This document discusses sources and effects of water pollution on human health. It outlines various sources of water pollution including sewage, industrial waste, pesticides, fertilizers and others. It describes the waste water treatment process including preliminary, primary, secondary and tertiary treatments. The secondary treatment involves biological processes like activated sludge process, trickling filters and anaerobic digestion to remove organic matter. Tertiary treatment further removes nutrients and disinfects the water. The document provides information on water quality standards and processing steps to treat domestic and industrial waste water.