Water Quality in Areas of Oil and Gas Production – Regional Groundwater Monitoring
As required by SB4 and detailed in the Model Criteria for Groundwater Monitoring in areas of Oil and Gas Well Stimulation (Model Criteria), State Water Board is to implement a Regional Monitoring Program in order to protect all waters designated for any beneficial use, while prioritizing the monitoring of groundwater that is or has the potential to be a source of drinking water. Factors considered for the Regional Monitoring Program include well stimulation treatments, among other events or activities that have the potential to contaminate groundwater, such as an oil and gas well failure or breach. Fluids produced or introduced in the well stimulation process including, but not limited to, produced water ponds and Underground Injection Control (UIC) wells will be examined in the Regional Monitoring Program.
The Regional Monitoring Program will be conducted in a phased approach, with the first phase anticipated to take approximately five years. The United States Geological Survey (USGS) is technical lead on implementing the Regional Monitoring Program, funded through a contract agreement with the State Water Board. The Scope of Work for contract agreements with the USGS can be found using the following links: Scope of Work 1- August 2014; Scope of Work 2- March 2016; and Scope of Work 3- May 2017.
The U.S. Geological Survey (USGS) has summarized in a letter dated January 22, 2018, its objectives, sample collection and analysis protocols, quality-assurance procedures, approaches, and reporting procedures used for the California State Water Resources Control Board's Regional Monitoring Program of Water Quality in Areas of Oil and Gas Production.
The main components of the Regional Monitoring program are:
- Characterizing and monitoring groundwater risk zones
- Surface activity effects
- Well integrity
Assessing potential water quality impacts related to these three components will help to systematically and comprehensively collect and interpret information that will support management and protection of waters designated for any beneficial use, while prioritizing the monitoring of groundwater that is or has the potential to be a source of drinking water.
The first phase of the Regional Monitoring Program will focus on characterizing and monitoring groundwater in potential risk zones and identifying where vulnerable beneficial use water resources are located. Part of that effort will systematically delineate aquifer zones containing less than 3,000 milligrams per liter (mg/L) total dissolved solids (TDS) and between 3,000 and 10,000 mg/L TDS to help create a tiered approach for the regional monitoring.
More information on the Regional Monitoring Program can be found on the USGS's California Oil, Gas, and Groundwater Monitoring Program website.
The USGS will implement the Regional Monitoring Program. The scope of work for 2016-2018 includes:
- Subsurface salinity mapping: Analysis of existing water quality data, estimating salinity from borehole geophysical logs, and analysis of surface/airborne electromagnetic geophysical data.
- Produced water characterization: The fate and transport of produced water in oil production areas will be assessed using samples from produced water ponds and underground injection wells. The produced water sampling effort will be coordinated with the Regional and State Water Boards, Division of Oil, Gas and Geothermal Resources (DOGGR), other CalEPA agencies, and oil and gas operators.
- Groundwater potential risk zone analysis: Monitoring will be conducted in groundwater zones at oil fields that have a higher potential to be impacted by oil and gas production-related fluids. Maps, graphs and/or three dimension visualizations will be prepared.
Data, information and status reports will be made publicly available on a regular basis. Formal reports on the status and findings of the Regional Monitoring Program are anticipated to be prepared on a biennial basis starting January 2018.
Exploratory sampling associated with the State Water Board's Oil and Gas Regional Groundwater Monitoring Program has been completed. The sampling was conducted September 2014 through January 2015 in coastal Los Angeles, Kern and Kings Counties by the USGS.
The data collected during the exploratory sampling is summarized in the following report: "USGS Open-File Report 2016-1181: Data from Exploratory Sampling of Groundwater in Selected Oil and Gas Areas of Coastal Los Angeles County and Kern and Kings Counties in Southern San Joaquin Valley, 2014–15: California Oil, Gas, and Groundwater Project"
The U.S. Geological Survey sampled water wells in the Los Angeles Basin and southern San Joaquin Valley, California, and oil wells in the San Joaquin Valley for analysis of multiple chemical, isotopic, and groundwater-age tracers. This report summarizes that work to evaluate the utility of using tracers for assessing oil and gas production activities on groundwater quality in California. The report is available at the following: “Preliminary results from exploratory sampling of wells for the California oil, gas, and groundwater program, 2014–15, Open-File Report 2016-1100.”
The U.S. Geological Survey compiled data that characterizes the intensity of petroleum resource development and proximity to groundwater resources. This report is available at the following: "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, Scientific Investigations Report 2018-5065."
The U.S. Geological Survey compiled a report to document the preliminary groundwater salinity mapping of 31 oil fields and adjacent aquifers. The data is summarized into 8 sub-regions across major oil-producing areas of central and southern California. This report is available at the following: "Preliminary groundwater salinity mapping near selected oil fields using historical water-sample data, central and southern California. Scientific Investigations Report 2018-5082."
Journal of Geophysical Research: Biogeosciences, March 2018, Volume 123, Issue 3, “Origin of methane and sources of high concentrations in Los Angeles Groundwater”. (2/12/2018). The full article is available upon request from USGS via Matt Landon at firstname.lastname@example.org.
Earth and Planetary Science Letters, August 15, 2018, Volume 496, pages 57-67, “Tracing enhanced oil recovery signatures in casing gases from the Lost Hills oil field using noble gases.” (8/15/2018) The full article is available upon request from USGS via Matt Landon at email@example.com.
Hydrogeology Journal, August 31, 2018, "Groundwater salinity mapping using geophysical log analysis within the Fruitvale and Rosedale Ranch oil fields, Kern County, California, USA"
Applied Geochemistry, November 2018, Volume 98, Pages 127-140, "Regional patterns in the geochemistry of oil-field water, southern San Joaquin Valley, California, USA"
Applied Geochemistry, July 2019, Volume 106, Pages 82-95, “Groundwater quality of a public supply aquifer in proximity to oil development, Fruitvale oil field, Bakersfield, California”
NEW - Environmental Science & Technology, August 7, 2019, “Occurrence and Sources of Radium in Groundwater Associated with Oil Fields in the Southern San Joaquin Valley, California”
Data collected from collected produced water samples from four petroleum wells in the southern San Joaquin Valley. This digital dataset contains the site information, analyzing laboratories and methods, and water chemistry and quality control results for these samples. The report is available at the following: Produced water chemistry data for samples from four petroleum wells, Southern San Joaquin Valley, California (2014)
Supporting data for the “Produced water chemistry data for samples from four petroleum wells, Southern San Joaquin Valley, California, 2014” (9/6/2016)
Data from the Fruitvale produced water ponds is available at the following link: Historical produced water chemistry data compiled for the Fruitvale Oilfield, Kern County, California (3/20/2018)
Supporting data for the “Produced water chemistry data for the Lost Hills, Fruitvale, and North and South Belridge study areas, Southern San Joaquin Valley, California” (6/7/2018)
Supporting data for the "Water and petroleum well data used for preliminary regional groundwater salinity mapping near selected oil fields in central and southern California" (7/24/2018)
USGS regional monitoring activities are presented at our semiannual stakeholder meetings. A recording of the most recent meeting is below: