Oceans, Lakes & Rivers

Two girls playing in the sand at the beach. In warm weather, oceans, lakes, and rivers are a source of swimming enjoyment across the country each year for about 91 million people over the age of 16 ¹. CDC’s Healthy Swimming web site is heavily focused on swimming in chlorinated and disinfected swimming venues. However, you will find useful information from the Environmental Protection Agency (EPA) and other groups that are focused on natural bodies of water like oceans, lakes, and rivers. Please remember that the Six steps for prevention of recreational water illnesses (RWIs) also apply to swimming in these
natural bodies of water.

Top Causes of Untreated Recreational Water Outbreaks

Top 14 Causes:*

Shigella
Norovirus
E. coli
Cryptosporidium
Avian schistosomes
Giardia
Leptospira
Algal bloom
Plesiomonas
Campylobacter, Copper, Enterovirus, Naegleria, Yersinia (tie)

For a complete listing of water-related surveillance data, see CDC’s Surveillance Summaries for Waterborne Disease and Outbreaks.

Checking Water Quality at the Beach

Local Beach Information: Check out whether bacterial levels in the water are monitored at your local beach and whether the beach is open for swimming (information available from EPA and is only for U.S. coastal/marine and Great Lakes beaches).
Beach Watch: EPA's homepage for their beach protection activities includes beach reports, references, action plans, upcoming meetings, and frequently asked questions.

Prevention

Before You Go to the Beach (EPA brochure) [PDF - 2 pages]: Since many factors affect the water quality at the beach, it is important for you to know about the environmental conditions that affect water quality. This brochure tells you what you need to know about beach water pollution, the health risks associated with swimming in polluted water, and who to contact if you think the water at the beach is contaminated.

Beach Management

The Beach Manager’s Manual: Harmful Algal Blooms [PDF - 8 pages]: Harmful algal blooms, commonly referred to as HABs, are an environmentally complex problem throughout the world. This document discusses HABs, their impact, and prevention strategies for beach managers and community members.

Reference

1. USDA, Forest Service. NSRE - National Survey on Recreation and the Environment. 2000.

* Based on tracking of waterborne outbreaks from 1978-2008. Only confirmed causes have been included in the analyses. For outbreaks with multiple causes, each agent counted toward the total. Outbreak reporting is dependent on capacity to detect, investigate, and report the outbreaks. This requires health effects to be measured and these health effects to be easily linked to water exposure. Clusters of illnesses associated with chronic chemical exposures are not part of waterborne disease outbreak reporting or part of these lists.