Greater Infrastructure Investments Needed to Reduce Combined Sewer Overflows

By Michael Mezzacapo, IJC

cso graphic combined sewer overflows
Figure 1: A graphic depicting a CSO event in extreme weather. Credit: Michael Mezzacapo

Many older sewer systems in Canada and the United States mix stormwater runoff with raw or partially treated sewage and discharge the excess into the Great Lakes during periods of heavy precipitation. These discharges are known as combined sewer overflow events (CSOs). CSO systems can handle typical rain events (Figure 1) but during more intense rain events the capacity of the treatment plant and its connecting systems is exceeded, causing the excess water to be discharged to a nearby lake or river (Figure 2).

CSO runoff can contain contaminants, including pathogens like E.coli and chemicals and nutrients like phosphorus and nitrogen, which impact the drinkability, swimability and fishability of Great Lakes waters. Outflows from CSOs also have health and economic impacts, resulting in drinking water supplies requiring greater and more costly treatment and beach closures in order to protect human health. The IJC recommends zero discharge of inadequately treated or untreated sewage into the Great Lakes and connecting waters in its recently released First Triennial Assessment of Progress (TAP) under the Great Lakes Water Quality Agreement.

The TAP report notes that in just one year, 20 Great Lakes cities in Canada and the US released a combined total of 92 billion gallons of untreated sewage and stormwater to the Great Lakes, mostly via CSOs. That’s roughly equal to 147,000 Olympic size swimming pools. Between Canada and the US, there are about 291 cities in the Great Lakes basin with antiquated sewer systems which release CSOs, 109 in Canada and 182 in the United States. The map below shows the discharge in millions of gallons per year between 2005-2008 for 49 cities in the US and Canada.

csos map great lakes basin
Map showing the discharge volume of CSOs for 49 cities between 2005-2008 within the Great Lakes basin. Credit: GLEAM

The release of wastewater just above Niagara Falls this summer by the Niagara Falls Water Board sparked public outrage and government fines. The July discharge was highly visible, occurring during the peak tourist season. Citizens may be unaware of how frequently CSO events occur around the Great Lakes basin. In 2014, a US Environmental Protection Agency report cited 1,482 untreated CSO events in US states within the Great Lakes basin. Although the province of Ontario issues guidance to municipalities on CSOs, there are no comprehensive reports detailing these events. Releases may intensify as aging sewer systems are impacted by a changing climate due to precipitation pattern shifts and population increases.

An Aug. 15 discharge of sewage into the Niagara River
An Aug. 15 discharge of sewage into the Niagara River. Credit: Christine Hess

Citizens may not notice impacts from CSO discharges. The old adage of “out-of-sight and out-of-mind” often comes into play. Those that live directly on the shoreline and frequent beaches are most likely to notice the foul smells and discolored waters, while others who aren’t adjacent to CSO releases may not even be aware they are occurring, although many states require public notice of such events.  Ontario does not require public notice of such events, though some cities do notify the public.

More than 35 million people rely on the Great Lakes for drinking water, recreation and employment. CSOs have the potential to cause human illness over large sections of the population, not just those who recreate in the contaminated water. A study published in the Journal of Environmental Health Perspectives detailed a 13 percent increase in emergency room visits related to gastrointestinal illness in Massachusetts following extreme precipitation events in areas with sewers that discharged CSOs into drinking water sources. Another study co-authored by IJC Health Professional Advisory Board member Dr. Tim Takaro noted that drinking water systems can prevent illness by developing planning tools and building resilience and capacity into infrastructure for future events; the study was done in Vancouver, British Columbia.

The IJC has consistently expressed concern about the need to increase the governments’ attention to water quality and human health. The IJC recommends in its recent TAP report that older sewer systems that contribute CSOs to the Great Lakes be upgraded to separated sewer systems which do not combine stormwater and sewage. In its 14th Biennial Report in 2009, the IJC highlighted the safety risk to human health by exposure to contaminants from CSOs through fish consumption, drinking water and swimming.

