Application and Assessment of Tools to Determine the Level of Concern of Emerging Contaminants from Municipal Wastewater Effluents on Aquatic Biota in Grand River

Principal Investigator - Mark Servos, Professor, University of Waterloo, 2013 - 2015

Application and Assessment of Tools to Determine the Level of Concern of Emerging Contaminants from Municipal Wastewater Effluents on Aquatic Biota in Grand River


Treated municipal wastewater has the potential to contain harmful substances called Emerging Substances of Concern (ESOC’s) which have been known to have disruptive impacts on the endocrine system of aquatic organisms. The endocrine system is a collection of glands that produce hormones to regulate metabolism, growth, tissue and sexual function, and development and reproduction, among other things. Disruptions to the endocrine system could result in impacts such as the feminization of male fish or the masculinisation of female fish, as well as embryonic deformities in fish.

Tools have been developed to identify indicators of endocrine impacts on organisms, but these tools need to be assessed for effectiveness. There is a need to understand the effects of wastewater ESOC’s at multiple levels of the food web, including prey, predators and massive predators, both on a molecular scale and on the population as a whole.

The project team, led by Canadian Research Chair Dr. Mark Servos, will focus on testing a suite of tools at three municipal wastewater impacted sites in the Grand River watershed in Southern Ontario.


This project will evaluate the efficacy of a suite of tools (toolbox) that is designed to assess the endocrine related responses of fish species when exposed to wastewater effluent.  This suite of tools will be tested through field work at three sites within the Grand River watershed of southern Ontario.  These sites are located at the outflow of treated wastewater, and represent high, moderate, and low effluent concerns.  Additionally, each site will have a reference site to compare outflow and non-outflow conditions.  These tools look at several exposure and effect indicators, across several levels of biological organization (i.e. molecular to population).

Collected fish will be measured, weighed, and have their overall condition assessed.  Sex ratio, spawning, fertilization and hatching success will be measured at each site.  The process by which fish generate steroids in the body can be affected by effluent; therefore steroidogenesis studies will be executed.  A suite of molecular markers will be used to improve assessment of biological impacts of municipal wastewater plant effluents.  Finally, stable isotopes are used in this study to measure the presence of effluent in fish tissues and the movement of fish.  Water samples will be taken to measure the presence and concentration of estrogen effluent.  “Indicator compounds” will be used in this study to measure the presence of ESOC in effluent.

The results of this assessment will be synthesized into a series of recommendations in regards to the future application of these tools.


Anticipated outputs include:

  • Host Grand River Watershed Forum to highlight project findings and discuss with partners
  • Hold mini-workshops with partners and plant operators
  • Produce end-user report – predicted for 2015
  • Participate in conferences, workshops, and peer reviewed publications to highlight findings


Anticipated Outcomes Include:

  • Informing and supporting decision makers and practitioners regarding the risks that various wastewater treatment options pose on aquatic ecosystems.
  • Potential changes in practice related to the use of the suite of tools.

Research Team

  • Mark Servos, Professor, University of Waterloo
  • Glen van Der Kraak, Professor, University of Guelph
  • Debra MacLachy, Professor, Wilfrid Laurier University
  • Chris Martyniuk, Professor, University of New Brunswick
  • Chris Metcalfe, Professor, Trent University
  • Mark McMaster, Study Leader, Aquatic Toxicology, Endocrine Disruptors in Wild Fish Populations, Environment Canada


  • Region of Waterloo,
  • City of Guelph,
  • Grand River Conservation Authority,
  • Ontario Ministry of the Environment