November 13, 2019

How a New Ecological Augmentation Remedy Option Could Advance Superfund Site Closures at Mining-Impacted Sites

Amanda Halter and Ashleigh Acevedo

What to do about mining and metals-related contamination is an increasingly pronounced concern under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), i.e., Superfund, regardless of whether a mine is still in operation, has been closed, or is an orphan mine under the care of the federal government. Plagued by insufficient financing and facing complex risk assessments and remediation decision-making, many such mining sites linger for years without resolution. In addition to their association with several different industrial operations, metals are of course also both naturally occurring and pervasive, making for particularly protracted, complicated, and ambiguous risk assessments outside the Environmental Protection Agency’s (EPA) dominant domain of managing threats to human health.

The quandary is that although many mining-impacted and metals-contaminated sites present little or no real human health concerns that have not already been managed through emergency or interim actions, ecological risks of varying and unclear magnitudes can remain for many years. When it comes to remedy selection for these risks, Superfund practice favors removing or treating contaminants. Office of Solid Waste & Emergency Response, Envtl. Prot. Agency, A Guide to Selecting Superfund Remedial Actions, Directive 9355.0-27FS (Apr. 1990); see 42 U.S.C. § 9621(b)(1) (“Remedial actions in which treatment which permanently and significantly reduces the volume, toxicity or mobility of the hazardous substances, pollutants, and contaminants is a principal element, are to be preferred over remedial actions not involving such treatment.”). But in certain sites, these standard responses can be a suboptimal solution––impractical and costly in time, treasure, and environmental impact relative to their potential benefits. Thus, at mine and metals sites where human health risks have been or are otherwise being managed and ecological risk considerations will predominate remedial decision-making, it may be time to break out of the source-control default and consider an additional alternative: an ecological augmentation remedy.

An ecological augmentation remedy is one that focuses on addressing overall ecological health of the site by increasing habitat or ecosystem productivity, rather than by the physical removal or capping of contaminants. At mine and metals sites at which only ecological risks remain, ecological augmentation may present a superior solution to the overall environmental problem when analyzed through the framework of the National Contingency Plan’s (NCP) nine remedy selection criteria. 40 C.F.R. § 300.430(e)(9).

Yet despite the availability of well-established science to support ecological augmentation as a remedy, it is infrequently—if ever—invoked under Superfund, though a variant has been embraced in some state programs, such as Texas’ Risk Reduction rules under the heading of “restoration.” This article evaluates the ability of EPA to adopt a policy that would allow for ecological augmentation under the current remedy-selection framework within CERCLA and its supporting regulations, and thereby address ecological risks at certain mining-impacted and metals-contaminated sites with a more efficient, more environmentally protective alternative.

The purpose of the CERCLA Superfund program was to establish authority and provide a financial vehicle and liability allocation to directly and comprehensively address contamination at sites that pose a real risk to human health and the environment. 42 U.S.C. § 9601. Since its inception, CERCLA has provided the federal government with the authority (through the EPA) to respond to the release or substantial threat of a release of any pollutant or containment that may present an imminent and substantial danger to public health or welfare and respond to a release or substantial threat of a release of a hazardous substance into the environment. Id. § 9604. The overarching purpose of the CERCLA response authority and remedial action provisions is to ensure that human health and the environment are protected. 40 C.F.R. § 300.430(f)(1)(i)(A). CERCLA gives the president (and EPA by delegation) broad authority to do what is “necessary to protect public health or welfare or the environment” 42 U.S.C. § 9604(a)(1).

Thus, Congress had the foresight to provide not only the authority to address public health implications of hazardous substance releases, but also to protect the environment. Unsurprisingly, the context in which CERCLA was created influenced the trajectory of EPA’s response authority. CERCLA arose after the specter of Love Canal in Niagara Falls, New York, where a dream community and school were built over a poorly constructed landfill from which 21,000 tons of chemicals (including dioxins, a carcinogen) were released. In a worst-case scenario, storage drums came to the surface of the landfill, the neighborhood and school ground were filled with noxious fumes, and birth defects, illnesses, and elevated white blood cell counts were pervasive throughout the community. After a presidential state of emergency was declared, the community was evacuated. News Release, Envtl. Prot. Agency, Love Canal Revealed a National Problem; Superfund Provided a Solution: EPA’s Superfund Task Force Continues to Ensure Cleanups Remain a Top Priority (Aug. 6, 2019) (referencing the Aug. 7, 1978, presidential federal emergency declaration and May 21, 1980, presidential federal emergency declaration designating the Emergency Declaration area for evacuations). The incident focused the public’s attention on the threat to public health from contaminated sites and the need for a comprehensive system to address them. The threat was humanized. In response, Congress created CERCLA to provide EPA with the authority to investigate, select, and compel remedies primarily to protect humans.

Since the primary focus of CERCLA was human health, at least initially, remedies generally include capping, treating, or removing contaminants, as well as access restrictions, thereby eliminating or minimizing human exposure pathways. Such approaches make sense when the focus is protecting individual humans; however, the assumption that what protects humans can be applied wholesale to the environment is not only anthropocentric, it can also be terribly wrong. That is because invasive remedies like removal and capping can lead to further environmental degradation as habitat is disrupted or destroyed.

And, as the program has evolved, many of the worst sites or portions of sites—i.e., those that present serious human health concerns—have been cleaned up or contained. Thus, resources and focus are shifted to ecological risk. However, that focus shifted without sufficiently adapting perspectives or approaches on remediation alternatives.

Yet human health risk and ecological risk are fundamentally different: whereas, we routinely focus, and should focus, our human health policies on mitigating risks to people, the value of individual ecological resources, i.e., an individual bird, worm, etc., is not one we typically recognize. That is, while we may care deeply about the exposures of an individual person and make remedy decisions accordingly, the exposures of a worm, insect, or benthic macroinvertebrate are simply not, or should not be, decision drivers, at least not without a clear-headed understanding of the ecological trade-offs. Using a human health–focused paradigm to make decisions about ecological risk assessment and remediation has led to protracted assessment processes and invasive remediations that too often provide little, if any, environmental benefit relative to the time and transaction costs involved.

That is, however, to be expected. Unlike impacts to human health, ecological impacts can be far more complex––rather than dealing with one species in a human health analysis, a proper ecological analysis almost always necessitates considering multiple species with sensitivity to varying threshold concentrations. Within the inherent complexity of the food web, ecological impacts can be more difficult to assess and remedy. In that vein, in the early days of CERCLA, significant uncertainty existed as to whether and to what extent damaged natural resources could be restored through what was, at that time, unproven science, and whether public resources could be used for such a purpose.

Consequently, when Congress amended CERCLA with the Superfund Amendments and Reauthorization Act of 1986 (SARA), it cut off access to Superfund funds for assessment of natural resource impacts during damage assessments so that the newly designated Superfund trustees, which excludes EPA, could assess damages and injury to, as well as destruction of or loss of, natural resources and be responsible for the restoration of trust resources injured by an uncontrolled release of hazardous materials. Pub. L. No. 99-499, Oct. 17, 1986, 100 Stat. 1613; 42 U.S.C. §§ 9507(c), 9607. Notably, only funding for natural resource damages assessment was cut off; Congress did not curtail EPA’s mandate to respond in a way to protect both human health and the environment.

Yet, cutting EPA out of Superfund monies for natural resource damages assessment effectively limited the holistic restoration perspective that more aptly fits ecological risk analysis. In effect, EPA was on one side of a dividing line, primarily focused on human health risks that necessitate cutting off exposures, and natural resource trustees were on the other, looking at ways to restore ecosystem-level damages. As a result, EPA’s purview has not meaningfully expanded to include innovative ecological augmentation-based solutions for minimally contaminated sites. Yet, where human health risks are absent or otherwise managed, such approaches can provide more holistic and efficient ecological risk management strategies than traditional remedies.

Ecological Augmentation Policy: A “New” Tool to Advance Site Remediation and Closure

What is proposed herein is that EPA can and should more holistically utilize ecological concepts and tools by adopting a policy that allows ecological augmentation as a remedy for site cleanup and closure. In some instances, where human health risks are either not present or have been addressed, the optimal response to contamination from an environmental perspective is not contaminant control or removal, but rather directly offsetting the ecological risks at issue through restoration or ecological augmentation that would counterbalance the decreases to ecological productivity or habitat degradation associated with the presence of the contaminants at issue.

