Field Observations and Hydrodynamic and Water Quality Modelling of Trout Lake, Ontario

Session: 47. - Physical Processes in Lakes

Bogdan Hlevca, Ministry of Environment and Climate Change, [email protected]

Abstract

Field studies conducted in the summer of 2017 investigated the hydrodynamics, and fate and transport of Perfluorooctanesulfonic acid (PFOS) in Trout Lake, which is the drinking water supply for the City of North Bay. Runoff, from a contaminated site inside the catchment basin, determines PFOS concentrations in the range of 120-250 ng/l at the mouth of a tributary. The levels of individual Perfluoroalkylated substances (PFAS) detected in Lee’s Creek are not above Health Canada’s guideline values (PFOS 600 ng/L). However, in USA in order to protect the population from a lifetime of exposure to PFOS from drinking water, EPA has established the health advisory levels at 70 ng/l. Therefore, given that the municipal drinking water intake is within 800 m from the creek’s mouth, and the properties of the contaminant (42 years half-time, nonvolatile and limited hydrophobicity), there are concerns about the effect on the health of the city population using municipal water and the private intakes. A three-dimensional integrated hydrodynamic and ecological model is used to show that the concentration in the lake increases very slowly in time, especially during the wet season, with considerable percentage of the contaminant being drawn by the municipal intake.

1. Keyword
hydrodynamic model

2. Keyword
water quality

3. Keyword
environmental contaminants

4. Additional Keyword
transport model

5. Additional Keyword
ecosystem health