alga
algae
chemical
contamination
danger
dirtiness
dirty
dnieper
ecology
environment
environmental
europe
flora
foam
garbage
green
grime
industrial
industry
lake
landscape
liquid
mud
natural
nature
nobody
ooze
outdoor
plant
poisonous
pollution
pond
reservoir
river
riverside
scenery
season
sewage
sky
slime
sludge
storage
stream
summer
sunny
surface
toxic
ukraine
water
wave