comprehensive site investigation and remediation objectives report

The Will Silty Clay Loam is a poorly drained soil with moderate permeability derived on outwash
plains and stream terraces from loess and loamy glacialfluvial deposits over sand and gravel
glaciofluvial deposits. Groundwater can be 1-2 feet bgs from January through May. The
Dunham Silty Clay Loam Soil Series is a poorly drained soil with moderate permeability derived
on outwash plains and stream terraces from loess silt over sand and gravel glaciofluvial
deposits. Groundwater can be 1-2 feet bgs from January through May.
2.5.2 REGIONAL HYDROGEOLOGY
Aquifers within this region can be broken down into four categories, which are listed below
(Burch et al, 2002).
(i)
(ii)
(iii)
(iv)
Sand and gravel deposits of the glacial drift,
Shallow dolomite formations, mainly of Silurian age
Deep sandstone and dolomite formations of Cambrian-Ordovician age, and
Deep sandstone aquifer (Mt. Simon)
The main aquifers in the region are glacial drift aquifers and bedrock aquifers. The following
bedrock aquifers exist in the region: Racine Dolomite, Galena-Platteville, Saint Peter
Sandstone of Ordovician Age, and Ironton-Galesville and Elmhurst-Mount Simon of Cambrian
age. Several public water supply wells for the City of Romeoville are screened in the
Silurian/Ordovician/Cambrian bedrock (see Section 2.55 and Appendix B).
The glacial drift aquifers in this region are limited to small glacial outwash/advance sand and
gravel seams in between till units. These aquifers are generally low yielding, thin and noncontinuous.
The significant drift aquifer lies within the thick deposits of glacial outwash of the
Henry formation. This aquifer exists in many of the major river valleys of the region and is
generally encountered less than 20 feet from the ground surface.
The uppermost bedrock aquifer system in the region is located in the Racine Dolomite. The
porosity and permeability of the Racine Formation is the result of fractures and dissolution
cavities. Yields in fracture zones can be greater than 1000 gallons per minute.
The main aquifer below the Racine formation is the Galena-Platteville aquifer. The Galena-
Platteville aquifer is overlain by the Maquoketa shale which acts as an aquitard. Beneath the
Galena-Platteville aquifer, several other bedrock aquifers exist which include the St. Peter
Sandstone Aquifer, Ironton-Galesville Aquifer and the Mt. Simon Sandstone Aquifer.
2.5.3 SITE GEOLOGY
Site borings were completed by V3 in January 2008 to May 2009. These borings provide
geologic interpretation to approximately 20 feet bgs. A total of 40 soil borings and monitoring
wells were installed by V3. The compilation of these boring logs and well construction logs
provides a descriptive understanding of the upper-most 20 feet of the Site’s geology (see
Appendix C). Five basic units were observed within the 20 feet:
• Light brown and gray mottled silty clay fill with bricks, sand and gravel
• Gray and brown silty clay or clayey silt with organic material, sand and/or gravel (not
continuous through Site)
Comprehensive Site Investigation Report V3 Companies, 6
Spartans’ Square Shopping Center May 2010