The debate unfolding in California over idle or abandoned oil wells located near schools, parks, homes, and care facilities risks drifting toward a familiar misconception: confusing proximity with danger.
No parent or caregiver wants to imagine industrial infrastructure posing a risk near places meant to protect vulnerable people. There are hazards associated with old oil wells, but steps can be taken to mitigate them and accommodate redevelopment and vibrant new land uses on sites with existing oil wells.
Land scarcity and housing demand are driving redevelopment into former oil fields, some of which appear as vacant lots surrounded by urban development. Redevelopment of these lands can unlock property value and support economic development, while protecting our health by mitigating the impacts of abandoned oil wells before and during the development process. In addition, various funding sources are available through multiple federal and state agencies.
Addressing Abandoned Oil Wells in California
California contains thousands of legacy oil wells embedded in developed cities as well as rural lands used for agriculture or environmental preservation (i.e., wetlands). California’s challenge is not simply where legacy wells are located, but how they are evaluated, managed, and regulated as land use changes.
San Diego County has far fewer oil and gas wells than counties such as Los Angeles, Ventura, Kern, and Santa Barbara. That difference is due to geology and the presence of petroleum reservoirs inherent in these areas.
Senate Bill 1137, enacted in 2022, created health protection zones around homes and other sensitive land uses in areas where idle or abandoned oil wells are present. The law reflects a long-overdue reckoning: California is far more urban today than when many of these wells were drilled decades ago. Mitigating any risk to the environment, public health, and safety requires technical clarity of when and how the wells were drilled, not just maps showing the location.
Idle and abandoned oil wells in California are not unregulated relics. Oversight falls to the California Geologic Energy Management Division, or CalGEM, which enforces detailed standards (California Public Resources Code [PRC] § 3208.1) for access to the well, wellbore integrity, and abandonment under state law.
CalGEM can require the well to be “re-abandoned” to modern standards—standards that are far more stringent than those in place decades ago. They emphasize verified cement isolation, groundwater protection, monitoring, and testing to confirm long-term integrity for redevelopment.
Development and Health Can Go Hand-in-Hand
Even in locations with disproportionately high numbers of abandoned oil wells, a strategic redevelopment project with qualified petroleum engineers or geologists (e.g., Pacific City in the City of Huntington Beach or the 2nd & PCH shopping center in the City of Long Beach) is successful. The due diligence team reviews historical well records (available from CalGEM), verifies well locations in the field, assesses vapor and methane conditions, and coordinates closely with regulators and local agencies using a systematic approach.
Where necessary, Vapor Intrusion Mitigation Systems (VIMS) are built into the project design. VIMS are proven to prevent toxic chemical vapors from contaminated soil and groundwater from entering buildings, thereby protecting indoor air quality. Done early during due diligence — before construction begins — helps identify potential hazards and addresses them, protecting public health and preventing costs from escalating.
Differentiating Wells and Funding
It is important not to treat all idle or abandoned oil wells the same. Most publicly available maps from CalGEM’s Well Finder show the different types of wells and the operator on record. Many wells remain the responsibility of active oil and gas field operators and are subject to idle well management plans, bonding requirements, and escalating plugging obligations under recent legislation.
Others are truly orphaned, with no viable operator remaining. For those wells, California has established a state-run orphan well program, which includes a process for safely plugging and abandoning wells and four funding sources. The sources are:
Ensuring Regulatory Enforcement
In February 2026, the Center for Biological Diversity highlighted sensitive land-use areas with vulnerable populations where oil and gas wells exist. Public awareness is essential, but the conversation cannot stop at cataloging proximity. The real challenge is ensuring that regulatory enforcement, redevelopment planning, and funding mechanisms are aligned to meaningfully reduce site-specific risk.
This requires collaboration among regulators, landowners, developers, environmental advocates, and local governments. It requires acknowledging uncertainty where it exists while recognizing the technical frameworks already in place. And it requires moving beyond headlines toward informed decision-making.
CalGEM recommends that engaging qualified professionals—those who understand CalGEM’s requirements and California’s regulatory framework—is critical to evaluating legacy wells safely and responsibly. The opportunity now is to apply those evaluations consistently, transparently, and early in the land-use planning process, so communities are protected and urban infill and redevelopment can proceed without unnecessary fear, delay, or oversimplification.
