Poor water quality in developing nations leads to millions of deaths from diarrhea and other illnesses each year. Contamination comes from natural chemicals in groundwater, industrial and agricultural waste dumping in rivers and lakes, and waste water from urban areas. Solutions being tried include hand pumps for groundwater, water filters, rainwater harvesting, and wastewater recycling, though the latter risks contaminating crops and groundwater. Improving water management policies and increasing resources for water treatment infrastructure is needed to preserve water quality.