Page 4: Guidelines for Canadian Recreational Water Quality – Third Edition
The primary goal of the Guidelines for Canadian Recreational Water Quality is the protection of public health and safety. This document provides guidance on the factors that can interfere with the safety of recreational waters from a human health perspective. It is intended to guide decisions by provincial and local authorities that are responsible for the management of recreational waters.
Recreational water quality generally falls under provincial and territorial jurisdiction. Responsibility for the safe management of recreational waters can be shared between the provincial-territorial authorities and the beach managers or service providers. The division of duties (e.g. responsibility for monitoring or the communication of results) may vary depending on provincial-territorial policies in place. Recreational waters are considered to be any natural fresh, marine or estuarine bodies of water that are used for recreation. These include lakes and rivers, as well as human-made constructions (e.g. quarries, artificial lakes) that are filled with untreated natural waters. The principal health risk associated with exposure to recreational water quality hazards is infection as a result of contact with pathogenic microorganisms. Other risks include injury or illness due to the physical or chemical properties of the water.
The Guidelines for Canadian Recreational Water Quality consider the human health risks associated with recreational activities--primary contact activities, such as swimming (this includes bathing/wading for the purposes of this document), windsurfing and waterskiing, as well as secondary contact activities, such as canoeing or fishing--in natural waters through intentional or incidental immersion. They establish guideline values for specific parameters used to monitor recreational water quality, including the bacteriological indicators of faecal contamination, cyanobacteria and their toxins, and values for physical and aesthetic objectives. This document also outlines a risk management approach to safe recreational water quality and describes the current scientific knowledge regarding the water quality hazards that can be encountered in the natural recreational water environment. It discusses pathogenic microorganisms of concern, water sampling and analysis, as well as emerging issues, such as faecal contamination of beach sand and faecal pollution source tracking.
Management of recreational waters
The protection and safe management of recreational waters require the cooperation of all stakeholders. The best approach is based on a preventive risk management strategy that focuses on the identification and control of water quality hazards and their associated risks before users could be exposed. As with drinking water, the multi-barrier approach provides this preventive strategy through an integrated system of procedures, actions and tools that collectively reduce the risk of human exposure to recreational water quality hazards. The effectiveness of these procedures, actions and tools is then verified or confirmed by monitoring results and the application of guideline values. The success of this approach rests primarily with the establishment of multiple barriers to protect watersheds.
Potential water quality hazards or risk scenarios that can affect the recreational water area need to be identified through an Environmental Health and Safety Survey. The results of this survey are then used to identify the appropriate procedures or actions that should be put in place as barriers. These may include physical actions, such as beach cleanup and grooming, or processes or tools to improve the effectiveness of the recreational water management program, such as monitoring, guidelines and standards, and education and communication strategies.
Guideline values and technical information
Guideline values for a variety of water quality parameters are one important component of the overall risk management approach to safe recreational water quality. They should be used together with the appropriate technical documentation provided for these parameters. Table 1 outlines the guideline values for the recommended water quality parameters. Considerations are also provided for parameters and water quality hazards for which guideline values cannot be established.
(Primary-Contact Recreation)Footnote *
|Geometric mean concentration (minimum 5 samples)||≤ 200 E. coli/100 mL|
|Single sample maximum concentration||≤ 400 E. coli/100 mL|
(Primary-Contact Recreation)Footnote *
|Geometric mean concentration (minimum 5 samples)||≤ 35 Enterococci/100 mL|
|Single sample maximum concentration||≤ 70 Enterococci/100 mL|
|Pathogenic Microorganisms (bacteria, viruses, protozoa)||Testing only needed when there is epidemiological or other evidence to suggest that this is necessary||No numerical guideline value|
|Cyanobacteria||Total Cyanobacteria||≤ 100,000 cells/mL|
|Cyanobacterial toxins||Total Microcystins||≤ 20 µg/L|
|Other Biological Hazards (e.g. schistosomes causing swimmer's itch; aquatic vascular plants and algae)||Recreational activities should not be pursued in waters where the responsible authority deems the presence of these organisms poses a risk to the health and safety of the users||No numerical guideline value|
|pH||For waters used for primary contact recreation||5.0 to 9.0|
|Temperature||Should not cause an appreciable increase or decrease in the deep body temperature of swimmers||No numerical guideline value|
|Chemical Hazards||Risks associated with specific chemical hazards will be dependent on the particular circumstances of the area and should be assessed on a case-by-case basis.||No numerical guideline value|
|Turbidity||To satisfy most recreational uses||50 NTU|
|Clarity||Clarity should be sufficient for users to estimate depth and to see subsurface hazards||Secchi Disc visible at a depth of 1.2 m|
|Colour||Colour should not be so intense as to impede visibility in areas used for swimming||No numerical value|
|Oil and Grease||Should not be present in concentrations that can be detected as a visible film, sheen, discolouration or odour; or that can form deposits on shorelines or bottom sediments that are detectable by sight or odour||No numerical value|
|Litter||Areas should be free from floating debris as well as materials that will settle to form objectionable deposits||No numerical value|
Indicators of faecal contamination--primary contact recreation
Escherichia coli is the most appropriate indicator of faecal contamination in fresh recreational waters, and enterococci is the most appropriate indicator of faecal contamination in marine recreational waters. Guideline values for E. coli and enterococci have been developed based on the analysis of epidemiological evidence relating concentrations of these organisms to the incidence of swimming-associated gastrointestinal illness observed among swimmers. The values represent risk management decisions based on the assessment of possible health risks for the recreational water user and the recognition of the significant benefits that recreational water activities provide in terms of health and enjoyment. The guidelines advised that recreational water areas routinely used for primary contact recreation be monitored at a minimum of once per week, with increased monitoring recommended for those beaches that are highly frequented or are known to experience high user densities. Similarly, under certain scenarios, a reduction in the recommended sampling frequency may be justified.
