Random Audit of Historical Water Quality Monitoring Data and Associated Operational/Landscape and Climate Data

Second report
Submitted to Commonwealth Department of the Environment and Heritage
Prepared by Professor Ian Rae

26 April 2007

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Executive summary

The second stage of the audit was conducted on 19 and 20 April 2007 at the offices of Forestry Tasmania in Hobart. Data for 60 spray operations during the period December 2000 to September 2006 were examined, and the extent to which they met the monitoring protocol was considered.

Analytical results for samples collected following 60 spray operations were examined, and consideration was given to the extent to which they met the monitoring protocol. Consequently, 113 determinations have been identified as meeting the criteria and are thus rated as eligible for use in the PIRI study. Usable results were reported for six herbicides and one insecticide. In none of the samples was any pesticide detected. Analyses for glyphosate were not performed after April 2004 (with few exceptions before and after).

The reasons for rejecting a small number of the results included spraying under high-wind conditions, inappropriate sampling site, delays in collecting samples and delays in submitting them for analysis. In a few cases, analytical results were not reported for sprayed pesticides, and in a few cases results were returned for pesticides that had not been sprayed. Such instances did not significantly affect the quantity of valid data available for assessment.