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Water Stewardship Division

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Protection of Water Quality at Manitoba Beaches

Each summer, thousands of bathers enjoy Manitoba's refreshingly cool waters and fine sandy beaches. A large number of popular beaches are located within easy commuting distances from major population centres. Included are the many kilometres of beaches along both the east and west shores of Lake Winnipeg and beaches located in the Whiteshell Provincial Park. Many beaches are also located throughout other regions of Manitoba, and are associated with provincial campgrounds or privately owned facilities.

Recreational Water Quality Guidelines

Water quality at beaches can be affected by both man-made pollutants and natural characteristics. Many jurisdictions, including Canada and Manitoba, have had recreational water quality guidelines in place for many years to protect public health and to ensure pleasant bathing experiences.

A task force in Canada, comprised of representatives from Provincial and Federal health and environment agencies, recently recommended a revised set of guidelines for use in Canada. The guidelines, entitled "Guidelines for Canadian Recreational Water Quality," were published under the authority of Health Canada in 1992. The most important elements of the Canadian guidelines have been adopted in the Manitoba Surface Water Quality Objectives for more specific application throughout Manitoba.

Guidelines have been recommended for fecal coliform bacteria to protect recreational water from contamination by organisms with the potential to cause disease. Fecal coliforms are a group of bacteria that originate in the digestive tract of warm-blooded animals, waterfowl and humans. The most common member of this group of bacteria is Escherichia coli, more commonly referred to as E. coli. Fecal coliforms normally do not cause illness themselves, but when present in large numbers, are often associated with more harmful disease-causing organisms. Thus, they are known as "indicator bacteria." The recreational water quality guideline for indicator bacteria is 200 fecal coliforms or 200 E. coli per 100 ml of sample. According to the Canadian guidelines, compliance should be based upon the average of at least five samples. Information provided by single samples is of limited value, since indicator bacteria can be variable within any beach area.

Common Illnesses Contracted By Bathers

The most common illnesses contracted by bathers are infections of the eyes, ears, nose and throat. These infections can be caused by bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus, which are most frequently transferred from one bather to another in crowded swimming areas.

The second most common group of illnesses contracted by bathers is stomach upset (gastroenteritis), typically caused by Salmonella bacteria or enteric viruses. Bathers have been found to contract slightly increased rates of gastroenteritis when fecal coliform bacteria become elevated. Symptoms of gastroenteritis include mild fever, vomiting, diarrhea and stomach cramps.

At least four major scientific studies have been undertaken in the United States, Europe, Israel and Canada within the last decade to examine the relationship between illness rates among bathers and water quality. It is estimated that about 1 to 2% of bathers may contract gastroenteritis when the guideline of 200 fecal coliforms per 100 ml of sample is exceeded. When the guideline is exceeded, bathers who frequently immerse their head have a slightly higher probability of contracting gastroenteritis compared with other bathers.

Major Beaches Routinely Monitored

Monitoring is done routinely in Manitoba to ensure that the guideline is not being exceeded. Each year, between 50 and 60 major beaches are monitored using internationally recognized protocols. At the present time, major beaches are monitored about once every two weeks. Multiple samples are collected from each beach on each sampling trip to ensure that the data are representative of the overall beach area. Included are the major beaches on Lake Winnipeg, in the Whiteshell Provincial Park, and in the south and central regions.

Comprehensive Beach Posting Policy Developed

In early 1994, Manitoba Environment and Manitoba Health developed a comprehensive policy to guide decision-making concerning the posting of warning signs near recreational waters. When assessment of all samples from a beach indicates, with reasonable statistical confidence, that the guideline is being exceeded, immediate resampling will take place. Resampling would also occur if any single sample contained more than 400 indicator organisms per 100 ml, as recommended by the Canadian guidelines. If beach water quality persists above the guideline and if, in the opinion of the Medical Officer of Health, an unacceptable risk is posed to bathers, warning signs will be posted.

Water Quality is Excellent

Extensive data collected from major beaches in Manitoba since the early 1980s indicate that water quality is excellent. Slightly elevated indicator bacteria densities are occasionally detected from most beaches, and at a slightly increased frequency at Lake Winnipeg beaches. This is expected, since many of Manitoba's beaches are surrounded by large human populations, and local wildlife and waterfowl have unlimited access. Upon resampling, densities have quickly returned to low levels.

Bathing Yes, Drinking No

While water quality is excellent at Manitoba beaches for bathing, most jurisdictions (including Manitoba) routinely recommend that untreated surface water should not be used for drinking purposes. A minimum treatment of at least disinfection is required. The guideline for recreation was developed with the recognition that a small amount of water may be accidentally ingested by bathers. However, regular consumption of larger amounts of untreated water may pose additional and unacceptable health risks.

For Further Information

For further information, including a list of beaches monitored in your area, or information on present beach water quality, please contact:

Water Quality Management Section
Water Science and Management Branch
Suite 160 – 123 Main St.
Winnipeg MB R3C 1A5
Telephone (204) 945-8146
Toll-Free 1-800-214-6497 (ext. 8146)