To protect human health and reduce exposure to untreated and inadequately treated sewage, the IJC recommends in its new TAP report that Canada and the US determine an accelerated and fixed period of time by which zero discharge of inadequately treated or untreated sewage into the Great Lakes will be virtually achieved. Given the importance of public health and lake recreation to the Great Lakes public and local economies, the IJC recommends that sufficient resources be dedicated to proactively and systematically improve the capacity of city sewer systems to respond to extreme storm events, especially as related to combined sewer overflows, in the areas of planning, zoning and adaptation.

The Canadian and US governments have slowed needed investment on infrastructure since the 1970s and 1980s, due to increasing demands placed on municipal budgets in other areas. The need for increases in funding was highlighted in a recent US Clean Watersheds Needs Survey, which found that over the next 20 years, six of the eight Great Lakes states (Minnesota, Wisconsin, Illinois, Indiana, Michigan and Ohio), will need an estimated US$77.5 billion to upgrade wastewater and stormwater infrastructure, by separating stormwater and sewage with adequate treatment capacity.

Tackling CSOs will require a concerted and calculated effort between local, provincial, state and federal governments. Engaged citizens can voice their concern over CSO releases and the need to increase spending to upgrade aging infrastructure by writing their local, state, provincial or federal governments. Citizens should inform themselves of CSO events in their area and obey signage for beach closures and fish consumption advisories. Finally, you can also have your voice be heard by submitting comments through

Michael Mezzacapo is the 2017-2018 Michigan Sea Grant Fellow at the IJC’s Great Lakes Regional Office in Windsor, Ontario.

Forecasting ‘Dead Zones’ to Help Protect Drinking Water

By Kevin Bunch, IJC

Cleveland, Ohio, depends on water from Lake Erie for its drinking supply, which can be affected by a hypoxic zone
Cleveland, Ohio, depends on water from Lake Erie for its drinking supply, which can be affected by a hypoxic zone. Credit: Rick Harris

A new tool in development should help water treatment plants in communities along Lake Erie prepare for when dead zones reach their shores.

Lake Erie is periodically affected by oxygen-poor hypoxic zones, also known as “dead zones” for how few things can survive in them. These zones form at the bottom layers of water in Erie’s central basin. Aside from being bad for aquatic life, hypoxic zones present a special challenge to water treatment facilities. The hypoxic zones can spread toward shorelines and temporarily impede operations for hours as treatment systems are set up to deal with the specific impacts of those conditions. The US National Oceanic and Atmospheric Administration, working with the Cooperative Institute for Great Lakes Research, hopes to lend a hand to water treatment plants with an experimental early warning system that would provide advance notice of potential hypoxic events.

Oxygen-deficient water often has a lower pH balance and may have higher concentrations of metals like manganese and iron, which can cause discoloration of treated water, according to Craig Stow, aquatic ecosystems modeling researcher at NOAA’s Great Lakes Environmental Research Laboratory. Water treatment plants can account for these water conditions, but operators need to know about those conditions to make the necessary treatment adjustments, and it takes time to retool their systems. Right now, they get alerted only when the hypoxic water has reached the intake.

“Hypoxic water can be treated, but it requires knowing hypoxic water is present to put those treatment adjustments in place,” Stow said. “Since these adjustments are more expensive to do or counter to normal treatment goals, you don’t want to be treating water all the time as if it were hypoxic.”

Hypoxic conditions typically occur in late summer, caused by long periods of high temperatures and stormwater events that wash fertilizer and manure off farms, and sewage from combined stormwater overflows into the lake. The nutrient input stimulates algal growth, and as that algae decomposes the aerobic bacteria feeding off it consumes oxygen, reducing the levels of dissolved oxygen in the water.

