(5) The undertaker must take such steps as are reasonably practicable to secure that any water  discharged into a watercourse or public sewer or drain pursuant to this article is as free as may be  practicable from gravel, soil or other solid substance, oil or matter in suspension.  (6) Nothing in this article overrides the requirement for an environmental permit under  regulation 12(1)(b) of the Environmental Permitting (England and Wales) Regulations 2016.  (7) In this article—  19. —(1) The undertaker may for the purposes of this Order enter on any land shown within the  Order limits or enter on any land which may be affected by the authorised development and—  (2) No land may be entered or equipment placed or left on or removed from the land under  paragraph (1) unless at least 14 days’ notice has been served on every owner and occupier of the  land.  (3) Any person entering land under this article on behalf of the undertaker—  (4) No trial holes are to be made under this article—  but such consent must not be unreasonably withheld.  (5) The undertaker must remove all temporary works and restore the land to the reasonable  satisfaction of the owners of the land once it has ceased to use the land for the purposes authorised  by this article.  (6) The undertaker must compensate the owners and occupiers of the land for any loss or  damage arising by reason of the exercise of the authority conferred by this article, such  ( a ) 1964 c.40.  ( b ) 1991 c.57.  (a) in accordance with plans approved by the person to whom the sewer or drain belongs, but  approval must not be unreasonably withheld or delayed; and  (b) where that person has been given the opportunity to supervise the making of the opening.  (a) “public sewer or drain” means a sewer or drain which belongs to Homes England, the  Environment  Agency,  a  harbour  authority  within  the  meaning  of  section  57  (interpretation) of the Harbours Act 1964( a ), an internal drainage board, a joint planning  board, a local authority, a National Park Authority, a sewerage undertaker or an urban  development corporation; and  (b) other expressions, excluding watercourse, used both in this article and in the Water  Resources Act 1991( b ) have the same meaning as in that Act.  (a) survey or investigate the land;  (b) without limitation to the generality of sub-paragraph (a), make trial holes in such  positions on the land as the undertaker thinks fit to investigate the nature of the surface  layer and subsoil and remove soil samples;  (c) without limitation to the generality of sub-paragraph (a), carry out ecological or  archaeological investigations on such land; and  (d) place on, leave on and remove from the land apparatus for use in connection with the  survey and investigation of land and making of trial holes.  (a) must, if so required before entering the land, produce written evidence of their authority  to do so; and  (b) may take onto the land such vehicles and equipment as are necessary to carry out the  survey or investigation or to make the trial holes.  (a) in land located within the highway boundary without the consent of the highway  authority; or  (b) in a private street without the consent of the street authority,  15 Authority to survey and investigate the land 