Improving municipal wastewater effects monitoring, developing next gen of science communicators

Posted by CRI Programs   |   March 22, 2017

Today, World Water Day (March 22) with its theme of “wastewater” is an opportunity to profile a prominent research program by a Canadian Rivers Institute (CRI) Science Director, Dr. Mark Servos, who is investigating municipal wastewater effluent impacts on the Grand River watershed. His research is demonstrating how the science used in the development of an environmental effects monitoring framework for municipal wastewater can address the water quality of receiving waters across Canada.
Dr. Servos is a Canadian leader in water quality research with a focus on the treatment, exposure, fate and effects of organic contaminants in the environment. His research is critical to addressing a serious national water issue: municipal wastewater is still the largest contributor to point-source pollution into Canadian waters[1].
“We have municipal wastewater treatment plants that are still operating with very poor treatment and pollutants are ending up in the rivers and degrading ecosystems. We need to improve how we do the treatment and need to improve the quality of the effluent that’s being discharged,” says Dr. Mark Servos, Tier I Canada Research Chair in water quality protection and is a professor of biology at the University of Waterloo (UW).
Dr. Servos and his team have been studying the Grand River watershed in southern Ontario for more than a decade, supporting the development of the monitoring frameworks for municipal wastewater to assess the effectiveness of new national secondary treatment standards.

In 2012 new Wastewater Systems Effluent Regulations were introduced under the Fisheries Act, establishing secondary treatment as a national standard for municipal wastewater treatment plants. It is important to note that other developed countries have legislated tertiary treatments for municipal wastewater, which applies a combination of biological nutrient, nitrogen and phosphorous removal.

At the same time, and somewhat serendipitously, the research has provided the baseline data for what Dr. Servos calls a “unique opportunity to follow the changes in the river response to a very large wastewater treatment plant infrastructure upgrade.”  The Municipality of Waterloo is currently in the midst of an $800 million initiative to upgrade their wastewater treatment plants to meet the new secondary treatment standard, and Dr. Servos has been able to document how the upgrades are impacting the river.

The rainbow darter, a small-bodied fish that is common to the riffle areas of the Grand River, were feminizing due to their exposure to chemicals that were released in the effluent from the wastewater treatment plants. The darters had changes in their physiology and changes in their histology. “We were collecting male darters who were developing eggs in their testes; this amount of intersex was some of the most severe in the world,” says Dr. Servos.

After some of the upgrade work was completed at one of the wastewater treatment plants, Dr. Servos’ research team documented a significant drop in the number of feminized male fish, from 100% showing feminization characteristics down to 29%. This sharp decline was not observed at a neighbouring wastewater treatment plant that has not undergone upgrades.


Students, studying under Dr. Mark Servos at the University of Waterloo, sample the Grand River while investigating the impacts of municipal wastewater on the rainbow darter before and after upgrades at the Kitchener wastewater treatment plants (top left).
Photo Credits for this story: University of Waterloo, Region of Waterloo

“The Grand River has experienced large algal blooms and people canoe and fish in the river, so it was important for the municipality that river health be addressed,” says Dr. Servos.  “The results from our research helps to strengthen the argument that these upgrades are important and worth the significant municipal financial investment.”
This study focused on one treatment plant, but the research can be scaled-up and contribute to refining the guidelines and implementation of monitoring programs for municipal wastewater management across the country. Approximately 900 (25%) municipal wastewater treatment plants across Canada must be upgraded to meet the new secondary treatment standard.
Endocrine disruptors, such as estrogen, may not have been a driving force behind the treatment plant upgrades but the research has been able to show the secondary benefits to the reproduction of fish. 
“Our research showed that wastewater treatment to meet the new secondary treatment standard, which targets organic materials and increased oxygen levels in the river, also led to the removal of a whole bunch of other chemicals, like estrogen that caused the intersex and feminization in the fish, and improved the local environment,” explains Dr. Servos. “We are developing the science that underpins the monitoring efforts needed at the provincial and municipal levels, says Servos.  “We’re not necessarily developing new tools for wastewater treatment, but we are using research-based science to try to validate the tools we do have.”
The decade-long study has been a multi-jurisdictional collaboration with diverse government partners at the municipal, provincial and federal levels, including the City of Guelph, Regional Municipality of Waterloo, Grand River Conservation Authority, Ontario Ministry of Environment and Climate Change, and Environment and Climate Change Canada.

Dr. Servos’ research is also an excellent example of the CRI network collaboration, having worked with a number of Science Directors, representing a diversity of disciplines on this project, including Drs. Karen Kidd (UNB; tracing contaminants in aquatic environments), Deborah MacLatchy (Laurier; ecotoxicology and comparative endocrinology), Chris Martyniuk (University of Florida; molecular responses to endocrine disrupting chemicals), Kelly Munkittrick (formerly UNB; molecular and mechanistic identification of markers of exposure and molecular pathways of effects), and Adam Yates (Western University; correlative and mechanistic linkages between human activities and ecosystem condition).


The large scope of the Grand River project has allowed Dr. Servos to train 16 graduate students and offer many opportunities for student work terms and technicians.
Another one of Dr. Servos’ philosophies when mentoring his students is to emphasize communication, both written and oral. “Effective writing in particular is very difficult but I feel strongly that it is an important aspect of their professional development,” says Dr. Servos.  “Students learn best from each other so I help to create structured environments where they can learn to write and be critical of each other in positive ways.” Dr. Servos provides multiple writing retreats for his students each year. In the past 5 years, his students have contributed to more than 20 peer-reviewed publications on wastewater.
Dr. Servos also strongly encourages his students to become involved in local outreach organizations and to give presentations to community groups and youth.  “Every time you can practice communication, it makes you a bit better.”
The applicability of Dr. Servos’ research, like much of the science done by CRI scientists, is something that he believes is important to his students. “Students are attracted to applying innovative approaches and the best science and instruments to a real issue that is significant for society.”

[1] Environment and Climate Change Canada. 2014. Wastewater Pollution. Accessed at:

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