The Environment Agency or the NRBW or the Civil Aviation Authority or any internal drainage board, dock undertakers, railway undertakers , airport operator or licence holder may, after giving reasonable notice to the sewerage undertaker concerned, at their own expense and on substituting an equivalent, take up, divert or alter the level of any sewers, drains, culverts or other pipes which—
In subsection (1) above "an equivalent", in relation to any sewers, drains, culverts or pipes means other sewers, drains, culverts or pipes which will be equally effectual and will entail no additional expense for the sewerage undertaker in question.
Any difference of opinion which arises under this section between a sewerage undertaker and any person as to whether any sewers, drains, culverts or pipes substituted or proposed to be substituted for sewers, drains, culverts or pipes of that undertaker—
may, at the option of the party complaining, be referred to a single arbitrator appointed by agreement between the parties or, in default of agreement, by the President of the Institution of Civil Engineers.
In this section—
"airport operator" means the person who is the airport operator for the purposes of Part V of the Airports Act 1986 in relation to an airport to which that Part of that Act applies; . . .
"dock undertakers" has the same meaning as in Chapter II of Part IV of this Act. ; and