Final

Question 1

3 point certain conditions

Answer 1

-Aquifer is homogeneous
-Aquifer is fully saturated
-Aquifer is isotropic
-Hydraulic head doesn’t change with time
-No soil / water compression
-No unknown boundary conditions
-Flow is laminar (this is the biggest problem)

Question 2

several ways to collect 3D GW data

Answer 2

-Screen standard wells at different depths
-Nested piezometers
-Packer system

Question 3

pumping test steps

Answer 3

1) Begin pumping from pumping well
2) Measure volume of water extracted in 1 minute
3) Monitor 2 observation wells at different distances
4) Record water levels at equilibrium condition
5) Solve the Thiem equation for unconfined flow to get conductivity

Question 4

unconfined aquifer thiem

Answer 4

k = [Q/π(b22 – b12)]*ln(r2/r1)

Question 5

confined aquifer thiem

Answer 5

T = [Q/(2π(h2-h1)]*ln(r2/r1)

Question 6

slug test steps

Answer 6

1) Lower a slug into the well, let h return to normal
2) Remove the slug from the well quickly, h drops
3) Record water level changes in the well over time
4) Calculate h/h0 (percent recovery) over time
5) Determine time where h recovers 37%
6) Use Hvorslev equation to calculate the hydraulic conductivity of the aquifer

Question 7

Hvorslev equation

Answer 7

k = [r2ln(Le/R)] / (2Let37)

Question 8

Transmissivity (T)

Answer 8

is the amount of water an aquifer can transmit to a pumping well
T = kb where b is the aquifer thickness & k is the hydraulic cond.

Question 9

Storativity (S)

Answer 9

amt. of water released by the aquifer per unit decline in head

Question 10

Theis equation

Answer 10

h0-h = (Q/4πT)*W(u)
u = (r2S/4Tt)
(drawdown)

Question 11

total dissolved solids (TDS)

Answer 11

Fresh water: 0-1,000 mg/L
Brackish: 1,001-10,000 mg/L
Saline: 10,001-100,000 mg/L
Brine: >100,000 mg/L

Question 12

Natural dissolved solids

Answer 12

Ca2+, Mg2+, Na+, K+, Cl-, SO42-, CO32-, HCO3-

Question 13

Class I (Special ground waters):

Answer 13

GW reservoirs that serve vital drinking water or ecological purposes and are vulnerable to contamination

Question 14

Class II (Current & potential drinking water sources)

Answer 14

Ground waters not currently used for drinking water or other uses, but important enough to protect

Question 15

Class III (Ground waters not available for use):

Answer 15

GW too saline or too polluted to be safely used for drinking water or ecological purposes

Question 16

heavy metals contaminates

Answer 16

Pb2+, Hg2+, Cd2+, Zn2+, Mn2+, Cu+, & Ni+

Question 17

Pump & treat systems

Answer 17

extract polluted GW & pass it through a treatment system to remove pollutan
Different kinds of treatment systems possible:
Activated carbon (most common)
Catalytic / thermal degradation
Heavy metals precipitation
Oil-Water Separator (OWS)

Question 18

Soil vapor extraction / air sparging (SVE/AS)

Answer 18

systems force volatiles into the gas phase
Volatilized contaminants are removed through vapor extraction wells

Question 19

Bioremediation

Answer 19

is the acceleration of microbial degradation by adding O2 & a C-source

Question 20

Phytoremediation

Answer 20

uses plants to remediate GW
Ideal application requires a hyperaccumulator

Question 21

ChemOX

Answer 21

injects a redox agent into the GW
The redox agent transforms a contaminant

Common ChemOx agents: MnO4-, SO52-, H2O2, O3

Question 22

Permeable reactive barriers

Answer 22

are passive remed. systems that remove contaminants in situ
PRBs use various materials specific to the pollutant
Examples: ZVI, zeolites, activated carbon, sawdust

Question 23

natural attenuation

Answer 23

Natural attenuation is a mix of bacterial degradation, natural decay, and dilution effects