Bacteria and Microorganisms
High bacterial levels may be found in stormwater runoff as a result of leaking sanitary systems, garbage, pet waste, etc.
Cat feces can contain a protozoan that has been linked to disease in humans and possible death in marine mammals.
The impact of bacteria on surface waters can cause harm to aquatic life and create health hazards, often making beach closures necessary.
Some microorganisms can make waterways unsafe for swimming, wading, and other types of water contact activities. A number of pollutants often attach to and are moved in water by sediment particles.
Some of these organisms are very difficult to remove by water treatment and may endanger people that depend on contaminated water bodies as their drinking water supply.
Hazardous Material and Waste
Numerous activities and materials in urban areas produce hazardous waste that can be easily transported by flowing stormwater. The intensity of activities such as vehicle traffic, maintenance and fueling activities, leaks and spills, and manufacturing processes in urban settings contribute heavily to the amount of pollutants present in adjacent surface waters.
Hazardous materials such as paint, solvents, pesticides, motor oil, and other vehicle fluids in stormwater, even in small quantities, may be toxic to some aquatic life and may accumulate in aquatic animals. Animals and people can become sick or die from eating diseased fish and shellfish or by ingesting polluted water.
Contact your local county household hazardous waste program or waste management company for information about the proper disposal of hazardous waste.
Increased water temperature can decrease a water body’s ability to support certain fish and aquatic organisms and can lead to increased algal growth.
Due to the general shallowness of stormwater flow over impervious surfaces, the temperature of runoff can increase. In addition, water stored in shallow, unshaded ponds and impoundments can increase in temperature.
Removal of natural vegetation (such as tree canopies) opens up water bodies to direct solar radiation, which can increase the water temperature.
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