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News release
Water quality in the St. Lawrence River from 1990 to 1997
Environment Minister confirms net improvement
Quebec City, March 26, 1999 – Among the scientific papers presented at AMERICANA 1999, the Quebec Department of the Environment today released its report Qualité des eaux du fleuve Saint-Laurent, 1990 à 1997. The report was written under the St. Lawrence Vision 2000 Canada-Quebec Agreement as part of a government effort to measure the environmental impact of clean-up measures launched in 1978 under the Quebec Wastewater Treatment Program (PAEQ) and continued under the province’s Municipal Wastewater Treatment Program (PADEM) in 1994. Nearly seven billion dollars have been spent under the two programs to date.
Written by a team of professionals and technicians at Environment Quebec’s Aquatic Ecosystems Branch, the report describes water quality in the St. Lawrence River from the outlet of Lake St. Francis to Ile d'Orléans and details the progress reflected in data collected from 1990 to 1997.
Major intervention
By the end of 1997, 73 municipalities along the river were being served by 35 wastewater treatment stations. Wastewater from 3.2 million persons, nearly 97% of the population near the river, was being treated. At the beginning of 1990, slightly over 1 million people, or 33% of this population, were served by wastewater treatment stations. Of the stations in service at the end of 1997, 16 had obtained notification of compliance, and the others were in the run-in stage or did not meet the Department’s requirements. Once all of the projects now slated have been completed, 41 wastewater treatment stations will be in service along the St. Lawrence River. Thanks to the PAEQ and PADEM programs, discharges from Quebec municipalities with sewer systems have dropped significantly. In the seventeen years between 1980 and 1997, phosphorous discharges were cut by 50%, suspended solids by 68%, and biochemical oxygen demand by 62%. Major clean-up efforts also took place in the industrial sector, particularly the pulp and paper industry.
Improvement measured over space and time
From the outlet of Lake St. Francis to the Island of Montreal, water quality is good, but beyond that point it deteriorates. The main problems and lost uses are in the water masses in the middle of the river and along the north shore downstream from Montreal. They are largely the result of bacteriological contamination from Laval’s untreated sewage (at the time of the study), untreated storm overflows and runoff, and especially the Montreal Urban Community and Longeuil wastewater treatment stations. Although these stations have physical-chemical treatment systems, they do not disinfect treated wastewater before discharging it into the river. The bacteriological pollution from this sector begins to lessen in Lake St. Pierre, but persists as far as Gentilly, about 125 km below Montreal.
However, data collected between 1990 and 1997 indicate a significant drop in phosphorous concentrations and conductivity at most sampling stations. In several places, turbidity, suspended solids and fecal coliform counts also fell. Downstream from Montreal, the figures show leaps forward after certain dates which correspond to the coming on stream of municipal wastewater treatment stations. The data suggest that municipal and industrial clean-up measures significantly improved water quality in the St. Lawrence River between 1990 and 1997.
Targeting future action
This report on our knowledge of the state of the environment makes it possible to evaluate how effective we have been at cleaning up the river and provides reliable, well-documented data to support future action.
The Department will maintain its monitoring program with a view to achieving this goal, and the data obtained will be used to measure the recovery of the St. Lawrence and its main tributaries as clean-up activities progress.
The report Qualité des eaux du fleuve Saint-Laurent, 1990 à 1997 may be obtained, in French only, from the Department’s Reception and Information Service at (418) 521-3830 or by calling 1 800 561-1616 toll-free (for those outside the Quebec City area). A summary of the results can also be obtained, in French only, at the following Internet web site: http://www.menv.gouv.qc.ca/eau/eco_aqua/fleuve/index.htm
Source:
Guy Gagnon, Communications Advisor
Communications Branch
(418) 521-3823, extension 4915
E-mail: guy.gagnon@mddep.gouv.qc.ca
For information:
Serge Hébert, Biologist
Aquatic Ecosystems Branch
(418) 521-3820, extension 4705
e-mail: serge.hebert@mddep.gouv.qc.ca
Également offert en français
Date modified: 1999/06/23 – Important Notices
