Answer:

mains

Answer	Crossword Clue
MAINS	Hydrant feeders
MAINS	Gas conduits
MAINS	Water or gas followers

MAINS	Water conduits
MAINS	Big pipes
MAINS	They may be accessed via manholes
MAINS	Underground lines
MAINS	Gas lines
MAINS	Water pipes
MAINS	Sewer lines
MAINS	Some water pipes

MAINS	Major water carriers
MAINS	Large pipes
MAINS	Water carriers
MAINS	Water lines
MAINS	Major conduits
MAINS	Reservoir conduits
MAINS	Principal pipes
MAINS	Conduits.

MAINS	Large pipes.
MAINS	Water pipes.
MAINS	Conduits from a reservoir.
MAINS	Underground utilities conductors.
MAINS	Principal ducts.
MAINS	Pipes.
MAINS	Water carriers.
MAINS	Primary pipes.

MAINS	Gas pipes
MAINS	Conduits
MAINS	Bounding and water
MAINS	Pipes
MAINS	Bounding and Spanish
MAINS	Certain conduits
MAINS	Sewers
MAINS	Sewer connections

MAINS	Pipelines
MAINS	They may be full of gas
MAINS	Underground conduits
MAINS	Sewers have them
MAINS	Sewer parts