How CSG threatens drinking water catchments

Stop CSG protest in Austimer. Photo: Stop CSG Illawarra

Coal seam gas (CSG) exploration and mining poses significant risks. Yet licences have been issued and development approved in vital drinking water catchments in NSW.

The promise

Before the last state election, then NSW opposition leader Barry O'Farrell made a promise to reverse this. He said: “The next Liberal/National Government will ensure that mining cannot occur ... in any water catchment area, and will ensure that mining leases and mining exploration permits reflect that common sense; no ifs, no buts, a guarantee.”

In a December 1 interview, now NSW Premier, O’Farrell told 2GB’s Alan Jones: “I don’t intend to allow — particularly after the drought we went through over a decade — mining or any other activity to threaten water resources.” He also said: “[CSG] exploration licences have been granted, in some cases permission to mine has been granted, in areas, frankly, that should never ever have been on the list.”

The real story

There are five big drinking water catchments managed and protected by the Sydney Catchment Authority (SCA). All are covered or encroached on by current CSG exploration licences. The catchments supply drinking water to two thirds of people in NSW.

These licences are titles granted by the government that define an area for oil or gas exploration and require that exploration activity take place.

Development consent for CSG wells — approval to drill and run them — has been granted in NSW drinking water catchments. This includes the approval of wells in SCA Special Areas, buffer zones established to protect drinking water quality. Unauthorised or illegal access to these areas attracts fines of up to $44,000.

The approvals are not simply a legacy of the previous government. New wells have been approved and drilled in SCA Special Areas since O'Farrell took office.

The NSW government said its new draft Strategic Regional Land Use Policy would protect water and the environment. But the policy does not rule out CSG development in drinking water catchments. In fact, the government does not even classify drinking water catchments as land of strategic importance.

The risks

CSG mining poses particular and unacceptable risks to drinking water catchments and water security:

1) CSG development requires land clearing. CSG exploration and mining requires clearing and degradation of large areas of land to create roads, drill wells, lay pipelines and build pumping, storage and other facilities. A CSG production field needs a wellhead about every 300 to 900 metres. Each well requires up to four hectares of cleared land.

But plants along rivers and streams, native vegetation and wetlands are vital to catchment health. Plants stabilise river and stream banks, and reduce erosion and flooding. Native vegetation in catchments retains rainfall and lowers the risk of excess runoff and flash flooding. It reduces soil and groundwater acidity and salinity, and lowers soil and nutrient loss into waterways. Likewise, wetlands store runoff, sediments, nutrients and other pollutants and reduce flooding.

2) CSG wells degrade over time. CSG mining requires wells that connect the land surface with coal seams. The wells must pass through any groundwater systems present. The industry stresses the integrity of wells, but they are made of materials — particularly steel and concrete — that degrade over time. When a CSG project ends, the wells — built and plugged with materials that degrade — remain.

3) CSG extraction unearths contaminated water and changes underground stress fields. CSG is trapped underground by water pressure. To mine the gas, this water must be drawn out of the coal seam to the surface. The water is salty, contains methane and can contain toxic and radioactive compounds and heavy metals.

This process also changes underground stress fields, which can lead to loss of surface water and subsidence or other seismic events.

When using fracking — a CSG extraction method that involves pumping water, sand and chemicals into the ground to fracture coal and increase the flow of gas out of the well — contaminants escape into the surrounding environment. Only 20% to 80% of fracking fluids are recovered.

Soil testing around CSG wells and wastewater ponds in the Pilliga forest found arsenic, lead, chromium, salts and petrochemicals.

CSG companies are not required to disclose the chemicals used in drilling. But desalinated CSG waste water released into the Condamine River contained boron, silver, chlorine, copper, cadmium cyanide, zinc and other toxic chemicals.

4) CSG mining depletes groundwater. Drawing water out of the ground depletes groundwater. It can lead to the draw-down of aquifers and surface water, critical sources of drinking water.

A 2009 NSW Office of Water report into drinking water catchment health said: “Groundwater is a significant resource in most catchments ... As well as being extracted for town supply, stock and domestic use, and irrigation and industrial use, groundwater is a major contributor to base flow in rivers and streams in dry periods, and in maintaining wetlands and other groundwater dependant ecosystems.

“Excessive extraction for human use can decrease the amount of groundwater available for maintaining surface aquatic ecosystems, and can also lead to salinisation of the resource.”

5) CSG poses fire risks, which threaten water quality. CSG is usually methane, a highly explosive and flammable gas. This can leak from pipelines, wellheads, waste water and processing plants. It can even escape from underground systems due to CSG drilling disturbance.

Researchers from the US National Oceanic and Atmospheric Administration said air sampling of unconventional gas fields in Colorado showed leakage rates of 4% on average, and up to 7.7%.

Fire threatens water quality. The NSW Office of Water report said :“Bushfires can have devastating effects on catchment health, destroying native vegetation, farmland and infrastructure. Areas burnt by bushfires are prone to accelerated soil erosion, resulting in enhanced sediment and nutrient export to the surface water bodies downstream. Removal of vegetation by fire also reduces the ability of catchment areas to retain rainfall.”

The campaign

Campaign groups Stop CSG Sydney Water Catchment and Stop CSG Illawarra support a ban on CSG exploration and mining in drinking water catchments. Since these campaign groups formed they have stopped any new drilling in their local areas.

The Illawarra campaign has delayed drilling so long that local CSG licences have now expired and some development approvals have lapsed.

However, these “people's moratoriums” are not yet reflected in changes in the law to protect drinking water catchments. Stop CSG Illawarra has launched a petition calling on the NSW government to ban CSG exploration and mining in drinking water catchment areas, with an aim to collect 10,000 signatures and trigger a debate on the issue in NSW parliament.