Pollution can be considered a degradation of the natural environment through various factors. Water pollution is the degradation or alteration of water that makes its use dangerous for human health, animal health or vegetation health. There are two kinds of pollution, punctual pollution and diffused pollution.

Source : http://www.epa.gov/owow/estuaries/monitor/pdf/monitoring_manual.pdf

Punctual Pollution (direct) is pollution from one identifiable area. The effluent from an industry is an example. This type of pollution is the most known and the most polluting in the short-term. Emissions of this type are generally more polluting than those produced by diffused pollution.

We can observe many sources of punctual pollution :

Fertilizer spill Pouring liquid manure on soil or in water Water course crossing by animals Animal defecation in water courses Pesticide spills Toxic product spills Discharge of toxic products in water courses Overflow of rain ditches Sewage overflow Sewage discharge Etc.

Diffused pollution (indirect) is the most widespread pollution and to this day the most harmful. This type of pollution contaminates air, soil and water over long periods. Generally, it is repeated and regular little doses over large surfaces. Diffused pollution is more difficult to control than punctual pollution because it is linked to a multitude of sources spread all over the land.

We can observe many sources of diffused pollution :

Pesticide spreading Fertilizer spreading (in excessive concentrations) Soil erosion Nautical motor activities (particularly two-stroke engines) Etc.

Reference :

Bonn, F. (2003) Écologie physique des bassins versants (GEO 400), chapitre 8 : Érosion et pollution diffuse.

Types of pollution in the watershed

Degradation of stream banks and sedimentation due to forestry practices. (Friel Brook) Bank erosion caused by extensive all-terrain vehicle activity. (Kinnear River)   Intermittent cattle access to streams may contribute, at some sites, to the relatively high variance in faecal contamination observed at low flows. Cattle damage banks of streams and river leading to increased erosion and the deposition of sediment in downstream waters. Nutrients, such as nitrogen and phosphorus, from the direct deposition of urine and feces may lead to unnatural enrichment of waters. (Aboujagane River) Solid waste (Tedish River). Impacts from solid waste in streams range from change of course and erosion of stream banks to oil spills and antifreeze from leaking auto parts. Waste can block drainage systems or structures causing flooding that impacts habitat, damages structures.