Rio Tinto Yarwun investigated for caustic contamination
A STORMWATER drain at Rio Tinto has been contaminated with caustic.
The Department of Environment and Heritage Protection was made aware in April this year that land in the vicinity of the Rio Tinto Yarwun caustic storage area was contaminated.
A Rio Tinto spokesperson said following heavy rainfall, Rio Tinto Yarwun discovered there was evidence of a small caustic release on land within their caustic storage facility.
"Immediate action was taken to control the release and remove the impacted soil," they said.
"The Department of Environment and Heritage Projection was notified and there was no evidence of harm to people or the environment."
The spokesperson said a historical defect in the storage inlet had previously allowed some caustic to flow between the storage container and its foundation.
"The storage inlet was modified in 2014 to remove this issue," they said.
"It is believed that over time small amounts of remnant caustic mixed with rainwater which tracked along the utility pipeline and resurfaced within the facility."
A Department of Environment and Heritage Protection spokesperson said the spill did not represent a "serious environmental risk".
"Caustic material moved off the Rio Tinto Yarwun caustic storage area into an adjacent stormwater drain, however contamination in the drain has now been removed and there is no evidence of an impact beyond the stormwater drain or in Gladstone harbour," they said.
"EHP has issued Rio Tinto Yarwun with a notice requiring the contamination to be removed from the site, which, as above, has already occurred.
"Decisions on further action, if any, will be informed by the outcomes of any investigation."
The Rio Tinto spokesperson said Rio Tinto Yarwun was committed to protecting the environment.
"Remediation work is under way with engagement of independent environmental experts," they said.
"Rio Tinto has also engaged an external auditor to verify the remediation work."
Caustic is used at Rio Tinto Yarwun to assist in the extraction of alumina from bauxite.