22 Figure 2.4- Aquifers in Consolidated Rocks from Pennsylvanian to

Site Safety Analysis Report for
the EGC Early Site Permit
Figure 2.4-22
Aquifers in Consolidated Rocks
from Pennsylvanian to
Silurian-Devonian 730-K
Legend
Pennsylvania aquifers - Sandstone and some
limestone in rocks of Pennsylvanian age
Mississippian aquifers - Limestone and sandstone
in rocks of Mississippian age
Silurian-Devonian aquifer - Dolomite and limestone
in rocks of Devonian and Silurian ages
Not a principal aquifer
Cambrian-Ordovician aquifers - Sandstone and
dolomite in rocks of Ordovician and Cambrian ages
Apprroximate study area (50-mi radius)
Data Source:
USGS, 1995a
N
Not to Scale
Site Safety Analysis Report for
the EGC Early Site Permit
Figure 2.4-23
Axes of Major Bedrock
in Central Illinois
Legend
Approximate Axis of the Bedrock Valley
Data Source:
Kempton et al., 1991
N
Not to Scale
Site Safety Analysis Report for
the EGC Early Site Permit
- 750
675 -
- 675
650 -
- 650
625 -
- 625
600 -
- 600
575 -
- 575
550 -
- 550
525 -
- 525
500 -
- 500
475-
- 475
450 -
- 450
425 -
- 425
NOTES:
1. G roundw ater Levels indicated on the subsurface section w ere obtained by interpolating betw een borings
w ith p ie zo m e te rs. In fo rm a tio n o n a ctu a l g ro u n d w ater levels exist only at boring locations w ith piezom eters.
It is p o ssib le th a t g ro u n d w a te r le ve ls b e tw e e n borings w ith piezom eters m ay vary from those indicated.
2 . T h e d e p th a n d th ickn e ss o f so il a n d ro ck stra ta indicated on the subsurface section w ere obtained by
in te rp o la tin g b e tw e e n b o rin g s. In fo rm a tio n o n a ctual soil and rock conditions exist only at boring locations.
It is p o ssib le th a t so il a n d ro ck co n d itio n s m a y vary from those indicated.
3. T he discussion in the text is necessary for proper understanding of the nature of the subsurface m aterials
4 . E le va tio n s re fe r to th e U S G S D a tu m .
Illinoian Sangamonian W isconsinan
- 700
YarM outhian
700 -
Legend
Q uaternary
- 725
K ansan
725 -
P ennsylvanian
B o rin g P -4 1
B o rin g P -7
P -3 7
P -1 4
P -3 8
P -3 9
P -1 0
B o rin g
B o rin g
B o rin g
B o rin g
B o rin g
B o rin g P -1 7
Figure 2.4-24
Near Site Cross Section of
Hydrogeologic Units
and Piezometric Surfaces
N o rth e a st
E le va tio n in F e e t
E le va tio n in F e e t
750 -
B o rin g P -2 0
Station S ite
S outhw est
LO E S S - B row n to m ottled brow n and gray clayey silt or silty clay w ith trace fine
sand; W eathered
W IS C O N S IN A N G LA C IA L T ILL - B row nish-gray to gray clayey silt or silty clay
w ith sand and gravel; C ontains irregular and discontinuous lenses of sand and
silt throughout (glacial outw ash and possibly local lacustrine deposits)
IN T E R G LA C IA L Z O N E - Includes dark gray to gray organic clayey silt or silty
clay (colluvial soils), greenish to bluish-gray clayey silt w ith sand and gravel
(rew orked Illinoian G lacial Till)
ILLIN O IA N G LA C IA L T ILL - B row nish-gray to gray clayey silt w ith sand and
gravel to very sandy silt or silty sand w ith som e clay and gravel
Interbedded outw ash deposits in upper horizons
LA C U S T R IN E D E P O S IT - B row nish-gray to black and gray clayey silt to silt,
organic in zones; Includes greenish to bluish-gray clayey silt w ith sand and gravel
(rew orked and w eathered pre-Illinoian G lacial Till); A ssignm ent to Yarm outhian
G lacial Stage is tentative
P R E -ILLIN O IA N G LA C IA L T ILL - G rayish-brow n to brow n silty clay and clayey
silt w ith som e sand and gravel; B row n color and relatively high clay content is
characteristic; Tentatively assigned to K ansan G lacial Stage on the basis of clay
analysis by Illinois State G eological S urvey
P R E -ILLIN O IA N A LLU V IA L & LA C U S T R IN E D E P O S IT - C onsists of grayishbrow n, brow n, and green clayey silt and silty clay w ith sand and som e gravel
(rew orked glacial till) and gray to brow n clayey silt w ith organic debris (lacustrine
or low energy alluvial deposit); Included as part of the M ahom et bedrock deposit
in areas w here it is underlain by sandy outw ash deposits
B E D R O C K - Interbedded layers of lim estone, shale, and siltstone assigned to
the M cLeansboro G roup, M odesto F orm ation on the basis of spore analysis of
the coal encountered in boring B -31
LIM E S TO N E - G reenish-gray, gray and brow n, fine to coarsely crystalline, silty,
thin bedded to m assive, num erous shale partings in zones, fossiliferous.