Substantively, ecological augmentation is akin to restoration. The science of restoration has been well developed already by natural resource agencies in the years since Love Canal. The human-focused perspective on the impacts of hazardous substance releases expanded dramatically with the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska. The public observed disturbing images of deceased and harmed wildlife and severely degraded habitat. In the face of public outcry, responsible parties, spent tremendous resources to quantify the damage to natural resources and meaningfully try to understand ecological risks and harms, thus launching modern restoration science. Since the Exxon Valdez incident, restoration has come into maturity as a viable science and methodology. In turn, parties have developed widely accepted eco-econometric tools to determine how much restoration would be required to mitigate a given ecological risk. 43 C.F.R. Part 11.

EPA can and should utilize this science to identify and scale ecological augmentation remedies that directly address the ecological risks at issue for a given site. Embracing an ecological augmentation remedy policy would allow EPA to approach cleanup and closure at candidate sites more expeditiously and holistically. These sites are generally characterized as those in which the level and type of contamination is such that there is no danger to human health or such dangers have been addressed already; the only existing or remaining effects are to natural resources. The extent of the injury is a loss to productivity of certain receptions within the ecosystem or even to the overall productivity of the system, but the contaminants do not biomagnify such that contaminants are increasing in concentrations in the tissues of organisms as they move up the food chain. Such conditions may occur when human exposures to contaminants have been addressed through removal, treatment, capping, or institutional controls, but some contamination remains that leaves questions about more complex, subtle ecological impacts.

In such circumstances, directly increasing ecological productivity and habitat can be superior to traditional remediation (i.e., removing contaminants) by providing overall net environmental and human use benefits more expeditiously. In other words, at certain sites, an ecological augmentation remedy could be a better-suited response action than traditional remediation or could complement traditional remediation in achieving maximum rehabilitation of a contaminated site by allowing, for example, the site to be put back to productive use, such as for fishing, camping, and other recreational opportunities, much more quickly than if a traditional remedy were selected, such as dredging.

Ecological augmentation also supplants traditional remedial options that can cause further ecological harm. Traditional remediation can involve tremendously invasive and immediately destructive methods to remove contaminants. While these areas may recover ecologically over time, ecological augmentation, at a minimum, can maintain the existing productivity. But when human health risks are not at play and thus do not have to be prioritized, the health and productivity of the ecosystem can be made part of the remedy instead of defaulting to remedies that may be more harmful to the very natural resources intended to be protected than is the contamination itself.

For example, extensive dredging of a water body bottom to remove contaminants can destroy the benthic community, but that same community, or certain species therein, may be affected only marginally by the presence of low-grade contamination. In such instances, it should be considered whether it may be better to leave that contamination in the environment rather than destroy the benthic species residing there, and to instead explore ecological augmentation as a vehicle for offsetting productivity losses.

Moreover, ecological augmentation often offers a much greater value than traditional remediation practices. The return on the investment can be much greater: whereas traditional remediation at candidate sites would require time- and cost-intensive operations for relatively little (and sometimes negative) ecological benefit, an ecological augmentation remedy could be implemented at a much lower cost and much more quickly while enhancing ecosystem services and functionality.

In short, ecological augmentation can provide the following benefits: (1) allow faster cleanups and site closures; (2) return sites to beneficial use more quickly; (3) reduce total spending on CERCLA compliance while achieving similar results; (4) free up resources to be used at sites that pose an imminent threat to human health; (5) protect public health by limiting ecological augmentation to those sites, or portions thereof, that do not have unmanaged human health risks; and (6) shift the cleanup focus from reducing the volume of contaminants to increasing the net benefits to the environment.

Ecological Augmentation at Mining-Impacted and Metals-Contaminated Sites

Ecological augmentation is particularly well suited for mining-impacted and metals-contaminated sites. The reality is that the numerous unresolved mines and metals sites are not massive environmental disasters. They are not characterized by millions of gallons of toxic, yellow-orange wastewater flowing through the Animas River watershed following a mine blowout, as was the Gold King Mine in 2015. See Envtl. Prot. Agency, Emergency Response to August 2015 Release from Gold King Mine, Many mine and metals sites, and sizeable portions thereof, have relatively low-level concentrations of contaminants that, though impactful, are not a threat to human health, or even direct threats to fish and wildlife. Rather, the sites have been sufficiently remediated to address human exposures or several ecological ones, and instead only less obvious and more complex ecological impacts remain. At many of these languishing mine and metals sites, operations ceased long ago, such that minimal, if any, contamination is still being introduced. The contamination that does exist has settled out over the years, so natural attenuation may have at least begun to create marginal gains in addressing some ecological risks, though not enough to close out the site. These sites languish because they cannot practically be prioritized or funded, assessment is unclear, and traditional remedies are impractical. Yet because contamination remains in place, they remain in Superfund limbo—not harmful enough to demand immediate attention and resources, but not innocuous enough to be closed.

At such mine and metals sites, ecological augmentation provides a viable alternative remedy to advance these sites to completion. Rather than continuing to linger for years without resolution, an ecological augmentation remedy would present a tool for addressing the remaining ecological risks relatively quickly, at a much lower cost, and often at a greater overall environmental benefit or less overall environmental harm than would removal of the remaining contamination.

Implementation within the Existing Remedy-Selection Framework

Under the human health risk management paradigm, EPA tends to be geared, and properly so, toward traditional dig, dredge, and cap remedies at most sites, but there is nothing that prevents EPA from embracing ecological augmentation and eco-econometric tools and incorporating them into remedial options analysis and selection when the focus shifts to ecology. In fact, CERCLA contemplates an environmental response that enables EPA to take a holistic vision of site closure by evaluating various factors in the remedy selection decision framework. CERCLA and the NCP provide a framework for remedy selection that does not prescribe the substance of such decisions or an exclusive suite of available decisions, despite the historic default to traditional remedial alternatives. 42 U.S.C. § 9621; 40 C.F.R. § 300.430(e)(9). Rather, CERCLA requires that in selecting a remedy, EPA consider several criteria that reflect the scope and complexity of the site problems, many of which can be comparatively best achieved through ecological augmentation at candidate sites. 40 C.F.R. § 300.430(e)(9)(ii).

Upon performing the comparative analysis under the NCP, the risks associated with leaving contaminants in place at a candidate site can be shown to outweigh the risks and costs of traditional remedial actions. Moreover, the risks would be addressed more directly or better mitigated by the ecological benefit of restoring some of the functions of the ecosystem that occurred prior to the release. If, for instance, productivity is the potential risk being managed, then productivity can be increased directly through an ecological augmentation remedy. In most instances, it is much less costly and time consuming, and the benefits are more readily apparent to the public when the ecological resources of a site are enhanced than when contaminants, which usually are not visible or causing low-level effects, are removed at typically great expense and disturbance.

The statute provides room for the use of ecological augmentation, as appropriate. And, conversely, neither CERCLA nor the NCP preclude EPA from selecting ecological augmentation as a remedy, assuming it emerges as the best alternative for a given sort or portion thereof through the remedy-selection framework. To be clear, this policy approach does not propose that EPA overlap with the work of natural resource trustees in the natural resource damages arena; it simply suggests that the science behind a viable remedial technology that has been well developed by the natural resource trustees can be used to inform EPA’s own cleanup program.

In this way, ecological augmentation provides EPA with a tool to take an overall more efficient and more environmentally––and publicly––beneficial approach when it considers remedial alternatives, consistent with the NCP’s charge to embrace innovative remedial options. See 40 C.F.R. §§ 300.430(a)(1)(iii)(E), (e)(2)(ii), (e)(5). Embracing this remediation tool would allow EPA to mitigate the remaining ecological risks without creating additional ecological damage, and to provide what can, in some circumstances, be a more palatable path forward. In many cases, this will reduce the prejudice toward more intrusive, time-intensive and costly remedies that, although they intend to mitigate some predicted ecological risk, too often do so in an indirect and costly way, and in many instances, end up creating actual ecological injury in the process due to their brute disturbance of the ecosystem. And, on the other hand, ecological augmentation mitigates the public’s (and sometimes EPA’s) reluctance to leave marginally ecologically impactful contamination in place for fear that this will be pejoratively perceived as a “do nothing” approach, when the ecosystem can instead be augmented to flourish.

To effectuate such a policy, neither statutory nor regulatory changes are necessary. It can be deployed immediately within the current NCP framework. See 40 C.F.R. § 300.430. EPA could adopt guidance embracing ecological augmentation as a remedy choice, and direct site project managers and EPA Regions to consider it as a remedy where site conditions warrant. Further, given the wide availability of mine and metals sites over which the EPA has control—particularly orphan mine sites where remedies are limited given the practicalities of funding remediation—EPA could utilize this option to finally reach closure at those sites, and to use those sites to pilot an ecological augmentation remedy to guide its broader utilization and develop further guidance on use of this tool in remedy selection.

Opportune Climate for Ecological Augmentation Tool

Almost since its inception, though it has had many successes, the Superfund program has been afflicted by inefficiency, unpredictability, untenable durations, and extreme cost. Those problems are often exacerbated when it comes to mine sites with less-than-obvious remedies and limited resources. And, with human health risks relatively well understood and expeditiously addressed, too much of EPA’s focus has become scattered across a wide array of sites and situations characterized by diffuse or complex ecological concerns that are distinct from the focus of the original drafters of the Superfund program —those with harsh, blatant impacts to human health. Through this complexity, those sites have been administered by the various EPA Regions in different ways. A side effect has been the diversion of scarce resources away from sites that present predominantly environmental, as opposed to human health, risks. And, for many sites, such as mine sites, where the potential for ecological risk is a dominant consideration, ever-decreasing risk and cleanup standards have led to years and many dollars spent futilely chasing assessment and removal of low levels of contaminants without fulsome cost-benefit analyses.

However, the current era of regulatory reform presents an opportunity to address much of this through the adoption of new policy. The current administration’s EPA has committed to evolving the Superfund program, with its notoriously protracted processes, to return contaminated lands and waters to beneficial public and commercial use more quickly. See, e.g., Envtl. Prot. Agency, Superfund Task Force Recommendations (July 25, 2017). Through the creation of the Superfund Task Force and related actions by the EPA, this administration has affirmed its commitment to evolve and improve the Superfund program by expediting closure and getting back to basics of addressing those sites that have languished too long.

In this moment, EPA can choose to add ecological augmentation to its arsenal of site remediation tools. While EPA’s default is contaminant-removal remedies with the intention to reduce risks to ecological receptors by reducing or eliminating contaminants, ecological augmentation can more directly address the ecological risks perceived to be at issue for a given site—such as reduced productivity, biomass, or increased mortality—by instead directly improving the ecological health of the site.

This policy proposal would further strengthen the Superfund program by refocusing on the EPA and Superfund program’s core mission: protecting both human health and the environment. At the same time, this approach helps reach closure, but does not compromise the effectiveness of the Superfund program. This could reduce the total number of sites the EPA is dealing with by more expediently reducing risks to human health and the environment, closing sites that primarily implicate ecological effects, and accelerating the reuse of properties whose natural resources were affected by hazardous substance contamination, allowing EPA to focus on the sites that present substantial problems to public health and the environment.

More specifically, this policy proposal provides EPA and responsible parties a greater opportunity to address mine and metals sites that have lingered without resolution for decades. While it may not be a remedy for all mine or metals sites in the United States, it certainly can provide a viable solution to advance several toward closure. And, rather than continuing to maintain mining-impacted and metals-contaminated sites with only ecological risks under the auspices of the Superfund program for another decade or more, ecological augmentation provides EPA and responsible parties a means to address ecological assessment and remediation holistically and relatively quickly. Thus, greater focus and resources can be devoted to those sites that present real problems to public health and the environment.


Amanda Halter and Ashleigh Acevedo

Ms. Halter, a partner in the Houston, Texas, office of the international law firm Pillsbury Winthrop Shaw Pittman LLP, is a member of the firm’s Environmental & Natural Resources practice section. She may be reached at Ms. Acevedo is an associate in the same firm’s Houston office and is also a member of the firm’s Environmental & Natural Resources practice section. She may be reached at