Advice regarding water intended for secondary-contact recreational activities
Due to increased interest from jurisdictions in distinguishing between primary contact activities and secondary contact activities, this current edition of the Guidelines takes an initial step at providing advice for secondary contact activities and faecal indicator concentration. There are insufficient epidemiological data available to derive precise health-based faecal indicator limit values intended to protect users engaged in secondary contact recreational activities from exposure to faecal contamination. Secondary contact is defined as recreational activity in which only the limbs are regularly wetted and in which greater contact (including swallowing water) is unusual. Because a lower degree of water exposure can be expected at most times during the majority of secondary contact recreational activities, there may be some waters in which a secondary contact use designation with separate water quality values is desired and considered Good to management and regulatory authorities. Advice is provided that the application of a factor of 5 to the existing geometric mean faecal indicator concentration used to protect primary contact recreation users may be used as an approach to establish faecal indicator limits. These values represent a risk management decision based on the assessment of the expected exposure scenarios and potential health risks for the recreational water user, and represents a tolerable and reasonable approach to protecting users engaged in a voluntary activity.
Other potential indicator organisms
The organisms most widely discussed as potential recreational water indicators include Bacteroides spp., Clostridium perfringens, F+ RNA coliphages and bacteriophages infecting Bacteroides fragilis. At present, none of these organisms meets a sufficient number of the requirements necessary to be successfully used as a routine indicator of recreational water quality. These organisms appear to be better suited as possible pathogen indicators or as faecal source indicators. Advances in detection and enumeration methods may improve the understanding of these organisms and the roles they may play in future recreational water monitoring programs.
Pathogenic microorganisms (bacteria, viruses, protozoa)
The challenges associated with the detection of pathogenic microorganisms in recreational waters are currently too great to recommend this practice as part of a regular monitoring program. Surveillance is necessary only during special circumstances, such as during waterborne disease outbreak investigations. Faecal indicators such as E. coli and enterococci are the best available indicators for the possible presence of enteric pathogenic microorganisms. However, the absence of the recommended faecal indicators should not be interpreted to mean that all pathogenic microorganisms are also absent.
Cyanobacteria and their toxins
Swimmer illnesses have been reported following exposure to toxic cyanobacterial blooms in recreational waters. Guideline values for cyanobacteria and their toxins (microcystins) have been established to protect against both the risk of exposure to microcystins as well as any harmful effects that may be possible as a result of exposure to high densities of cyanobacterial material. Waters shown to exceed the established guideline values or those in which a bloom has developed may result in human exposure to cyanobacterial material or cyanotoxins in amounts sufficient to be harmful to human health. A swimming advisory may be issued at the discretion of the responsible authority. Contact with waters where an advisory has been issued should be avoided until the advisory has been rescinded.
Other biological hazards
Recreational water activities should not be pursued in areas where other biological hazards are present in significant quantities such that they pose a risk to the health and safety of recreational water users. Examples include the presence of organisms responsible for swimmer's itch and dense growths of aquatic plants.
Physical, aesthetic and chemical characteristics
Physical, aesthetic and chemical characteristics of water can have an impact on recreational water users. Recreational waters should be of good aesthetic quality and should be free from substances that impair its aesthetic appreciation. Aesthetic components can also impact the health and safety of recreational water users where visibility has become significantly impaired.
Guideline values for specific chemical parameters in recreational waters cannot be specified. In general, potential risks from exposure to chemical parameters will site specific and be much smaller than microbiological risks. It is important for beach operators or service providers to have a mechanism in place to ensure that risks from potential chemical hazards are identified and adequate action is taken.
Faecal contamination of beach sand
Beach sand can present an important non-point source of faecal contamination to recreational waters. Sand may provide a favourable environment for microorganisms of faecal origin, permitting them to survive for longer periods than in the adjacent waters. Physical factors such as wave action, storm surges, tidal activity and high swimmer load can result in the transference of faecal microorganisms from foreshore and nearshore sand and sediments to waters used for swimming.
Further research is needed to determine the relationships between faecal indicator bacteria and the possible presence of faecal pathogens in beach sand, as well as the potential implications for human health. Barriers that collectively reduce the risk of exposure for beach users could include public education campaigns, improved beach sanitation practices, appropriate sand grooming practices and actions designed to discourage the activities of animals (birds and other wildlife) within the beach area.
Faecal pollution source tracking
Faecal pollution source tracking is an emerging field that focuses on understanding the specific sources of faecal contamination affecting an area. Numerous chemical and microbiological source-tracking tools have been described. A good understanding and formulation of the nature of the faecal contamination problem are required before any faecal source tracking study can be considered.
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