Lake Erie isn’t a static body – water is constantly being churned around, and occasionally this brings the hypoxic water from the bottom layers of the central basin near the shore and to the water intake pipes located near cities. By adapting an existing Lake Erie computer modeling framework used for other types of forecasts (like meteorology), Stow believes an effective early warning system can be developed to alert water managers that a hypoxic zone could be heading toward their intakes so that managers can adjust their treatment methods accordingly, possibly up to a few days in advance.

The project got underway in 2016. In the initial stages the warning system involved taking existing models focused on water temperature and other conditions and adding hypoxia to it, but chemical and biological components – like phytoplankton growth and phosphorus inputs – will be included later.

An additional goal of the project is to determine whether adding nutrient and biological components to the model will improve the accuracy of the hypoxia simulations over a purely physical model, according to Stow. A model that includes chemical and biological components may have additional applications, such as forecasting algal blooms, which would be helpful for water managers, anglers and boaters.

Seasonal changes through 2005 show how Lake Erie’s hypoxic (low-oxygen) zone develops in the central basin in July through September
Seasonal changes through 2005 show how Lake Erie’s hypoxic (low-oxygen) zone develops in the central basin in July through September. Credit: NOAA

NOAA researchers also are reaching out to groups with a stake in such a warning system. Water treatment and management agencies, Ohio Sea Grant and the Ohio Environmental Protection Agency are just some of those who could use the early warning system.

“The drinking water plant managers not only benefit from sharing operational information and research, but also by establishing lines of communication between water utilities and researchers that help identify common areas of interest,” Scott Moegling, water quality manager at Cleveland’s Division of Water, wrote in a NOAA blog post. “The end result, researchers providing products that can be immediately used by water utilities, is of obvious interest to the water treatment industry on Lake Erie.”

The current effort is focused on the US side of the lake. Stow said Canadian information isn’t available right now, but there have been discussions with Canadian agencies on collaboration efforts.

Ontario has been working along similar lines on its Lake Erie coastline, however.

Communities along the north shore of Lake Erie contend with the upwelling of hypoxic water, according to Todd Howell, Great Lakes ecologist with Ontario Ministry of the Environment and Climate Change. Fish kills have been reported that were linked to hypoxic water reaching the shoreline, and the ministry has conducted water quality monitoring that has confirmed that hypoxic water is reaching the coastline. Upwelling also can push nutrients like phosphorus from the lake bottom to the surface, giving algal blooms an additional food source in the summer.

Howell said the province has acquired and deployed a real-time sensor system offshore of Port Glasgow, located off the central basin of Lake Erie. The system is designed to detect low-oxygen water and upwelling, and was first deployed in late summer 2016.

“Our intent is to deploy the system annually over the May-to-November period,” Howell said.

The Ontario Great Lakes Intake Program has routinely monitored nutrient, chemical and chlorophyll characteristics and concentrations at water intakes along the north shore since 1976. While this has not been specifically developed to detect hypoxic water, the data it has collected suggests indirectly, through phosphorus detections, that there has been upwelling occurring around some central basin water intakes. A 2015 report prepared by Freshwater Research for the ministry recommends collecting more evidence of hypoxic events along the north shore.

Since receiving funding a year ago from the NOAA Center for Sponsored Coastal Ocean Research – which is studying hypoxic zones in the Gulf of Mexico and other waters – Stow said his team has an early version of their dissolved oxygen model online right now. The researchers are working on predicting hypoxic zones and watching to see how reality matches the model, by using profilers and sensor strings in the lake that measure oxygen and water temperature. Those will be retrieved in the fall to refine the model. Part of the project also includes studying how these hypoxic zones form in the first place.

Stow said the early warning system could be operational within the next few years, at which point it would be run by NOAA’s forecasting unit.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Get Involved: Lead, Lakes and Student Research

By IJC staff

This issue of Great Lakes Connection focuses on the IJC’s draft Triennial Assessment of Progress. We urge you to take the time to peruse the report and add your input, then come back to this post.

