Comment on the hydrogeochemical information in IPD ref.#88774 report

In this document there is insufficient hydrogeochemical data from deep borehole sampling to support the conclusion that groundwater in the deep zone, ie. below 600 metres, is stagnant and that advective groundwater flow in this zone is insignificant. Since the geosphere is the major long term barrier to the potential long term migration of contaminants from the repository to the biosphere this is a major ommission. In recent decades a large hydrogeochemical data base for deep groundwaters on the Canadian Precambrian Shield has been generated from AECL research areas and deep minewater sampling programs much of which has been published in scientific journals. The proponent should compare the Revell Lake results to these data. The one figure data that has been provided (figure 14.5) shows that chloride concentrations at depth are much lower than expected when compared to other sites. This suggests that either mixing with shallow meteoric waters is occurring or the deep samples are contaminated with drill water. Unfortunately, there is no data presented in this document to resolve the issue.