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and 3) laboratory permeability testing of core samples (vertical and horizontal directions).
The methodology and results of testing by the first two techniques (packer and slug testing)
is presented in Appendix D of this report and includes all such testing performed to date
(1991 and 1992). Table D1 of Appendix D summarizes open-hole packer testing results,

and Table D-2 of Appendix D presents the results of slug testing in completed wells.

The 1991 report contains an appendix of packer and slug testing data performed up to that
time (Janes, 1991). The 1991 report also contains all laboratory permeability testing results
for core samples.

San Gabriel Formation: A total of 15 open-hole, constant-head packer tests were conducted
' in open borings (C-7A, C-18A and MW-23A, Plate 7B) drilled in San Gabriel Formation‘
rocks (Table D-l, Appendix D). The injection flow rates used to maintain constant head
ranged from about 15 gallons/hour (gph) to 65 gph. From these data, in-situ hydraulic
conductivity values calculated for basement rocks were generally consistent and ranged from
about 7x105 cm/sec to 3x10‘6 cm/sec. Calculated transmissivities ranged from less than one

gallon per day/foot (gpd/ft) to nearly 10 gpd/ft. Five slug tests (three falling head,
two rising head) were performed in wells completed in the San Gabriel Formation
(monitoring wells C-7A, MW-lO and MW-13, Plate 7B). In general, hydraulic conductivities
derived from these data were consistent with packer testing results, although slightly greater

values in the 10‘4 cm/sec range were calculated from tests performed in well MW-10.
Calculated transmissivities were also comparable to those of packer testing, but ranged as
high as about 300 gpd/ft in one test conducted in well MW-10.

Eocene Rocks: Three packer tests (constant head) were performed within open borings
drilled in Eocene rocks (Table D-l, Appendix D). In-situ hydraulic conductivity values
derived from these tests generally ranged from 8.3x10'5 cm/sec to 8.4x10*S cm/sec. Overall,

hydraulic conductivity values were orders of magnitude larger than laboratory values
obtained in core permeability testing, which averaged 5x10‘9 cm/sec (Janes, 1991). Since
packer testing covers a greater interval than core sample permeability testing, in-situ values
are likely indicative of secondary porosity development (i.e., fractures), and are believed to

be more representative of the average hydraulic conductivity for Eocene rocks.
Transrnissivities derived from packer testing were as low as 2x104 gpd/ft (boring 011) to
more typical ranges of 2 gpd/ft to 20 gpd/ft.

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