OK, thanks. We’ve compiled a few items of possible interest below, from opportunities to help shape drinking water policy in Canada to conducting research on Lake Erie.

Students aboard a University of Toledo research vessel
Students aboard a University of Toledo research vessel. Credit: University of Toledo/YouTube

Lead in Drinking Water – Health Canada is asking for comments on a report related to lead in drinking water. A Federal-Provincial-Territorial Committee on Drinking Water has assessed information on lead with the intent of updating a drinking water guideline. Comments must be received before March 15.

In the US, the Environmental Protection Agency is seeking public comment on a proposed rule to require plumbing manufacturers to put “lead free” markings on pipes and fittings used for drinking water. The deadline is April 17.

Lake Research Student Grants – The Michigan Chapter of the North American Lake Management Society and Michigan Lake and Stream Associations are seeking proposals for a Lake Research Grants Program. Organizers are looking for projects that increase the understanding of lake ecology, strengthen collaborative lake management, build lake partnerships and/or expand citizen involvement in lake management. Proposals are due Feb. 17.

Land-Lake Ecology – The University of Toledo Lake Erie Center is looking for undergraduate applicants for its Summer 2017 Research Experience for Undergraduates program. This is a nine-week (May 30-July 28) paid fellowship funded by the National Science Foundation. For more information, see the program page. The deadline to apply is Feb. 24.

Onward – Please pass this information along to a colleague or friend who might be interested.

Let us know of any items you’d like to see included in future updates (or shared on social media). Send them to Executive Editor Jeff Kart




Safe Drinking Water Requires Several Steps

By Kevin Bunch, IJC

Credit: US EPA
Credit: US EPA

One of the Great Lakes Water Quality Agreement’s objectives is to make sure that the lakes are a source of safe, high-quality drinking water. The safer that source water is, the less money and effort needed by local utilities for treatment. To inform people who consume Great Lakes water, Canada and the US have rules on the books requiring water utilities to report on the quality of the drinking water they provide.

Municipal water systems in Canada and the US are required to make sure water is safe after its been treated, but protecting water at the source is just as important. Some potential contaminants can’t be easily removed at treatment plants, and water treatment is generally an expensive procedure. As a result of active efforts to protect water sources and treat incoming water, however, public utilities in both countries provide safe drinking water except in cases of rare, well-publicized disasters, such as recent lead in Flint, Michigan’s drinking water, or Walkerton, Ontario’s E. coli outbreak in 2000. Part of the International Joint Commission’s task under the Great Lakes Water Quality Agreement is to assess whether those sources of water are being protected. The Commission has found “that drinking water in the basin was very likely to be safe given present treatment measures for presently identified biological, chemical and physical contaminants.”

Under the US Environmental Protection Agency’s Safe Drinking Water Act guidelines, all community water systems across the United States must prepare an annual “consumer confidence report.” If the utility serves more than 10,000 people, the report must be mailed out. Otherwise it can be mailed, posted publicly or made available in a local newspaper. For example, see 2015 reports here on the Eastpointe, Michigan, water system and here on the Rochester, New York, water system.

These reports explain where a system’s drinking water comes from, testing done for contaminants like nitrates, barium, chlorine, copper and lead, and testing results. Not all contaminants are necessarily harmful – some, like sulfates or iron, only impact the taste or appearance of water. But some, like lead, can have major impacts on human health. The EPA sets minimum safe standards for drinking water, though states can adopt stricter standards.

“The information contained in (these) reports can raise consumers’ awareness of where their water comes from, help them understand the process by which safe drinking water is delivered to their homes, and educate them about the importance of preventative measures, such as source water protection, that ensure a safe drinking water supply,” the EPA wrote in the summary of its final approved rule in 1998.

Under the Ontario Safe Drinking Water Act, the Ontario Ministry of Environment requires annual reports – such as these from Toronto – from every drinking water plant that serves more than 100 people. These reports are not necessarily sent to every resident, but are typically found on the city website of the municipality providing the water. Ontario also requires that owners of community drinking water systems test water in the plumbing inside a home or building and in distribution pipes throughout an area to make sure there is no contamination between the water plant and the water coming out of your faucet.

