Point and Non-Point Sources
The discharge of effluents in receiving water body at a specific site are referred to a point sources in contrast to the inflow of pollutants in a different manner over a larger area referred to as non-point sources. Generally, point sources bring in very large volumes of effluents at one point in the river such as discharge from sewage treatment plants, thermal power plants and industries.
Effluents discharged Iron1 point sources are relatively more amenable to checks and control. However for non point sources such as run-off from agricultural fields and deforested areas into surface water bodies, seepage into ground from crop lands, logged forests and construction sites are somewhat difficult to control because significant pollution occurs during rain, storm or when snow melts.