FLOOD07651

• County: Statewide
• Basin: Statewide
• Title: Groundwater Pumping Tests: Design and Analysis
• Date: 12/1/1997
• Floodplain - Doc Type: Educational/Technical/Reference Information

88 GROUNDWATER PUMPING TESTS

T = 1.146 X 10'(62)1.0/1.45 T = 4900 gpdlft
S = 4.9 X 103(0.01)5.6/[2.693 X 103(20)'] S = 0.00025

SiI = 3.6 min,

t" = 180 min

W(u,,) = 4.9 X 103(3.6)/[1.146 X 10'(62))
W(Ull) = 2.4827

un = 4.92 X 10-'

rn = {[4,9 X 103(180)4.92 X 10-']1
[2.693 X 103(2.5 X 1O-')j} If'

r" = 253 ft

Si' = 3.0 ft t12 = 1000 min

W(ud = 4.9 X 103(3)/[1.146 X 10'(62)] W(ud = 2.0689

\1;, = 7.72 X 10-'

r12 '" {[4.9 X 1()3(1.0 X 103)7.72 X 10-']1
[2.693 X 103(2.5 X 1O-')j} 112

r12 = 750 ft

.....
Ll..
C
~
o
-0
~
C
L
Cl

Time-drawdown graphs for the observation wells are pre-
sented in Figure 5.3.
The average values of aquifer transmissivity and
storativity are 4900 gpd/ft and 0.0002, respectively. Based
on an average aquifer thickness of 8 ft, the hydraulic con-
ductivity is 613 gpdlsq ft. Available data indicate that the
aquifer is a t.hin strip of fine sand and some gravel approxi-
.mately 600. ft wide which trends northeast to southwest
through the pumping test area. Well storage capacity
impacts were appreciable until about 11 minutes after
pumping started.
A pumping test was conducted in Case Study 5.3 in
November 1979 using a small-diameter production well
located in southwestern Indiana (see Davis and Walton,
1982, pp. 841-848). The production well encountered 93 ft
of unconsolidated deposits, 207 ft of sandstone, 30 ft of
limestone, 126 ft of shale, and 4 ft of coal. The casing with a
radius of 0.25 ft extended from land surface 97 ft through
the unconsolidated deposits and into bedrock.

1
2
3
5
7
9
11
16

100.0

CASE STUDIES 89

10.0

O. I

0.1 I 10 100

Timg Aftgr Pumping Stortgd

Figure 5.3. Time-drawdown graphs for Case Study 5.2.

The pump in the production well was discharged at a
constant rate of9 gpm for a period of 6 hours, and water
levels in the production well were measured at frequent
intervals. Recovery was also observed for a period of 6
hours. Time-recovery data for the production well are pre-
sented in Table 5.3.

Table 5.3. Database for Case Study 5.3

Time After
Pumping
Stopped
(min)

1.0

Adjusted
ReCovery
(ft)
5.91
16.36
18.98
33.55
.46.11
57.02
65.23
84.87

Time After
Pumping
Stopped
(min)
23
35
56
79
110
170
240
300

1000
(Min)

Adjusted
Recovery
(ft)
107.32
126.77
150.01
163.37
179.86
191.02
201.13
203.74