brook
canal
cascading
cement
chemical
concrete
construction
contamination
corrosion
danger
dirty
drain
drainpipe
dump
ecology
environment
factory
flow
flowing
fluid
industrial
industry
influence
irrigation
lake
liquid
natural
nature
old
outlet
pipe
pipeline
pollution
pour
problem
rainwater
refinery
river
run
sewage
sewer
splatter
steel
stream
substance
torrent
toxic
tube
two
water