1. Source Terms Constant Concentration Injection Well Recharge May be introduced at the boundary or in the interior of the model

2. Q Constant Concentration (Z&B, p. 283) cscs at boundary e.g., NAPL source area

3. Injection Well Qc s well

4. Recharge R, c s Mass Flux = R (  x  y) c s

5. Problem Set #3 Source Terms and Chemical Reactions Constant Concentration Injection Well Recharge retardation 1 st order decay

6. Problem Set #3 Two Layers This screen shows a constant concentration source. Contours of head are also shown. Confined layers

7. Note the water table Flow field for an unconfined upper layer with areal recharge and a recharge source cell.

8. Problem Set #3 Parts 1 and 2: Produce breakthrough curves under different assumptions about the source term and chemical reactions.

9. Problem Set #3 – Part 3 - Remediation TVD Solution Numerical error caused by high Peclet number

10. Central Finite Difference Solution

11. Problem Set #3 – Part 3 - Remediation TVD Solution Numerical error caused by high Peclet number

12. Courant Number Cr < 1 Peclet Number P e < 4

13. Pumping well is represented by 4 nodes 50 m grid

14. 100 m grid spacing Peclet number = 5 50 m grid spacing upper left node in the pumping complex Peclet number = 2.5 TVD solution

15. 100 m grid 50 m grid – near center of pumping compex TVD Solution