Industry Pollution and the St. Lawrence River
Analyzing spatial and water quality data to determine the effects of industry on the river
St. Lawrence Watershed, area of focus is the part labeled 'St. Lawrence River'
Introduction
The St. Lawrence river is one of Canada’s priority ecosystems, at once an international, an intra-Quebec, and a multiprovincial system. Stretching over 3,000 kilometers, it provides vital shipping routes, drinking water, and resources for the surrounding population. Originating in the province of Quebec and extending into Ontario, the Great Lakes, and New York, the St. Lawrence river is one of Canada's most important waterways.
Unfortunately, the river and it's surrounding environment have long struggled with issues of pollution and contamination from industry and agriculture. Industry and manufacturing have long been associated with environmental pollution, whether that be by air, land, or water; and because the St. Lawrence is a major shipping route it has been a prime location for companies to set up shop. This has led to an ongoing pollution problem that has plagued the area for decades.
Info-graphic explaining the origin and transportation of effluents. See specifically the 'Industry' and 'Mining' portions.
In this study of the area, we will only be focusing on water pollution specifically from industrial effluents. Effluents are waste products from manufacturing processes that are treated and released into the surrounding environment. Using location data for industries on the river's banks along with water quality data over the period 2019-2023, we will assess the impact of these effluents on the local environment and examine current conservation efforts focused on improving water quality along the basin.
Below is an explanation of the 5 main categories of industries that border the St. Lawrence river: Fabrication of Paper and Pastes, Processing Residual Materials, Mining, Petrochemicals, and Metal and Mineral Processing. Each use different processes and chemicals, thus posing multiple challenges in addressing pollution.
Paper and Paste Mills
The pulp and paper sector produces a wide range of products using residual logs and wood chips from sawmills and recycled paper products. The resulting 'pulp' is used on-site or shipped off-site to produce paper products such as printing paper, paper boxes or tissue paper.
The manufacturing process uses water, heat, and chemicals to break down cellulose from wood fibers. These processes create many toxic and hard to degrade byproducts, so managing effluents is crucial. Numerous studies have shown the negative effects of these byproducts, specifically in larval fish development (see citations for more information). Wastewater generated from the manufacturing process is treated on or off site by primary, secondary and sometimes tertiary treatments before the effluent is discharged.
Mining
The mining sector encompasses a wide range of activities, mostly simplifying down to the extraction of precious metals and minerals from the earth. Of the mines being looked at in the St. Lawrence River area, most deal with gold, iron, copper, zinc, and lead.
Minerals are extracted from the earth using heavy machinery, then processed at a separate location using various chemical and physical processes. Mines can be in three different stages of operation: active exploitation (active), post extraction (no longer actively extracting resources), and enhancement (upgrades or renovations to equipment or processes). The level of activity in each site will determine the amount and type of effluents it releases.
Mining waste is an area of active concern as it floods the surrounding environment with metals and minerals in high concentrations. Mining has long been known to have severe impacts on environmental health, leading to heavy regulation of this sector's effluent.
Metal and Mineral Processing
After raw materials are extracted from the ground they are sent off to processing facilities to be refined into more pure product.
The main processing phases are: separation of valuable minerals from unwanted minerals, recovery of valuable minerals from the ore, and metal production and refining. Most of the emissions produced during these stages are released into the air, but some are also released into the water and land.
Some main sectors of metal and mineral processing on the St. Lawrence include aluminum and alumina processing, metal smelting, cement production, iron and steel processing, and iron ore pelletizing.
Petrochemicals
The petrochemicals sector relates to all processes associates with oil, including refining and the products used in the process. In the St. Lawrence study area there are only two petrochemical facilities, both being oil refineries.
The oil refining process starts by heating crude oil in a furnace. The oil is then sent to a distillation tower, where it is separated by boiling point. Next, the material is converted by heating, pressure, or a catalyst into finished products including fuels like gasoline and diesel, asphalt, and solvents.
