Waste waters

waters used for domestic or industrial purposes and obtained the additional admixtures hereat changing an initial chemical composition or physical characteristics; waste is also called the waters flowing off territory of the inhabited areas, industrial and agricultural plants as a result of a deposition of precipitation, irrigation of lands or watering streets; there are distinguished three general categories of waste waters: domestic (households keeping and fecal), industrial (from economic activity), natural (from melted snow and heavy showers (rains).