are connected by a network of roads, pipelines, and compressor stations. Over time, wells may be spaced more closely in order to extract the remaining methane. Produced water The produced water brought to the surface as a byproduct of gas extraction varies greatly in quality from area to area, but may contain undesirable concentrations of dissolved substances such as salts, naturally present chemicals, heavy metals and radionuclides. In many producing regions the water is treated, such as through a Reverse Osmosis plant and used beneficially for irrigation, water for livestock, urban and industrial uses, or dust suppression. Pilliga Scrub In 2012 Eastern Star Gas was fined for "discharging polluting water containing high levels of salt into Bohena Creek" in the Pilliga Scrub. There were "16 spills or leaks of contaminated water" including "serious spills of saline water into woodland and a creek." In 2012, a NSW Legislative Council inquiry criticised the use of open holding ponds, recommending that "the NSW Government ban the open storage of produced water." Powder River Basin Not all coalbed methane produced water is saline or otherwise undesirable. Water from coalbed methane wells in the Powder River Basin of Wyoming, US, commonly meets federal drinking water standards, and is widely used in the area to water livestock. Its use for irrigation is limited by its relatively high sodium adsorption ratio. Groundwater Depending on aquifer connectivity, water withdrawal may depress aquifers over a large area and affect groundwater flows. In Australia, the CBM industry estimates extraction of to of groundwater per year; while the National Water Commission estimates extraction above a year. Power generation In 2012, the Aspen Skiing Company built a 3-megawatt methane-to-electricity plant in Somerset, Colorado at Oxbow Carbon's Elk Creek Mine. Coalbed methane producing areas Australia Coal Seam Gas resources are in the major coal basins in Queensland and New South Wales, with further potential resources in South Australia. Commercial recovery of coal seam gas (CSG) began in Australia in 1996. As of 2014, coal seam gas, from Queensland and New South Wales, made up about ten percent of Australia's gas production. Demonstrated reserves were estimated to be 33 trillion cubic feet (35 905 petajoules) as of January 2014. Bowen Basin Surat Basin Sydney Basin Canada In Canada, British Columbia is estimated to have approximately of coalbed gas. Alberta, in 2013, was the only province with commercial coalbed methane wells and is estimated to