There are lots of terms that are used for water quality that can sometimes be confusing. Hopefully this will help with a few of them.
Point and Non-Point Source Pollution
Pollution originating from a single, identifiable source, such as a discharge pipe from a factory or sewage plant, is called point-source pollution. Pollution that does not originate from a single source, or point, is called nonpoint-source pollution. Liquid, solid, and airborne discharges from point sources as well as pollutants from nonpoint sources may go either into surface water or into the ground water.
Nonpoint source pollution can include:
- Excess fertilizers, herbicides and insecticides from agricultural lands and residential areas
- Oil, grease and toxic chemicals from urban runoff and energy production
- Sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks
- Salt from irrigation practices and acid drainage from abandoned mines
- Bacteria and nutrients from livestock, pet wastes and faulty septic systems
- Atmospheric deposition and hydromodification
According to the USEPA, States report that nonpoint source pollution is the leading remaining cause of water quality problems. The US EPA has much more information available on this issue.
We all live in a watershed.
A "watershed" is an area of land that drains into a water body such as a lake, wetland, stream or river. No matter where you live, you’re in a watershed. The water body is at a lower elevation than the surrounding land. When rain falls on the ground it will run downhill into the waterbody. It is this area of and that drains in the river or creek that is the watershed, or drainage area. The quality of water within a watershed depends on how the land is used. Human activities and developments can affect and degrade the water quality.
Topography determines where and how water flows. Ridge tops surrounding a body of water determine the boundary of a watershed. Imagine turning an open umbrella upside down in the rain. Rain that hits anywhere within the umbrella's surface area would go to the bottom at the center of the umbrella. Any rain that didn't hit the umbrella would fall to the ground. The umbrella is like a watershed; it collects everything that falls into it.
Watersheds come in all shapes and sizes. Some are huge, like the Mississippi River Basin. Some are local creeks and rivers, like Indian Creek or Harker's Run.
A tributary is a small river or stream that merges or flows into a larger river or stream. A river is typically has several tributaries, and the larger the river, typically the more tributiaries it contains. Here in Butler County, our main river is the Great Miami. The Great Miami has multiple tributiries, including:
- Dicks Creek
- Elk Creek
- Four Mile Creek
- Gregory Creek
- Pleasant Run
- Indian Creek
- and many more smaller ones.
The Great Miami is in itself a tributary... of the Ohio River, which is a tributary of the Mississippi River. Our river systems are a huge network, just like the blood vessels in your body.
When you see a river or creek that looks like chocolate milk, this is caused by erosion. Erosion is the transportation of soil and other sediments through the action of water, wind, gravity, and ice. For example, when it rains, soil can be eroded from farm fields, construction sites, and other disturbed areas. Through the network of drainage ditches and storm drains this soil can end up in our rivers. River banks can also erode adding to the sediment in our creeks. You may not think that something natural like sediments could be a problem, however these sediments can alter habitat, increase temperatures which decreases oxygen level and many other issues. To help reduce erosion and the sedimentation of our creeks try to keep areas vegetated. Along our stream banks, try not to mow up to the edge as our turf grasses have shallow root systems that cannot do much to slow erosion.