FLOOD07651

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

100 GROUNDWATER PUMPING TESTS
10.00

Figure 5.7.

Observation .Well 5

....
u...
c:
..
o
"0
..
o
L.
o

Table 5.7.

CASE STUDIES 101

The production well was screened opposite the lower 60 ft
of the aquifer. The casing and screen had inside diameters
of 30 in.
The test was started a.t 9:45 a.m. and was continued for 4
hours until 1:40 p.m. The discharge rates from the produc-
tion well were 1000, 1280, and 1400 gpm. Test data are
presented in Table 5.7.
The calculated values of well loss coefficient for steps 1
and 2 and step 2 and 3 are 0.04 sec'/ft'and 0.11 sec'/ft',
respectively. Computations are as follows:

Database for Case Study 5.7

Feet to
Water

Time

9:23a.m.
9:50
9:55
10:00
10:10
10:15
10:20
10:30
10:35
10:52
11:00
11:25
11:30
11:50
12:00
12:15p.m.
12:30
12:45
12:50
1:00
1:15
1:30
1:40

23.95
29.13
29.23
29.30
29.30
29.32
29.37
29.35
29.36
29.40
29.39
29.43
30.97
31.01
31.02
31.04
31.08
31.08
31.90
31.95
31.92
31.90
31.93

10 100 1000 10000

Time After Pumping Started (Min)

Time-drawdown graph for observation well 5 in Case Study
5.6.

I. 00

0.10

0.01
I

10.00

....
.....
c:
..
o
-c
..
o
L.
o

I. 00

105

'106

0.10

0.01 2
10

103

104

Distance Squared (Sq Ft)
Figure 5.8. Distance-drawdown graph for Case Study 5.6.

C,.2 = (1.59/0.62 - 5.4312.22)/(2.22 + 0.62)
Cl.2 = 0.04 sec'lft'

Pumping Rate
(gpm)

o
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1260
1260
1260
1260
1260
1260
1400
1400
1400
1400
1400