Freshwater makes up less than three percent of earth's water, but is the source of virtually all drinking water.55 percent of that water comes from reservoirs, rivers, and lakes, These sources, called surface water, are vulnerable to pollution discharged out of pipes and precipitating out of the air but the primary source of their pollution today is runoff, pollutants washing off the land.
These nonpoint or scattered sources are not easily traceable. fertilizers used in agriculture and on golf courses and suburban lawns account for a major portion of nonpoint source pollution. Runoff containing manure from livestock and poultry producers has
Sources of loading phosphates to waterways.
been a major source of surface water pollution. More than 150 pathogens found in livestock manure pose risks to humans. (according to the 2000 National Water Quality Inventory). Human and Environmental Health Effects
Fertilizer, animal manure, and waste-treatment plant effluent all contain nutrients that stimulate excessive plant and algal growth in freshwater bodies. When the plants die and decompose, dissolved oxygen is depleted, causing die-offs of fish and other species living in the water. Persistent organochlorine insecticides, such as DDT, deposited in lake sediments can bioaccumulate, harming the fish and birds that eat them.Human and animal fecal waste contain disease-carrying organisms such as the bacterium Escherichia coli (E. coli) and pathogens that causes cholera, typhoid, and cryptosporidiosis. Cholera is rarely seen in the United States, but E. coli outbreaks are not rare, and in 1993, more than fifty people died, and an estimated 400,000 became ill from a massive outbreak of cryptosporidiosis in Milwaukee, Wisconsin. The outbreak was attributed to a failure in drinking water treatment, allowing the cyst form of the parasite, introduced by animal waste, to pass into tap water...