Environmental assessment of coal seam gas lacks scientific back-up

Take care! The precautionary principle can only go so far without data to rely on. Jeremy Buckingham

Yesterday, the Federal government issued new recommendations for methods to estimate emissions from conventional gas and from coal seam gas production. So what did we learn?

The proposals seek to refine direct measurement of fugitive emissions from CSG wells that vent gas during a well work-over or well completion. In particular, they define the way in which direct measurement is conducted when fracking is used as a component of the extraction process. The new recommendations are based upon EPA guidelines introduced in the United States in 2011

Coal seam gas projects in Australia must undergo environmental assessment before approval. Environmental assessment requirements for CSG projects have been strengthened at both the State and Federal level. Particularly, where the project affects a water resource of national environmental significance, Federal regulation may require additional environmental evaluation.

Despite all of this, the effectiveness of environmental assessment for CSG projects remains questionable because of the absence of definitive scientific analysis regarding how CSG extraction and fracking affects groundwater tables, land stability and the density and volume of carbon emissions.

Both State and Federal legislation specifically incorporate the “precautionary principle”. This fundamental environmental principle says where there are threats of serious or irreversible environmental damage, we don’t have to wait for scientific certainty before introducing measures to prevent degradation of the environment.

This principle recognises that environmental problems generally arise in settings of risk and uncertainty. It accepts that environmental harms often do not manifest themselves until an extended period of time has elapsed.

The principle is, however, misleadingly simple. The critical question is how much “precaution” should be applied in a given circumstance. This has proven to be so variable that no single formulation exists to support a decision-making rule.

A literal reading would suggest that no CSG project should be approved in the absence of full scientific certainty regarding environmental impacts. Clearly, Australian regulators have not adopted this approach in the context of CSG projects to date.

Most environmental assessments of CSG projects are based on potential environmental impacts. This type of predictive assessment is necessarily speculative and consequently, less rigorous. For example, a CSG project planned near the Great Artesian Basin will have a high likelihood of affecting groundwater aquifers that feed into the basin.

Depleting these reserves could significantly affect the sustainability of fragile ecological systems in these areas and thereby pose a threat of serious or irreversible damage.

But, because the complex nature of groundwater connectivity is not fully understood, no definitive evaluation of the impact of CSG mining upon groundwater aquifers currently exists.

An environmental assessment of a proposed CSG project based upon the precautionary principle will therefore examine the possibility that mining in this area will deplete the aquifer and further, that depletion will cause serious environmental damage.

The precautionary principle will preclude a regulator from approving a CSG project on the grounds that there is no definitive scientific evidence to suggest that environmental damage will be caused.

It does not, however, provide any ultimate mandate. While the possibility of future environmental degradation must be taken into account, this assessment factor may be offset by other factors such as the immediacy of tangible economic benefits.

The real difficulty lies in the absence of any ongoing environmental assessment of approved CSG projects under either state or federal regulation. Once a CSG project is approved, the approval is enduring and the explorer is not required to undergo further environmental evaluation, even if new scientific data emerges.

And a CSG assessment can’t be suspended on the basis of inadequate environmental data.

How has the government responded to these difficulties? At the State level, it has introduced further layers of environmental review. In New South Wales, for example, when a CSG project affects areas mapped as “bio-physical strategic agricultural land” it has to undergo an additional layer of environmental review by an Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development.

The process evaluates whether the proposed activities are likely to result in permanent or long-term loss of the land or to adversely affect agriculture.

This evaluation has three aspects to it, each of which is heavily dependent upon scientific data. The evaluation must consider whether:

  • CSG affects the land by reducing its agricultural productivity (because of surface area disturbance and subsidence, affects on soil profile, fertility and rooting depths, soil salinity, changes to soil pH, and impacts on highly productive groundwater)

  • the proposal would significantly affect “critical industry clusters” through surface area disturbance, subsidence, reduced access to agricultural resources, reduced access to support services and transport routes and loss of scenic and landscape values

  • there are any issues relevant to the new NSW Aquifer Interference Policy.

The Independent Expert Scientific Committee is preparing bio-regional assessments for all areas where CSG development is planned. These assessments seek to evaluate the ecology, hydrology and geology of the areas and determine the potential risks of CSG mining to water resources.

But without completed research modelling on groundwater impacts, surface area disturbance, and soil fertility, how good can these assessments be? As Geoscience Australia has stated, the “current groundwater modelling is inadequate in terms of scale and detail to identify the impacts of multiple CSG developments on groundwater interactions”.

The position is not improved at the Federal level. The new water trigger in the Environmental Protection Biodiversity Conservation Act 1999 (Cth)(EPBC) means many CSG projects will have to be assessed federally.

The difficulty, however, is that the federal environmental assessment process is not measurably different to the state process. It continues to endorse the precautionary principle and is therefore likely to follow a similar “predictive” assessment regime.

The new Federal recommendations for the reporting of fugitive emissions from CSG projects represent a possible shift in perspective. This is especially the case with the proposed “well sampling” requirements which link the number of samples that need to be taken with the volume of well completions and also specify the number of years over which the emission sampling may be measured.

This “higher order” approach to scientific measurement will enhance the accuracy of outcome which, in turn, precludes the need to rely too heavily upon the precautionary principle.