Long-term freshwater quality data from federal and federal-provincial sampling sites throughout Canada's aquatic ecosystems are included in this dataset. Measurements regularly include physical-chemical parameters such as temperature, pH, alkalinity, major ions, nutrients and metals. Collection includes data from active sites, as well as historical sites that have a period of record suitable for trend analysis. Sampling frequencies vary according to monitoring objectives. The number of sites in the network varies slightly from year-to-year, as sites are adjusted according to a risk-based adaptive management framework. The Great Lakes are sampled on a rotation basis and not all sites are sampled every year. Data are collected to meet federal commitments related to transboundary watersheds (rivers and lakes crossing international, inter-provincial and territorial borders) or under authorities such as the Department of the Environment Act, the Canada Water Act, the Canadian Environmental Protection Act, 1999, the Federal Sustainable Development Strategy, or to meet Canada's commitments under the 1969 Master Agreement on Apportionment.

Historical water quality data measured on a continuous basis at over 23 locations across Canada is included in this dataset. Most locations include hourly temperature, dissolved oxygen, pH, specific conductance and turbidity. Data are collected by Environment and Climate Change Canada (ECCC) and in partnership with other federal departments and provinces and territories to enable the detection of short-term water quality events, and to determine trends in water quality, especially at transboundary sites (or Federal waters) in support of Federal legislation and international agreements, or to report on the status of Government of Canada priority aquatic ecosystems.

Water quality and ecosystem health data collected using a risk-based monitoring approach to support the Great Lakes Water Quality Agreement are included in this dataset. By conducting regular, systematic measurements of the physical, chemical and biological conditions of the Great Lakes Environment and Climate Change Canada (ECCC) is able to: measure the natural changes and conditions of water quality; determine changes over time, at various locations, of water contaminants and/or threats; support development of science-based guidelines for water, fish, and sediment; identify emerging issues and threats; track the results of remedial measures and regulatory decisions; report and assess science results through performance indicators and in an Open Science environment to support an ecosystem approach to environmental and resource management in the Great Lakes. Data are collected by Environment and Climate Change Canada to meet federal commitments related to the Great Lakes as transboundary waters crossing, inter- provincial and international borders under the authorities of the Department of the Environment Act, the Canada Water Act, the Canadian Environmental Protection Act, 1999 and the Boundary Waters Treaty including the commitments under the Canada-United States Great Lakes Water Quality Agreement.

The map shows the locations of water quality network stations operated by the federal Water Quality Branch, Department of Fisheries and the Environment, and the provincial Water Quality Branches of Quebec, Ontario, Saskatchewan, Alberta, and British Columbia. The federal and provincial monitoring programs provide natural water quality data, data on environmental contaminants, and interpretive information to a wide field of users in support of water resources management programs, pollution control and environmental assessment studies, legislation and research, and federal-provincial, interprovincial, and international agreements. The programs are designed essentially to detect and quantify water pollution, to determine water quality trends on a national and regional basis, and to measure the effectiveness of remedial pollution control measures on surface waters. In this way a better understanding will be achieved of the behaviour and fate of pollutants in the environment and their effects on physical, chemical, and biological systems. This increased knowledge will contribute to improved water resource planning. Initially, the International Hydrological Decade network consisted of about 200 sampling stations located on major rivers and streams across Canada. Besides providing data for industrial, municipal, and other government agencies, the network was designed to explore methods for predicting water quality conditions in streams, using existing and new data, and to study correlations of water quality, stream discharge, geological formations, and meteorology.

The Canadian Environmental Sustainability Indicators (CESI) program provides data and information to track Canada's performance on key environmental sustainability issues. The water quality in Canadian rivers indicators provide a measure of the ability of river water across Canada to support plants and animals. At each monitoring site, specific water quality data are compared to water quality guidelines to create a rating for the site. If measured water quality remains within the guidelines, it can maintain a healthy ecosystem. Water quality at a monitoring site is considered excellent when parameters in a river almost always meet their guidelines. Conversely, water quality is rated poor when parameters usually do not meet their guidelines, sometimes by a wide margin. These indicators provide information about the state of surface water quality and its change through time, to support water resource management. Information is provided to Canadians in a number of formats including: static and interactive maps, charts and graphs, HTML and CSV data tables and downloadable reports. See the supplementary documentation for the data sources and details on how the data were collected and how the indicator was calculated. Supplemental Information Canadian Environmental Sustainability Indicators - Home page: https://www.canada.ca/environmental-indicators

