17. Any person authorised by SEPA under regulation 31(4) must produce evidence of that person's authorisation before that person exercises any powers conferred by that authorisation.S
18. Except in an emergency, in any case where it is proposed to enter any premises used for residential purposes, or to take heavy equipment on to any premises which are to be entered, any entry by virtue of this paragraph shall only be effected—S
(a)after the expiration of at least seven days' notice of the proposed entry given to a person who appears to the authorised person in question to be in occupation of the premises in question; and
(b)either—
(i)with the consent of a person who is in occupation of those premises; or
(ii)under the authority of a warrant by virtue of Part 3 to this Schedule.
19. Except in an emergency, if an authorised person proposes to enter any premises and—S
(a)entry has been refused and that person apprehends on reasonable grounds that the use of force may be necessary to effect entry; or
(b)that person apprehends on reasonable grounds that entry is likely to be refused and that the use of force may be necessary to effect entry,
any entry on to those premises by virtue of this regulation may only be effected under the authority of a warrant issued in accordance with Part 3 of this Schedule.
20. If an authorised person proposes to exercise the power conferred by paragraph 11 in the case of an article or substance found on any premises, that person must, if so requested by a person who at the time is present on and has responsibilities in relation to those premises, cause anything which is to be done by virtue of that power to be done in the presence of that person.S
21. Before exercising the power conferred by paragraph 11 in the case of any article or substance, an authorised person must consult—S
(a)such persons having duties on the premises where the article or substance is to be dismantled or subjected to the process or test; and
(b)such other persons,
as appear to that authorised person appropriate for the purpose of ascertaining what dangers, if any, there may be in doing anything which that person proposes to do or cause to be done under the power.
22. No answer given by a person in pursuance of a requirement imposed under paragraph 13 will be admissible in evidence against that person in any criminal proceedings.S
23. Nothing in this schedule will be taken to compel the production by any person of a document of which that person would on grounds of legal professional privilege be entitled to withhold production on an order for the production of documents in an action in the Court of Session.S
24. A person who enters any premises in the exercise of any power conferred by these Regulations must leave the premises as effectually secured against unauthorised entry as that person found them.S