53.—(1) In any case where—
(a)any land has been designated as a special site under Article 51(7) or 52(4), or
(b)a district council has identified any contaminated land (other than a special site) in its district,
the enforcing authority shall, in accordance with such procedure as may be prescribed and subject to the following provisions of this Part, serve on each person who is an appropriate person a notice (a “remediation notice”) specifying what that person is to do by way of remediation and the periods within which he is required to do each of the things so specified.
(2) Different remediation notices requiring the doing of different things by way of remediation may be served on different persons in consequence of the presence of different substances in, on or under any land or waters.
(3) Where two or more persons are appropriate persons in relation to any particular thing which is to be done by way of remediation, the remediation notice served on each of them shall state the proportion, determined under Article 54(7), of the cost of doing that thing which each of them respectively is liable to bear.
(4) hings by way of remediation which the enforcing authority may do, or require to be done, under this Part are things which it considers reasonable, having regard to—
(a)the cost which is likely to be involved; and
(b)the seriousness of the harm, or pollution of waterways or underground strata, in question.
(5) In determining for any purpose of this Part—
(a)what is to be done (whether by an appropriate person, a district council or any other person) by way of remediation in any particular case,
(b)the standard to which any land is, or waterways or underground strata are, to be remediated pursuant to the notice, or
(c)what is, or is not, to be regarded as reasonable for the purposes of paragraph (4),
a district council shall have regard to any guidance issued for the purpose by the Department.
(6) Regulations may make provision for or in connection with—
(a)the form or content of remediation notices; or
(b)any steps of a procedural nature which are to be taken in connection with, or in consequence of, the service of a remediation notice.