Ключевые слова: aqueduct, bedraggled, biology, chemistry, circular, clean, construction, culvert, design, dicth, dirty, discharge, draining, ecology, ecosystem, effluent, environment, environmental, factory, flow, industry, outdoor, pipe, plant, point, pollution, pond, pool, purity, recycle, removal, sample, sanitary, sedimentation, separation, sewage, sewer, sewerage, sludge, smell, splash, sterilization, storage, treatment, waste, wastewater, water, waterspout,