California Oil, Gas, and Groundwater Program

Salinity within Geologic Formations Can Vary Considerably

Manager’s summary of Stephens and others, 2018

This study models subsurface salinity in the vicinity of Fruitvale and Rosedale Ranch oil fields.

Some key findings:

  • Thickness and depth of fresh and brackish groundwater varies across these oil fields.
  • Salinities vary within the Chanac formation from 5,000 to about 30,000 ppm TDS.
  • This variation is systematic.
  • Variation is caused by (1) clay layer thickness, (2) distance from a major freshwater recharge source, and (3) faults.
Fruitvale water wells, oil and gas wells, and resistivity logs shown downstream from Lake Isabella on a map
Study location with black line showing surface location of cross section shown in the 3d model. Explore the model using the "Explore the Model Results in 3d" button below.
Explore the Model Results in 3d
Fruitvale and Rosedale Ranch groundwater total dissolved solids along a cross section
Geophysical logs.