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Management of the Issue of Mercury in Hydroelectric ReservoirsQuébec • Canada
Roger Schetagne, Mercury Program Manager, Hydro-Québec Production,75 René-Lévesque Blvd. West, 10th Floor, Montréal, Québec, Canada, H2Z 1A4Email : [email protected]
Information tool produced in French, English and Cree,in the form of a table mat
Risk Management
At the onset of the La Grande hydroelectric project, the mercury issue related to reservoirs was virtually unknown. The Native Cree Indians were informedas soon as monitoring revealed significant increases of mercury levels in fish.
Hydro-Québec’s Corporate Research Program on Mercury
Hydro-Québec established a Mercury Research and Management Program to address the issue of increasing mercury levels in fish caused by hydroelectricdevelopment. The following activities were included in this program:
• monitoring of mercury levels in fish of modified environments of the La Grande complex;• development of models predicting mercury levels in fish;• assessment of risks to piscivorous fauna;• the study of the sources and fate of mercury in natural environments and hydroelectric reservoirs of Northern Québec;• research on mitigation measures;• assessment of the health risks and benefits associated with the consumption of fish.
A number of these studies were carried out in collaboration with Canadian universities and Government organizations such as the Canadian Wildlife Serviceand the National Science and Engineering Research Council of Canada (which supported part of the funding of the HYDRO-QUÉBEC-NSERC-UQAMEnvironmental Chair).
The James Bay Mercury Agreement
In addition to its Corporate research program on mercury, Hydro-Québec was part of the James Bay Mercury Agreement signed between the Governmentof Québec, the Cree of Québec and Hydro-Québec. The overall objective of this Agreement was to reduce the health risks and provide for remedial measuresallowing the Cree to carry on their traditional hunting and fishing activities and maintain their way of life. This 10 year Agreement (1987-1996), with a totalbudget of 18 M$ (of which 12 M$ was paid by Hydro-Québec), dealt with Health, Socio-cultural and Environmental aspects of the mercury issue.
A critical review of potential mitigation measures aimed at reducing the increases of mercury levels in fish of young reservoirs failed to reveal any realisticsolution. Activities were oriented towards remedial measures aimed at reducing health risks by providing low mercury bush food:
• subsidies for family and community fishing in natural lakes;• subsidies for coastal fisheries of anadromous species;• wildlife enhancement schemes;• schemes to increase harvesting of migratory waterfowl, etc.
Information tools, such as booklets, maps and videos, were developed and information campaigns were carried out in the Cree communities to explainthe mercury issue and the health risks and benefits related to fish consumption. Fish consumption advisories were also distributed to Cree sport andsubsistence fishers, according to exposure criteria of the Cree Regional Board of Health and Social Services of James Bay.
Fish consumptionadvisories in the form of
maps distributed tosport fishers
Informationcampaigns in
Cree Communities
Fish consumption advisories
Hudson Bay
CA N A D
A
Q U É B E C
0 400 800 km
For each new project, fishconsumption advisories for non-native sport fishers were alsoprepared in collaboration withQuébec Public Health agenciesaccording to Canadian andprovincial exposure criteria.
Abstract
The development of hydroelectric reservoirs causes temporary increases of mercurylevels in fish. A management program has been implemented to reduce health risksrelated to mercury exposure which includes: the signing of the James Bay MercuryAgreement; the study of the source and fate of mercury in Northern Québec; the monitoringof mercury levels in fish and of the Cree exposure to mercury; public information campaignsand fish consumption advisories.
Outline of the Project
The James Bay territory, located inNorthern Québec, Canada, liesbetween the 48th and 55th Northparallels and covers 350 000 km2. TheLa Grande hydroelectric complexcomprises eight generating stationsand required the impounding of eightreservoirs with a total surface area of12 953 km2.
Features of the Project Area
The whole territory, which is part of the Canadian Shield, is divided into a coastal plain,with scattered peat bogs and clay deposits, and a hilly plateau covered by a large numberof lakes. The annual average temperature is around -4°C. The region is home to some12 000 Cree Indians, belonging to 9 communities.
Major Impacts
After reservoir impoundment, mercury concentrations increased temporarily in all fishspecies. Peak concentrations reached levels 3 to 7 times those measured in surroundingnatural lakes. Concentrations in the non-piscivorous species, such as lake whitefish(Coregonus clupeaformis), have returned to levels typical of natural lakes 10 to 19 yearsafter impoundment. In the piscivorous northern pike (Esox lucius), the rate of declinestrongly suggests that natural concentrations are reached between 20 to 30 years afterimpoundment. These increases in fish mercury levels considerably reduce the recommendedrate of fish consumption in order to respect the level of mercury exposure consideredsafe by public health authorities.
Hydro-Québec's Corporate ResearchProgram permitted a comprehensiveunderstanding of the biogeochemicalprocesses involved in the production ofmethylmercury in reservoirs and its transferto fish. A Monograph on the sources andfate of mercury in natural environmentsand hydroelectric reservoirs of NorthernQuébec was published (Lucotte et al.,1999). It is presented in the form of 14 peerreviewed papers addressing the issue ofmercury in natural lakes, terrestrialenvironments, hydroelectric reservoirs andfish eating wildlife, with an overall synthesis.
The compensation type mitigationmeasures selected and financed underthe James Bay Mercury Agreement,encouraged traditional hunting and fishingactivities. Replacement fisheries aimed atnon-piscivorous species were the mostfavoured by the Cree communities. Thesefisheries were monitored to prevent anyrisk of overharvesting. The implementationof the mitigation measures program hascontributed to a reduction in the Cree'sexposure to mercury and helped maintaintraditional hunting and fishing activities(Chevalier et al., 1997).
