Santos has pleaded guilty to four charges stemming from the leaking of contaminated water from a coal seam gas treatment plant and lodging inaccurate water reports.

The 10,000-litre spill occurred in June 2011, when the site was still under the control of Eastern Star Gas, which Santos only acquired in December of that year.

Wilderness Society spokeswoman Naomi Hogan was at the NSW Land and Environment Court yesterday, where the matter was adjourned.

She was joined by fellow protesters, who want Santos held accountable for a spill that left “multiple football fields” of land “all dead”.

“If they get the message they can get away with pollution, it’s not sending a great message to communities that are really concerned about this industry bulldozing across (them),” she said.

Defence lawyer Dean Jordan told the court the company had made a concerted effort to address the “inherited legacy issues” at the site, including spending $17 million rehabilitating affected areas.

He argued the company was entitled to leniency, as it had assisted authorities, to which Justice Brian Preston replied: “All they’ve done is what they should’ve done.”

Santos Energy NSW general manager Peter Mitchley said: “Santos has acted transparently throughout the process, releasing a report on the operational issues uncovered in the Pilliga and bringing them to the attention of the regulator.”