14 November 1971

Department of Agriculture Victoria

Analyses of Water for 2,4,5-T Residues

11 water samples from near forest areas sprayed with 2,4,5-T for wattle control by aerial spraying in July 1971.

Pesticide used - 2,4,5-T Butyl Ester in No 2 Fuel Oil at the rate of 1 lb a.i./5 gallons oil/acre

Results of analysis - parts per thousand million

Fiery Creek:
before spraying                      0.7ug/L
24 hours after spraying           6.3ug/L
after 15/7/71                          0.5ug/L

Blue Range (Mansfield):
before spraying 7/7/71 9am                     2.2ug/L
during spraying 8/7/71 9am                     1.9ug/L
during spraying 9/7/71 8am                     6.5ug/L
17 hours after spraying 10/7/71 10am      1.5ug/L
42 hours after spraying 10/7/71 11am      0.7ug/L
After rain                                                0.5ug/L

Buffalo River:
before spraying                                          0.8ug/L
(Myrtleford) within 24 hours.                        0.5ug/L
After Spraying                                            5.0ug/L

Comments:

A calculation based on 1 lb/acre application of 2,4,5-T shows that water a foot deep directly sprayed could have an initial concentration of about 400 parts per thousand million....