FAQ

The figure below provides a diagram to convey the general means of how fluids are extracted from geologic formations deep below the ground and processed onsite. The IOF produces and sells crude oil, natural gas, and propane as shown in the upper right of the diagram. A significant amount of water is produced from this operation, which is filtered, treated and recycled/reinjected back into the original formation.

In general, an oil/water/gas mixture is pumped from oil-bearing formations and are processed through the gas plant, various tank systems, and the water plant. These systems along with the oil production wells and water injector wells are all under vapor recovery to keep the gas from emitting into the atmosphere.

Tank systems typically consist of a series of wash, crude oil storage, and produced water tanks. Wash tanks receive the oil/water mixture from oil production wells and serve to separate the gas/oil/water mixture by means of gravity clarification. Clarified crude oil is sold and conveyed offsite via a pipeline owned and operated by others. The gas layer is conveyed to the gas plant for further processing, and the water is sent to the water plant for filtration and extraction of residual oil entrained in the water.

The gas plant processes the gas conveyed from the oil production wells and the tank systems and converts the gas into natural gas, propane, and natural gas liquids (NGLs). Natural gas is conveyed by offsite pipelines owned by others. Produced propane is stored temporarily onsite and shipped offsite by means of certified trucking companies owned by others. And the NGLs are combined with clarified crude oil prior to sale.

The water plant processes the water through a series of clarification tanks and filtering units. Residual crude oil is skimmed and returned to wash tank systems. Filtered water is then conveyed and injected back into the original oil/water formation.

The State of California has the strictest oil production-related health and safety standards in the nation. Over 20 government agencies oversee oil and gas operations in California and our company. Like other oil and gas producers, we must comply with each agency’s guidelines in order to obtain permits to continue to operate in the county and the state. Primary regulatory agencies include:

Sentinel Peak Resources complies with all California Air Resources Control Board (CARB) and South Coast Air Quality Management District (AQMD) regulatory measures. This means we must permit all sources with the potential to emit air contaminants, or equipment that manages fluids (crude oil, gas, and production water) that could emit, prior to operation. We are required to monitor and report on that equipment and any associated emissions to both agencies to remain in good standing and continue to operate. We are also subject to scheduled and unscheduled audits as part of our permit oversight and compliance.

As all pumping units are powered by electricity, and the field does not have a large amount of fossil fuel powered equipment, the facility GHG emissions are below the CARB formal GHG reporting threshold.

The Inglewood Oil Field is also governed by the Baldwin Hill Community Standards District (CSD), which places additional regulations and testing requirements on the oil field. Through the CSD, we conduct soil gas monitoring, additional groundwater monitoring, and participate in monthly meetings with the community to discuss oil field activities.

To learn more about our environmental, social and governance initiatives, please refer to Sentinel Peak’s website at www.sentinelpeakresources.com.

The IOF has oil production wells, production water injection wells, and idle wells (ref. FAQ #2). As of November 2023, the following is a list of the number of active and idle wells in the IOF:

The listing will be updated annually concurrent with the submittal of the annual drilling, re-drilling, and abandonment plan.
The last well drilled in the IOF was in June of 2014. Although we do reserve the right to propose new wells for drilling, there currently are no plans for installation of new wells.

SPR typically targets to plug and abandon 12 wells each year.

For more information on the IOF wells and associated plans on the wells, please see the annual drilling, re-drilling, and abandonment plan.

Yes, the Los Angeles Department of Regional Planning conducted two Health Risk Assessments (HRAs), one as part of the Environmental Impact Report for the CSD and an updated study in 2020. A third HRA was completed as part of the air quality study required by the Settlement Agreement; the air quality report and associated HRA was completed in 2015. In addition, as also required by the Settlement Agreement, the County Public Health Department conducts a periodic Health Assessment and Environmental Justice Study. The first study was completed in 2011, a second study is currently underway by Public Health with the assistance of UCLA. The following are instructions and links to each of the three previous studies conducted and reported in 2008, 2011, 2015, and 2020:

a. 2008 HRA. This is the original baseline HRA. It is associated with and contained in the EIR. Select the “Background” tab on the main website (Baldwin Hills CSD - LA County Planning) and scroll down to “Final EIR Documents”. Then click on “Baldwin Hill CSD Final EIR” and the “Baldwin Hill CSD Final EIR – Appendices.” These links provide the zip files for download. After downloading, the “Inglewood Oil Field Baseline Health Risk Assessment,” the HRA writeup is found in Section 4.3.1.4. Supporting calculations are provided in the second zip file, which are appendices b, c, and d.

b.2011 Department of Public Health “Inglewood Oil Field Communities Health Assessment (February 2011)”: InglewoodOilField_ReportCombinedwAppendix.pdf (lacounty.gov)

c. 2015 HRA. “Baldwin Hills Air Quality Study” (113 pages): Baldwin Hills Final Report (lacounty.gov).

d. 2020 HRA. INGLEWOOD OIL FIELD Health Risk Assessment Report: https://planning.lacounty.gov/wp-content/uploads/2022/10/bh_health-risk-assessment-report.pdf

For comparative purposes, the table below provides the overall summary results for each completed HRA and the results of the South Coast Air Quality Management Districts’ Multiple Air Toxics Exposure Studies (MATES). MATES results are provided for the Los Angeles Basin and include total risk from all air pollution sources including mobile sources (i.e., not specific to any single source or industry). Cancer, chronic, and acute risks for each HRA are listed below together with corresponding State threshold levels. Levels above State thresholds are subject to regulatory measures to further minimize health risks; levels below State thresholds are not. For further details, please check the links to each HRA and MATES as provided below.

* http://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies. Corresponding Multiple Air Toxics Exposure Studies (MATES)
studies completed by SCAQMD; III in May 2008; IV in May 2015; V in August 2021.

With reference to the MATES results, there has been substantial improvement in air quality regarding air toxics emissions and exposures, however, the health risks continue to be high within the south coast air basin, especially near sources of toxic emissions such as the ports and transportation corridors. Diesel PM, while also substantially reduced from past MATES, continues to dominate the overall cancer risk from air toxics. The reduction in diesel PM emissions within the basin has resulted in significant improvement in cancer risks in the areas adjacent to the ports which was the area with the highest cancer risks in previous MATES.