Sewage

• Sewage water not properly treated is the number one cause of pollution in United States beaches, according the Environmental Protection Agency. Water may overflow, due to storms, causing untreated or poorly treated sewage to run into the water. Sewage plants may also have faulty equipment or are not following regulations, meaning the sewage waste that plants dump intentionally into the water does not meet EPA or government standards. The problem with this sewage going into swimming or drinking water is that human waste contains microorganisms that can make humans and other animals ill.
  
  

Pesticides

• The United States farms the most food than any other country in the world. A lot of this food is crops that farmers control using pesticides, which are mainly chemicals. These pesticides can reach water supplies through illegal dumping, irresponsible use and through agricultural runoff. Not only can pesticides run into streams, rivers, ponds, lakes and the ocean, but pesticides can also get into the groundwater, which roughly half of the people in the United States use for drinking water.
  
  

Industrial Waste

• Industrial waste is any bi-product of industrial facilities, such as automotive shops, factories and nuclear plants. This type of water pollution can put products like lead, arsenic and asbestos into drinking and swimming water. The Environmental Protection Agency tests for and regulates the use of these and other harmful pollutants that the various industries in the United States create.
  
  

Storm Runoff

• When there are heavy rains in urban areas, sewage treatment facilities that handle both storm runoff and sewage can overload and dump water that is not sufficiently treated. Heavy rains also carry surface pollutants in cities into the storm runoff, adding more pollutants to the sewage. Storm drains and sewage facilities may also overflow during storms, pushing waste back up to street level through drains. The rainwater then pushes this waste into local water sources, such as ponds and rivers.