Ground-water development in East St. Louis area, Illinois. Urbana, IL ...

CONSTRUCTION FEATURES AND YIELDS OF WELLS
Large capacity wells in the East St. Louis area are
drilled by the cable tool method, the reverse hydraulic
rotary method, or by clam shell type diggers. Collector
wells have been constructed in the East St. Louis area
by several industries. Most domestic and some irrigation
wells are driven; a few dug wells are still used for domestic
supplies.
Industrial, municipal, and irrigation wells are usually
drilled to bedrock or bit refusal. Several wells just south
of Alton terminate at the top of clayey and silty material
immediately above bedrock. According to Bergstrom
and Walker (1956) the maximum thickness of the
clayey and silty material is 25 feet. Production wells are
usually cased through the finer alluvial deposits in the
upper part of the valley fill and have perforated pipe
sections or commercial screens opposite the lower coarser
alluvium or valley-train deposits. There are two types
of drilled wells in the area: natural pack and artificial
pack. Materials surrounding the well are developed in
place in the case of the natural pack well; materials having
a coarser and more uniform grain size than the natural
formation are added around the well in the case of
the artificial pack well. As shown in table 18, the thickness
of the pack in wells in the area generally ranges
from 6 to 11 inches.
Depth
(ft)
Table 18.
Casing
depth
(ft)
Construction Features of Selected Wells
Casing
diameter
Length
(in) (ft)
Diameter
(in)
Screen Record
Material
or manufacturer
Slot
number
or size
(in)
Artificial
pack
thickness
(in)
103 0-73 26
30
26
Everdur
30 11
Johnson
110 0-34 26 76 26 Porous
none
36 36 concrete
85 0-49 30 36 30 Porous
none
40 40 concrete
95 0-47 26 48 26 Porous
none
36 36 concrete
120 0-76 16 44 16 Slotted ¼ X 2½ 9.5
pipe
108 0-73 24 35 24 Everdur 60 6.0
Johnson 100
100 0-63 14 37 12 Slotted ¼ X 2½ 7.0
pipe
105 0-85 12 20 12 Slotted
6.0
pipe
111 0-81 16 30 16 Cook 20
30
114 0-84 16 32 16 Cook 20
40
111 0-81 16 30 16 Cook 20
40
80
98 0-78 18 20 18 Layne 4
Shutter
115 0-85 16 30 16 Cook 30 6.0
105 0-89 10 16 10 Cook none
115 0-100 12 15 12 Johnson 60 none
Several types of well screens have been used in the
East St. Louis area. Porous concrete, wood, slotted pipe,
and commercial screens are in use. Economic considerations
rather than proper well design criteria have governed
the types of screens in use. Screen diameters generally
vary in diameter from 6 to 30 inches, and screens
vary in length from 5 to 76 feet. Screen slot openings
vary depending upon the characteristics of the formations
encountered or the characteristics of the artificial
pack.
Ten collector wells have been constructed in the East
St. Louis area, and six are still in use. Four collector
wells at the Granite City Steel Company were not in continuous
operation in 1962, but were tested periodically
and operated occasionally during the summer months.
The collector well consists of a large diameter, reinforced
concrete caisson from which horizontal screen laterals
project radially near the bottom. The standard caisson
is 13 feet in diameter. The horizontal screen laterals are
fabricated from heavy steel plate, perforated with longitudinal
slots, and may be 8 to 24 inches in diameter and
100 to 450 feet in length, depending upon geologic conditions
and design of the unit (Mikels and Klaer, 1956).
Thorpe concrete wells are in wide use by municipalities,
industries, and irrigation well owners. Thorpe concrete
wells consist of a concrete casing and porous concrete
screen either 26 or 30 inches in inside diameter
with walls 5 inches thick. Lengths of screen vary from
24 to 76 feet. Thorpe concrete wells have been in operation
for as long as 35 years. However, in some cases
Thorpe concrete wells have been abandoned because of
reduction in yield after a few months operation.
Driven wells are usually not greater than 50 feet in
depth depending upon the thickness of the alluvium overlying
the coarser sand and gravel deposits. The driven
wells consist of lengths of 1.25- or 2-inch diameter pipe
with a drive (or sand) point at the lower end of the
pipe.
About 500 relief wells were drilled in the East St.
Louis area by the U.S. Corps of Engineers near and on
the land side of levees fronting the Mississippi River to
control underseepage beneath levees during floods. Several
artificial pack relief wells were also drilled along
the Cahokia Diversion Channel. Relief wells in the area
range in depth from 47 to 103 feet. Casings and screens
are 8 inches in diameter and the pack thickness is about
7 inches. The screens are constructed from redwood or
treated Douglas Fir and range in length from 19 to 71
feet. The screens are spiral wound with No. 6 gage galvanized
wire and have 18 slots, 3/16 by 3 1/4 inches per
spiral.
Slotted pipe screens are widely used in irrigation
wells in the East St. Louis area because of their low cost.
In comparison, only a few industrial and municipal
26