The R.C. Harris Water Treatment Plant is one of several that serve the Toronto area. Credit: r h via Flickr
The R.C. Harris Water Treatment Plant is one of several that serve the Toronto area. Credit: r h via Flickr

Every year, Ontario also releases a Minister’s Annual Report on Drinking Water, which includes a section on provincial efforts to protect drinking water. Topics include climate change, First Nations-specific issues, source water protection and other concerns specific to the Great Lakes. The province also regularly releases the Chief Drinking Water Inspector Annual Report, which focuses on source water protection, the quality of drinking water across the province, and water test results at the point of use (including for substances like lead).

Water and its protection and safety is an issue that unites people in both countries, particularly around a watershed as massive as the Great Lakes. The safeguards in place to protect source waters – and public reporting of testing results – provide important assurances that we can continue to enjoy a cool drink of water.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Protecting Our Sources of Drinking Water: Implementation of Source Protection Plans across Ontario

By Chitra Gowda, Conservation Ontario

Ontario’s 2006 Clean Water Act is part of the province’s multi-barrier approach to ensure clean, safe and sustainable drinking water by protecting sources including lakes, rivers and wells.

A multi-barrier approach to safe drinking water. Credit: Conservation Ontario
A multi-barrier approach to safe drinking water. Credit: Conservation Ontario

Under this legislation, the drinking water source protection program was established with funding from the Ontario government. This resulted in the development of science-based assessment reports and local source protection plans by multi-stakeholder source protection committees, who are supported by conservation authorities, the Severn Sound Environmental Association and the Municipality of Northern Bruce Peninsula. Conservation authorities operate on a watershed basis and bring together stakeholders across different political boundaries to contribute to the health of our rivers, lakes, and groundwater, supporting public health as part of their work in natural resource management.

The science-based local assessment reports identify vulnerable areas mapped around municipal wells and intakes in lakes and rivers, and identify certain activities as threats to municipal drinking water sources in these vulnerable areas.

Information on vulnerable areas is available from the Ontario Ministry of Environment and Climate Change website.

Source protection plan policies either recommend or require that actions be taken to address activities identified as threats. Action tools range from a soft approach, like education and outreach, to a strong approach such as risk management plans or prohibition of an activity.

Ontario has approved all 22 source protection plans, a significant milestone toward improved public health in Ontario.

Implementation of the 22 source protection plans is well underway across the province by various implementing bodies, including municipalities, provincial ministries and conservation authorities. There are many examples of progress in protecting the quality and quantity of sources of municipal drinking water as a result of these plans.

Through new implementation powers under the Clean Water Act, provincially trained and certified risk management officials at municipalities, conservation authorities and other agencies are implementing policies requiring risk management plans and prohibition. Risk management plans include measures to manage activities like hazardous waste chemical storage, fuel storage, manure spreading, fertilizer use, and road salt application in certain vulnerable areas. Monitoring these measures is handled by risk management inspectors.

Risk management officials and landowners working together. Credit: Ausable Bayfield Conservation Authority, Quinte Region Conservation Authority
Risk management officials and landowners working together. Credit: Ausable Bayfield Conservation Authority, Quinte Region Conservation Authority

Municipal official plans and zoning bylaws are being updated across the province to comply with local source protection plans. Municipalities are screening development and building applications for source protection plan policy applicability. Policies may apply to new or expanded development to manage activities like stormwater management pond discharge, storage of hazardous chemicals, and to maintain recharge to groundwater supplies. Some applications are flagged for local risk management officials to review.

Provincial ministries also are screening applications. The Ontario Ministry of the Environment and Climate Change developed procedures for the review and approval of permits to take water, environmental compliance approvals (for waste disposal sites, sewage works or application of untreated hauled sewage to land) and pesticide permits (for land application). The procedures will ensure that these permits and approvals include terms and conditions to protect sources of municipal drinking water.

