Coal seam water a big challenge

Courier Mail
Tuesday 9/6/2009 Page: 56

QUEENSLAND'S coal seam gas industry, seen as a key energy and economic source for the state, is being asked how it will deal with the Sydney Harbour-sized amount of potentially hazardous water it could produce each five years. Agricultural businesses, fearing damage to waterways and crop land, have been seeking an end to coal seam gas companies' main practice of leaving untreated in large pools the highly salty, poor quality water displaced during CSG extraction.

The Queensland Government has begun to respond to those concerns with a ruling last month that coal seam water was an environmental hazard for which safe disposal was needed "There are significant ecological risks associated with disposal of (CSG water) and, without treatment, the Government believes the beneficial uses of CSG water are limited," a Queensland infrastructure and planning department discussion paper said in May.

In a 2006-07 report, members of the Independent Audit Group for Salinity appointed to review progress on implementing the Murray-Darling Basin Salinity Management Strategy asked Queensland to assess the salinity and chemical risks from coal seam water to land, groundwater systems, vegetation and surface water in the Condamine-Balonne catchments.

Nevertheless, 12.5 billion litres of coal seam water was produced in Queensland in 2007 and most went into evaporation ponds that range in size from one to 100 hectares. The Government's May discussion paper said there were "generally widespread concerns about evaporation ponds and the long-term legacy associated with salt stored in them".

It said disposal of an annual volume of 100 billion litres of coal seam water based on some estimates of the potential size of a liquefied natural gas industry using CSG in evaporation ponds would require a 100sq km area within 15-30 years. Sydney Harbour contains about 500 billion litres of water.

The Queensland and federal governments are encouraging the development of coal seam gas for export and for domestic gas fired electricity sources that would emit less greenhouse gases than coalfired facilites. But in March the Australian Academy of Technological Sciences and Engineering called for the Federal Government to find out and discuss with the public the best ways to power homes and businesses when impacts on human health, crops, biodiversity and the climate are quantified and included in the costs of the different sources of electricity generation.

The Queensland Government has now suggested the CSG industry co-operates to develop and fund a CSG water aggregation and disposal system to deal with coal seam water in the Bowen and Surat basins in central and southern Queensland. CSG Producer Queensland Gas Company spokesman Hedley Thomas said it was investigating the options for dealing with its coal seam water in an "acceptable, sustainable manner" and couldn't yet give cost estimates.

Santos spokesman Matthew Doman said it was spending an initial $50 million to use coal seam water on forestry projects, a method it says should take care of most of the water it produces. Rural lobby group AgForce said it was a given that coal seam water must be treated but there were also issues with treated water.

"You can create a new environmental set of conditions by putting unusually large amounts of water in an existing waterway so there are still some issues with that," AgForce president John Cotter said. "The Government's move to look at this in a strategic way is good. Evaporation ponds and the sludge they produce have been a key concern for agricultural producers and local communities. "We've seen mine overflows from disused mines, so there's all sorts of issues with this water sitting there and the last thing you want is that overflow getting into the Condamine Basin." he said.