environmental
algae
background
chemical
contaminated
contamination
danger
dirty
drain
drainage
dump
ecology
environment
eutrophication
flow
flowing
garbage
grass
green
industrial
industry
lake
landscape
liquid
natural
nature
nobody
oil
old
outdoors
pipe
pipeline
plant
polluted
polluting
pollution
pond
remediation
river
sewage
sewer
stagnant
stream
substance
surface
toxic
waste
water