Road signs that identify drinking water protection zones are being installed across Ontario to increase awareness of protecting valuable sources of drinking water. The installations are through collaboration with the Ontario government,  municipalities, conservation authorities, and others.

A road sign marking a drinking water protection zone. Credit: Quinte Region Conservation Authority
A road sign marking a drinking water protection zone. Credit: Quinte Region Conservation Authority

Septic systems in certain vulnerable areas are subject to mandatory maintenance inspections every five years per the Ontario Building Code. Several of these inspection programs have been initiated across Ontario in the past five years, tied to approval of assessment reports. Information on maintaining your septic system is available from Ontario’s SepticSmart! website. Tips on how to manage road salt in order to lessen damage to the environment and impacts to water sources are available from Conservation Ontario.

Some drinking water supplies in Ontario have known water quality issues, which are monitored and managed in order to ensure safe drinking water. Source protection plans include policies to address activities on the landscape that could contribute to a water quality issue. For example, for a nitrate issue in a municipal well, the policies may require that fertilizers are applied to crops at a specified rate to reduce groundwater contamination.

You also can help protect Ontario’s sources of drinking water. Brochures are available in French and English.

Chitra Gowda is source water protection lead at Conservation Ontario. Additional contributors to this article include Diane Bloomfield (project manager, Halton-Hamilton Source Protection Region), Jenna Allain (project manager, Ausable Bayfield Maitland Valley Source Protection Region), Keith Taylor (project manager, Quinte Region Source Protection Region), Rhonda Bateman (general manager, Sault Ste. Marie Region Conservation Authority), and Tim Cumming (communications specialist, Ausable Bayfield Maitland Valley Source Protection Region).

University of Waterloo Students Investigate Treatment Options for Protecting Drinking Water from Harmful Algal Blooms

By Amy Yang, Howard Tong, Gunjan Desai, Carlos Manzo
University of Waterloo

In June, the governments of Canada and the United States committed to new phosphorus reduction target loads for Lake Erie to control harmful algal blooms and protect the lake as a source of safe drinking water. The challenges of treating water contaminated with high levels of microcystin-LR, a toxin produced by blue-green algae, underscores the need to achieve the targets.

A fourth-year environmental engineering design project from the University of Waterloo examined the implications for one community by investigating how the toxin can be further treated in a drinking water treatment plant. The design team provided the preliminary technical and cost requirements needed to retrofit a medium-sized water treatment plant drawing water from Lake Erie to meet Ontario’s drinking water standard for microcystin-LR.

The fourth-year design group photo after a presentation pitch. From left to right: Carlos Manzo, Gunjan Desai, Howard Tong, Amy Yang. Credit: Shalaba Kalliath
The fourth-year design group photo after a presentation pitch. From left to right: Carlos Manzo, Gunjan Desai, Howard Tong, Amy Yang. Credit: Shalaba Kalliath

Microcystin-LR is a cyanotoxin that can be produced from harmful algal blooms (HABs). It was evaluated because it is regulated by Ontario Drinking Water Standards at 1.5 micrograms per liter (mg/L). As a toxin, it can cause symptoms such as diarrhea and skin irritation. The team took a conservative estimate of incoming toxin concentration of 100 mg/L — comparative to the largest concentrations of microcystin-LR found in 2014 when Toledo was forced to issue a “do not drink” notice to water users. It should be noted that these levels of microcystin-LR have never been found at the intake of the drinking water treatment plant examined in the design project.

Before investigating what technologies would be practical to implement in addition to existing processes at the plant, a base case evaluation was completed. That evaluation determined that existing processes would result in a concentration of about 17 mg/L of microcystin-LR in the plant’s discharge. A number of technologies were investigated through a literature review to determine which treatment method would be most ideal to reduce the remaining concentrations to an acceptable level.

