5.—(1) An authorisation shall not be granted in relation to–
(a)any direct discharge of any substance in list II;
(b)any disposal or tipping for the purpose of disposal of any substance in list II which might lead to an indirect discharge of that substance;
(c)any other activity on or in the ground which might lead to an indirect discharge of any substance in list II, unless that activity has been subjected to prior investigation.
(2) An authorisation may only be granted if, in the light of any such investigation, it includes conditions which require that all necessary technical precautions are observed to prevent groundwater pollution by any substance in list II.
(3) The following powers shall be exercised if it is necessary to do so for the purpose of avoiding pollution of groundwater by substances in list II–
(a)in the case of any discharge from a highway drain or road drain which contains such substances, the powers conferred by section 86(1) of the Water Resources Act 1991 or section 30G(1) of the Control of Pollution Act 1974 (prohibition of certain discharges by notice);
(b)in the case of any activity falling within paragraph (1)(c) above and not falling within sub-paragraph (a) above, the powers conferred by regulation 19.