英文關鍵字
cleaning
concrete
construction
dirty
district
domestic
drain
drainage
drainpipe
ecosystem
effluent
engineering
environment
excavate
facility
filtration
industrial
industry
infrastructure
irrigation
municipal
outdoors
pipeline
piping
plant
pollution
purification
recycling
reservoir
sanitary
sanitation
sewage
sewerage
sludge
smell
station
storage
system
tank
technology
toilet
toxic
tube
underground
urban
utility
waste
wastewater
water