Watershed Protection Division - Health Risks of Storm Drains Health Risks of Storm Drains Home

Health Risks to People Swimming Near Storm Drains

Urban runoff can cause health risks to people that swim in a close vicinity to where storm water outlets enter waterways. Illnesses such as:

  • Earaches
  • Sinus Problems
  • Diarrhea
  • Fever
  • Rashes

can be a result.

Studies have found that people swimming in front of a flowing storm drains are 50% more likely to develop a variety of symptoms than those that swim 400 yards away from the same drains.

What causes illnesses from water?

The existence of microorganisms (bacteria, viruses, and protozoans) are found in all ecosystems and are essential to all forms of life. Many of these can be non-harmful and are essential to a functioning ecosystem. Some of the helpful functions include human digestion of food, aiding in proper treatment of wastewater, and carrying out functions necessary to sustain the food chain. The helpful microorganisms are known as antigenic.

The microorganisms that cause diseases are known as pathogenic. The three most common pathogenic microorganisms found in polluted water are:

  1. Bacteria - are tiny single-celled organisms are present in the bodies of all living creatures, including humans. Bacteria play a vital role in processes such as decomposition and digestion. Raw sewage, effluents, and natural waters contain large numbers of bacteria. Some well-known diseases caused by bacteria include cholera, dysentery, shigellosis, and typhoid fever.
  2. Viruses - can't be recognized by ordinary light microscopes, viruses normally are found by the symptoms they cause in hosts. All viruses are parasites and must grow on living tissue. Viruses in urban settings can be found in feces and domestic waste. Viruses can survive for extended periods of times in natural water environments and can occasionally become resistant to treatment processes, making them a public health concern. Viruses of concern that are transported by water include hepatitis A, Norwalk-type virus, rotavirus, and adenovirus.
  3. Protozoans - are single celled organisms that can grow up to 5 millimeters long, and live almost exclusively in aquatic environments. Pathogenic Protozoans compose about one-third of the entire class. They can cause serious health problems such as gastrointestinal disease, dysentery, and ulceration of the liver and intestines.

Where do they come from?

Pathogens can enter water through non-natural sources (point and non-point sources) or be naturally occurring in the environment. Some point sources are wastewater treatment facilities. Non-point sources include land and road runoff, septic systems, or sanitary sewer overflows.

Wildlife, domestic animals, and birds may also contribute pathogens to the environment.

Some Symptoms and Illness
Gastroenteritis (includes diarrhea and abdominal pain), salmonellosis, and cholera.
Fever, common mid, gastroenteritis, diarrhea, respiratory infections, and hepatitis.
Gastroenteritis, giardiasis (including diarrhea and abdominal cramps), and dysentery.

What can I do to protect myself?

There are several measures you can take to protect yourself. These include:

  1. Swim in areas with good water circulation rather than in protected inlets.
  2. Don't put your head underwater especially near storm drain outlets.
  3. Do not swim directly in front of storm drains.