6(1)The nominated undertaker shall not deposit any polluting material on, in or over the canal and shall not without the consent of the Board—
(a)deposit any other materials on, in or over the canal; or
(b)notwithstanding anything in paragraph 9 of Schedule 2 to this Act (which authorises the discharge of water in connection with the construction or maintenance of works authorised under Part I of this Act), discharge any water directly or indirectly into the canal.
(2)Any consent of the Board required under this paragraph shall not be unreasonably withheld and—
(a)shall be deemed to have been given if it is neither given nor refused within 28 days of the submission of the request therefor; and
(b)may be given subject to such reasonable requirements as the Board may make—
(i)in the case of a deposit, so as to ensure that the use of the canal is not obstructed or rendered less safe, and
(ii)in the case of a discharge, concerning the reimbursement by the nominated undertaker of expenses incurred by the Board in disposing of the water so discharged, being expenses which the Board would not have incurred but for the discharge.