Bedrock geology for the study area is mapped as
Point Edward Formation of the Canso Group. Bedrock of the Point
Edward Formation typically consists of red and minor grey-green
variably calcareous siltstone and sandstone and limestone (Geological
Map of the Sydney Basin, Cape Breton Island, Nova Scotia, Nova Scotia
Department of Mines and Energy, 1986).
Surficial geology for the study area is mapped as being underlain
with sandy glacial till over bedrock (Surficial Geology of Cape
Breton Island, Nova Scotia, Geological Survey of Canada, 1988).
Based on recent environmental investigations in the vicinity of
the site, slag and fill deposits overly areas of Sydney Harbour
and Muggah Creek. Much of the southern end of the Steel Plant facility,
between the Victoria Road overpass and Muggah Creek, also consists
of fill. At various location, the fill is reported to contain iron
and steel debris, clinker, ash, coal, brick, general refuse, wood
and miscellaneous construction debris.
The fill and slag material is described as being loose to compact
and relatively porous. Estimated and known thickness of the fill
and slag material are as deep as 22 meters and the bottom of the
slag material has been measured four to six meters below sea level
in the High Dump area (NDA/JWA, 1990 & CBCL/CRA, 1999). In most
site areas, fill is likely less than four metres in depth.
A regional study of hydrogeologic conditions in the Sydney Coalfield
area was completed in 1986 (Baechler, 1986). Data contained in the
study can be used to provide relative hydrogeological and hydraulic
conductivity of the main hydrogeological units located in the study
area. Local surficial groundwater movement and flow at the site
is likely controlled by underground utilities, building foundations,
fill and other man-made structures. Overall groundwater flow is
expected to follow topography and move in a southwest direction.
No groundwater spring or seeps have been identified on the site.
A small pond located in the slag reclamation area in the northwest
corner of the site contains standing water that reportedly fluctuates
with the tidal cycle.(pers. comm., D. Hemmings). The ground surface
around the pond is located and the pond itself is located approximately
250 metres from the shore of Muggah Creek. This information indicates
that the slag fill may be highly permeable, and the water table
within the fill is hydraulically connected to Sydney Harbour.