While a disposal licence is in force it shall be the duty of the appropriate Agency to take the steps needed—
(a) for the purpose of ensuring that the activities to which the licence relates do not cause pollution of water or danger to public health or become seriously detrimental to the amenities of the locality affected by the activities; and
(b) for the purpose of ensuring that the conditions specified in the licence are complied with.
For the purpose of performing the duty which is imposed on the Environment Agency or SEPA, as the case may be, by the preceding subsection in connection with a licence, any officer of that Agency authorised in writing in that behalf by that Agency may, if it appears to him that by reason of an emergency it is necessary to do so, carry out work on the relevant land and on any plant or equipment to which the licence relates.
Where the Environment Agency or SEPA incurs any expenditure by virtue of the preceding subsection, it may recover the amount of the expenditure from the holder of the disposal licence in question, or if the licence has been revoked or cancelled from the last holder of it, except where the holder or last holder of the licence shows that there was no emergency requiring any work or except such of the expenditure as he shows was unnecessary.
Where it appears to the appropriate Agency that a condition specified in a disposal licence . . . is not being complied with, then, without prejudice to any proceedings in pursuance of section 3 or 6(3) of this Act in consequence of any failure to comply with the condition, that Agency may—
(a) serve on the licence holder a notice requiring him to comply with the condition before a time specified in the notice; and
(b) if in the opinion of that agency the licence holder has not complied with the condition by that time, serve on him a further notice revoking the licence at a time specified in the further notice.