Pre-Visit Activities : Pollution : Background Sixth - Eighth Grade Online Curriculum : Watersheds

Key Points
Key Points will give you the main information you should know to teach the activity.

Top

Detailed Information
Detailed Information gives more in-depth background to increase your own knowledge, in case you want to expand upon the activity or you are asked detailed questions by students.

Water pollution in our watersheds is an issue that affects us all. It affects us directly through our drinking water and indirectly through slow changes in the environment. We have been aware of the problems and solutions for decades. Industry and individuals have made important changes in their practices and daily lives but there is still a lot that can be done.

There are different types of pollution that affect the water in our watersheds. One type is categorized as point source water pollution. Point source water pollution enters the environment from an identifiable source, such as from a discharge pipe of a factory. Industries that have identifiable discharges include sewage livestock farms, landfills, and water treatment plants. These industries discharge many different kinds of pollution, ranging from livestock manure to industrial chemicals.

The discharge of materials from point sources is regulated by state and federal government agencies. These industries are issued a National Pollutant Discharge Elimination System permit. This means that the pollutants are controlled and monitored as they are emitted into streams, rivers and other bodies of water. The emissions must meet the guidelines of the permits or the facility may be heavily fined. There are some facilities that do not meet the guidelines of laws passed by the state and federal governments. These facilities are not breaking the laws. They have been “grandfathered” through the laws. Many of these facilities were operating before the laws were created and are not able to comply without spending lots of money on refurbishing major parts of the facility. The companies that run the facilities would possibly go bankrupt if they were made to comply with the laws.

Point sources of pollution, such as the industries mentioned above, contribute a great amount of pollution to streams, rivers, and other bodies of water, but they do not contribute a majority of the pollution. The Environmental Protection Agency estimated that 50% of the pollution in our nation’s waters comes from non-point sources. Non-point sources of pollution are the products of everyday activities by people like you and me.

Non-point source pollution is pollution that comes from sources that cannot be directly located. An example of non-point pollution is the fertilizer that people put on their lawns. When excess fertilizer washes off of the lawn during a rainstorm it can enter the watershed as runoff. Runoff is water that flows on the surface across lawns, roads and other landscape features. Pollution can be carried or dissolved in runoff and enter the watershed. Once in a body of water, the pollution can be sensed with the proper equipment, but it can not be directly linked to any particular lawn in the community. It is pollution that originated from an indistinguishable (non-point) source. Runoff originates from urban areas, agriculture land, construction sites, lawns, and some industries, such as mining. The main elements of polluted runoff are heavy metals, salts, sediment, nutrients, and bacteria.

Many of our daily activities can contribute to non-point source pollution, including lawn and landscape maintenance; car maintenance; use of vehicles; and construction of structures, like homes, highways and shopping malls. In these activities, we apply fertilizers and pesticides; spill small amounts of oil and gasoline; and dig up the ground causing soil erosion. The chemicals and loose soil stay in the area until there is precipitation. The water from a rainstorm falls in these areas, picks up the pollution, and then flows towards storm drains and streams and rivers.

When the rainwater goes directly into a stream it carries all of the pollution with it. Storm drains, though, are not always a better destination for the rainwater. Many towns’ storm drains and water treatment systems are unable to cope with the high volume of water that runs through them during a storm. When this happens the runoff is diverted directly into the watershed. The runoff contains heavy metal, salts, oils and soil, sometimes in high concentrations. These types of events have been called “shock loadings.” Shock loadings can temporarily make the water unfit for life. In many communities, beaches are closed to recreational activities immediately after a rainstorm. The runoff from the storm carries too much pollution into the water for it to be safe to swim.

What can we do? Point source water pollution is under strict regulations, so we are already helping the environment by restricting how industries pollute water environments. We cannot entirely eliminate pollution from industries because we need them to support our way of life. But we can still develop new and better methods of reducing industry’s waste.

There are many things that we can do to help reduce non-point source water pollution. As people participate in a variety of activities, they contribute little bits of non-point source pollution. Each person or activity is not contributing dangerous levels, but all of the little bits added together can be damaging to the environment, wildlife and people. The key to lessening non-point source pollution is education. If everyone understands how their activities contribute to pollution, maybe they can make small changes in their activities that will help reduce their own pollution contribution. Examples include using a little less fertilizer on their lawn and reducing the amount of oil they spill when working on their cars.

Towns and cities can reduce the amount of non-point source pollution by increasing the frequency of street cleaning, encouraging people to take mass transit, enforcing stricter regulations concerning construction site runoff and use of fertilizers and pesticides. Towns and cities review potential pollution sources in their area and generate Best Management Practices (BMP’s) to deal with them. Examples of BMP’s include planting buffer zones of vegetation in certain areas. The buffer zones absorb runoff and allow it to be slowly emitted after the rainstorm, preventing some of the shock loading of watersheds.

Point source and non-point source water pollution can be reduced if people and community leaders have the information they need. Taking care of the water in our watersheds is a responsibility we all must share. We are all a part of the problem and we can all be a part of the solution.

Point Source And Non-point Source Water Pollution
Common types and sources of point source (ps) and non-point source (nps) water pollution. Also included is information about how the pollution enters the watershed (runoff, ground water, or direct) and what some Best Management Practices (BMP’s) are that may help reduce the amount or affect of the pollution from these sources.