Contaminated machinery washings were contained in an enclosed wash-down facility.

A lined compost-straw-topsoil biobed removed 68–98% of individual pesticides.

Drainage field irrigation removed a further 68–99% of residual pesticide.

Mean total pesticide concentrations were 57 μg L⁻¹ after drainage field irrigation.

Evidence of pesticide accumulation at depth within the drainage field.