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Water Pollution Secrets Revealed!

What is pollution?

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Pollution is the contamination of the land, water or air by substances that can harm humans and environmental health. Water pollution can be categorized into two types: point source pollution and nonpoint source pollution.

Point Source Pollution

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Point source pollution is from a single identifiable source of pollution. If you can point to the source of pollution, it is point source pollution! Unregulated discharge from point source pollution can have negative effects on drinking water and can restrict recreational activities such as swimming and fishing. To help combat pollution, the Clean Water Act requires point source dischargers to obtain permits before any effluent can be discharged. All effluent must be treated prior to discharge in order to remove or reduce the amount of potentially harmful pollutants.

Common point source polluters are:

  • Factories
  • Sewage Treatment Plants
  • Large Farms

How do point source polluters deal with their pollutants (effluent)?

  • Discharge effluent directly into the water
  • Send effluent to sewage treatment plants, where it is treated before it is discharged
  • Treat effluent on site before discharging it 

Nonpoint Source Pollution

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Nonpoint source pollution is typically a result of runoff, which is the flow of water from rain events, snow melt, or other sources over land. Nonpoint source pollution comes from many different sources and locations, making it difficult to pinpoint the exact source. For example, when it rains, water runs over parking lots, lawns, and farms, collecting materials left on the ground’s surface. These materials can include yard clippings, fertilizers, pesticides, and motor oil that can cause harm to local waterways and the surrounding environment.

Nonpoint source pollution has negative impacts on the economy. As commercial fishing and costal tourism depend on clean, healthy water, water pollution can easily affect both. Water pollution can cause massive fish kills (or population reduction), which renders fishermen unable to work. When the ocean water at beaches becomes contaminated, people are unlikely to visit (due to the high health risks) and then local businesses suffer from loss of customers.

What can be done to prevent water pollution?

Point source pollution is highly regulated and under the control of local governments. Nonpoint source pollution, however, has such a wide range of sources and types that many things can be done around homes, businesses and schools to help prevent water pollution. Understanding what can be a pollutant and how it can enter the water system is the first step in preventing water pollution. Below are different potential water pollutants, how they can impact water quality, and what can be done to make sure that they do not contribute to water pollution.

Pesticides and Toxic Chemicals

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Potential Source: Pesticides can enter waterways through spray drift, as a result of applying the pesticide during windy conditions, and also through the over application of the pesticide (using more than needed or recommended).

Recommended Actions:

  • Only apply sprayed pesticides during non-windy conditions.
  • Carefully read and follow the instructions and labels of the pesticide.
  • Use only the amount recommended on the labels (more does not mean better!).

Potential Source: Toxic chemicals, such as spilled fuels and motor oil, are often washed off of driveways and into storm drains where they enter waterways and impact water quality.

Recommended Actions:

  • Quickly clean up spilled fuel (kitty litter is a wonderful absorbent).
  • When changing motor oil, place a tarp under the work area to catch any drips or spills.
  • Always take used motor oil to a recycling facility or auto store and NEVER dump it down a storm drain or onto dirt.

Nitrogen and Phosphorus

Potential Source: Runoff from fertilizers and animal waste can cause hypoxia (low levels of oxygen in the water). This occurs because added nutrients in the water can cause algae to grow exponentially (algal blooms). The algal blooms block light and cause temperatures changes in the water that can be detrimental to aquatic organisms. As the algae die, bacteria populations increase exponentially because they feed on the dying algae. This explosion of bacteria levels will deplete any oxygen in the water and will cause fish and other aquatic organism die offs. The algal blooms can also be potentially harmful to human life. This whole process is called eutrophication.

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Recommended Actions:

  • Carefully read and follow the instructions and labels of the fertilizer.
  • Use only the amount recommended on the labels (more does not mean better!).
  • Never use fertilizer before a big rain event as the nutrients will wash away before they can be utilized by the plants or enter the soil.
  • Always clean up after pets and farm animals.
  • Properly store and dispose of animal waste.
  • Never put animal waste down a storm drain.

Bacteria and Viruses

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Potential Source: Runoff from human and animal waste cause pathogenic microbes (bacteria and viruses) to enter waterways and cause potentially fatal human diseases. Another potential source of bacteria and viruses into local waterways is from septic systems. Septic systems that do not function properly (or have failed outright) can cause untreated wastewater to enter the environment.

Recommended Actions:

  • Always clean up after pets and farm animals.
  • Properly store and dispose of animal waste.
  • Never put animal waste down a storm drain.
  • Properly care for and maintain the septic system.
  • Have septic systems pumped at appropriate intervals, which is based on the septic tank size and number of people living in the house.


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Potential Source: Chemicals from plastic, metals and other types of trash can leach in to the environment. Some animals will even try to eat small, fragmented pieces.

Recommended Actions:

  • Always dispose of waste responsibly and appropriately.
  • Recycle trash when possible.

Suspended Sediments

Potential Source: Erosion from bare, exposed soil like those in unplanted agricultural fields, on the slopes around houses, and at construction sites can block out the sunlight in the water and cause the water to change temperature. These changing temperatures can be detrimental to aquatic plants and animals. The blocking of the sunlight is also detrimental to aquatic plants.

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Recommended Actions:

  • Protect against erosion and soil loss by mulching exposed, bare areas on residential properties.