1995 May: Jandalot Mound (WA). Pesticides: Glyphosate, Metribuzin, Metoxuron

Glyphosate: 380ug/L

Metribuzin: 0.3ug/L

Metoxuron: 0.5ug/L

“Glyphosate, a phosphonic acid herbicide commonly used in home gardens, industrial sites and non-selectively in agriculture, was detected in Bore JE6A from the Water Supply Treatment Plant at 38014L. This is a significant concentration of herbicide in groundwater…The occurrence of glyphosate in the deep, but not th eshallow, groundwater at this site suggests rapid direct transport to the deeper aquifer, with little opportunity to bind to soil minerals. This may be possible through soil fissures, or damaged bore construction.

The tritium activity of this groundwater (0.9TU) suggests it is older than 25 years and the depth to water table is 9.7m. This information, combined with the presence of glyphosate, suggests that recently contaminated water is mixing with older water in this aquifer.Groundwater is rarely analysed for the presence of glyphosate due to the compound’s immobility through the vadose zone. This is possibly the first occasion glyphosate has been reported in Australian groundwater…”

Source: A Groundwater Quality Assessment of the Jandakot Mound, Swan Coastal Plain,
Western Australia. R.M. LARSEN, K.L. WATKINS, N.A. STEEL,S.J. APPLEYARD AND J. BAULD. RECORD 1998/18. Australian Geological Survey Association