Jenny Webster-Brown Director Waterways Centre for Freshwater Management

1. Groundwater Quality
Introduction and Overview
Jenny Webster-Brown

2. UNESCO 2000

3. Natural Resources Canada. http://geoscape.nrcan.gc.ca/h2o/okanagan

4. Well 1
Well 2
Unsaturated zone
River
Unconfined aquifer
Confined aquifer

5. River
Unconfined aquifer
Confined aquifer

6. Groundwater Quality
Function of:
• Host rock composition (high water:rock ratio)
• Depth and age
• Composition of recharge & infiltration from unsaturated zone1
• “Mobility” of particular chemicals2
1. Problem contaminants include:
– Soluble ions and metals (e.g., nitrate,
boron, zinc and arsenic in absence of
2. Depends on ability to adsorb onto
oxygen)
mineral surfaces, which retards access
to, and movement in, groundwater
– Microorganisms from sewage
Contaminants with more limited mobility
– Soluble organic substances
include:
– lead
– phosphate
– arsenic in presence of oxygen

7. Emergence of water quality problems related to human activity
1850 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990