FINANCIEROS DERIVADOS
MONTO NOCIONAL DE VENCIMIENTO DE DERIVADOS POR AÑO (cifras en millones de pesos)
As with other countries worldwide, monitoring program coverage and timely response to bloom events are challenged by geographic constraints and cost and logistics, particularly in areas with low population densities. Specific designs of drinking water treatment systems and the associated cost of operation varies widely from jurisdiction to jurisdiction (Statistics Canada, 2010). Most jurisdictions use the MAC of 1.5 μg/L microcystin-LR from the Guidelines for Canadian Drinking Water Quality in treated drinking water (Health Canada, 2002). As noted above, this guideline is considered protective of human health against exposure to other microcystins (total microcystins) that may also be present within a drinking water supply. As a
general rule, microcystin-LR is not a parameter with regularly scheduled monitoring frequencies, and most municipal drinking water treatment plants monitor for algal toxins only when a bloom occurs. However, municipalities with a history of bloom formation will typically monitor their water supplies with greater frequency. At a national level, very few (~4-5%) municipal water treatment plants have identified or responded to cyanobacteria as a source water issue (Statistics Canada, 2010).
For recreational waters, some of the more densely populated provinces or regions with greater economic and technical resources have developed their own bloom risk management programme (BMRP), largely based on the Health Canada (2012), and/or WHO (2003) frameworks. Many regions, however, have no formal monitoring or risk management programme in place. Table 1 summarises the national and regional drinking and recreational water quality guidelines and standards currently in place across Canada.
British Colombia is Canada’s third largest province. It borders the west coast of the country and has a diverse geography and a wide variance of climate. The most heavily populated coastal regions rarely experience freezing temperatures and can have extended bloom seasons, particularly in areas with more intense anthropogenic impacts. Northern and interior lakes in British Columbia have few occurrences of blooms in drinking or recreational water supplies. A regionalized provincial surface water management system is coordinated from the Health ministry and regional offices, but responsibility for sampling generally rests with the water supplier. A draft BRMP of vigilance, sampling, analyses and advisories has been developed to provide standardised first-level response and long term risk management, with particular vigilance for problematic waterbodies. To increase cost effective coverage of the numerous waterbodies across the province, it proposes the following surrogate or rapid screening methods: i) spring total phosphorus (TP) levels of 20 μg/L and 10 μg/L as threshold indicators of moderate and low risk of cyanotoxins, respectively, to guide monitoring effort; and ii) field test kits to screen water and bloom material for toxins and assist in decisions on risk management. Alberta is the most densely populated of the three Prairie Provinces. The landscape is characterized by mountains, boreal lowlands and prairie grasslands with a wide diversity of waterbodies which range dramatically in productivity and human impact and use. Though pristine in the mountains, the majority of lakes are naturally eutrophic and in the more populated central parkland and southern grassland regions, this is exacerbated by intense agriculture and other human activities. Water supply, drought and extensive irrigation play a major role in southern Alberta. In recognition of this inherently high risk, the province has conducted cyanotoxin research to identify at risk lakes and reservoirs and the toxins most prevalent including various microcystin analogues, neurotoxins, cylindrospermopsin and BMAA. Methods for rapid determination of toxin levels are under study. Provincial regulations require all regulated drinking water treatment plants drawing surface water to test for microcystin-LR during July-August which is the high risk bloom-period. Testing for total microcystin was introduced in 2005 and has become a routine water quality parameter in all government funded lake monitoring programs. Alberta was also one of the first provinces to develop a standardized BRMP (Hrudey and Watson, 2006). Under this programme, which follows the Canadian recreational water quality guideline of 20 µg/L total microcystins, The province supports a pilot public beach monitoring program for total microcystins during the open water season (June- August) in select, heavily used recreational lakes. A centralized public advisory system is also under development.
The prairie province of Saskatchewan also follows the Canadian drinking water guideline for microcystin-LR for their treated municipal drinking water supplies, but has no formal BRMP. Recreational water quality alerts are usually based on the presence/absence of visible blooms. No routine recreational water testing is conducted, although recreational waters are surveyed every 5 years in some regions. Bloom reports are investigated or referred to applicable agencies as required.
Manitoba has more than 110,000 lakes including Lake Winnipeg, currently considered the 6th largest and most eutrophic North American Great Lake. This prairie province has an unmitigated continental climate with temperature extremes, extensive risk of floods, drought and intense storms. Lakes and rivers receive drainage from intensive farming operations across very large catchments often extending across both in the US and Canada. Agricultural activities and human settlement are concentrated in the south and west regions, where there is also greatest surface water impairment and risk of blooms. Manitoba applies the Canadian drinking water guideline for microcystin–LR for municipal supplies and the Canadian recreational water guideline for cyanobacterial cells and microcystin. In addition, the province has developed a provisional protocol on algal bloom and toxin monitoring/reporting again based largely on the Health Canada (2012) and WHO (2003) frameworks, and a public website of updated advisories at a number of public beaches.
