The Aquatic Ecotoxicology Microcosm Facility is located at the University of Guelph and consists of thirty PVC-lined round tanks (microcosms) that are designed to replicate freshwater pond ecosystems. The microcosms were constructed in 1995 and has been in continuous use since that time. The microcosms have a water depth of 1 m, a diameter of 3.9 m, and a capacity of approximately 12,000 L of water and are open to the elements e.g., rain, light, temperature.

Each microcosm is a stable independent model ecosystem capable of supporting multiple trophic levels under natural conditions.   They are supplied with source water from a large permanent on-site well-fed reservoir.  It is from this pond that natural zooplankton, phytoplankton and other invertebrate communities in the microcosms are established.  Sediments can be introduced, providing benthic habitat for influent and aerially colonizing invertebrates, and the development of naturally occurring and introduced aquatic plant communities.  Small fish can be introduced if desired, typically in enclosures, and growth, development and reproduction monitored. Concurrent studies can be conducted throughout the year, facilitating seasonal assessments.  Once a study is complete, a new experiment can be readied within a few weeks.

Current and previous research has examined the ecological impacts and chemical fate of pesticides, PAHs, fluorinated compounds, and veterinary and human pharmaceuticals.