Point Source Pollution
Point Source Pollution is defined as the single source of pollution from which pollutants are discharged such as pipes, ships or factories. Factories and sewage treatment plants are the most known types of point source pollution. Factories of oil refineries, pulp and paper mills, chemicals, electronics, automobiles, etc, discharge one or more form of pollutants in their disposed waters called as effluents. Some factories dispose their waste directly into the water while others prefer to treat it themselves before disposing and still others send their waste to sewage treatment plants for the treatment. These treatment plants treat human waste and dispose the treated waste to stream or river.
Whereas, some factories and sewage treatment plants handle waste material by mixing it with urban runoff, storm water that flows over surfaces, in a joint sewer system. As soon as the water crosses these runoffs, it accumulates chemicals and pollutants which are then directly sent into a sewer system. However, the sewer system is unable to handle the volume of water accumulated during rains due to which some of the combined runoff and other sewage overflows from the sewer system. This leads to disposal of the waste untreated into the nearest water body. This combined sewer overflow system is considered point source pollution that can cause severe damage to human health and the environment.
Other discharges from point sources can lead to water pollution and can restrict activities like fishing and swimming. The effect of the chemicals discharged, on the aquatic environment, depends on the type of chemical, its concentration, timing of its release, weather conditions, etc.
Besides, large farms that raise pets such as cows, pigs, chicken, etc, are some of the other sources of point source pollution. The untreated animal waste is discharged directly in the water bodies as raw waste, thereby, adding to the levels and rate of pollution.
To control such discharges, Clean Water Act has established the National Pollutant Discharge Elimination System (NPDES). Under this act, factories, sewage treatment plants, etc, have to obtain permission from EPA before discharging their waste into water bodies. Prior to theis, all the sources are supposed to implement latest technologies to treat their effluents to decrease the level of pollutants.
This kind of pollution is easy to manage as it can be traced to a single source like pipes, etc. Some factories and sewage treatment plants directly connect themselves to the water bodies and create point source pollution. Since, it comes from a single identifiable source, point source pollution is easier to control.
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