Concrete Batching 2(5)
Schedule 1 of the Environment Protection Act 1993 states:

2—Manufacturing and Mineral Processing

(5) Concrete Batching:
the conduct of works for the production of concrete or concrete products that are manufactured or are capable of being manufactured by the mixing of cement, sand, rock, aggregate or other similar materials, being works with a total capacity for production of such products exceeding 0.5 cubic metres per production cycle.

What this means:
Most concrete batching will exceed 0.5 cubic metres per production cycle (either fixed or mobile) - the only exceptions are producers who do small batches for onsite production of moulded products (such as concrete bird baths, benches etc).

The following guidelines provide information for operators on best environmental practice:
How to I apply for an EPA Licence: Go to the EPA website: Licensing | EPA