Where We Are Working

There are 487 onshore oil and gas fields in California; these were classified as high, medium, and low priority for detailed study as part of the COGG program based on the intensity of petroleum resource development and proximity to groundwater resources (Davis and others, 2018). Each year, a new set of high priority fields is selected based on feedback from the State Water Board and Regional Boards. The map shows what kind of work has been done in which fields to date.

Oil and Gas Fields

Work beginning in 2016

Work beginning in 2017

Work beginning in 2018

Fields not yet sampled or analyzed

high priority fields (Davis and others , 2018)

moderate and low priority fields (Davis and others , 2018)

Black border denotes protected groundwater mapped from 2015-2018 using existing water sample data (Metzger and Landon, 2018)

*Ongoing water sample data compilation and analysis to map protected groundwater is occurring in all remaining oil fields.

References

2018

Davis, Tracy A., Landon, Matthew K., and Bennett, George L.V, 2018, Prioritization of oil and gas fields for regional groundwater monitoring based on a preliminary assessment of petroleum resource development and proximity to California’s groundwater resources, U.S. Geological Survey, Scientific Investigations Report, SIR 2018- 5065, DOI: 10.3133/sir20185065

Metzger, Loren F., and Landon, Matthew K., 2018, Preliminary groundwater salinity mapping near selected oil fields using historical water-sample data, central and southern California, U.S. Geological Survey, Scientific Investigations Report 2018- 5082, DOI: 10.3133/sir20185082