Long-term freshwater quality monitoring data for over 40 sites in the St. Lawrence River basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) as well as through the Canada-Quebec Water Quality Monitoring Agreement and the St. Lawrence Action Plan to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions. Data for sites operated by the province are available from Quebec's Sustainable Development, Environment and the Fight against Climate Change Ministry. Supplemental Information http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lan g=En&n=50947E1B-1

Long-term freshwater quality monitoring data for over 13 sites in the Columbia River Basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) and under the Canada-British Columbia Water Quality Monitoring Agreement to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions. Supplemental Information. http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lang=En&n=50947E1B-1

Long-term freshwater quality monitoring data for six sites in the Assiniboine - Red River Basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions. The information informs the Lake Winnipeg Basin Initiative and supports activities of the Prairie Provinces Water Board (PPWB). Supplemental Information. http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lang=En&n=50947E1B-1

Long-term freshwater quality monitoring data for over 10 sites in the Pacific Coastal Basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) and under the Canada-British Columbia Water Quality Monitoring Agreement to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions. Supplemental Information http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lang=En&n=50947E1B-1

Ontario has a comprehensive set of measures and regulations to help ensure the safety of drinking water. The following dataset contains information about the drinking water systems, laboratories and facilities the Ministry of the Environment, Conservation and Parks is responsible for monitoring to ensure compliance with Ontario's drinking water laws. The dataset includes information about: * the number and type of registered systems and laboratories * drinking water quality test results * adverse water quality incidents * activities to support reduced lead in drinking water * enforcement activities related to inspections * orders and convictions * system operator certification

In 2016-2019 water samples were collected at Lake of the Woods as part of a research program to determine sources and fate of nutrients in nearshore areas. These included samples of lake water, groundwater, streams, and septic wastewater. The samples were analyzed for nutrients (total and dissolved P, nitrogen species, artificial sweeteners and other trace contaminants, major ions and various dissolved metals and other elements. Some of these data have been used/published in journal articles (Robertson et al., 2019, 2021; Van Stempvoort et al., 2019, 2020, 2021; Danielescu et al., 2021).

Hamilton Harbour is located at the west end of Lake Ontario. It was designated as one of 43 Areas of Concern in 1987 under the GLWQA where 11 beneficial uses of the harbour were deemed impaired. One of the primary recommendations of the Hamilton Harbour Remedial Action Plan was to decrease nutrient loads to Hamilton Harbour and establish water quality targets to decrease undesirable algae and improve water clarity. This long term data set consists of spatial and temporal water quality data collected in Hamilton Harbour since 1987 to measure ecological response of remedial efforts. Supplemental Information Funding for this study was provided in part by the Government of Canada’s Great Lakes Action Plan (GLAP) and in support to the Hamilton Harbour Area of Concern. . In 1987 under the revised Great Lakes Water Quality Agreement, 43 areas of concern (AOC), 12 of which are located in Canada, were identified as having severely impaired beneficial uses and water quality. As funded by the Great Lakes Action Plan, a Remedial Action Plan was formed for each area of concern bringing together experts from government, industry, municipalities and environmental non-government organizations to address these impacts. Today over 900 restoration projects have been successfully completed by Environment and Climate Change Canada and partners including Wastewater Treatment Plant upgrades, fish and wildlife habitat restoration, and water quality improvements. Today Wheatley Harbour (Lake Erie), Collingwood Harbour and Severn Sound (Georgian Bay) have been de-listed as an area of concern. Spanish Harbour and Jackfish Bay (Lake Superior) are now areas in recovery. Today scientific monitoring and research is continuing in the remaining AOCs to measure response of remedial efforts. For more information please visit: https://www.canada.ca/en/environment-climate-change/services/great-lakes-protection/areas-concern.html

The Canadian Environmental Sustainability Indicators (CESI) program provides data and information to track Canada's performance on key environmental sustainability issues. The Water quality in Canadian rivers indicators provide a measure of the ability of river water across Canada to support plants and animals. At each monitoring site, water quality data are compared to water quality guidelines to create a rating for the site. If measured water quality is below the guidelines, it can maintain a healthy ecosystem. Water quality at a monitoring site is considered excellent when parameters in a river very rarely exceed their guidelines. Conversely, water quality is rated poor when parameters usually exceed their guidelines, sometimes by a wide margin. These indicators provide information about the state of surface water quality and its change through time, to support water resource management. Information is provided to Canadians in a number of formats including: static and interactive maps, charts and graphs, HTML and CSV data tables and downloadable reports. See the supplementary documentation for the data sources and details on how the data were collected and how the indicator was calculated. Supplemental Information Canadian Environmental Sustainability Indicators - Home page: https://www.canada.ca/environmental-indicators

Long-term freshwater quality monitoring data for over six sites in the Yukon River Basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) and in partnership with Environment Yukon to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions. Supplemental Information. http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lang=En&n=50947E1B-1

Pesticides surveillance data in freshwater from federal and federal-provincial sites at various locations throughout Canada are included in this dataset. Measurements mostly include pesticides but could include physical-chemical parameters such as temperature, pH, alkalinity, major ions, nutrients and metals. The number of sites varies from year-to-year, and sampling frequencies vary from one location to another, as surveillance activities are adjusted according to evolving environmental pressures and governmental programs. Data are collected in order to determine baseline water quality status, determine event-based pulse concentrations, evaluate the effectiveness of management actions, verify compliance with water quality objectives, and/or identify emerging issues. Additional information on the surveillance project allows suitable data interpretation and can be obtained by contacting the data authority. More pesticides data are available as part of the National Long-term Water Quality Monitoring Data. http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lang=En&n=50947E1B-1

Long-term freshwater quality monitoring data for over 14 sites in the Fraser River Basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) and under the Canada-British Columbia Water Quality Monitoring Agreement to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions. Supplemental Information. http://www.ec.gc.ca/eaudouce-freshwater/default.asp?lang=En&n=50947E1B-1

This dataset is a collection of measurements which make up two water quality indexes: Nutrients, Physical and Major Ions (NPMI) Index and Metals Index. The measurements are taken at two different locations along the Hornaday River annually in early-July. Project Rationale: Water quality is a widely used measure for assessing and monitoring the condition of freshwater ecosystems. The chemical composition of water influences the biological productivity and species composition of rivers. Changes in the water quality in the rivers and creeks in the Western Arctic can act as early indicators of ecosystem change. The presence of contaminants, such as persistent organic pollutants (POPs), heavy metals, and radionuclides are a concern because they can have negative effects on Arctic ecosystems and human health. Furthermore, a changing climate in the Arctic can influence the nutrient levels in the streams and rivers as more nutrients will be released from thawing permafrost. As the expected effects of climate change on Arctic ecosystems are still unknown, continuous monitoring is paramount.

Water quality and ecosystem health data collected in the Great Lakes and priority tributaries to determine baseline water quality status, long term trends and spatial distributions, the effectiveness of management actions, determine compliance with water quality objectives and identify emerging issues are included in this dataset.

This project monitors water quality at 14 sites (streams and lakes) within the Long Beach Unit of the Park. A total of 46 water quality parameters are recorded at each site twice per year (spring and fall), including concentrations of nutrients, metals, and physical properties. The thresholds applied to the data are standards prescribed by the federal or provincial government for freshwater aquatic life and overall water quality is ranked based on the annual average CCME WQI (Canadian Council of Ministers of the Environment Water Quality Index). This measure is used to report and act on issues related to water quality and water pollution in the park from external sources, answering the important questions of: (1) Is water quality, in selected streams or lakes of the Long Beach Unit, within set water quality limits for aquatic wildlife as determined from concentrations of anthropogenically generated contaminants and (2) Is the overall water quality within the specified quality bounds?

Long-term freshwater quality monitoring data for sites in the Maritime Coastal basin for the past 15 years or longer for nutrients, metals, major ions, and other physical-chemical variables are included in this dataset. Monitoring is conducted by Environment and Climate Change Canada (ECCC) and Parks Canada as well as through the Canada-New Brunswick Water Quality Monitoring Agreement, the Canada-PEI Water Annex, and through collaborative work with the province of Nova Scotia to assess water quality status and long-term trends, detect emerging issues, establish water quality guidelines and track the effectiveness of remedial measures and regulatory decisions.