Leading the Way in Preventing Wet Weather Pollution

In 2005, Dr. Jiri Marsalek was presented with the Environment Canada Citation of Excellence for his 30 years of work on wet weather pollution science and urban water management. He continues to work in Canada and abroad to find better ways to manage urban stormwater so that it does not inundate urban areas or pollute nearby streams and lakes. 

What is wet weather pollution?

City dwellers may assume the water that runs off roofs, sidewalks, streets and parking lots and flows down the drain is treated before spilling into lakes and rivers. However, this isn’t always true. Such runoff (also called stormwater) is conveyed by two types of sewer systems to the receiving waters. In separate systems, stormwater is carried by storm sewers and either discharged directly into receiving waters, or partly reduced in volume and treated at various stormwater management facilities (e.g., ponds). In the older parts of Canadian cities, stormwater may be discharged into combined sewers, where it mixes with municipal wastewater. During heavy or prolonged rainfall, when combined sewer systems do not have the capacity to handle such flows, excessive flows are discharged as “combined sewer overflows” (CSOs) into nearby receiving waters. Thus, the term wet-weather pollution refers to the pollution conveyed by discharges of stormwater and CSOs.

Both types of discharges contain large loads of solids and fecal bacteria, and can contain harmful chemicals that will contaminate aquatic ecosystems and affect our drinking water sources. Municipal governments and urban water managers need information, tools and technologies to prevent or minimize this kind of contamination. Jiri Marsalek has been working with colleagues within Environment Canada and in external organizations to develop such tools, often leading projects and initiatives.

During the past 5-8 years, he has worked with the City of Toronto to improve water quality conditions of Toronto’s waterfront and watersheds. As an expert, he advises on the Toronto Wet-Weather Flow Master Plan, which represents the largest planning initiative in the country with an investment of $1billion from the City over the course of the next 25 years. The ultimate goal is that Toronto be de-listed as an Area of Concern in the Great Lakes Basin. On the technology side, one of Dr. Marsalek’s main contributions to the initiative has been development of a polymer-aided high-rate treatment system for combined sewer overflows. The treatment facility is scheduled to be constructed and in operation by 2011, with the intent to minimize negative impacts of CSOs on the Don River and Toronto’s Waterfront Area of Concern.

And this is not the first time that Dr. Marsalek has played a key role in a large-scale water management initiative. In the mid 1970s, under the Canada-Ontario Agreement on Great Lakes Water Quality, he led efforts to upgrade the urban drainage design practice. By demonstrating the performance of the U.S. EPA Storm Water Management Model in research studies and running training courses, he made it possible to move from the former practice of using an outdated empirical formula to a new practice using advanced computer modelling. In the early 1980s, he was involved in a joint project with the Ontario Transportation Ministry to design new road and bridge deck drainage systems. His designs made it possible to remove water from the road surface more efficiently. On implementation, the changes were said to save $30,000 per kilometre on a four-lane highway, even more in today’s dollars. In the 1990s, he worked with many university colleagues on advancing the understanding of various best practices for managing urban stormwater and its pollution.  

Over the years, Jiri Marsalek has worked extensively with the Great Lakes Sustainability Fund, the Ontario Ministry of the Environment (MOE), and various consulting and municipal engineers on wet-weather pollution management. These collaborations have produced tools such as a manual on control and treatment of CSOs (CSO Treatment Technologies – a Comprehensive Design and Resource Manual, published in 2004), as well as many contributions to stormwater management manuals. Currently, he is at work on an MOE task force addressing Stormwater Management in Changing Climate.

International achievements

Dr. Marsalek has been highly involved in urban hydrology on the international level, co-authoring a UNESCO manual of urban drainage, teaching several courses on this topic in developing countries, and most recently serving as leader of the urban water management project of UNESCO’s International Hydrological Programme. This last project led to publication of a book on Urban Water Cycle Processes and Interaction (Taylor & Francis Publishers, 2008). Other contributions to the international community have included roles as secretary and chair of the International Association for Hydraulic Engineering and Research (IAHR) and the International Water Association (IWA) Committee on Urban Drainage, a group of more than 700 urban drainage professionals striving to research and promote advanced urban drainage. He has also organized and led ten NATO research workshops on urban water and flood risk management. He continues to work with international teams developing innovative techniques for dealing with environmental problems that affect cities across Canada and around the world.

Fast facts

Jiri Marsalek is the recipient of two honorary doctorates: the first from the University of Technology, Lulea, Sweden, for contributions to scientific and engineering advances in urban water management (2006), and the second from Aalborg University in Denmark for contributions to scientific and engineering advances in controlling impacts of urbanization on aquatic ecosystems (2008).

He is author of more than 350 publications, including 115 refereed journal papers; co-author or editor of 19 books or special journal issues on urban water management; and co-author of 28 book chapters.

Links

Road Drainage: Securing Public Safety, Economic Competitiveness and Enhancing Environmental Sustainability (Research into Action to Benefit Canadians)

International Association for Hydraulic Engineering and Research (IAHR) and International Water Association (IWA) Joint Committee on Urban Drainage (activities of the Committee, including the annual newsletter)