Because the processes use complicated raw materials, complex procedures, and complicated chemical reactions, its wastewater generally contains many toxic organic and inorganic substances. Both categories of chemicals are poisonous in large concentrations, leading to big impacts on local wildlife and habitat. As they are also very hard to break down once they have entered the ecosystem, they must be heavily regulated to avoid oversaturation.
Residual Materials
The final sector is the processing of residual materials. It is composed of many locations that process different waste materials, most falling under the category of paper waste or waste from municipal trash incinerators.
Waste from this sector can take a variety of forms and is processed in a variety of ways; though on the whole, most waste products are emitted in the form of smoke or steam.
Industry on the St. Lawrence
See below for a map of industries on the banks of the St. Lawrence, organized by sector.
Map of Industries by Type on the St. Lawrence River (See Citations 1 for link to data). Click on a point to see it's name, sector, and which chemicals it emits.
We see in the graphs above distribution of both types of industries bordering the river, as well as their total emitted effluents organized by sector. The paper industry is one of the largest industrial sectors in Quebec, and this is reflected above in a large percentage of industries bordering the river being associated with paper manufacturing. The process of making paper produces many side products, so it makes sense paper is the number one emitter of effluents. It is, however, interesting to note that though the Petrochemical sector only takes up only 3% of the pie chart (representing only 2 facilities), it is has the third largest volume of emitted effluents because of the large amount of chemical byproducts the refining process produces.
Water Quality
Taking a look now at water quality, using a data set from Canadian government's website, we can compare overall water quality to industry location. In this map, water quality was assessed over a 2 year period from 2018-2020, and is based on the combined assessment of Ammonia, Chlorophyll, Nitrogen, pH, Phosphorus, and Turbidity parameters.
Overall Water Quality vs Industry Location (2)
The area has long struggled with issues of water quality, and this is reflected in the data with the majority of the sites falling under the 'Fair' category. Now, lets take a closer look at a handful of parameters to understand on a deeper level what's going on. Below is a spatial assessment of 8 water quality parameters, taken from data monitoring water quality on the St. Lawrence from 2029-2023 (3).
pH is the measurement of how acidic water is, and it is an important indicator of river health. Values going outside the standard range of 6.5-9 indicate unhealthy water. Only one site on the St. Lawrence fell outside this parameter, so pH is not an indicator of pollution in this area.
Dissolved oxygen (or DO) is the measurement of how much oxygen is dissolved in the water. A healthy ecosystem will have a DO of above 5mg/L, ideally being around 9mg/L. Mapped here are sites that had DO levels below 5 mg/L, indicating there is not enough oxygen present for these ecosystems to function properly. Low DO is a common characteristic of industrial water pollution.
Nitrogen is an important nutrient that helps sustain life in aquatics system. However, too much nitrogen can cause too much growth, an issue that will be discussed later. Here we see sites with levels of dissolved nitrogen that exceed the natural standard level of 0.63 mg/L. Over the four years, many sites have exceeded this limit, indicating human contamination of the water.
Phosphorus, like nitrogen, is another important nutrient for aquatic life. Represented here are sites that exceed the natural levels of 0.03 mg/L, again indicating anthropogenic factors. Too much phosphorus can have big impacts on river ecosystem health, something that will be discussed in more detail later.
The final nutrient being looked at here is ammonia. In natural environments without contamination, ammonia levels should be around 0.1 mg/L. Mapped here are sites that exceed this parameter, a clear sign there has been human contamination in the area.
Transitioning from nutrients, we now look at non-naturally occurring organic molecules. These are chemicals not found in nature and can only exist through man-made processes. The points in blue represent sites where Polychlorinated biphenyl's (or PCB's) were found in the water. They are created through many different manufacturing processes and have harmful effects on stream health. This group of chemicals are banned as of present day, but take a long time to break down so are still found in areas with historically high industrial contamination.
This next group of industrial chemical are called Polybrominated diphenyl ethers (also known as PDBE's). PDBE's are flame retardants, and are used to slow the ignition and spread of fire. In high quantities, these chemicals are very toxic; however, over the four year period no sites showed unsafe levels compared to drinking water standards. It is important to note that even in safe levels, the existence of these chemicals and their spread throughout the basin indicates wide industrial contamination.
