canal

chemical

concrete

conduit

construction

corrosion

dirty

drain

drainage

dump

ecology

environment

environmental

factory

floating

flow

flowing

fluid

garbage

generation

gushing

industrial

industry

liquid

mud

natural

old

pipe

pipeline

polluted

polluter

pollution

pouring

river

road

rust

rusty

sewage

sewer

sewerage

site

sluice

stagnant

steel

stream

toxic

treatment

tube

waste

water