Return to Tips menu
The Clean Water Book: A Guide to Reducing Pollution in your Home and Neighborhood
Published by NJDEP, 1988
The last few decades have taught us many lessons about the environment. A key one is that the environment is a single system that is richly interconnected. The burying of waste chemicals underground prior to the 1980's had seemed environmentally acceptable, but eventually the chemicals leaked into and contaminated ground water supplies. Disposal of sludge in the ocean seemed environmentally acceptable when it was begun but concerns are now being raised about the effects of this practice on ocean quality.
In short, we are learning that "out of sight, out of mind" simply does not work in dealing with waste and the environment.
Another lesson we have learned over the past decade or so is that serious pollution can come from many small sources and not just from industry and sewage treatment plants. Billions of dollars have been spent on improving treatment of industrial waste and sewage, and the reduction in such `point source' pollution has been dramatic in some areas.
But we have found that pollution from many miscellaneous sources -- called "non-point source" because it isn't released from specific points such as pipes -- also has a serious impact on water quality. In some areas non-point source pollution is a greater problem than pollution from sewage and industrial waste treatment.
Think of your home and property as an "ecosystem", a mini-environment that is full of many potential non-point sources. What chemicals and other wastes are released in your ecosystem and where are they going? Although we don't want to turn back progress, we do want to be very careful about overusing chemicals or having them find a way into our water supplies. Pet wastes, fertilizer and other chemicals in your yard and driveway can be carried by rainwater into local streams. A single quart of motor oil can potentially contaminate a million gallons of drinking water. Faulty septic systems can contaminate ground water, and airborne chemicals can be picked up by rain and carried down into water supplies.
WHAT IS NON-POINT SOURCE POLLUTION?
Non-point source pollution can be defined as pollution that comes from many miscellaneous or diffuse sources rather than from a specific point such as the outfall of a pipe from an industrial or sewage treatment plant. Whereas pollution from point sources has been regulated under State and Federal laws since the early 1970's, non-point source pollution is only now becoming a major focus of pollution control efforts.
Every chemical or waste product that can be carried by rainfall into storm sewers and streams becomes a part of non-point source pollution, unless it is picked up by soil and absorbed or neutralized. Common examples are fertilizers, herbicides, insecticides, spilled motor oil and animal waste from pets, wildlife and farm animals.
As a way to visualize non-point source pollution, think of how snow looks along roadsides a week or so after a snowfall. All of the dirt, grime, oil and grease that you can see are non-point pollutants, and will end up in our streams.
Other significant sources of non-point source pollution, or NPS, include:
In terms of environmental impacts, we can break down these non-point sources into types of pollution and look specifically at how they affect us:
Nutrients: In addition to carbon, hydrogen and oxygen, all plants require a number of nutrients in order to grow and reproduce. Three of these major nutrients are nitrogen, phosphorus and potassium. When an oversupply of these are present in streams, lakes and estuaries, algae and aquatic weeds will grow to the point that they will compete for oxygen and space in the water with other aquatic life, including fish. Overgrown vegetation in lakes will eventually prevent recreational use for fishing and swimming. Such lakes are typically the result of nutrients from fertilizers from farms and lawns that are carried into the lake by stormwater run-off.
Sediments: Sediments are soil particles carried by rainwater into streams, lakes and estuaries. Sediments can accumulate and fill in stream channels and lakes, which contributes significantly to flooding. The soil particles can also carry chemical pollutants and nutrients with them into the water. In addition, the suspended soil particles in the water may reduce light needed for photosynthesis by plant life, clog the gills of fish and have other negative effects on aquatic life.