Eeyou Namess Corporation
The James Bay Mercury Agreement was recently renewed with an additional budget of 27 M$ (Mercury Agreement 2001). A non-profit organization, theEeyou Namess Corporation, was established to implement the activities of the Agreement which consists of Monitoring and Research Programs as wellas Fishery Restoration and Development Programs. The affairs of the Corporation are managed by a Board of Directors comprised of 4 persons appointedby the Cree Regional Authority and 3 persons appointed by Hydro-Québec.
The risk management program demonstrated that the mercury issue can be adequately managed through appropriate monitoring, compensation measures,and information and communication campaigns informing fishers on the health risks and benefits of fish consumption.
Results of the Risk Management Program
Q
0 400 800 km
The La Grande hydroelectric project
Legend735-kV and 450-kV c.c.RoadCategory I landsCategory II landsCategory III lands
TownVillageSubstationGenerating stationProposed generatingstation
La Grande-1
Robert-BourassaLa Grande-2-A La Grande-3
La Grande-4
Laforge-1
Brisay
Eastmain-1(planned)
La Grande 3reservoir
Robert-Bourassareservoir
La Grande 4reservoir
Opinacareservoir
EOL diversion
Opinaca
MistassiniLake
Rupert
NemiscauAlbanel
WaswanipiChibougamauMatagami
Waskaganish
Eastmain
Wemindji
Chisasibi
JamesBay
Kuujjuarapik (Inuit)Whapmagoostui (Cree)
Laforge 1reservoir
Caniapiscaureservoir
Caniapisc
au
Bienville Lake
Lemoyne
Mistissini
Oujé-Bougoumou
Nemaska
Radisson La Grande RiverChissibi
Tilly
Chibougamau
Abitibi
Sakami Lake
Boyd Lake
Eastmain
PointeLouis XIV
James Bay territory Laforge-2
Laforge 2reservoir
La Grande 1reservoir
Eastmain 1 reservoir(planned)
LA GRANDE COMPLEXWATERSHED
Radisson
100 km500
N. B.
UNITED STATES N. S.ONTARIO
HudsonBay
JamesBay
LabradorSea
Boston
QUÉBEC
600 k
m
UngavaBay
P. E. I.
NF&L
Treaty land
James Bayterritory
Montréal
Treaty land
James Bayterritory
55°
51°
53°
55°
BroadbackNottaway
Grande riv ière de la Baleine
49°
167
113109167
TOTA
L M
ER
CU
RY
(m
g •
kg-1
)
AGE OF RESERVOIR (Years)
2 4 6 8 10 12 14 16 180.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
West
20
Opinaca
Robert-Bourassa La Grande 3
CaniapiscauLa Grande 4
Naturalcondition
NORTHERN PIKE (700 mm)
AGE OF RESERVOIR (Years)
0.93
0.30
East0.36
0.92RANGE OF MEAN CONCENTRATIONS
MEASURED IN NATURAL LAKES
Temporary increases of mercury levels in a piscivorous fish of theLa Grande complex
C.-M._6100_RS_04_2004_040505.fh8
Temporary increases of mercury levels in a non piscivorous fish ofthe La Grande complex
TOTA
L M
ER
CU
RY
(m
g •
kg-1
)
AGE OF RESERVOIR (Years)
2 4 6 8 10 12 14 16 180.0
0.7
20
Opinaca
Robert-Bourassa
La Grande 3
Naturalcondition
0.6
0.5
0.4
0.3
0.2
0.1
0.20
0.05
LAKE WHITEFISH (400 mm)
RANGE OF MEAN CONCENTRATIONS MEASURED IN NATURAL LAKES
Reasons for Success
The management of the mercury issue at the La Grande complex wasa true success because Hydro-Québec took immediate action, informedrapidly all those concerned and sought collaboration and partnershipsto properly address the issue.
References
Chevalier, G., Dumont, C., Langlois, C., Penn, A., 1997.Mercury in northern Québec: role of the mercury agreementand status of research and monitoring. Water, Air andSoil Pollution, vol. 97 (1977), p 53-61.
Lucotte, M., Schetagne, R., Thérien, N., Langlois, C., Tremblay, A., 1999.Mercury in the Biogeochemical Cycle: Natural Environmentsand Hydroelectric Reservoirs of Northern Québec. Berlin:Springer. 334 p.
Processes involved in the temporary increase of methylmercury productionand transfer in reservoirs
• No increase in mercury load • Addition of food for bateria
Decomposition Methylation Bioaccumulation
MeHgMeHgMeHg
PassivePassivePassivereleasereleaserelease
MeHgMeHgMeHg
SPMSPMSPM
DrawdownMinimum water level
Natural lake level
Maximum water level
Sediment
Periphyton
Groundcover
and humus
Hg2+
Hg2+
ActiveActiveActivebiologicalbiologicalbiologicaltransfertransfertransfer
MeHgMeHgMeHg2 to 30%2 to 30%2 to 30%
Processes involved in the temporary increase of methylmercury productionand transfer in reservoirs
• No increase in mercury load • Addition of food for bateria
Decomposition Methylation Bioaccumulation
ip
MeHgMeHgMeHg
PassivePassivePassivereleasereleaserelease
MeHgMeHgMeHg
SPMSPMSPM
DrawdownMinimum water level
Natural lake level
Maximum water level
Sediment
Periphyton
Groundcover
and humus
Hg2+
Hg2+
ActiveActiveActivebiologicalbiologicalbiologicaltransfertransfertransfer
MeHgMeHgMeHg2 to 30%2 to 30%2 to 30%
Mercury Monograph
