Ключевые слова: 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,