There are two main types of water pollution: Point Source and Non-point Source pollution.
Point Source Pollution
Point source pollution is water pollution coming from a distinct identifiable source. An example of that is the discharge from a sewage treatment plant or a factory. These sources are relatively easy to locate and easy to measure and monitor. The federal Clean Water Act, which was passed in 1972 addresses all forms of water pollution. Point sources were easier to address and were tackled first. Although all water pollution from point sources is not totally controlled, there are programs in place that address this form of pollution and require industries, etc. to monitor and report any discharges they make.
Non-Point Source Pollution
This is pollution that comes from large land surfaces such as streets, roads, lawns, and fields. The exact origin of non-point source pollution can’t be pinpointed so it’s harder to monitor or measure. And of course it is more difficult to control for that reason. This form of water pollution has become the focus of many agencies and organizations starting in the 1980′s and continues today. It is a huge job to control non-point source (NPS) pollution. The average citizen has more impact on NPS pollution and therefore has a bigger role in controlling it. An amount of excess fertilizers leaving your lawn, for example, may seem insignificant , but when you add up each person’s seemingly insignificant amount, it adds up to a great deal of pollutants entering our waters! Therefore the average citizen can really make a difference in protecting and restoring their clean water supply. Because NPS pollution effects everyone’s clean water, it’s important for us to work together to ensure there is enough safe and healthy water now and for future generations.
Examples of NPS pollution include excess fertilizers and pesticides leaving farm fields, lawns and golf courses. They also include sediment leaving construction sites, farm fields, road construction areas and lands with recent disturbance from timber harvests. Other examples include pollutants from our streets such as gasoline, oil, heavy metals and salts. It is believed that malfunctioning on-lot sceptic systems also contribute a large share of the polluted runoff entering our waters.