Abstracts

various scales within the moraine complex. Historically studies use environmental age tracers
to examine flow and mixing in aquifers (Solomon et al. 1995), though on the scale of
the Oak Ridges Moraine there have been few studies that have attempted to integrate such
a diverse set of environmental isotopic and geochemical tracers to constrain groundwater
pathways and ages.
Stable isotopic results from this study have defined three distinct groundwater types;
post-glacially recharged waters with no tritium and depleted oxygen isotopic signatures,
a minority of samples are recharged from waters having undergone evaporative processes
and represent monitoring wells with a direct connection to surface waters and finally the
majority of samples have measurable tritium (up to 183.5 TU), suggesting a large component
of recently recharged meteoric water. As with Fritz et al 1987 these samples show
isotopic change with geographical distribution across the study region. Mixing between
these groundwater groups is prevalent as a result of usage. Rare gas data combined with
stable isotopes and environmental tracers will help to understand the different flow systems
within the ORM, mean residence time, temperature at the time of recharge and mixing.
185 - Groundwater Resources and Use in York Region – Lessons
Learned from Source Water Protection
Donald Ford
Toronto and Region Conservation, Downsview, Ontario, Canada
Tom Bradley
Regional Municipality of York, Newmarket, Ontario, Canada
The Clean Water Act, 2006 was created to ensure the protection of drinking water in Ontario
through the development of watershed-based source protection plans. These plans
are the first step in a multi-barrier approach to ensure safe drinking water for the residents
of Ontario. The plans are based on technical assessments of the many different sources
of drinking water and the potential quality and quantity threats to those sources. Part of
these assessments is a comprehensive analysis of groundwater and surface water resources
available as compared to the ecological and human uses of those resources.
Water budgets show each part of a watershed’s hydrologic system, and use data to describe
how much water enters a watershed, how much water is stored within it, and how
much water leaves it through both natural and human processes. This information helps
determine how much water is available for human use while ensuring sufficient water
for key natural heritage features and functions. Groundwater forms a critical part of any
water budget. Recharge in headwater areas or even outside of the surface catchment of a
watershed, may support critical ecological functions and human abstraction in the middle
and lower reaches.
The Regional Municipality of York (York) and the Toronto and Region Conservation
Authority (TRCA) have been working together with respect to water budget modeling
since 2005. These efforts began with the development of a conceptual water budget for
the entire TRCA jurisdiction and culminated in an integrated surface water/groundwater
IAH-CNC 2015 WATERLOO CONFERENCE
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