OF GROUNDWATER?
Taps on Fire But is this gas biogenic?
shale gas development has clearly contaminated groundwater and drinking water wells with methane Robert Howarth, the David R. Atkinson Professor of Ecology & Environmental Biology at Cornell University, in a formal written submission to the EPA, 2010
WHAT DOES INDUSTRY SAY?
there have been over a million wells hydraulically fractured in the history of the industry. not one reported case of a freshwater aquifer ever having been contaminated from hydraulic fracturing Rex Tillerson Chairman of Exxon Mobil Congressional Testimony, 2010
WHAT DO WE REALLY KNOW ABOUT GROUNDWATER CONTAMINATION ASSOCIATED WITH SHALE GAS EXPLOITATION?
Complaints of contamination by iron, manganese, arsenic, benzene Occurrence of high methane in Dimock water wells documented by PA DEP (state regulators) High methane later confirmed by Duke study (Osborne et al. 2011)
Background levels of iron, manganese, and arsenic in water wells not near shale gas drilling similar to those near gas wells Boron, Strontium and C/H isotope measurements in water wells are consistent with absence of impact from leakage from shale gas wells Groundwater saturated in Methane is in a significant number of water wells overlying the Marcellus Shale and the Barnett Shale
Scientific Facts on Groundwater Contamination No scientifically confirmed examples of hydraulic fracturing fluids contaminating groundwater EPA s Pavillion Wyoming study is far from conclusive Four examples (over the last 60 years and 100,000 s of wells) are well documented of groundwater contamination being caused by underground blowouts of gas wells (not shale gas)
20 significant surface spills in Pennsylvania 2009 to 2011. Forty % of the spills were of flowback or produced water (the largest spill being between 9,000 and 13,000 L) Fifteen % were of fracturing fluid (the largest spill being 16,000 L). In addition drilling mud (up to 24,000 L), drilling waste, diesel fuel Ten % hydraulic fluid. Five % was a release of hydrostatic testing water
Causes of Surface Spills A large portion of surface spills in PA were caused by operator error Worker training and worker retention appear to be key issues A few cases of sabotage Social aspects should not be overlooked
Regulatory Lessons Baseline quality measurement of groundwater wells ahead of drilling are essential Surface spills on site or from road accidents are the greatest risk to groundwater Improving well-bore integrity is critical for ongoing, longterm prevention of groundwater contamination. Science has the technology to determine sources of contamination but these need to be made available to regulatory agencies
WHAT ABOUT ATMOSPHERIC EMISSIONS?
widespread air pollution with compounds such as the carcinogen benzene is prevalent in both Texas and Pennsylvania Robert Howarth, the David R. Atkinson Professor of Ecology & Environmental Biology at Cornell University, Article in Yale- Environment-360
The state of Texas reports benzene concentrations in air in the Barnett shale area that sometimes exceed acute toxicity standards [TCEQ, 2010] Robert Howarth, the David R. Atkinson Professor of Ecology & Environmental Biology at Cornell University, Article in Yale- Environment-360
A NGO View on Emissions The Dallas-Fort Worth area has seen a dramatic impact on its air quality from natural gas drilling in the Barnett Shale (Michaels et al., 2010)
1200 HP Compressor NOx --16 T/Y; CO 18 T/Y; VOCs 3 T/Y; HAPs 0.5 T/Y
Barnett Shale Gas Wells Drilling into an Urban Environment
Engine Emissions
Tracking Benzene Plumes
Barnett Shale: Benzene Emissions Gas Processing Plants
What Levels of Benzene are Dangerous? Chemical Short-Term ESL Long Term ESL Benzene 54 1.4 Toluene 170 330 Ethylbenzene 460 290 m/p Xylene 80 42 O Xylene 380 42
What do Emissions Measurement Tell Us? (1) average concentrations of VOC species typically less than 1 ppb (roughly comparable or slightly higher contemporaneous AutoGC in Fort Worth and DISH; (2) observed VOC levels in plumes associated with nearby compressor stations were small and cannot be unambiguously assigned.
What do Emissions Measurement Tell Us? Typical average levels of key pollutants: Benzene 0.203 ppbv Toluene 0.330 ppbv o-xylene 0.046 ppbv Ethylbenzene 0.031 ppbv These averages are one or two orders of magnitude below the long term ESL.
Regulatory Lessons Promote Low Emission Completions (Green Completions) Promote electric compression and drilling rigs rather than diesel Develop mechanisms for detecting and fixing leaking infrastructure Formaldehyde and Acrolein emissions from compressor exhausts equal concerns to direct VOC emissions
What do the Lawyers say? The fracing industry should prepare to be blamed for a myriad of environmental problems until scientists and geologist are better able to define and evaluate the risk and/or extent of contamination caused by fracing fluids.
Summing Up a. Australia has a strong capability in water management but regional integrated approach needs to be implemented b. Real risks have not been the focus of the public debate in the US and Australia should direct regulatory attention to them: a) surface spills, b) well integrity, c) equipment maintenance c. The best outcomes if industry moves beyond regulation to identify and adopt better practices
Thank You