Detection of benzene – Albert Park, Broadbeach Waters
Incident Description
On 1 March 2024 a sample was collected from a drinking water fountain in Albert Park in response to a complaint from a member of the public. Analysis results showed that BTEX compounds were detected from the sample collected from the drinking water fountain. These compounds were not detected in the nearby hydrants or the water meter supplying the site. Benzene was detected at a concentration of 0.004 mg/L which is above
the ADWG health guideline value of <0.001 mg/L.
Corrective and Preventive Actions
Prior to the laboratory analysis being completed proactive measures were taken to protect public health. This included the isolation of the drinking water fountain and the supplying water meter; both were locked and tagged
out. Immediately upon notification of the ADWG exceedance the incident management procedures were activated. DRDMW and Queensland Health were notified of the exceedance.
The investigation concluded that the likely cause of the issue was a fuel or oil spillage in the park over the area where the polyethylene service line supplied the drinking water fountain. (City of Gold Coast Drinking Water Quality Management Plan 2023-24)
Based on health considerations the concentration of benzene in drinking water should not exceed 0.001 mg/L.
GENERAL DESCRIPTION
Benzene is a clear, colourless-to-yellow liquid and highly flammable aromatic hydrocarbon. It is presentin petroleum products such as motor fuels and solvents, and motor vehicle emissions constitute the mainsource of benzene in the environment. Benzene occurs naturally in crude oil and coal and is an additive and a by-product of oil-refining processes. It constitutes approximately 1-2% of unleaded gasoline by volume (US DHHS, 2011). Tobacco smoke is another significant source of exposure (WHO, 2010). It also occurs in natural gas and emissions from volcanoes and forest fires.
Human exposure to benzene occurs primarily through inhalation (WHO, 2010). When released to surface waters, benzene rapidly volatilises to the air (WHO, 2010). Benzene is not persistent in surface water or soil and either volatilises to air or is degraded by bacteria under aerobic conditions (WHO, 2010). For water contamination, benzene is therefore of most concern in groundwater. Benzene can also occur in foods and drinks as a product of the reaction between benzoate and ascorbic acid, and has been found in soft drinks in the UK at concentrations as high as 0.028 mg/L (FSA, 2006).
Benzene is also used widely as an industrial solvent by the chemical and pharmaceutical industries in theproduction of styrene/ethylbenzene, cumene/phenol and cyclohexane. The use of benzene as a solvent has been greatly reduced in recent years. Unlike other petroleum hydrocarbons such as ethylbenzene, toluene and xylene the odour threshold for
benzene is relatively high at 10 mg/L (WHO, 2003). ADWG 2011