There are two main requirements for any persons using chemicals on waterways. One is Legal Obligations and this is paired with Duty of Care which is the second.
Chemical labels are not always clear BUT…. if there are ‘Do Not’ statements your legal obligation is to do as it says.
Duty of Care = Best Practice A contractor or landholder needs to be seen to be ensuring they are conducting due diligence and documenting what they are going to do to address any risks with the chemical use. This is the best practice management that anyone can do, especially a contractor.
Round-up Bioactive is the only chemical currently registered for use on a waterway. Wetting agents used in Brush-Off are usually what is contraindicated for waterways. The label on Brush-Off highly recommends use of a particular wetting agent, but it is not mandatory.
There are provisions in the Act that suggest an employer can be at risk if they have not followed due diligence in ensuring that a contractor has a Commercial Operator Licence and has made sure they demonstrate the steps involved in risk mitigation.
Notes from a meeting with Felicity Collins (Chemical Standards Officer, Agricultural Services and Biosecurity Operations, Department of Economic Development, Justice, Transport and Resources) March 2016