SYDNEY/CANBERRA, May 24 (Reuters) - Australia's northeastern state of Queensland has blocked a carbon capture and storage project proposed by commodities giant Glencore as it could irreversibly harm groundwater used by farmers, the state government said on Friday.

The pilot project aimed to pump 330,000 metric tons of liquified carbon dioxide into an aquifer 2.3 km (1.4 miles) underground, in what Glencore called a test case for onshore carbon storage in Australia.

The project "is not suitable to proceed due to potential impacts on groundwater resources," the state's environment department said in a statement, however, adding that similar projects would also be blocked.

Glencore did not immediately comment.

Farm groups had protested that the project risked poisoning part of the Great Artesian Basin, a network of groundwater deposits spanning much of eastern Australia.

The proposed site was not a contained aquifer and the carbon dioxide "could migrate, likely causing irreversible or long-term change to groundwater quality and environmental values if the project were to proceed," the statement added.

Such changes could include greater concentrations of contaminants such as chloride, sulphate, salinity and various metals and metalloids including lead and arsenic, it said.

The department said the groundwater was used for agriculture, irrigation, and stock watering.

Its decision acknowledged the importance of the Great Artesian Basin to multiple stakeholders and made clear that other carbon capture and storage projects would not be viable there, it added. (Reporting by Peter Hobson; Editing by Clarence Fernandez)