Ключевые слова: background, build, canal, cement, concrete, conduit, construction, deep, dirt, dirty, drain, drainage, drainpipe, dump, ecology, equipment, excavator, flow, flowing, fluid, garbage, ground, hole, industrial, industry, infrastructure, liquid, nature, old, piled, pipe, pipeline, pollution, river, sewage, sewer, sewerage, shore, stream, toxic, treatment, tube, wall, wash, waste, water,