ABSTRACT
Used oil should be collected and re-used as chainsaw chain lubricant or as grease for rods. Substantial spillage (e.g. more than 10 liters) of undiluted drilling fl uids, fuels, oil or other potentially harmful chemicals should be reported as soon as possible to the responsible authorities, and effective clean-up measures undertaken immediately. Closed water reticulation system should be used for drill fl uids wherever possible. Where this is not practical, any necessary discharge to a water course should meet agreed standards.
