Extensive emissions examinations
December 3rd, 2014
News this week that the CSIRO has been commissioned by the New South Wales environmental regulator to conduct a year-long study of fugitive methane emissions from a range of sources has caused great excitement amongst industry naysayers, who have been quick to prejudge the outcome.
The NSW Environment Protection Authority has asked the CSIRO to examine fugitive emissions from twelve separate sites, including wetlands, landfills, coal mines and coal seam gas fields.
The study commenced in June this year, and builds on two recent studies on fugitive emissions.
A recently published report from Southern Cross University which contained some significant qualifying statements, including this:
“From our data we cannot conclusively say that the elevated concentrations are due to CSG mining activities as we have no information about the area before the commencement of CSG mining”
“(I)n the Darling Downs the methane and carbon dioxide can be coming from sources other than CSG such as wetlands, feedlots and vehicles.”
This is a report that needs to be viewed in context – the researchers themselves acknowledge that there are a range of possible sources, and that there is no conclusive evidence linking elevated concentrations with CSG development.
The CSIRO have previously examined the fugitive emissions issue. In its report to the Commonwealth Department of the Environment on “Field Measurements of Fugitive Emissions from Equipment and Well Casings in Australian Coal Seam Gas Production Facilities”, CSIRO researchers found that of the 43 sites tested:
“All were found to have some level of emissions, although in all cases these were very low compared to overall production.”
The report concluded:
“(Emissions) were very much lower than recent estimates of CH4 emissions from unconventional gas production in the United States.”
The report also stated:
“No evidence of leakage of methane around the outside of well casings was found at any of the wells sampled.”
In addition to these two studies, gas developers are also conducting their own fugitive emissions studies in coal seam gas producing areas.
In the Pilliga, Santos has commenced air studies across the region, collecting background or baseline data on the levels of methane in the atmosphere prior to development, while at Camden, AGL undertook a twelve-week monitoring program to determine emissions levels from their existing coal seam gas project.
The results of that study are instructive – the average methane concentration was 2.1ppm (parts per million). This is in line with methane concentrations measured in urban areas commonly ranging between 1.8ppm and 3.0ppm, and are lower than readings measured inside a house in the local area.
One of the key criticisms levelled at fugitive emissions studies to date is that of a supposed lack of baseline studies against which to measure results from operating gas infrastructure.
The Commonwealth Department of the Environment commissioned engineering consultancy Pitt & Sherry to undertake a literature review on emissions monitoring methodologies for unconventional gasfields.
On baselines, the report says:
“Baseline data could potentially still be collected within an active unconventional gas field extraction lease as long as it is collected away from any existing or historical extraction areas; however, monitoring across several areas would be required to understand the spatial variability in natural seepage levels to assess whether baseline data from other areas within a region could be assumed to be representative of background for an area that is already active and for which no local baseline data is available.
Where no baseline measurements have been made, and if it is shown that the spatial variability in natural emission levels is significant so that baseline data from other areas within the region may not be representative, then estimates of the contribution of CSG production activities on seepage fluxes could be calculated based on a nominal baseline level measured at the time of implementing the reporting protocol. “ (Page 16)
So it seems baselines can be determined after all. Imagine that. It seems that, once again, science will beat unsubstantiated claims.
The latest CSIRO report will be a welcome addition to a growing body of information about fugitive emissions – and will hopefully help to draw a line under the scaremongering of anti-industry activists.