Finding the Appropriate Support to Minimize Risk
We recommend finding an engineering firm, preferably with a background in the petroleum industry and a successful track record in remediating brownfields and performing highly structured due diligence. Your engineer will likely rely on the expertise of a geologist or hydrogeologist, depending on the location. You’ll want more than a due diligence consultant; you’ll need, in states like California, a California-licensed professional petroleum engineer (PE) and a California-licensed professional geologist (PG). Evaluating risks is complex, and firms like SCS Engineers provide the expertise to assess the land, complete the required plug-and-abandonment process for the wells, and make properties valuable, sustainable, and useful again.
Author: Senior Project Manager and Geoscientist Tim Rathmann. Confer with Tim or an expert in your area at SCS Engineers, or reach Tim on LinkedIn.
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Pennsylvania has a problem. A $2 billion problem.
From 2005 to 2015, I managed the plugging of nearly 1,000 wells in Pennsylvania, New York, and West Virginia. Many of the wells were old wells open to the atmosphere, leaking water, gas, or oil. My research indicated one firm had drilled tens of thousands of wells until the 1990s. Responsible companies like Shell Oil Company plugged many of the wells during my tenure after they learned they had acquired old wells through land transactions.
Many more wells were abandoned or orphaned for every responsibly plugged well.
The Pennsylvania Department of Environmental Protection (PADEP) stated there are nearly 27,000 abandoned and orphaned wells on the state and private property. PADEP estimates it will cost $1.8 billion to plug the known wells. In addition, there may be as many as 200,000 unaccounted wells. Large and smaller operators abandoned many of these wells 50-100 years ago. By 1880, 4,000 wells were producing in the Bradford Oil District alone, yielding 50,000 barrels of oil daily. Oil City had 2,000 wells along the shores of the Allegheny River. In the 1940s, the Drake property near Bradford, Pennsylvania, had over 800 wells on 1,200 acres. Many of these wells had since been abandoned or orphaned.
The abandoned/orphaned wells present several potential problems: surface water contamination, groundwater, or drinking water; methane migration to water wells or basements; hazardous air pollutants and greenhouse gas (GHG) emissions; and open holes.
Why have so many operators abandoned their wells without plugging them? And why are wells not properly plugged? The answers are multifaceted.
Inadequate plugging. In the early days, regulation of the oil and gas industry was motivated by the need to protect the oil and gas resources and not the environment. Many wells before the 1950s were either not plugged or plugged with little cement. Often tree stumps, brush, wood, and rocks, with a sack of cement thrown in, were used to plug wells. Even wells plugged in the 1950s and 1960s are not adequately plugged. When cleaning out old wells, we found junk in the hole like a deer skull, tools, brush, wireline, and trash.
Funding and Grant Programs
To address these environmental and safety issues, on November 15, 2021, the federal government enacted the Bipartisan Infrastructure Law, which allocated $4.7 billion to create a new federal program to address orphan wells. Nearly every state with documented orphaned wells submitted a Notice of Intent (NOI) indicating interest in applying for a formula grant to fund the proper closure and cleanup of orphaned wells and well sites.
Pennsylvania applied for and has received an initial grant of $25 million. The state applied for and received a Phase One Formula Grant of $79 million and is eligible for an additional $315 million Performance Grant in future years. The law also provides a separate $500 million program for the remediation of orphan wells on federal land, which the Department of the Interior (DOI) Bureau of Land Management will implement.
The DOI released draft Formula Grant Guidance to the states and the public on January 23.
Pennsylvania Act 136 of 2022 (Act of November 3, 2022, P.L. 1987, No. 136 Cl. 58 – OIL AND GAS) became effective January 3, 2023. This legislation amends Title 58 (Oil and Gas) of the Pennsylvania Consolidated Statutes to provide a mechanism for using grant money. It provides $40,000 for every eligible orphan well plugged with a depth of 3,000 feet or less or the actual cost of the qualified well plugger to plug the well, whichever is less. The Statutes also provide $70,000 for every eligible orphan well plugged at a depth greater than 3,000 feet or the actual cost of plugging, whichever is less.
In the event the qualified well plugger encounters unusual technical difficulties due to the condition of an orphan well, the department may, at its discretion, amend the grant award to cover the additional cost, with adequate documentation of those unexpected additional costs, if it doesn’t exceed the amount of the grant for a specific orphan well.
Success in managing this pressing issue requires dedicated effort and expertise from environmental professionals, in addition to government funding, who consider these factors:
Ownership due diligence. Researching ownership through title and tax records.
Where there are challenges, there are opportunities.
The investments to plug and remediate abandoned and orphaned wells create jobs, advance economic growth, reduce hazards, and greatly reduce GHG emissions to meet carbon reduction goals.
The process requires close coordination between the state, geologists, environmental engineers, and drillers. All are benefactors, and beneficiaries, along with the general public and the environment.
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