a race of 0.05 foot/day over a 500 foot area.     Figure 5.2
shows   the idealized aquifer, the simulated solution and
the hand calculated solution using the Hantush method(9).
The two solutions show a deviation of about 2 feet during
the early part of the simulation. A finite difference grid
spacing of 100 feet and a constant timestep of 30 days were
used in the modeled analysis.
The second process modeled is the transport of seepage
in the aquifer.   The verification of this process is pro-
vided by modeling an instantaneous slug of a given mass of
seepage     in    a    homogeneous,     isotropic    aquifer
(K = 10 feet/day, n = 0.25) under a uniform, constant gra-
dient of 20 feet/mile. Neither solution considers retarda-
tion or chemical change. The hand solution is computed by
solving the one dimensional equation of seepage trans-
port. Figure 5.3 shows the aquifer and a cross section of
the seepage slug 9 years after injection for the computer
simulation and the hand solution.

Golder Associates

March, 1982

-26-

786085