1993: However, the discovery in February 1993 of high levels of Fenamiphos (up to 1000ug/L) and atrazine (up to 2000 ug/L) in Dianella Perth, Western Australia, indicated that the storage and handling of chemicals by pest control operators may cause severe groundwater contamination and could pose a health risk to nearby residents with private wells.

1992: Dianella (Perth) Groundwater contaminated with Atrazine and Fenamiphos

1992-1993: However, the discovery in February 1993 of high levels of Fenamiphos (up to 1000ug/L) and atrazine (up to 2000 ug/L) in Dianella Perth, Western Australia, indicated that the storage and handling of chemicals by pest control operators may cause severe groundwater contamination and could pose a health risk to nearby residents with private wells.

https://info.ngwa.org/GWOL/pdf/952464163.PDF