How is water naturally filtered or purified?
A basic introduction to natural filtering of water can be found on-line at the USGS “Water Science for Schools” website. The address for the site’s ground-water-quality page is: http://ga.water.usgs.gov/edu/earthgwquality.html Natural filtering is a big topic. Some filtering takes place when water flows over the ground, such as when muddy water from a plowed field or a construction site flows through grass or weeds on its way to a stream. Some of the mud is filtered out. In addition, some filtering takes place when the water is in lakes or streams, through the actions of plants and bottom-dwelling animals (like freshwater clams and mussels) that take in water, remove nutrients, and put it out again. Here’s a page that talks about filtering in wetlands: http://il.water.usgs.gov/proj/lirb/pubs/esr/Environ10.html Here’s another, longer, but very good piece about wetlands. The part about natural filtering is in the section called “maintenance of water quality”: http://water.usgs.gov/nwsum/
A basic introduction to natural filtering of water can be found on-line at the USGS “Water Science for Schools” website. The address for the site’s ground-water-quality page is: http://ga.water.usgs.gov/edu/earthgwquality.html Natural filtering is a big topic. Some filtering takes place when water flows over the ground, such as when muddy water from a plowed field or a construction site flows through grass or weeds on its way to a stream. Some of the mud is filtered out. In addition, some filtering takes place when the water is in lakes or streams, through the actions of plants and bottom-dwelling animals (like freshwater clams and mussels) that take in water, remove nutrients, and put it out again. Here’s a page that talks about filtering in wetlands: http://il.water.usgs.gov/proj/lirb/pubs/esr/Environ10.html Here’s another, longer, but very good piece about wetlands. The part about natural filtering is in the section called “maintenance of water quality”: http://pubs.water.usgs.gov/W
