Hinkley Groundwater, Chromium-6 and Erin Brockovich

Hinkley is an unincorporated community in the Mojave Desert of San Bernardino County, about a dozen miles west of Barstow. From 1952 to 1964, Pacific Gas and Electric (PG&E) let chromium-6 wastewater from its Hinkley compressor station drain into unlined ponds, and it reached groundwater. As of October 2026, the state Lahontan Water Board says the plume is not migrating, but cleanup continues and no final cleanup level has been set.

Where is Hinkley, California?

Hinkley lies in Hinkley Valley, where groundwater moves through sand and gravel left by the Mojave River, as the USGS explains.

The Lahontan Water Board's PG&E Hinkley page puts PG&E's natural gas compressor station roughly two miles southeast of town. Barstow is about 12 miles to the east. If you are coming from Helendale, see our Helendale and Silver Lakes guide; for Barstow, see our post on the BNSF Barstow International Gateway.

How did chromium-6 get into Hinkley's groundwater?

The station added hexavalent chromium (chromium-6) to its cooling-tower water to fight corrosion. The Board's 2015 Cleanup and Abatement Order says that water, untreated, went to unlined ponds through 1964. From there it soaked down to the water table, roughly 80 feet below.

Per the same order, PG&E stopped using chromium for this purpose in 1965 and switched to lined ponds in 1972. In late 1987 the utility told the state about the contamination. The Board's first cleanup order followed on December 29, 1987.

What was the Erin Brockovich case and settlement?

Hinkley residents sued PG&E over the contaminated water. NPR reported that PG&E agreed to pay $333 million. The ABA Journal dates that payout to 1997, while a 2019 Grist article says the money was divided among 633 plaintiffs. Reported figures vary slightly from source to source.

NPR notes the case inspired the 2000 film Erin Brockovich. Grist and the ABA Journal describe it as an Oscar-winning movie with Julia Roberts in the title role. The film is a dramatization that condenses and alters events, so read it as a story drawn from the case, not a record of it.

How big is the Hinkley chromium plume?

In 2015, the Board's order measured the upper-aquifer plume at roughly 8 miles by 2 miles. It stretches north through Hinkley Valley toward Harper Dry Lake Valley. The order also flags areas farther out where the parties disagreed on whether the chromium came from PG&E or from nature.

Today, the Board's project page says PG&E's monthly reports show the plume held south of Thompson Road. The October 2026 Status of Actions states that second-quarter 2026 data show "plume migration is not occurring."

What does the cleanup order require?

The order in force is Cleanup and Abatement Order R6V-2015-0068, which has since been amended. PG&E must keep the plume from spreading and shrink it. Its key goals for the southern plume:

PG&E injects ethanol to feed native bacteria that turn chromium-6 into a less mobile form. It also pumps groundwater and uses it on farm fields. Materials for the Board's January 2025 meeting count 68 extraction wells and roughly 725 monitoring wells, with about 89% of the chromium mass removed so far.

Slides from PG&E in that packet claim the 50 ppb goal was reached in 2024. An earlier March 2024 report by PG&E's consultant said progress was on track but that more work might be needed. We did not find a Board ruling on the December 2025 goal in its 2026 status reports.

Why was the background chromium level debated?

Desert groundwater can carry some chromium-6 naturally. That makes the cleanup target a return to natural background, not zero. The 2015 order set interim background caps of 3.1 ppb for chromium-6 and 3.2 ppb for total chromium, drawn from a 2007 study PG&E paid for.

That study was contested. The USGS notes that its limits, and disagreement over background levels, left the plume's true edge uncertain. The Board turned to the USGS for a new study in 2015.

The USGS released its findings in April 2023. Its background estimates were 3.8 µg/L for the valley as a whole, 4.8 µg/L in the north and 2.8 µg/L in the eastern area around the compressor station. It also concluded the plume caused by people is bigger than the one regulators had mapped.

Views still differ. In the January 2025 Board packet, a summary from the community's independent review manager said residents generally felt a 9 ppb background figure was too high and did not match the USGS work.

Where does the Hinkley cleanup stand in 2026?

The Board issued Investigative Order R6-2026-0014 on July 28, 2026. It directs PG&E to deliver a feasibility study that will help the Board choose a cleanup level for chromium in groundwater. The final study is due July 28, 2027.

Other recent steps, per the October 2026 report:

• The Board signed off on revised deep-zone capture metrics on October 15, 2026.
• PG&E asked to change sampling at 39 monitoring wells; Board staff were still reviewing the request.
• PG&E's third-quarter 2026 plume map was due November 10, 2026.

Did PG&E buy homes and provide replacement water?

Yes. NPR reported in 2012 that owners within a mile of the contamination could choose a whole-house water treatment system or sell to the utility. By then, over 200 owners had sold. In 2019, Grist reported the utility held roughly two of every three properties in Hinkley.

The 2015 order records that PG&E ended bottled and whole-house water on October 31, 2014. It still requires PG&E to supply interim bottled water within 10 business days if a domestic well linked to its releases tests above 10 ppb chromium-6. The January 2026 report says PG&E began bottled water at one home after a nearby monitoring well rose in 2024. Results from that group of wells have since stayed under 10 µg/L.

What is California's chromium-6 drinking water standard?

California's first chromium-6 limit took effect in 2014, and a Sacramento County court struck it down in 2017, per the State Water Board's chromium-6 page.

The Board adopted a new 10 µg/L (10 ppb) maximum contaminant level in April 2024, and it took effect October 1, 2024. The Board's adoption announcement gives water systems with more than 10,000 connections two years to comply, and those with fewer than 1,000 connections four years.

The limit covers public water systems. A private well is up to its owner. Across the High Desert, from Hinkley to Lucerne Valley, well water can contain natural chromium.

Buying a property with a well near Hinkley: what should you check?

1. Check the plume maps. The Lahontan PG&E page posts maps by quarter; the latest as of November 2026 covers the second quarter of 2026. Project files are also on GeoTracker. The page lists a staff contact at (760) 241-7373.
2. Test the well. Pick a lab accredited through the State Water Board's ELAP program; its map helps you find one. Ask for chromium-6 on top of the standard tests.
3. Know the county guidance. San Bernardino County Environmental Health says owners pay for their own well tests. It suggests a yearly check for bacteria and nitrates, plus other concerns such as arsenic, fluoride, iron, manganese and sulfur.
4. Look for free programs. The State Water Board's private well testing page links a directory where you can pick your county and see state-funded testing programs.
5. Read the disclosures. Ask the seller for past well test results and any letters to or from PG&E or the Board.

How Pleasant Hill can help

If you are looking at rural property with a well in the Hinkley or Barstow area, we can help you line up the right records and a water test before you commit. You can search homes, request a free home valuation, or contact us. Broker Dustin Bynum and Nancy Navarro in Hesperia work the High Desert.

General information, not legal, tax or lending advice. Rules, fees and rates change; confirm with the agency linked above or ask us. Pleasant Hill Real Estate Group · CA DRE Corp. #01997374 · AZ Entity Lic. #LC694532000 · Equal Housing Opportunity.