Page 189 - Water and wastewater engineering

4-44 WATER AND WASTEWATER ENGINEERING

4-12. Two wells located 106.68 m apart are both pumping at the same time. Well A pumps
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3
at 0.0379 m /s and well B pumps at 0.0252 m /s. The diameter of each well is 0.460
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2
3
m. The transmissivity is 4.35 10 m /s and the storage coefficient is 4.1 10 .
What is the interference of well A on well B after 365 days of pumping? Report your
answer to two decimal places.
4-13. Using the data from Problem 4-12, find the total drawdown in well B after 365 days
of pumping. Report your answer to two decimal places.
4-14. If two wells, no. 12 and no. 13, located 100.0 m apart, are pumping at rates of
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3
0.0250 m /s and 0.0300 m /s, respectively, what is the interference of well no. 12 on
well no. 13 after 280 days of pumping? The diameter of each well is 0.500 m. The
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5
2
transmissivity is 1.766 10 m /s and the storage coefficient is 6.675 10 .
Report your answer to two decimal places.
4-15. Using the data from Problem 4-14, find the total drawdown in well 13 after 280 days
of pumping. Report your answer to two decimal places.
4-16. Wells X, Y, and Z are located equidistant at 100.0 m intervals. Their pumping rates
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3
3
are 0.0315 m /s, 0.0177 m /s, and 0.0252 m /s respectively. The diameter of each
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3
well is 0.300 m. The transmissivity is 1.77 10 m /s. The storage coefficient is
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6.436 10 . What is the interference of well X on well Y and on well Z after 100
days of pumping? Report your answer to two decimal places.
4-17. Using the data in Problem 4-16, find the total drawdown in well X at the end of 100
days of pumping. Report your answer to two decimal places.
4-18. For the well field layout shown in Figure P-4-18 , determine the effect of adding
a sixth well. Is there any potential for adverse effects on the well or the aquifer?
Assume all the wells are pumped for 100 days and that each well is 0.300 m in
diameter. Well data are given in the table below. Aquifer data are shown below the
well field data.

Knotquite Well Field No. 1
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Well no. Pumping rate (m /s) Depth of well (m)
1 0.0221 111.0
2 0.0315 112.0
3 0.0189 110.0
4 0.0177 111.0
5 0.0284 112.0
6 (proposed) 0.0252 111.0

The aquifer characteristics are as follows:
Storage coefficient 6.418 10 5
2
Transmissivity 1.761 10 3 m /s
Nonpumping water level 6.90 m below grade
Depth to top of artesian aquifer 87.0 m