A total of 14 technologies were analyzed, including powdered activated carbon (PAC), granular activated carbon (GAC), micro filtration, potassium permanganate, and nanofiltration and reverse osmosis. These independent technologies also were evaluated in combination with other technologies.

Because of the location of the drinking water treatment plant and existing infrastructure, many of the technologies researched were deemed unfit for practical use.

For example, previous studies have shown biofiltration to be effective in removing microcystin-LR. However, most of those studies were conducted in Australia. The climate of Australian waters compared to southern Ontario waters is vastly different for most of the year.

The project also considered chlorination, which is effective as an oxidant to eliminate microcystin-LR. However, high concentrations of chlorine may cause cell lysis (breaking of the cell), which in turn could release even more toxins into the water that needs to be treated within the drinking water treatment plant.

With such a complicated issue, a number of issues were examined to see which technologies would be most practical for the location studied. These included cost, sustainability, plant compatibility and simplicity.

After considering technical advice, visiting the drinking water treatment plant, laboratory work and evaluating alternatives, a top technology was determined: a combination of potassium permanganate and powdered activated carbon (which is currently being used at the drinking water treatment plant along with other processes).

Potassium permanganate acts as an oxidant, and has been shown in studies to be strong enough to oxidize the extracellular toxin without causing significant damage to the cell (which reduces the likelihood of further releasing toxins into the drinking water supply). Powdered activated carbon is porous and has a high surface area, which would allow the toxins to adsorb onto the surface of the powdered activated carbon.

This top technology would cost CDN$20,000 (purchasing a potassium permanganate injection and storage infrastructure) with an annual chemical cost of about $48,195, equivalent to a daily chemical cost of $132. These cost evaluations were made based on daily treatment (in reality, most HABs occur from July to September).

Other treatment methods that scored high in the evaluation and are considered potential options include use of potassium permanganate, a combination of chlorination and biofiltration, a combination of chlorination and PAC, as well as biofiltration.

These recommendations were specific to the drinking water treatment plant investigated. Therefore, the types of technology and dosages may change depending on the water composition coming through the plant and existing plant infrastructure. Nonetheless, they point to the fact that reducing phosphorus inputs is needed to avoid additional drinking water treatment costs for communities surrounding Lake Erie.

Amy Yang, Howard Tong, Gunjan Desai, Carlos Manzo are recent graduates from the University of Waterloo Environmental Engineering program who conducted the study with the assistance of technical advisers.

Ontario as a Model for Clean Drinking Water

By Raj Bejankiwar and Salma Ahmed, IJC

drinking water david j flickr
Credit: David J

As the largest surface area of freshwater on earth, the Great Lakes have long been a source of drinking water for millions of Canadians and Americans. This dependence on the Great Lakes calls for stringent care to secure the quality of water into and out of the region’s drinking water systems.

However, the sustainability of the Great Lakes is under constant physical, chemical and biological stresses. Most of these stresses are due in part to our collective behavior as a society. As new and emerging challenges present themselves, the public grows skeptical of the quality of drinking water. In wake of water quality incidents like Ontario’s Walkerton tragedy in 2010, the ongoing water crisis in the city of Flint, Michigan, and the Toledo Ohio water crisis of August 2014, the integrity of the Great Lakes water basins as a source of drinking water has never been more important. Legislation, science and governance are critical to restoring and protecting the quality of these binational waters. This includes commitments by the Canadian and US governments to ensure waters of the Great lakes are fishable, drinkable and swimmable as outlined in the Great Lakes Water Quality Agreement.


Incidents in history have served to reaffirm the importance of the condition of drinking water at the source. In May 2000, a large storm event hit Walkerton, Ontario, and washed cattle manure into a town well that leached into the groundwater table. A total of 2,300 residents of Walkerton became ill from drinking the water and seven died from the worst-ever outbreak of E. coli bacteria in the history of Ontario. Justice Dennis R. O’Connor was appointed commissioner of the Walkerton inquiry and made sweeping changes to the safeguarding of Ontario’s drinking water by establishing the Safe Water Drinking Act of 2002. This act features the recognition of source protection as the first barrier of the multi-barrier approach in providing safe drinking water.