S H A LE - G ray to dark gray shale, carcoraceous to calcareous; clayey in zones,
expansive, slickensides; occasional concretion
S ILT S TO N E - Light gray siltstone, m icaceous, fine sandy, cross-bedded in zones;
occasional interbedded layer of silty sandstone
Data Source:
CPS, 2002
Not to Scale
Site Safety Analysis Report for
the EGC Early Site Permit
15 mi
Figure 2.4-25
Wells Within a
15-mi Radius of the Site
McLean County
Legend
10 mi
EGC ESP Site
Site Buffer: 5-mi Radius from Site
Well Locations - Total Depth (ft)
0
< 100
100 - 200
200 - 400
> 400
Water: Lakes and Rivers
County Boundary
5 mi
DeWitt County
Logan County
Data Sources:
ISGS, 2002
U.S. Census Bureau, 2000
U.S. Census Bureau, 2002
Piatt County
Boone
Jo DaviessStephenson
McHenryLake
Winnebago
Carroll Ogle
DeKalbKane
DuPageCook
Whiteside Lee
Rock Island
Henry
Kendall
Bureau
La Salle
Will
Grundy
Putnam
Kankakee
Stark
Marshall
Knox
Livingston
HendersonWarren
Peoria Woodford
Iroquois
McDonough
Ford
Tazewell
McLean
Fulton
Hancock
Mercer
Macon County
Mason
Schuyler
Logan DeWittChampaignVermilion
Adams Brown Cass Menard
Piatt
Macon
Douglas
MorganSangamon
Pike
Edgar
Scott
Christian MoultrieColes
Shelby
Greene
Clark
Calhoun Macoupin
EffinghamCumberland
Jersey Montgomery
Fayette
JasperCrawford
MadisonBond
ClayRichlandLawrence
Clinton Marion
St. Clair
Wayne Wabash
Monroe WashingtonJefferson
Edwards
Hamilton
White
RandolphPerry
Franklin
Jackson
SalineGallatin
Williamson
Johnson Hardin
Union
Pope
AlexanderPulaskiMassac
0
2
Miles
4
8
Site Safety Analysis Report for
the EGC Early Site Permit
Figure 2.4-26
Location of Piezometers, CPS
Test Well, and Water Table
in Site Vicinity
Legend
CP S Te s t We ll
Functiona l P ie zome te r (As of 12 - 77)
Non-Functiona l P ie zome te r (As of 12 - 77)
Infe rre d Wa te r Ta ble Contour, Wis cons ina n De pos its
P ie zome te r Ins ta lle d in J uly/Augus t 2002
Flow Line
E -5B
E -2B
P-40
P -37
D -30
D -31
O W -6
NOTES
E -4B
E -3
25
E -1B 7
E-6B
B-1 B-2
B-3
1. Da tum is me a n s e a leve l
2. P ie zome te r ins ta lla tion da ta a re lis te d in Ta ble 2.3-15
3. Ba s e ma p modifie d from US GS , 15' S e rie s topogra phic ma p:
Ma roa , Ill., 1957
CPS
Test W ell
720
D -46 O W -1
D -11
D-3
D -50
D -19
D -47
D -48
D -23
OW-2
D -8
O W -8
OW-3
O W -3
E -7
[Writer’s Note: Need to confirm piezometer names.]
715
O W -5
Data Source:
CPS, 2002
OW-7
O W -7
OW-4
O W -4
N
0
1
S ca le in M ile s