“ground monitoring scheme” means a scheme for monitoring ground subsidence which sets  out the apparatus which is to be subject to such monitoring, the extent of land to be monitored,  the manner in which ground levels are to be monitored, the timescales of any monitoring  activities and the extent of ground subsidence which, if exceeded, must require the undertaker  to submit for Cadent’s approval a ground mitigation scheme;  “ground subsidence event” means any ground subsidence identified by the monitoring  activities set out in the ground monitoring scheme that has exceeded the level described in the  ground monitoring scheme as requiring a ground mitigation scheme;  “in” in a context referring to apparatus or alternative apparatus in land includes a reference to  apparatus or alternative apparatus under, over, across, along or upon such land;  “maintain” and “maintenance” includes the ability and right to do any of the following in  relation to any apparatus or alternative apparatus of Cadent including retain, lay, construct,  inspect, maintain, protect, use, access, enlarge, replace, renew, remove, decommission or  render unusable or remove the apparatus; “plan” or “plans” include all designs, drawings, specifications, method statements, soil  reports, programmes, calculations, risk assessments and other documents that are reasonably  necessary properly and sufficiently to describe and assess the works to be executed;  “rights” includes rights and restrictive covenants, and in relation to decommissioned apparatus  the surrender of rights, release of liabilities and transfer of decommissioned apparatus;  “specified works” means any of the authorised works or activities undertaken in association  with the authorised works which—  “undertaker” means the undertaker as defined in article 2(1) of this Order.  20. —(1) Except for paragraphs 21 (apparatus of Cadent in stopped up streets), 26 (retained  apparatus : protection of Cadent), 27 (expenses) and 28 (indemnity) of this Part of this Schedule  which will apply in respect of the exercise of all or any powers under the Order affecting the rights  and apparatus of Cadent, the other provisions of this Part of this Schedule do not apply to  apparatus in respect of which the relations between the undertaker and Cadent are regulated by the  provisions of Part 3 (street works in England and Wales) of the 1991 Act.  (2) Paragraphs 24 and 25 of this Part of this Schedule apply to diversions even where carried out  under the 1991 Act, in circumstances where any apparatus is diverted from an alignment within  the existing adopted public highway but not wholly replaced within the existing adopted public  highway.  21. —(1) Without limitation on the scope of the generality of any other protection afforded to  Cadent elsewhere in the Order, where any street is stopped up under article 13 (permanent  stopping up and restriction of use of streets and private means of access), if Cadent has any  apparatus in the street or accessed via that street Cadent will be entitled to the same rights in  respect of such apparatus as it enjoyed immediately before the stopping up and the undertaker will  grant to Cadent, or will procure the granting to Cadent of, legal easements reasonably satisfactory  to Cadent in respect of such apparatus and access to it prior to the stopping up of any such street or  78 Apparatus of Cadent in stopped up streets  On Street Apparatus  (a) will or may be situated over, or within 15 metres measured in any direction of any  apparatus the removal of which has not been required by the undertaker under paragraph  24(2) or otherwise;  (b) may in any way adversely affect any apparatus the removal of which has not been  required by the undertaker under paragraph 24(2) or otherwise; and/or  (c) include any of the activities that are referred to in paragraph 8 of T/SP/SSW/22 (Cadent’s  policies for safe working in proximity to gas apparatus “Specification for safe working in  the vicinity of Cadent High Pressure Gas pipelines and associated installation  requirements for third parties GD/SP/SSW/22”); and 