What You Should Know contribute to microbiological pollution. National standard tests for E. coli and Water flow, temperature, level of acidity, enterococci, a group of bacteria, indicate chemical composition, amount of organic The quality of the level of possible contamination from material, and especially what runs into or is Virginia’s natural human waste. Non-disease causing waters, including dumped into the water influence how many bacteria can also come from animals or ocean, bays, rivers, and what kinds of organisms are present. multiply readily in certain types of water so streams and lakes, high levels of these indicator bacteria do is monitored not necessarily mean the water is unsafe. regularly. There Why Avoid Natural Water Likewise, water that tests negative for are a number of After a Heavy Rain? indicator bacteria could contain disease- factors including causing organisms. In general, the higher naturally occurring During a heavy rainfall, pollution from the the indicator level, the more likely it is that organisms, rainwater runoff and land washes into rivers, lakes harmful bacteria are present, increasing the human impacts that make it impossible to and streams and risk that people will become ill from the guarantee that any natural body of water is eventually water. free of health risks. Most of the organisms in Virginia’s recreational waters probably do winds up in not cause human illness or are in such low our coastal What Are the Risks? levels they will not make anyone sick, but waterways. there is no way to be sure. Because natural Pet, bodies of water, especially rivers, are so livestock The most common waterborne illnesses changeable, officials can only make general and are gastrointestinal and may cause statements about the health risk of certain wildlife vomiting, diarrhea or nausea. These bodies of water; they cannot say exactly wastes, and illnesses result from swallowing water what the condition of a specific body of untreated waste water contaminated by disease causing water is at any particular time. from sewage treatment plants microbiological organisms. Less commonly, that are overloaded by an excess of skin, ear and eye infections can result from rain water can all end up in natural waters contact with contaminated water. Although recreational water users may inadvertently used for recreation and pose risks to Where Do Organisms Found in swallow water, deliberately drinking from human health. Water Come From? rivers, streams or lakes is never recommended. All natural waters contain algae, bacteria, viruses How is Health Risk from Natural and parasites. These Waters Determined? microbiological organisms come from plants, animals Because testing water for bacteria, viruses, and sometimes, humans. and parasites that cause illness is difficult, Agricultural and urban time consuming and costly, two bacteria runoff and improperly or have been selected to use as indicators of partially treated sewage possible contamination from human waste. People who have a weakened immune What You Can Do To Protect Yourself system may get sick from much lower levels of harmful organisms than healthy people, • Look for posted signs and follow the and should avoid any contact with natural advice on them. bodies of water. • Do not swim in water that is SSaaffeellyy stagnant, muddy, smells Some waters may unpleasant, or has an unusual color. be contaminated with toxic • Try to avoid swallowing river, stream EEnjnjooyy substances. or lake water. The risk of • People who have a weakened immune illness is VViirgrgiinniia’a’ss system should avoid contact with VViirgrgiinniia’a’ss greater for natural bodies of water. persons eating sh from those • Prevent direct contact between NaturaNaturall waters than it is broken skin and recreational water. for swimmers. • Avoid swimming several days after a The Virginia heavy rainfall. WWaatteerrss Department of WWaatteerrss Health issues sh • During extremely warm periods, keep consumption advisories when levels of your head out of the water, use nose contaminants found in sh exceed safe clips or hold your nose shut, and avoid levels and recommends that people limit or stirring up sediment in shallow fresh eliminate consumption of certain types of water areas. sh from those waters. Warning signs and • Do not drink alcoholic beverages or brochures on shing regulations provided use drugs when swimming or boating. by the Department of Game and Inland Fisheries notify the public of shing • Avoid areas where you may become trapped in rocks or debris by fast advisories. owing water. • Avoid ood waters that can carry hidden debris and cause injury. • Do not add to the risk; use appropriate toilet facilities.

For more information, contact your local health department, the regional Department of Environmental Quality oce serving your area or visit our website at: Protecting You and Your Environment www.vdh.virginia.gov www.vdh.virginia.gov/epidemiology/dee