The final parameter we will look at is Bisphenols, which are a group of chemicals associated with plastic production. Again, these were found only in safe concentrations, but nonetheless their existence in the water speaks to industrial contamination throughout the area.
Similar to the above analysis, in 2017 the Canadian government also took a similar look at nitrogen and phosphorus . Over a 2 year period (2017-2019), they looked at concentrations of these two nutrients to determine how many sites along the St. Lawrence had nitrogen and phosphorus levels above the recommended standard.
2 year analysis of nitrogen and phosphorus levels on the St. Lawrence
During the years 2017-2019, they found that at most of the water quality testing stations surveyed, results showed over 50% of the samples contained levels of nitrogen or phosphorus that were above standard water safety guidelines.
Excess amounts of these nutrients can cause harmful algal blooms, which contribute to degradation of water quality, damaging the health of all freshwater ecosystems. These algal blooms take up too much of the systems oxygen and replace it with carbon dioxide, creating a toxic environment that few species are adapted to live in. This not only harms the environment but can also disrupt fisheries, tourism and agriculture, and make it more expensive to treat drinking water, leading to potential negative health consequences.
We see now the St. Lawrence river has long struggled and continues to struggle with industrial pollution, but what is being done about it?
Conservation Efforts
While it's clear the area has had continued pollution issue, the local and national governments have taken large measures over the years to implement numerous programs focused on making the river safe and healthy again.
1978
Quebec Water Purification Program: a water treatment program set up by the Ministry of Environment in Quebec overseeing three categories: urban, agricultural and industrial wastewater treatment.
1988-1993
St. Lawrence Action Plan: A plan between the governments of Quebec and Canada to fund projects aimed at cleaning up the river and surrounding area.
1993-2003
St. Lawrence Vision 2000: Part of the broader St. Lawrence Action Plan, it includes numerous initiatives such as: establishment of a joint program to monitor the state of the St. Lawrence, development of a sustainable shipping strategy on the St. Lawrence, involvement of numerous community organizations in clean-up efforts, and completion of almost a hundred technology transfer and development projects that help cut the use of pesticides.
2005-2010
St. Lawrence Plan for Sustainable Development: a federal-provincial initiative, it is the main framework used to develop priorities and action at the basin-wide scale. This includes the implementation of a long-term monitoring program, which provides the data from which this StoryMap is based on.
2011
St. Lawrence Action Plan is revamped: the governments of Canada and Quebec re-up their promise to invest in river clean-up projects for the next 15 years.
2014
Overview of the State of the St. Lawrence River report is prepared. An extensive report detailing the progress of all previous clean-up efforts, as well as what still needs to be done to improve water quality.
Section of the St. Lawrence used for recreation
Over the decades of clean-up work and millions of dollars in funding, toxic effluents into the St. Lawrence from the 50 most-polluting plants have been reduced by more than 95%, and thousands of hectares of natural land have been preserved. However, this does not mean the work is done, as continued vigilance and clean-up efforts must keep happening to ensure the protection of this natural environment.
By continuing to advocate for clean-up efforts in and around the St. Lawrence river as well as continued water quality legislation and monitoring of industrial effluents, we can make sure this vital habitat stays clean and healthy for all who depend on it. Whether that be organisms who use the river as their home, shipping companies who need it for commerce, or people living near by using the river for drinking water or recreation, everyone benefits from a cleaner and less polluted St. Lawrence.
St. Lawrence Seaway
Acknowledgements
All data used for GIS analyses from the Government of Canada's website and DataStream platform (see citations below). Five main datasets were used throughout the analysis: Industrial Effluents, Overview of Water Quality in Canadian Rivers, St. Lawrence Long-term Water Quality Monitoring (2000-present) combined with National Long-term Water Quality Monitoring Data, and the DataStream Portal.
Project created for the Intro to GIS class (GEG 310) under the direction of Professor Larissa Montas
