The operation has been authorised by Kiama Council and the Environmental Protection Authority, and requires Boral to treat the water before it is pumped out to sea, and test water quality levels.

It is understood there is a huge volume of water to be released at 160L per second from Monday to Friday over the course of six months.

The water is being pumped under the Princes Highway along a channel out to sea.

The stormwater accumulated over an extended period within its inactive quarry pit at Bombo.

The Office of Environment and Heritage has not tested the water quality at Bombo since the operation began.

Its daily water pollution forecast website recommends, as a general precaution, swimming at beaches in the Illawarra region should be avoided for up to one day after heavy rainfall or for as long as stormwater is present.

The most obvious signs of stormwater pollution are water discolouration as well as debris in the water and on the tide line.

In a statement to the Kiama Independent a Boral spokesperson said the company was in the process of lowering the level of stormwater accumulated over an extended period within its quarry pit at Bombo.

“The decision to pump out the stormwater follows consultation with both the Environment Protection Authority and Kiama Council,” the spokesperson said.

“The stormwater being pumped will be regularly monitored and tested for quality purposes.”

The spokesperson said the water was not being processed from the quarry.

“The water being pumped is simply stormwater runoff which has collected within the quarry void from the natural catchments upstream,” the spokesperson said. 

“Stormwater runoff from the quarry operations has been flowing across Bombo Beach for the entire 40 years extraction has been conducted. 

“We see no additional risk being posed to beach visitors, although as a precaution ongoing monitoring and testing of the water's quality has been arranged.” 

Kiama Council and the NSW Environment Protection Authority were consulted prior to commencement of the stormwater pumping. 

“Boral notes that Bombo Beach features a flagged and patrolled section at which swimming and related activities can take place under supervision,” the spokesperson said. 

“We advise beach visitors to adhere to any instructions or advice provided by lifeguards and Council with regard to safety. 

“Basic precautions associated with any body of water should also be observed, such as the appropriate supervision of children and pets, and maintaining awareness of the potential for sudden changes in water levels or flow.

“Stormwater will continue to be pumped from the quarry void until the volume of water has reduced to a more appropriate level.  

“The stormwater pumping program will continue as required to achieve a more appropriate volume and level of water within the inactive quarry void.”