Keith White, P.G., C.P.G. (Arcadis, Inc.) will present:
“Winning with Karst: Effectively Managing Contaminated Karst Aquifers”
In terms of groundwater (and contaminant) movement and remediation, karst aquifers are in a league of their own. Groundwater flow in these systems does not follow Darcy’s Law, the fundamental equation that describes the relatively slow movement of fluid through porous media. Furthermore, data from monitoring wells alone cannot definitively characterize groundwater flow directions and rates; nor can they adequately delineate the extent of groundwater contamination. In addition, at the typical site scale, groundwater flow directions and rates cannot be reasonably predicted using computer models. Worse yet, computer models that can reliably simulate contaminant transport in karst aquifers do not even exist. Indeed, compared to other geologic settings, the science of remediating karst aquifers is immature.
Despite these challenges, contaminant problems in karst aquifers are tractable — that is, contaminated karst sites can be properly understood and managed, and remedial objectives that protect human health and the environment can be achieved. There are situations where, despite the immature nature of karst remediation, active remediation is warranted and becomes an integral element in a site closure strategy. There are also situations where remediation is not practicable, but where the risks posed can be properly managed, allowing for no active remediation or even closure.
This presentation will provide an overview of:
Case histories will be presented where karst sites have been successfully remediated or properly managed. The case histories will highlight several approaches and tools that were used to transition sites into long-term O&M (operation and maintenance) or even to closure.