Ontario is the most populated of the Canadian provinces. As the 2nd largest province (1,076,395 km2), approximately 15% of Ontario is covered by freshwater. Drinking water is regulated by Ontario drinking water quality standards as prescribed under the provincial Safe Drinking Water Act. This includes a drinking water standard of 1.5 μg/L for microcystin-LR. Provincial water quality objectives for recreational water quality currently do not include values for algal toxins; however, the province has developed a response guide for field staff responding to blooms events, which outlines roles and responsibilities of the departments and the local Health Units. It is currently being updated to reflect new information and lab screening methods. A second document is being developed as a resource to assist Health Units in making decisions on public health issues associated with blooms.
Quebec is the largest of the ten provinces with a total area of 1,542,056 km2, of which approximately 11 % is covered by surface water. As the second most populous province, Quebec has recently experienced negative impacts on surface water quality (e.g., eutrophication) associated with intense agriculture and other human activities. Blooms are being reported in both lakes and large rivers, many of which being used for recreational purposes or drinking water sources. Toxin-producing species have been identified, though toxin concentrations measured in treated drinking water supplies to date, have been below the Canadian drinking water quality guideline value. Quebec has been proactive in developing a provisional BRMP and has adopted guidelines for total microcystins in drinking water (1.5 μg/L) and recreational water (16 μg/L) that are consistent with the Canadian values. In addition, guidelines for concentrations of anatoxin-a in drinking water (3.7 μg/L) and recreational water (40 μg/L) have also been developed. Though provisional, public consultation on proposed changes to the drinking water regulation has taken place.
Table 1: National and regional drinking and recreational water quality guidelines and standards currently in place across Canada
Drinking Water Treatment Plants(b)
Water Quality Guidelines
Jurisdiction Population (a)
Cyanobacte- ria identified as source water issue (%) Cyanobacteria- related treat- ment modify- cations (%) Amount of surface water treated (m³ 106) Treatment costs (CDN $) per 103 m3 % house- holds on muni- cipal supply c Drinking Recreation
Bloom Risk Manage- ment Program in place Health Canada: MC-LR: 1.5 μg L-1 Health Canada; MC-LR: 20 ug L-1; Cells: 100 000 ml-1
Canada 34 278 400 3.9-4.7 5186 124
Alberta 3 742 800 4.4-5.4 1,8 485 196 64
(provisional)
British Colum- bia 4 554 100 6.9-7.4 6.9-7.4 731 61 69
Manitoba 1 243 700 6,2 6 106 211 50
New Brunswick 753 200 0-5 0 80 97 58
Newfoundlandand Labrador 509 100 ND ND 132 114 72
(under development)
Nova Scotia 943 400 0 0 101.6 158 73
Yukon, NW Territories 43 600 (NWT) 34 300 (YK) 0 0 6.2 1144 ND
Ontario 13 282 400 4.6-5.1 4.6-5.1 1733 139 54
d
Prince Edward Island 143 500 0 0 0 0 ND
Quebec 7 943 000 1.3-3.7 1.3-3.7 1697 96 60 (provisional) MCtotale: 1.5
μgL
-1 ATXf: 3.7 μgL-1 (provisional) MCtotale: 16 μgL-1 ATXf : 40 μgL-1
(provisional)
Saskatchewan 1 052 100 7.6-8.5 6.9-7.1 114 327 70
Nunavut 33 300 NDa Statistics Canada 2010; b Statistics Canada, 2009, Environment Accounts and Statistics Division, Survey of Drinking Water Plants (survey number 5149; 2007 Households and the Environment
Survey relating to drinking water decisions of Canadian households); c for the census metropolitan area around a major urban core with a total population of at least 100 000; d In Ontario,
With the exception of New Brunswick, the Atlantic Provinces (Nova Scotia, Prince Edward Island, Newfoundland and Labrador) have few bloom-related issues identified in municipal drinking water sources or recreational waters and BRMPs have not been rigorously developed. Most drinking water in these provinces is derived from groundwater. In particular, Prince Edward Island derives all of it’s drinking water from groundwater sources. In New Brunswick, an apparent recent increase in bloom events has been addressed under the provincial Clean Water Act which states that “the water shall be free of algae blooms that impair use of habitat for aquatic life, or use for primary or secondary contact activities”. A provincial BRMP was developed by the province to respond to specific events, in addition to routine monitoring of selected lakes. Sampling and advisories are issued based on the presence of a bloom (from a visual inspection) and identification of cyanobacteria in samples.