HYDROGEOLOGICAL CHARACTERIZATION OF A LEGACY WASTE STORAGE SITE AND THE CHALLENGE OF COMMUNICATING UNCERTAINTY

Analytical groundwater and contaminant transport models rely on estimates of hydrogeological parameters that can range from two to three orders of magnitude. The effect parameter variability has on the results of groundwater and contaminant transport modelling was assessed for a legacy nuclear waste storage site in southern Ontario. Site specific hydrogeological parameters were estimated from groundwater measurements collected and hydraulic response testing completed at the Site. A 2D groundwater flow and contaminant transport model was developed and three hundred and seventy-five scenarios were modelled by manipulating hydraulic conductivity, dispersivity, and recharge estimates. The results indicate hydraulic conductivity, dispersivity, and recharge all effect contaminant breakthrough times and under/overestimate breakthrough by up to 50 years. The results of the sensitivity analysis exemplify and confirm that models are only ever tools to test potential outcomes and are limited in their ability to predict future scenarios. The model developed for the Site offers one line of evidence that advective transport of contaminants below waste storage area would be slow, but the model ignores the stratigraphic heterogeneity and geochemical processes that would influence the rate and distance contaminants travel. The inherent uncertainty of modelling results prompted research into how people interpret and respond to scientific uncertainty. There is a need for the ongoing research into the communication of scientific estimations and depoliticizing scientific results. Questions into how trust effects public buy-in and how to educate without overwhelming the public remain unanswered. Further research into how to effectively communicate scientific results and the inherent uncertainty is needed.

Name thesis:degree_name

Master of Science (M.Sc.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Civil Engineering

Grantor

University of Saskatchewan

Year dc:date.issued

2020

Author dc:creator

• Steele, Colleen

Committee members dc:contributor.committeemember

• Barbour, Lee
• Lindsay, Matt
• Elwood, David
• Patrick, Robert

• Hydrogeology
• Uncertainty

Handle dc:identifier.uri

https://hdl.handle.net/10388/12967

OAI identifier oai:identifier

oai:harvest.usask.ca:10388/12967