Pollution Sources

Many things contribute to storm water pollution including:

  • Bacteria and Viruses - Bacteria is washed with animal excrement and leakage from sewers and septic tanks into waterways. These organisms can cause disease in both animals and humans. Biological contaminants come from litter, organic matter, and animal waste.
  • Businesses - Fuel, soap from equipment washing, waste process water, hazardous liquids.
  • Construction - Sediment, wash water from concrete mixers, used oils and solvents, landscaping materials (trees, shrubs, soil additives), vehicle fluids (oil, gas and antifreeze)
  • Floatables - Floatables are pieces of litter in the water. They may be contaminated with toxic chemicals and bacteria. Commonly observed floatables include cigarettes, plastic containers, wrappers, and cans. Floatables such as these are generally the result of careless handling practices or littering.
  • Metals - Metals such as lead, zinc, mercury, copper, and cadmium in water, can be toxic to humans, aquatic life and other animals that drink the water. Metals come from vehicle exhaust, weathered paint, metal plating, tires and motor oil.

    Nutrients - Nutrients such as nitrogen and phosphorus result in excessive plant growth that clogs waterways, blocks sunlight, and reduces oxygen available to fish and other aquatic life. Some sources of nutrients are fertilizer, excrement, and detergents.

  • Oil & Grease - Petroleum products (gasoline, oil, and grease) may be toxic to aquatic life, even in small amounts. Oil and grease in storm drains can generally be traced to automotive leaks and spills or improper disposal of used oil and automotive products into storm drains.
    The City of Wheat Ridge provides resources for a free place to dispose of motor oil for recycling. Please contact the Public Works Department at (303) 205-7600 for additional information.

  • Oxygen Demanding Substances - The biochemical breakdown of organic materials (leaves, excrement and street litter) washed into waterways decreases levels of dissolved oxygen in water. Organisms that live in all waterways consume organic materials and in doing so utilize oxygen. Too much organic material can cause a reduction of dissolved oxygen to levels that will not support desired aquatic life.

  • Pesticides, Herbicides & Fertilizers - Excess amounts of pesticides, herbicides, and fertilizers applied to yards, lawns and greenways are washed into streams during rainfall events. These chemicals can cause increased algae growth and toxicity to organisms.

    Residential Areas - Pet waste, vehicle fluids (oil, gas and antifreeze), paint, pesticides, solvents, batteries, hazardous wastes, grass clippings, tree trimmings, leaves, street litter, soap from car washing.

    Sediment - Sediment can be harmful to aquatic life such as plants, fish, and other animals that live in lakes and streams because it blocks the light needed to support the habitat. Also, sediments can carry chemicals that are toxic and that cause the oxygen in water to be used up.  Sediments clog fish gills and fill in the places they hide. They can also cover the bottoms of streams, harming the habitat needed by aquatic insects and plants. Sediment generally is the result of soil erosion from lawns, hillsides, and gardening/landscaping activities. Large amounts of sediment can reduce the capacity of streams to carry storm runoff requiring tax dollars to clean the streambed.

    Toxic Substances - Gasoline, household products, and paint thinner are examples of toxic substances. These substances can deplete oxygen in waterways and cause toxic effects in living organisms.