Stormwater pollution occurs when stormwater runoff washes away loose sediment, chemicals, trash, pet waste or other pollutants. This water ends up in desert washes, basins or it can seep underground and adversely affect our fragile desert environment.

The following everyday products and materials can pollute our stormwater.

• Oil and engine fluids

  Oil and grease left on roads and driveways is washed away during rain and flood events. These chemicals are highly toxic to desert plants and animals. It only takes four quarts, or about one oil change, of used motor oil to foul 1 million gallons of water.

• Soap and residues from car washing

  When you wash your car in a driveway, dirty water and soap ends up in storm drains or desert washes, bringing pollutants with it. Soap and vehicle residues can severely damage fragile desert ecosystems.

• Litter

  During storms, rainwater carries litter from our streets and sidewalks into storm drains and desert washes. This can plug storm drains and harm the plants and animals which make our desert environment so unique and beautiful. Litter causes toxicity as it breaks down and can suffocate turtles, birds and other aquatic life.

• Pet waste

  Pet waste may contain harmful bacteria or parasites that can last up to 10 years. If these organisms get into our stormwater, they can spread disease to wildlife, other pets, and even people.

• Household hazardous wastes and products

  Household hazardous wastes include leftover cooking oil, paint, batteries, drain openers, and much more. If these are improperly used, stored, or disposed of, they can be released into stormwater and cause great environmental harm. For information about household chemicals, see EPA's Web site on non-point source pollution.

• Fertilizers

  As rainwater flows across land, it picks up fertilizers and carries them to storm drains, which lead to desert washes. Nutrients from fertilizers feed algae blooms, which can clog pipes and create an unpleasant landscape. When the algae die and decompose, the oxygen level in the water drops, killing aquatic organisms.

• Pesticides, herbicides and insecticides

  These chemicals are designed to kill a variety of pests. During storms, rainwater washes these chemicals from plants and the soil. When pesticides are released into the environment, they can kill or severely harm native plants, animals and insects.

• Yard waste

  Throwing away green wastes (leaves, tree branches, other green wastes) in the yard, in streets, over the fence, or in washes and alleys can add to stormwater pollution and clog storm drains. 

• Eroded Soil

  Erosion caused by construction and other activities introduces fine sediments that clog the sensitive habitat for amphibians. Fertilizers, pesticides, or other chemicals in the soil are carried along with it and can accumulate in the tissues of organisms and be highly toxic in aquatic environments.