Contributed by Todd Perry, CEO, PPM Consultants
There’s a quiet revolution underway in how we manage underground storage tank (UST) releases—and it’s long overdue. For years, many programs have focused on compliance in its most technical form: making sure the paperwork is right, the test dates are current, and the boxes are checked. But those of us in the trenches know that compliance isn’t the finish line. Closure is. And not just closure for closure’s sake—but safe, scientifically sound, risk-informed closure that protects people and the environment while allowing sites to move forward.
The EPA FY25 Mid-Year UST Program Report and the companion Exposure Threat Assessment Policy Statement mark a notable shift in that direction. These documents signal that it’s not enough to simply monitor tank tightness or replace parts on schedule. We must also consider the actual exposure threats posed by a release and apply science, data, and judgment to guide our decisions—especially when it comes to legacy cases that have lingered for years.
The EPA data show that the national UST compliance picture is improving. In fact, more than 80% of inspected facilities are in compliance with spill, overfill, and corrosion prevention rules. Roughly 71% have effective release detection systems. Those numbers are encouraging. But here’s the challenge: there are still thousands of sites across the country with old, unresolved petroleum releases—and many of them are stuck in regulatory limbo. These cases may not present an imminent threat, yet they remain open because traditional closure checklists haven’t been satisfied. In these situations, the real question isn’t just “Are they in compliance?” but “Are they still a risk?”
That’s the essence of the Exposure Threat Assessment Policy Statement, published in September 2025. The document reframes how we should think about long-term environmental risk. It urges regulators and stakeholders to focus on three core principles: identifying and eliminating exposure threats, applying multiple lines of evidence to confirm site conditions, and documenting institutional and engineering controls that protect receptors over the long haul. The EPA isn’t saying “lower the bar”—it’s saying, “aim at the right target.” And that target is real-world exposure risk—not just a number on a lab report.
This concept isn’t new, but it’s finally taking root at the national level. Across the country, the best-performing UST programs are embracing risk-based decision-making that aligns with the EPA’s guidance. They’re tailoring cleanup goals based on land use, groundwater use, vapor intrusion potential, and the presence—or absence—of viable exposure pathways. They’re calculating site-specific target levels (SSTLs) using groundwater models, vapor attenuation factors, and leaching scenarios. Some are using formal tiered frameworks that range from simple screening for low-risk sites to full risk modeling for complex urban plumes. These aren’t shortcuts—they’re scientific tools that help us make better, faster, and more defensible decisions.
Another critical element of modern risk-based programs is what I call “threats-first logic.” Before considering a No Further Action (NFA) determination, the best programs require that free product be removed to the extent practicable, indoor air risks be evaluated and mitigated, and drinking water threats be fully addressed. This prioritization aligns squarely with the EPA policy. It ensures we’re not chasing contaminant concentrations in a vacuum—but focusing first on whether people or resources are truly at risk.
To do this well, oversight agencies need strong internal protocols and a commitment to scientific integrity. We’ve seen programs use cancer risk thresholds of 1×10⁻⁵ and hazard indices of 1.0 as baselines, adjusting as needed for sensitive populations. Some go further, allowing case-by-case risk thresholds based on land use controls and engineered barriers. Importantly, these decisions are not made in isolation—they’re supported by peer-reviewed technical guidance, structured decision frameworks, and transparent documentation. That kind of structure builds confidence with stakeholders—especially when closure decisions become politically or legally sensitive.
Let’s be clear: this is not a call to abandon compliance. Strong compliance programs are still the foundation of UST oversight. The EPA FY25 data underscore the importance of operator training, digital tracking systems, and proactive communication with tank owners and consultants. Many states are implementing tiered enforcement strategies that escalate only when deadlines are missed, creating a collaborative rather than punitive dynamic. Compliance efforts are most successful when paired with education, shared tools, and clear expectations. That’s how we prevent tomorrow’s releases while managing today’s.
And while we’re building stronger compliance programs, we should also be looking ahead—because risk-based closure is where the future lies. That’s why so many of us are closely watching the adoption of the ASTM E3488-25 “Moving Sites to Closure” (MStC) standard. This document offers a structured yet flexible playbook for embedding closure thinking into every phase of site management. It emphasizes clear decision points, documented risk communication, and the use of site-specific exposure scenarios to guide remediation and closure. Whether or not a state has formally adopted MStC, the spirit of the standard is showing up in policy changes, new guidance documents, and internal training programs across the country.
The MStC approach complements the EPA’s exposure threat policy perfectly. Together, they create a roadmap for moving beyond static, one-size-fits-all rules toward dynamic, science-based closure strategies. Programs that embrace this model are seeing real progress. They’re reducing backlogs, closing low-threat sites with confidence, and focusing their resources where they matter most: on the sites that still pose risk.
At the end of the day, we need to stop thinking of compliance and closure as separate goals. They’re two halves of the same mission. Compliance keeps new problems from emerging. Risk-based closure resolves the old ones. And when they work in tandem, we can protect public health, promote redevelopment, and restore trust in environmental programs.
The challenge isn’t whether we have the tools—we do. The challenge is whether we’re willing to change our mindset, refocus our efforts, and let science lead the way. The EPA has set the tone. The MStC framework has laid out the path. Now it’s up to us—to close the gap with science.
If you’d like to see more articles like this on a weekly basis, consider subscribing to the PPM Environmental Journal. Click HERE to subscribe.