access chamber
base
block
building
cable chamber
cement
circle
circular
city
concrete
confined space
construction
cover
crushed
drainage
duct
fundament
gravel
gray
hatch
hole
industrial
industry
inspection chamber
lid
loop
maintenance hole
manhole
metal
mouth
new
open
opening
orifice
pipe
pit
plate
rock
round
sewage
sewer
sewerage
site
stone
top
tube
underground
urban
utility hole
without