The penalty notices were issued by the NSW Environment Protection Authority (EPA) after BlueScope failed to operate plant and equipment in a proper manner and exceeded permissible limits for cyanide in water discharges at its Port Kembla plant.

According to the EPA, the licence breaches occurred during a stave replacement program at the Number 5 Blast Furnace in May last year, when blast furnace gas condensate with higher-than-expected levels of cyanide was discharged to a stormwater drain.

BlueScope reported the incident to the EPA and implemented measures to minimise harm to the environment.

An EPA investigation found although BlueScope was aware increased cyanide levels could occur in water discharges during the maintenance work, the company believed their operational procedures were adequate to manage environmental risks.

‘‘Routine testing of the condensate by BlueScope Steel failed to detect the elevated levels of cyanide that were being generated,’’ EPA Illawarra manager Peter Bloem said. ‘‘The company allowed these higher-than-permitted levels of cyanide to discharge into the Iron Making East Drain, which connects to Port Kembla inner harbour.’’

Mr Bloem said EPA testing just after the incident found a cyanide concentration of 0.54 milligrams per litre, well above the permitted licence limit of 0.2 milligrams per litre.

  ‘‘Approximately 30 dead or dying fish were also observed in the drain. There were no observed effects on Port Kembla harbour,’’ he said. 

BlueScope has since put in place additional controls and updated its operating procedures.

BlueScope was also issued an infringement and told to undertake a pollution reduction program after a separate water pollution incident in July 2014.

The incident involved the discharge of coke oven gas condensate containing cyanide to the same drain and also resulted in the death of fish.