392 ITU‐T's Technical Reports and Specifications [b‐26] also lists the buildings and their affiliated facilities for various underground pipelines (Table 1). Table 1 – Buildings and their affiliated facilities for various underground pipelines [source: CJJ 61‐2003, b‐26] Pipeline type Buildings affiliations Water supply Water source well, water supply pump station, water tower, reservoir of clean water, purifying pond Valve, water meter, hydrant, air evacuation valve, mud valve, preserved joint, valve pit Drainage (rainfall, slops) Drainage pumping station, drain trap, septic tank, purification structures, ground outlet for covered drain Inspection pit, drop well, dry box with seal, flushing manhole, catch basin, inlet and outlet, water grate, effluent device Gas, heat, industry pipelines Pressure regulating house, gas station, boiler house, power station, gas tank, cooling tower Expansion joint, exhaust/drain/effluent device, condensate well, various cellar wells, valve Electricity Power substation, power distribution room, cable examine hole, electricity tower/pole Pole transformer, open ground transformer, various cellar wells, examine hole Telecommunication Transit exchange, control room, cable recondition hole, telecommunication tower/pole, repeater station Connector box, distribution box, various cellar wells, examine hole NOTE ‐ Different countries may have other national standards or regulations for functional classification of underground pipelines as well as the buildings and their affiliated facilities. Surface and above ground utilities. In addition to the above, there are a number of surface services mentioned in [b‐1] and elsewhere such as: Roadways Footpaths Tramways Street lighting Wireless networks Corridors for trees (e.g., to provide cooling and absorb polluting gases (NOx and CO2) Arrangement of solid waste collection facilities/bins. Utility corridors could radiate out from a central location such as a central railway station or could terminate at a point near a river so that water flow by gravity can be easily exploited throughout the system.