Point and non-point source Pollution

What is pollution? Pollution is “any substance that is added to air, water, soil or food that threatens the health, survival or activities of humans and/or other organisms.” It could be in the form of matter or energy, e.g. nitrates which cause algal blooms or an increase in temperature which will cause a decrease in the dissolved oxygen in bodies of water.

Two different ways in which pollution may enter the environment and their management poses different challenges TypesDefinitionManagement strategies and issues Point Source Non-Point Source

Give examples of point pollution

Point source pollution Point source pollution comes from a single, identifiable source e.g. a smokestack, drain pipe or car exhaust. For these reasons it is generally easier to manage this type of pollution as its impact is more localized and legal action and responsibility can be more easily assigned. However because point sources may be scattered and extremely numerous (tailpipes of millions of cars) it is a difficult task to manage.

Non-point source pollution

Non-point source pollution (see above) on the other hand comes from dispersed and not easily identified sources, e.g. run-off from farm land. This is much harder to identify and therefore to manage and to assign responsibility

Two different ways in which pollution may enter the environment and their management poses different challenges TypesDefinitionManagement strategies and issues Point Source Pollution released from a single source e.g. sewage effluent released by pipe into a stream, or smoke from a factory chimney Easier to monitor emissions at source Easier to control emissions at source Responsibility easily established and managed by law Non-Point Source Pollution released from different sources e.g. pesticides from farmers’ fields or man single sources such as the exhausts of cars in a city Monitoring requires extensive survey techniques Emissions control requires widespread changes Responsibility shared among many require greater effort i.e. effects are spread over a wider area