4.1.12.C+pd+2

Parameters of a Watershed
Water pollution is defined as anything in the water that should not normally be there. The sources of water pollution are divided into two categories; point source and non-point source. Point pollution enters the watershed at a specific point, such as a factory or a drainage pipe. Non-point pollution enters the watershed by way of surface runoff (mbgnet.net 2002).

The environmental quality of a watershed can be determined in part by the amount of pollution in the watershed that affects the water quality. Chemical pollutants from agricultural, industrial, and commercial human activities can all be leaked into the surface runoff or infiltration. Soil that is carried in the streams and rivers of a watershed can also be considered a factor that affects the environmental quality of the watershed. All of the pollution in a watershed is carried to a larger body of water and eventually to the oceans (mbgnet.net 2002).

Forms of chemical data that are used to assess the quality include temperature, pH levels, and dissolved oxygen. Chemical level regulations vary depending on the the watershed to protect the aquatic life (Environmental Protection Agency 2002).

Five categories of monitoring data are used to asses the water quality of water sheds. They are biological integrity data, chemical data, physical data, habitat assesments, and toxicity testing. Biological integrity data are measurements of biological communitites used to determine if the wate supports life. Chemical data is taken from water, sediments, and fish tissue. Metals, oils, pesticides, and nutrients are measured to determine causes and sources of pollution. Temperature, flow, dissolved oxygen, and pH level are physical data (Environmental Protection Agency 2006).

[|http://www.epa.gov/waters/305b/assessing_quality.html] 4.1 Watersheds pd2