Evaluation of Federal Requirements for Plugging Orphaned Oil and Gas Wells: A Missouri Case Study

Orphan Wells in Missouri

There are an estimated one million orphaned oil and gas wells across the United States—abandoned sites with no responsible party to ensure proper closure and cleanup, often due to corporate bankruptcies. As fossil fuel production declines and more wells are left behind, the number of orphaned wells is expected to grow. Without oversight, these aging wells leak methane, volatile organic compounds (VOCs), and brine, contaminating groundwater, degrading air quality, fueling climate change, and in some cases, posing explosion risks. Plugging orphaned wells is essential to protect public health, the environment, state economies, and community safety.

The Biden Administration made historic investments in orphan well remediation through the Infrastructure Investment and Jobs Act (IIJA) and the Inflation Reduction Act (IRA). These federal funds enabled states to begin or expand plugging programs, including efforts to prioritize wells in marginalized and environmentally overburdened communities. While actions taken by the Trump Administration removed key environmental justice (EJ) screening tools from federal platforms, states are moving forward with their plugging programs. This report provides guidance to help state agencies continue prioritizing well plugging efforts in communities most at risk—especially those historically underserved or disproportionately exposed to pollution.

Introduction to Plugging Orphan Wells

Orphaned oil and gas wells pose serious threats to both the environment and public health. As oil and gas production declines, the cost of plugging wells, shutting down facilities, and cleaning up contamination often exceeds what companies are willing—or able—to pay. Weak bonding requirements have left these costs uncovered, resulting in a growing crisis. Around the world, millions of orphaned wells are leaking methane, other greenhouse gases, and toxic hydrocarbons, which degrade air quality, contribute to ground-level ozone, and accelerate the climate crisis. 

State and local governments typically lack the millions or even billions of dollars required to reclaim these sites—restoring them to stable, natural, or usable conditions. This report examines Missouri’s efforts to leverage federal funding to plug orphaned wells and critiques the federal standards guiding how states prioritize wells for remediation. 

Federal and State Funding Landscape

While the Trump Administration initially paused the distribution of federal funds for orphan well plugging operations, recent discussions with state regulators have clarified that the programs are again active .  Unfortunately states will not be required to consider environmental justice impacts in their well plugging prioritization plans or in the disbursement of funds.

The Biden administration initially tied orphan well funding to the Justice40 Initiative, which aimed to direct at least 40% of federal environmental investments to disadvantaged communities. However, the elimination of Justice40 requirements (Executive Order 14008) and other federal environmental justice (EJ) tools by Trump on March 1, 2025 has left states largely on their own to determine how to allocate resources.

Despite federal agencies no longer publishing EJ tools, states can still access them. The U.S. EPA’s EJScreen (Version 2.3) and the Council on Environmental Quality’s Climate and Economic Justice Screening Tool (CEJST) are now hosted by Harvard University at screening-tools.com and available on GitHub.

Environmental and Public Health Risks

Decades of neglect and weak regulation have led to the deterioration of idle and orphaned wells. As metal components corrode, wellbore integrity fails—resulting in methane and hydrocarbon leaks. These emissions include volatile organic compounds (VOCs), which are toxic and, in some cases, carcinogenic. Leaks contribute to smog formation, pose explosion risks in enclosed spaces, and drive climate change.

Figure 1 below shows the locations of unplugged wells in Missouri. With few active wells generating revenue, most remaining unplugged wells are likely to become orphaned.

Figure 1.  Orphaned and Active Oil and Gas Wells in Missouri

Federal Funding Opportunities

The Missouri Department of Natural Resources (DNR) estimates approximately 5,000 orphaned or abandoned wells require plugging.Nationwide, the total exceeds one million. In response, the federal government has allocated $1.6 billion to states for plugging efforts—a significant start, though insufficient to address the full need. 

So far, Missouri has received $5 million in federal funding to begin plugging its orphaned wells, along with an additional $3 million to locate wells and test for leaks. The state is also eligible for up to $27 million more through federal formula grants to continue these operations.

Plugging Prioritization in Missouri

FracTracker Alliance met with the Missouri Department of Natural Resources to discuss their approach to plugging orphan wells using federal funds.

To use federal funding effectively, Missouri must identify which wells pose the greatest risks. While other states like California have published prioritization frameworks, Missouri has not. Instead, the DNR has hired two analysts to develop a strategy and ensure that funds are distributed equitably—avoiding favoritism toward affluent communities and ensuring marginalized areas are prioritized.

Initially, Missouri used just the U.S. EPA’s EJScreen tool to assess well locations, but federal guidelines in 2024 required the use of CEJST for prioritization. Although CEJST was considered the standard under Justice40, both tools remain useful for evaluating risk and equity. While the tools are no longer hosted on federal websites, both tools can still be used.

A critical component of any prioritization strategy is identifying actively leaking wells. Research shows high leak rates: up to 66% among idle wells, with orphaned wells likely to leak at even higher rates due to lack of oversight. Missouri has begun contracting environmental consultants to conduct leak detection, following the lead of activists like Laurie Barr in Pennsylvania, who organizes community research days to document orphaned wells and assess methane emissions.

Assessment Approach

This assessment evaluates Missouri’s orphaned wells by environmental justice criteria using both EJScreen and CEJST. While the tools draw from similar data sources, they use different methodologies to determine what constitutes a disadvantaged area.

EJScreen Analysis

EJScreen compiles demographic, environmental, and emissions data into a user-friendly platform. For this analysis, we counted the number of EJ indicators in the 80th percentile for each census block group. Indicators include PM2.5, ozone, diesel PM, air toxics cancer risk, traffic proximity, and more.

Wells in block groups with multiple indicators in the 80th percentile were prioritized. This analysis identified 770 wells—about 16% of Missouri’s total orphaned wells—as high priority.

Figure 2. Distribution of Wells by Count of EJ Indicators in the 80th Percentile.

CEJST Analysis

CEJST identifies disadvantaged tracts as those within the 90th percentile for at least one of 18 environmental or socioeconomic indicators and the 65th percentile or above for low-income households. Based on this methodology, 1,370 orphaned wells (28.5% of the total) were located in disadvantaged census tracts.

However, CEJST has limitations. It excludes cumulative burden and racial demographics and therefore may not capture real-world exposure risks as comprehensively as EJScreen.

Population Density Considerations

Neither CEJST nor EJScreen explicitly considers population density—a key oversight. Plugging wells in densely populated areas offers greater public health benefits by protecting more people. This is especially important in cities like Kansas City and St. Louis, where many high-risk wells are not in CEJST-defined disadvantaged tracts.

Figure 3. Map of Orphaned Wells in Kansas City, MO

Figure 4. Map of Orphaned Wells in St. Louis, MO

Conclusions

Relying solely on one EJ screening tool or on federal definitions of disadvantaged communities can hinder the effectiveness of orphan well remediation efforts. A comprehensive strategy must account for population density and cumulative burden to ensure that investments deliver the greatest public health and environmental benefits. Regulators in Missouri would benefit from incorporating the results of both EJScreen and CEJST to identify wells that exist in “disadvantaged” communities and then prioritize plugging efforts within and beyond this subset using EJScreen. Additional datapoints of well density, population density, and population distribution within census designated areas should also be considered.

By integrating multiple tools and considering both risk and impact, Missouri can develop a more equitable and effective approach to prioritizing orphan well plugging—one that serves the most people in the communities that need it most.