Associate Professor Isaac Santos
COAL SEAM GAS AND THE ENVIRONMENT
A massive growth of the coal seam gas industry has occurred in NSW and QLD in the last decade. Even faster growth rates are predicted for the next decade. However, our basic understanding about the influence of CSG mining on the environment remains very limited.
In addition, fugitive greenhouse gas emissions from CSG fields have not been investigated in Australia yet. We recently made a submission to the government reporting the first, but still very preliminary, observations of greenhouse gases in the atmosphere of an Australian CSG field. Our submission has generated intense debate in the media:
Our group has the expertise and cutting edge technology to assess greenhouse gases in water and the atmosphere of CSG fields. We recently obtained a large infrastructure grant from the Australian Research Council that puts us in an excellent position to fill some of the major emerging knowledge gaps. Our group is interested in addressing the following questions:
Will creek hydrology and chemistry be impacted by coal seam gas exploration? Many of our creeks are thought to be fed by groundwater seepage. We are investigating whether fracking and groundwater extraction by CSG mining will interfere with groundwater surface water exchange using natural geochemical tracers such as radon.
What is the baseline groundwater chemistry in coal seam gas exploration areas? It is unresolved whether aquifer connectivity will be disturbed by CSG exploration. We propose to determine the baseline chemical composition of groundwaters potentially (or currently) impacted by CSG exploration and to prepare regional maps of groundwater chemistry. We believe methane concentrations and isotopes are a priority chemical analysis in this context. SCU has all the analytical facilities and expertise to perform high precision measurements of all key chemical parameters.
What is the net input of greenhouse gases into the atmosphere associated with CSG mining? Fugitive emissions are unintended gas losses that may occur anytime from the early gas exploration stages all the way to the end users. Current estimates (from overseas) for methane fugitive emissions range from about 0.1 to 8% of the total gas produced. We currently assume the Australian CSG industry fugitive emissions to be at the low end of the spectrum. While this is clearly possible, it has not been verified by any independent studies in Australia.
SCU has cutting edge technology to detect leakages of gases from wells, pipelines, compression stations or ponds. We can map gases such as methane and carbon dioxide (concentrations and isotopes) with high precision and great spatial resolution. Our portable, high precision instrumentation can be deployed in a car or small aircraft to obtain real time results that can be used to determine the sources of methane and carbon dioxide to the atmosphere (e.g. natural wetland sources as opposed to leakage of gases from CSG industries). We plan to link our field observations to cutting edge physical models to quantify full cycle fugitive emissions from CSG activities.
I am currently investigating nitrogen cycling in permeable sediments using a combination field and laboratory experiments. We suspect that high primary production in nutrient-starved coral reef environments is supported by rapid organic matter recycling in permeable sediments. Most previous studies on benthic nitrogen cycling have focused on muddy sediments. The key difference between muddy and sandy sediments is their permeability, which allows water to flow through pore spaces between the sand grains. Flushing of porewaters results in a greater transport of oxygen and organic matter into the sediment, leading to mineralisation rates as high, or higher, than muddy sediments.
SUBMARINE GROUNDWATER DISCHARGE
I use radionuclides as tracers of submarine groundwater discharge (SGD). SGD is an important, but overlooked and invisible global source of trace elements and nutrients into the coastal ocean. Radon and radium isotopes are excellent SGD tracers as they are highly enriched in groundwaters relative to surface waters and they are conservative in seawater. I am currently using radon to trace groundwater discharge into Australian estuaries surrounded by coastal acid sulphate soils.
SUBTERRANEAN ESTUARIES BIOGEOCHEMISTRY
I am also interested in carbon and nutrient cycling in subterranean estuaries. Nutrient cycling in subterranean estuaries can be fuelled by oxygen and organic matter inputs driven into the aquifer by tidal pumping. Nutrient and dissolved organic carbon production dominates in subterranean estuaries, while nutrient removal dominates in surface estuaries. After accounting for biogeochemical additions into subterranean estuaries, SGD-derived nutrient fluxes can be dramatically enhanced.
MAJOR RESEARCH GRANTS
-$260,000 (DP120101645) Are subterranean estuaries a source or sink of greenhouse gases?, Lead Chief Investigator, 2012-2014
- $310,000 (DP110103638 "Unravelling the synergistic effect of ocean acidification and pore water advection on carbonate sediment dissolution: a global sink for CO2?" 2011-2013. CI 2 of 3.
-$546,670 (LP110200975) Unravelling the cycling of nitrogen along a subtropical freshwater-marine continuum using a multi-isotope, multi-tracer and modelling approach 2011 to 2014. CI 2 of 4.
- $607,000 (LP100200732) "Resolving nitrogen and phosphorus transformations along subterranean estuary-sediment/water interface continuums in carbonate sands" 2010 to 2013. CI 2 of 3.
-$150,000 (LE140100083) - "A gamma spectrometry facility for cutting edge environmental geochemistry investigations" 2014. CI 1 of 5.
-$240,000 (LE130100153) "A liquid chromatography/ gas bench: isotope ratio mass spectrometer for new and novel carbon and nitrogen research in coastal systems" 2013. CI 2 of 5
-$250,000 (LIEF LE120100156) A high precision, automated system for studying greenhouse gas cycling in coastal environments, Lead Chief Investigator, 2012
- $170,000 (LE100100013) "Eddy Correlation Lander Array" 2010. CI 4 of 12.
Other Category 1 Grants
- $84,410 "Are groundwater inputs driving de-oxygenation, acidification and eutrophication." Herman Slade Foundation. 2009 to 2012. Project Leader.
-$300,000. "A carbon budget for the Great Barrier Reef". Great Barrier Reef Foundation. 2013/2014. CI
-$400,000. "Increasing carbonate chemistry data for the Great Barrier Reef".2013/2014 to 2014/2015. CI
- $30 000 ($15 000 NOROC, $15 000 SCU) "Preliminary assessment of groundwater and creek water chemistry in CSG exploration areas of the Northern Rivers Region"
-$24,000 " Do residential canal estate developments increase greenhouse gas emissions from Australian estuaries? Australian Academy of Sciences W H Gladstone Fund. Lead CI.
- $18,080. "Is groundwater discharge a major source of nutrients and eutrophication to Brisbane Water?" - Gosford City Council. 2012-2014. CI 2 of 3.
- $12,000(NZ) "Unravelling submarine groundwater discharge in New Zealand estuaries" ISAT Fund - New Zealand Academy of Sciences" 2010.
Updated: 10 December 2013