Investigation at Black Rock near Geelong
Following comments in the media in June and July 2006 about the impact of Barwon Water's ocean outfall at Black Rock on the environment, EPA Victoria conducted an investigation into water quality at nearby beaches.
Barwon Water operates a treatment plant at Black Rock to treat sewage and trade waste from the Geelong region, which is then discharged from an ocean outfall, 1.2 kilometres offshore.
EPA requires Barwon Water to undertake monitoring of the effluent and nearby beaches to ensure both public health and the environment are protected. The results to date indicate the water quality is safe for swimming and surfing.
EPA will continue to monitor the performance of the Black Rock treatment plant to ensure that the discharge continues to perform within licence limits.
View the results of samples (Adobe PDF file, 46KB) collected at beaches near the Black Rock outfall and at the Black Rock Treatment Plant.
Controlling wastewater discharges
Industrial and commercial operations that can discharge significant amounts of wastewater to the environment are controlled by EPA's works approval/licensing system. The works approval and licensing system ensures that EPA reviews proposed works before they are constructed and, when they are brought into service, discharges are controlled by licence conditions.
Bacteria
EPA testing on 30 June 2006 showed levels of the bacteria enterococci and E.coli were low at nearby beaches (less than 10 organisms/100mL).
Enterococci is recognised as the best bacterial indicator for measuring faecal contamination in marine recreational waters according to the World Health Organisation and the (Australian) National Health and Medical Research Council. E.coli is another recognised indicator of recreational water quality. The State Environment Protection Policy (Waters of Victoria) 2003 specifies objectives for both enterococci and E.coli.
The EPA licence places controls on the quality of the effluent that can be discharged and requires extensive water quality monitoring. Ongoing assessment of water quality monitoring has shown enterococci levels at nearby beaches to be within those that are safe for recreational use.
Phenol
Comments were made about phenol levels at the nearby beaches. Phenols are commonly contained in household cleaners and used by industry and discharged to sewer.
The acceptable level for phenols in the environment is based on the Australian and New Zealand Environment and Conservation Council Guidelines 2000. These levels are based on taste and odour thresholds that occur at much lower concentrations (more stringent) than those for protecting human health.
Treatment plants provide a high degree of removal of phenols prior to discharge. EPA testing of Barwon Water's discharge on 30 June 2006 indicated no detectable phenols.
Testing at the beaches also showed no detectable phenols. Barwon Water's Black Rock treatment plant is operating in accordance with its EPA Victoria licence. Monitoring undertaken by Barwon Water has also indicated low levels of phenols.
Based on the current information the phenol levels reported at the beach present no health risk.
Metals
Concerns were also raised about heavy metals levels at at the nearby beaches. Heavy metals are found at low levels in sea water and in treated waste water.
The acceptable level for heavy metals in the environment are also based on the Australian and New Zealand Environment and Conservation Council Guidelines 2000. Levels are specified for recreational and ecosystem protection.
Testing at the beaches showed no elevated levels of heavy metals. Barwon Water's Black Rock treatment plant is operating in accordance with its EPA Victoria licence. Monitoring undertaken by Barwon Water has also indicated low levels of heavy metals.
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