Pesticides Polluting Geelong Drinking Water

August 23, 2006

Environmental groups are concerned that traces of hexazinone, a herbicide associated with weed control in pine plantations has been consistently detected by Geelong’s Drinking Water Authority, Barwon Water, since December 2004.

Friends of the Earth Melbourne learnt about the pollution from a Freedom of Information request to Barwon Water.

The results have disturbed Friends of the Earth Plantations Research Officer, Anthony Amis.

Mr Amis said "From the information gained from the FoI, Barwon Water has detected Hexazinone on 34 separate occasions since December 2004. It has shown up consistently now for 18 months. 10 samples during that time have been detected at the inlet to the Moorabool Water Treatment Plant near Meredith.” 

”It appears that the pollution is occurring from a massive pine plantation owned by Hancock Victorian Plantations at Korweinguboora, located south of Daylesford.” said Mr Amis.  “What is alarming is that the herbicide is being detected 50km downstream near Meredith.  Is it also getting through the system into people’s drinking and washing water?” Mr Amis asked.

”Our organisation has had concerns about this plantation for some time” said Mr Amis.

About 1400 hectares of the plantation lie within the Moorabool River (She Oaks)Proclaimed Water Catchment, which includes the headwaters to the Moorabool River East Branch, which feeds into Barwon Water's supply network. Friends of the Earth estimates that over 4 tonnes of the herbicide has and will be used on the plantation over a 8-9 year period.

Once plantations are logged, herbicides are used to knock out competing weeds. Hexazinone is usually applied one year or so after logging.  It is usually used to kill Silver Wattle and Dogwood which may be regenerating amongst the pine trees.

The herbicide is usually applied in a granual form, with release of the herbicide occurring during rainfall. “Everytime it rains at Korweinguboora we could expect to see traces of Hexazinone leaching offsite into the Barwon Water supply system” said Mr Amis.  “This is a totally unsustainable outcome. These plantations are an environmental nightmare” Mr Amis added.

The herbicide is residual with a half life of 200 days or more.  Hexazinone is also highly soluble in water, meaning that it is more readily transported away from the application site by rainfall.

"Approximately half of the plantation has been logged in the past few years conceivably meaning that pollution will continue to occur off the site for some years to come" said Mr Amis.

Mr Amis added that "although only one of the readings breached the Australian Drinking Water Guideline Limit of 2 parts per billion, people should be concerned about the cumulative effect if this poison is ingested.  If this herbicide continues to be used in the catchment, in a worse case scenario we could be looking at leaching continuing for another 5-6 years, because logging the plantation won't cease until 2009/2010. This means that a cumulatative effect could occur with people being exposed consistently to hexazinone at low levels.  What is the health impact of this?”.

”Our greatest concern is the potential health impacts on pregnant women, young children and people with chemical sensitivities. We want the pesticide banned from domestic water supplies” Mr Amis said.

According to the US EPA, Hexazinone is a severe eye irritant and has been placed in Toxicity Category I (the highest of four levels) for primary eye irritation.  It is slightly toxic through the acute oral route (Toxicity Category III) and very mildly toxic through the acute dermal and acute inhalation route. 

”It is an outrage that a US based company can threaten a city’s drinking water for 18 months and get away with it” said Mr Amis. “The other issue of concern is the ecological impact of the herbicide on aquatic ecosystems, particularly on freshwater algae. Hexazinone pollution of the Moorabool River could cause a ripple effect through the aquatic food chain.  We also have concerns about the impacts on the Daylesford Mineral Springs, as the plantations are also located in a recharge area” said Mr Amis.

”It appears that Barwon Water have been asleep at the wheel on this” said Mr Amis.  “I first raised this matter with Barwon Water in 2002.  The Geelong Advertiser also raised the matter in October 2002 and Barwon Water were quoted then as saying, “there was no chance of contamination as aerial spraying of pesticide would not be used around Korweinguboora reservoir”. “How wrong they were” Mr Amis stated. “The pollution has been caused by ground based operations”.

“At a meeting with Barwon Water as late as July 1st last year they stressed to representatives of Friends of the Earth, Otways Environment Council and Gellibrand Clean Water Network that plantations within water supplies are considered to be a low risk, almost a non-event.  Why would they make these claims when they were already aware that Hancock Victorian Plantations had been polluting Barwon Water’s domestic supply for 7 months with hexazinone and that they had served Hancock Victorian Plantations with a contravention notice two months earlier? Something doesn’t seem right. I feel that I have been totally misled by Barwon Water” Mr Amis said.  “Could it be that Barwon Water wanted this kept quiet because they are also managers of pine plantations surrounding Bostok Reservoir?”

“This information needs to be made public.  People have an absolute right to know what could be threatening their health” Mr Amis said.

The FoI revealed that a Barwon Water Briefing Note stated that Hexazinone had been detected as early as December 2004.  Barwon Water stated; "Repeat testing of hexazinone in the Moorabool catchment has confirmed the herbicide to be present in low levels, well below the Australian Drinking Water Guideline and health values. However, the long half-life and slow release formulation warrant concern that the level of hexazinone may increase if further application were to occur."

Barwon Water then wrote to Hancock Victorian Plantations in April 2005 serving a contravention notice under section 169(1) of the Water Act 1989 on Hancock to permanently discontinue the application of Hexazinone in all Barwon Region Water Authority water supply catchments.

In February 2006 this notice was lifted by Barwon Water, despite Hexazinone still be detected in samples taken by Barwon Water in January and February 2006. “Why was the notice lifted when the herbicide was still being detected?” Mr Amis asked.

Mr Amis added; "The residents of Geelong should be under no illusion that they quality of their drinking water will be safe as long as this plantation continues to be sprayed.  Several other herbicides are also used in the plantation including Clopyralid, Glyphosate, Metsulfuron Methyl and Triclopyr. There are a couple of other pine plantations in the catchment that may also cause problems in a couple of years”.

Information on Korweinguboora Plantation can be found at;

The plantation is leased by Hancock Victorian Plantations, who purchased the logging and spraying rights from the Victorian Plantation Corporation in 1998. The plantation was established in the 1970’s, with herbicides used at that time being the infamous 2,4,5-T. 

For more information call Anthony Amis on 9419 8700
Loris Duclos on 0427 874 552