Geology Reference
In-Depth Information
drilled in this area in June 1964. The brine-to-oil ratio
was about 10:1, and nearly 236,000 barrels of salt water
were pumped into three ponds from June 1964 to July
1965. Dissolved solids in the brine averaged 60,000
mg/L, and of this about 35,000 mg/L consisted of the
chloride ion (Pettyjohn, 1971).
The accompanying figures (Figures 15.1, 15.2,
15.3) show the location of four brine-disposal pits,
three oil wells, 25 observation wells, and a water
well. The observation wells averaged 25 feet in depth
and were installed in late 1965, following cessation
of brine disposal, to monitor the movement of the
contaminated groundwater. Shale bedrock is over-
lain by up to 30 feet of alluvial material consisting
of a mixture of sand, silt, and clay. The average
hydraulic conductivity
(K)
of the alluvial material,
which contains the contaminated water, is about 25
ft/day, and the average effective porosity
(n
e
)
is 0.15.
The water table gradient (I) can be determined from
a water-table map.
The objectives of the exercise are to determine
the direction and rate of flow of the contaminants in
the ground and to evaluate the possible contamination
of a nearby water well.
FIGURE 15.1
Map showing configuration of the water table in March 1969.
