A case study of a chemical spill: polychlorinated biphenyls (PCBs) 2. hydrogeological conditions and contaminant migration

Journal Article · Tue Jun 01 04:00:00 EDT 1982 · Water Resour. Res.; (United States)

DOI:https://doi.org/10.1029/WR018i003p00535· OSTI ID:6728387

Schwartz, F W ^[1]; Cherry, J A; Roberts, J R

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1. Univ. of Alberta, Edmonton, Canada

The purpose of the second paper in this pair is to describe the hydrogeology and to account for the observed patterns of PCB contamination of the Federal Pioneer site in Regina, Canada. Six major hydrostratigraphic units were identified from detailed test drilling and sampling. From the surface downward these are a thin surface fill, the Regina clay, the Condie silt, the till zone, the interglacial silt, and the Regina aquifer system. This latter unit is an important source of potable groundwater. At present the nearest wells are hundreds of meters from the site. The permanent water table is situated below the Condie silt in sandy glacial till. An active perched groundwater system has developed within the thin fill layer beneath the floor of the plant. The extensive lateral flow of ground-water in this zone has contributed significantly to the spreading of PCBs to at the site. The PCBs have also moved downward through fractures in the Regina clay and in the upper part of the Condie silt. It can be expected that capillary forces will halt the downward movement of Inerteen 70-30 as fractures narrow or stop. However, the possible existence of fractures connecting the contaminated zone to the Regina aquifer system or the potential for transport as a dissolved phase in the groundwaters may permit PCBs migrate downward to the aquifer or to flow laterally off-site. The most significant hazard represented by the spill is the potential for contamination of future water supply wells that may be placed near the site or aquifer contamination that could result if future drilling provides pathways for contaminants through poorly sealed wells or test holes.

• OSTI ID: 6728387
• Journal Information: Water Resour. Res.; (United States), Journal Name: Water Resour. Res.; (United States) Vol. 18:3; ISSN WRERA
• Country of Publication: United States
• Language: English

Related Subjects

520200* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AQUIFERS
AROMATICS
CANADA
CHEMICAL SPILLS
CONTAMINATION
DRILLING
ENVIRONMENTAL TRANSPORT
FAILURES
FRACTURES
GROUND WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROLOGY
MASS TRANSFER
NORTH AMERICA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
POLYCYCLIC AROMATIC HYDROCARBONS
SASKATCHEWAN
WATER
WATER TABLES
WELL DRILLING