What are the trends in the condition of recreational waters and their effects on human health and the environment?
Importance of Recreational Water
People use the nation's rivers, lakes, and coastal waters for many different forms of recreation. Some recreational activities take place in or on the water, such as swimming, boating, fishing, whitewater rafting, and surfing. Other activities are enhanced by being close to water, such as hiking, nature viewing, and hunting waterfowl.
Condition of Recreational Waters
Condition focuses on the physical, chemical, and biological attributes that determine a water body's ability to support recreational activities. These attributes vary widely, depending on the activity, but fall into two main categories: human health and ecological systems.
- Human health. These attributes—primarily concerned with pathogens and chemical contaminants—determine whether people can enjoy recreational activities without risk to human health. People can be exposed to contaminants if they swim in contaminated waters or near storm water or sewage outfall pipes, especially after a rainfall event.
People can be exposed to contaminants through skin contact, by swallowing water, or through eating recreationally-caught fish (see Consumable Fish and Shellfish). Effects can range from minor illnesses to potentially fatal diseases. Children, the elderly, and people with compromised immune systems are most at risk.
- Ecological systems. These attributes are associated with ecological systems that support recreation. Examples include the status of fish, bird, insect, and other invertebrate communities and the chemical and physical characteristics of the water that affect these populations and their habitat.
These attributes also contribute to aesthetic qualities that are important for recreation. For example, the presence of dead fish or visibly unhealthy plants might diminish one's enjoyment of recreation in or near the water. Ecological effects can also affect human health. For example, harmful algal blooms such as red tide can cause neurotoxic shellfish poisoning and respiratory irritation in humans.1
The condition of recreational waters is affected by chemical and biological contaminants, as well as other stressors.
- Sources of contaminants. A wide range of sources contribute chemical and biological contaminants, which affect both human health and ecological systems. Sources include storm water and sediment runoff, direct discharge from industrial facilities and sewage treatment systems, atmospheric deposition (such as acid rain), and recreational activities themselves (such as outboard motor exhaust and overboard discharge of sanitary waste).
The abundance of chemicals and pathogens can be affected by land use and land cover (such as paved surfaces and forestry and irrigation practices) and by weather and climate.
- Other stressors to recreational waters can affect habitat, species makeup, and important ecological processes. For example, changes in land cover (such as removal of shade trees) can raise water temperature above the viable range for certain fish species. Hydromodifications such as dams may create some recreational opportunities (such as for boating), but also may obstruct migrating fish species such as salmon.
New ROE indicators based on data from EPA's newer monitoring programs for coastal and Great Lakes beaches and other recreational waters are under consideration and will be added to the ROE as they are developed.
Over the past decade, EPA has implemented comprehensive, systematic national efforts to collect and report this information. The Beaches Environmental Assessment and Coastal Health Act of 2000 provided the impetus for improvements in state-level monitoring and reporting to EPA on the condition of coastal and Great Lakes beaches. Individual states monitor these beaches for a set of indicator bacteria.
Although there is no requirement for the frequency of monitoring, data are reported at least annually. Recently available data from EPA's National Aquatic Resource Surveys and other independent EPA studies present additional opportunities for developing ROE indicators on the recreational condition of lakes, including the Great Lakes, and rivers and streams.
No reliable, national-level indicators are available to describe trends in health effects associated with contaminated beach waters. This is because many of the symptoms are common ailments such as stomach discomfort and sore throats, which tend to be under-reported and cannot necessarily be linked with water exposure. Continual improvements to the CDC's Waterborne Disease and Outbreak Surveillance System may create future opportunities to fill this indicator gap.
 National Research Council. 2000. Clean coastal waters: Understanding and reducing the effects of nutrient pollution. Washington, DC: National Academies Press.