Further the report claims the leaking of what was "coal fines" - which turned the creek black - was "non-toxic".

During heavy rains on the weekend of August 8, coal waste sludge from South32's Dendrobium mine at Kembla Heights flowed into Brandy and Water Creek, which runs through the Redgum Ridge estate at Figtree.

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The miner was required to submit an Environment Assessment Report with the Environment Protection Authority on Monday, which the Mercury understands was done late on that day.

While the miner did not publicly release the report, a spokesman outlined some of its findings.

"We commissioned external consultants to conduct a detailed assessment of any impact on the environment and have provided a copy of the report to the NSW Environmental Protection Authority," the spokesman said.

"The report found there has been limited measurable impact to stream ecology and there was no evidence of fish or fauna mortality.

"The coal fines were considered to be non-toxic."

The spokesman said the clean-up operation had started before the report was submitted on Monday.

"South32 has undertaken clean-up activities along parts of Brandy and Water Creek and American Creek," the spokesman said.

"This has involved the removal of coal fines found in the two creeks.

"We take our environmental responsibilities seriously. We have kept community groups informed, including local councils, residents and other stakeholders."

The spokesman said the incident happened due to a release of water from a sediment pond, located at Dendrobium Mine's Kemira Valley Coal Loading Facility, containing coal fines.

While the spokesman did not say how much water had flowed from the sediment pond into the creek, the EPA has put it at around 10 megalitres - or 10 million litres.

An EPA spokesman said the body would now spend time going through the South32 report to see if additional changes were required to the miner's Environment Protection Licence.

"This work is complex," the spokesman said.

"Of particular importance is a scientific assessment of the nature and extent of environmental impacts to the creek system, and the examination of options to restore downstream creeks from the impacts from the incident, considering if any creek clean-up is possible without further damaging the creek."

In its assessment of the report the EPA will also be looking to see "if further clean-up is possible and warranted".

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