2,4,5-T residues in stream water following aerial spraying for woody weed control in the Narbethong Plantation.  R. J. McKimm and P. Hopmans.  June 1978.  11 pp. (unpubl.)

SUMMARY

In July 1977 a study was made of 2,4,5-T concentrations in Old Mill Stream, Narbethong following aerial spraying in a young pine plantation on the catchment. The area sprayed was 108 ha at a rate of 1.12 kg 2,4,5-T/ha. Strips of native vegetation had been retained for at least 40 m on either side of two gullies dissecting the area. The stream immediately below the sprayed area was sampled twice daily for 5 days before spraying, and at 12 minute intervals for a period of 13 days during and following spraying. The 12 minutes samples for each hour were combined before analysis. 2,4,5-T was detected in the samples only on the 7th and 8th day following spraying, during a period of heavy rain. On the 7th day the maximal concentration was 10 ug/l with all other values 4.3 ug/l or less. On the 8th day the maximal concentration was 1.0 ug/l. According to National Health and Medical Research Council Standards the maximal safe level of 2,4,5-T in drinking water for human consumption is 20 ug/l. 2,4,5-T could not be detected (i.e. less than 0.3 ug/l) in samples collected 2.5 km downstream of the spray area at any time during the period of the study.

Also published:

McKimm, R.J. and Hopmans, P. (1978)  2,4,5-T residues in stream water after aerial spraying in the Narbethong Plantation, Victoria.  Aust. For. 41 (4): 215-22.