The operations, previously owned by Eastern Star Gas, were acquired by Santos when it acquired that company in 2011.

The EPA report noted saline and heavy metals contamination of ground water after leaks at the company's containment Pond 3.

The risk of contamination spreading into nearby groundwater bores was also raised in the report, with four bores reported registered within 5km of the site.

The report said the bores were used for stock and domestic purposes and targeted depths greater than 30m below ground level.

The Lock the Gate Alliance has jumped on the report, saying Santos cannot clean up the mess.

"This report reveals a lot of important information that should have been released to the community over a year ago," Lock the Gate campaign coordinator Carmel Flint said.

"The report reveals for the first time that not one, but two, aquifers have been polluted - one at 20m depth and another at 35m - and that the deeper aquifer has four stock and domestic bores within 5km.

"It shows that the salinity of the wastewater in the dam is almost as salty as seawater and that the shallower polluted aquifer is now extremely saline.

"Perhaps the scariest aspect of this report is that it confirms that CSG wastewater has leached a number of heavy metals out of the soil into the water table - including uranium."

The anti-coal seam gas advocates have also taken aim at the EPA for using Santos supplied findings, saying the regulatory body referred only to information provided by Santos or consultants of Santos.

The NSW Ministry of Health supplied raised concerns over that issue in the report.

"It would be appropriate that the NSW Office of Water be invited to independently review the technical memorandum," the body said.

"As the technical memorandum was obtained from Santos through an EPA notice, it would be appropriate for your office [the EPA] to refer the technical memorandum through to the NSW Office of Water to establish that the conclusions in the report are likely to be accurate."

Santos has responded to Lock the Gate's attack, saying it was working with the EPA to mitigate the contamination.

"Lock the Gate's media release concerning the EPA's report into operations at Bibblewindi repeats incorrect allegations it ran in March," a Santos spokeswoman said.

"Santos has cooperated at all times with the EPA in its inquiry after notifying the EPA in May 2012 and again in March 2013 after recording elevated levels of naturally occurring elements in isolated water underlying the holding pond.

"Santos continues to monitor the isolated groundwater underlying the pond where the leaked water remains contained.

"Rehabilitation works are continuing and will be further assessed, in consultation with the EPA, once the existing water from Pond 3 has been emptied and transferred to the new water treatment facility at Leewood.

"Monitoring will continue to ensure the isolated groundwater underlying the pond is rehabilitated.

"There remains no risk to people or livestock."