Ключевые слова: cement, circular, concrete, culvert, dirt, dirty, ditch, drain, drainage, drainpipe, duct, dump, earth, engineering, environment, flow, flowing, gray, ground, hole, industrial, industry, infrastructure, liquid, nobody, outdoor, outside, pipe, piping, pollute, polluting, pollution, round, runoff, sewage, sewer, soil, stream, tube, tubing, tunnel, waste, water, waterway, winter,