Highlights of OGS-GSC collaboration on regional groundwater studies: 2016-2017

Abstract

The Ontario Geological Survey (OGS) and Geological Survey of Canada (GSC) groundwater collaboration in Southern Ontario is currently half-way through a five year project cycle ending March 31st 2019. Following earlier updates on work completed this update will be provided under five principal themes. 1. Framework for Sustainable Groundwater Use: The 3D bedrock modelling activity has developed a 57 layer formation working model. This model is being used to guide QA/QC throughout the stratigraphy. Database enhancements are focussed on shallow formation of significance to potable water. A wrap-up document to the November 24th 2015 workshop on a Groundwater Framework was released as a GSC publication. The surficial modelling work is continuing on data capture and development of an authoritative stratigraphic reference framework and online access via the Groundwater Information Network (GIN). 2. Supporting Great Lakes Water Accords: Work has advanced on development of a conceptual framework for evaluating groundwater - surface water interactions and impacts on the quality and quantity of water and ecosystems. This aligns well with issues identified in Annex 8 of the Great Lakes Water Quality Agreement. 3. Methods Development for Regional Groundwater Studies: Methods are being advanced through analysis of seismic reflection, downhole geophysics, geochemistry data and infrared survey data. Passive seismic data was collected in the Wasaga Beach area in the vicinity of OGS boreholes and OGS-GSC seismic data. The objective is to verify the utility of this technique to mapping depth to bedrock surface. The value of collecting down-hole seismic profiles using the mini-vibe was investigated and demonstrated to provide significantly improved results. Regional methods for soil moisture studies using Radarsat II and SMOS are ongoing. Data were captured along 20 km of Lake Simcoe shoreline by an infrared airborne survey to investigate groundwater - surface water interaction and to coordinate with a lake based radon survey. 4. Case Studies: Data collection has been completed in a number of areas. Seismic reflection data were collected in Simcoe central and Niagara area complimented by borehole geophysics. pXRF analysis of continuous core to develop a subsurface chemostratigraphic framework has been expanded to include Simcoe County and Waterloo. A geostatistical approach was applied within the Innisfil Creek subwatershed to determine the uncertainty of 18 hydrostratigraphic units. Characterization of Newmarket Till cementation was initiated and preliminary results are available on carbonate cementation in the matrix. Contract work was initiated on consolidation of information on municipal well information within Source Water Protection documents. Additionally work is ongoing on the hydrostratigraphic classification of wells within the PGWMN. 5. Science and Technology Exchange: Manuscript submissions are in progress for a special issue of Canadian Journal of Earth Sciences with ten manuscripts in various states of review. It is hoped that a 2017 publication remains feasible. Project results are available via OGS - GSC publication streams, conference proceedings, and journal publications. An overview document on the project was published in the Ontario Geological Survey Report of Activities for 2016.