(1)  In any proceedings under this Act, if it is alleged that a person has contravened section 50 , 51 , 51A or 53 , it is a defence if –

(a) in the case of an offence arising solely from the emission of a pollutant, maximum quantities, concentrations, emission rates, discharge rates or overall volumes of the particular pollutant have been set in a State Policy, an environment protection policy, a condition or restriction specified in an environmental licence (other than a condition referred to in section 42Z(2)(a) , (b) , (c) or (d) ), or as a condition in a permit or a major project permit, within the meaning of the Land Use Planning and Approvals Act 1993 , and it is shown that those quantities, concentrations, emission rates, discharge rates or overall volumes were not exceeded; or

(b) in the case of any other offence –

(i) a State Policy, environment protection policy, environmental licence, permit or a major project permit, within the meaning of the Land Use Planning and Approvals Act 1993 , provides that compliance with specified provisions of that instrument will satisfy the general environmental duty in respect of an activity, and it is shown that those provisions, insofar as they relate to, or involve, the act or omission comprising the offence were complied with; or

(ii) a code of practice, made and approved in accordance with the regulations, provides that the taking of specified measures will satisfy the general environmental duty in respect of an activity, and it is shown that those measures, insofar as they relate to, or involve, the act or omission comprising the offence were taken.

(2)  The defences applied under subsection (1) are in addition to, and do not derogate from, the general defence under section 55 .