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Environmental mg/L 3. You decide to use pump and treat to remove the ETB from th

ID: 235107 • Letter: E

Question

Environmental
mg/L 3. You decide to use pump and treat to remove the ETB from the groundwater. You are told that the aquifer is contaminated for 1000 ft. The groundwater has a concentration of 1 ppb and you need to remove it down to 0.05 ppb. The aquifer has a hydraulic conductivity of 1000 gal/ft2-day, a hydraulic gradient of 0.003 and an area of 50 ft. Calculate how long it will take to remove the ETB to acceptable levels if you pump the water at the same rate as the flow in the aquifer. (10 pts) days 4. You are brought in as an engineer to remove the ETB from the groundwater. Your boss recommends that mediation and soil/vapor extraction. What information would you need to know to you look into determine if either of these techniques will work? (5 pts)

Explanation / Answer

using darcy law:

Q=-KAdh/dl

k=1000gal/ft2-day

A=50ft2

dh/dl=0.003

=1000*50*0.003

=150m3

Now,

K=VL/Ath

t=?

V=150m3

Now, t= 150/50*0.003*1000

=0.2 days

Information need to know whether bioremediation or vapour extraction technque will work:

Perform additional ground water analyses to know the pollutant concentration in current time as well as variations in ground water quality over a period of time

Through site investigation of the area including topography and geology of the area

conduct pilot tests and pump tests to confirm effectiveness of the techniques that maximize the removal of ETB from ground water