Question

A 25 cm well fully penetrates a confined aquifer of 35 m thickness and has a permeability of 13.5 m/day When a steady state discharge of 2400 L/min was being pumped for a long time, observation well at radial distances of 140 m indicated drawdown of 2.2 m, Find: 1) The transmissivity of the aquifer, 2) The drawdown at the pumping well, 3) The radius of influence, 4) The drawdown at 30 m from the well

Answer #1

A 30 cm well penetrates 45 m below the static water table. After
a long period of pumping at a rate of 1200 lpm, the drawdown in the
wells 20 m and 45 m from the pumped well is found to be 3.8 and 2.4
m respectively. Determine the transmissivity (=K*aquifer width) of
the aquifer. What is the drawdown in the pumped well?

a) A well is pumped at an equilibrium flow of 454 gpm to
determine a confined aquifer permeability. The
thickness of the aquifer is 100 ft and the drawdown in observation
wells is noted as 3 ft and 9 ft at 100 ft and 10 ft respectively,
from the pumped well, What is the permeability¿
b) Using the same data as a) exceptmconsider an
unconfined aquifer that was totally saturated
before pumping, what is an estimate of permeability¿

5) A pumping test was conducted in a confined aquifer using a
constant pump discharge of 6.00 m3/hr. The drawdowns
measured at an observation well located 20.0 m from the pumped well
are in the following table. Determine the aquifer transmissivity,
the storage coefficient, and the drawdown after 50 hours.
Time(hr)
0.05
01.0
0.20
0.50
1.0
2.0
5.0
10.0
20.0
S at 20m well
0.52
0.66
0.79
0.98
1.11
1.25
1.43
1.57
1.71

An unconfined aquifer is 25 m thick. Groundwater is being pumped
out from a 0.10 m diameter fully penetrating well. The pumping rate
is Qp=0.15 m3 /min. The aquifer is relatively sandy with a
hydraulic conductivity of 8.2 m/d. Steady-state drawdown of 1.5 m
is observed in a monitoring well 3 m away from the pumping well.
Estimate (a) the drawdown 10 m away from the pumping well, (b) the
drawdown in the pumping well.

A 20 inch diameter well fully penetrates a 100 ft deep
unconfined aquifer. Drawdowns at two observation wells located at
90 feet and 240 feet from the pumping well are 23 feet and 21.5
feet respectivly. K = 1400 gpd/ft squared
Determine discharge Q from pumping the well in gpm

NEED PART B ONLY
A)Determine the conductivity K in gallons/day/ft^2 of a fully
penetrating well in a confined aquafer. The aquifer is 100ft think
with a steady state pumping rate of 1200 gpm. The drawdown is an
observation well 75 ft away is 14ft and the drawdown in the second
observation well 500 ft away Is 1.2ft
B) if the above data of pumping rate, drawdowns in different
wells are for an unconfined aquifer, what will the conductivity be?
What...

1. Drawdown at a 0.20 m diameter, fully-penetrating well, which
has been pumping at a steady rate of 2500 m3/day for a
long time, is determined to be 1.2 m. Drawdown at an observation
well 10 m away is 0.90 m.
a. The aquifer is unconfined with a hydraulic head far from the
well of 10.0 m. Determine the hydraulic conductivity of the
aquifer.
b. How would your answer change if your aquifer was confined and
3 m in thickness?...

Observational wells were drilled in a cone of depression of
artesian (confined) well. The drawdown in the observational wells
at 9 m and 18 m from the center of the well were found to be 12 m
and 10 m, respectively. If the hydraulic conductivity of the
aquifer is 2.5 mm/min and the pumping flow rate from the well is
407 m3/hr
(i) Determine the thickness of the aquifer.
(ii) Find diameter of the well if the drawdown at...

a)A well is pumping from a confined aquafer. If after steady
state is reached, the drawdowns at 100m and 200m from the well are
3.6m and 2.4m respectively. Find the transmissivity of the aquifer
if Q = 600m3/d ?
b)Maximum annual peak discharges for a stream for a five-years
period are : 180, 150, 140, 160, 170 (all in m3/s) find the 20
years max. discharge using Gumble method

Two wells are drilled 50 m apart in an aquifer which has K =
0.05 cm /s. The original height of the phreatic surface above the
aquiclude is 12.2 m. The wells are pumped at a rate of 10 L/s. It
is estimated that the effect of the pumping extends a distance of
600 m from the center of the well group. Determine the shape of the
drawdown curve. The well diameters are 0.5 m.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 11 minutes ago

asked 18 minutes ago

asked 30 minutes ago

asked 40 minutes ago

asked 57 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago