Applying Net Environmental Benefit Analysis to Contaminated Sites

Exxon Valdez oil spill site

Exxon Valdez oil spill site.

First, do no harm….

Or at least don’t do more harm than good.

That’s the idea behind NEBA—Net Environmental Benefit Analysis—as applied to the cleanup of contaminated sites. As defined by a vintage 1990s Department of Energy paper on the subject, net environmental benefits are:

“…the gains in environmental services or other ecological properties attained by remediation or ecological restoration, minus the environmental injuries caused by those actions.”

Spills like Exxon Valdez Spurred the NEBA
The NEBA concept originated with the cleanup of large marine oil spills. One of the first formal considerations of Net Environmental Benefits was the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989. After the spill, the U.S. National Oceanic and Atmospheric Administration (NOAA) looked at whether high-pressure, hot water washing of unconsolidated beaches might actually do more harm to the intertidal habitat—and the plants and animals that depend on it—than just simply letting the oil degrade naturally.

Since then, NEBAs have been used for a few other types of cleanups, including metals contamination in wetlands and organic contamination in sub-tidal sediment, but only infrequently and on an ad hoc basis.

No current NEBA Guidelines, However…
Formal consideration of net environmental benefits has not been more widespread in cleanup decisions, probably because federal and state cleanup frameworks, such as Washington’s Model Toxic Control Act (MTCA), do not explicitly allow consideration of the harm of the cleanup itself and don’t provide guidelines for when the process would apply and how the benefits and impacts should be evaluated.

But that might be changing. At least it is in Washington State, where the Department of Ecology thinks that the NEBA’s time has come. Ecology is working on new draft Terrestrial Ecological Evaluation (TEE) guidance that, for the first time, lays out the implementation of NEBA at cleanup sites under MTCA.

NEBA and Abandoned Underground Mines
In conjunction with Ecology, Hart Crowser has already “test driven” the NEBA concept as it applies to the cleanup of abandoned underground mines. Many of these sites pose risks to terrestrial plants and animals because of the toxic metals such as copper and zinc left behind in tailings and waste rock.

Although the risks to individual organisms living on the waste material might be high, the overall risk to plant or wildlife populations are often fairly low because the extent of the waste material is so small. Nonetheless, the remedy selection process under MTCA would typically lead to a decision to cap the contaminated material with clean soil or to dig it up and haul it away to be disposed of elsewhere.

Bringing Common Sense into Cleanup Decisions
But what if the cleanup involved building an access road? Through mature forest? Or up a steep, exposed mountain side? Or across a stream or wetland? How are those habitat or ecosystem injuries balanced against the benefits of the cleanup itself? Ecology’s upcoming NEBA guidance should go a long way to addressing these dilemmas and bringing some common sense into certain cleanup decisions.

“Especially Valuable Habitat”
The new guidance is expected to introduce the concept of “Especially Valuable Habitat” and how to use it as a threshold for judging whether or not a NEBA may be appropriate for a particular site. It’s also expected to allow some flexibility regarding how injuries and benefits are quantified and balanced.

In the meantime, check for updates on when the new guidance is expected at Ecology’s website.