A decade and a half later Flint, Michigan, switched the city’s source of drinking water from Lake Huron and the Detroit River to the Flint River. Officials decided against adding an anti-corrosive agent to the water treatment process. This proved to be a mistake, as highly corrosive water from the Flint River caused lead to leach from transportation pipes into the drinking water supply. Elevated levels of lead were found in the blood of the Flint community and residents had to resort to drinking and bathing with bottled water during the transition back to the old water supply in October 2015. A state-commissioned report from Flint-based engineering firm Rowe Professional Services lays out a multi-decade plan that is expected to cost at least $216 million to restore Flint’s water supply infrastructure. More than a year after the contamination was discovered, many Flint residents are still unsure of the safety of their water supply and continue to use bottled water to drink, bath and cook.


In 2014, Toledo, Ohio, issued a “do not drink” warning for three days to about 400,00 water users when a toxic algal bloom arose close to a water intake pipe. The type of algae that the bloom contained produced a toxin called microcystin. Since the incident, governments working to put the Great Lakes Water Quality Agreement into action have made significant strides to cut down the amount of algae-feeding phosphorus that gets into Lake Erie’s tributaries, notably the Maumee River.

The Ontario Approach

Relying on the Great Lakes as a source of drinking water demands that stringent care be taken. Today through development of comprehensive safety mechanisms, drinking water standards are maintained from source to tap. For more than a decade in Ontario, more that 99.9 percent of water quality tests have continued to meet the province’s strict health-based water quality standards. This is due in part to protection at the source, maintenance throughout the transportation process, diligence in the treatment of water, and security in making it available to the public.

Water for Ontario residents is drawn mostly from Lake Ontario and Lake Erie. There is a multi-barrier approach to protecting the source water, including designated intake protection zones, well head protection zones and drinking water intake protection zones — all with protection plans developed in part by local committees.

 Intake protections zones for the Windsor drinking water treatment plant. Credit: Essex Region Drinking Water Source Protection Authority

Intake protections zones for the Windsor drinking water treatment plant. Credit: Essex Region Drinking Water Source Protection Authority

Water is treated on a multi-tier basis. It’s tested for parameters such as microbiological, chemical and nutrient concentrations, trace metals and pH (acidity). Each water treatment plant in the province is equipped with primary, secondary, and tertiary courses of treatment to address these parameters.

This method of treatment reinforces the notion of how policy and the scientific process ensure that the system of treatment supports the larger structure of how water is handled nationwide. However, policy surrounding water quality is one only side of the coin. Taking action on a local level through engagement in the community is another.

Written into Ontario’s Clean Water Act was the opportunity for community and public consultation on water quality. Through forming a Source Water Protection Advisory Committee, local communities can identify potential risks or threats to their water and plan and implement actions to reduce or eliminate these threats.

Source Protection Authorities across Ontario sought public comments on draft source protection plans in 2011. During 2012, comments were taken into consideration and plans were finalized and implemented from 2013 to 2015. These source protection plans will be updated depending on individual risk assessments carried out by source protection authorities, who are mandated to seek public comments during that time.

A holistic approach to water quality management can prevent incidents like Walkerton, Toledo, and Flint from happening again. Getting involved in the discussion surrounding water quality in your community can help to keep waters fishable, drinkable and swimmable.

Swimming at Burleigh Falls in Ontario
Swimming at Burleigh Falls in Ontario. Credit: Martin Cathrae

Raj Bejankiwar is a physical scientist and deputy director at the IJC’s Great Lakes Regional Office in Windsor, Ontario.

Salma Ahmed is a student intern, also at the Windsor office.