Keeping Mercury Out of the South River -- Will It Work?
The South River and South Fork of the Shenandoah River have struggled with a legacy of industrial mercury pollution since the late 1920s. This year, the Virginia Department of Environmental Quality has approved a plan to begin remediating and restoring contaminated riverbanks. WMRA's Kara Lofton reports. This story has been updated.*
We are standing outside Constitution Park in Waynesboro.
MICHAEL LIBERATI: That’s the former DuPont Plant, now Invista Plant.
Michael Liberati is the project director for DuPont. He manages remediation projects like this one for the industrial giant all over the country. Here on the bank of the South River, Liberati is overseeing a project to replant vegetation on riverbanks laced with mercury so it doesn’t continue to leach into the water. On this stretch, though, one of the most contaminated on the whole river, the soil has to be removed first. He points at two smokestacks in the distance.
LIBERATI: So that’s the area that the original input of mercury from the plant to the river occurred.
For decades, the DuPont plant here made rayon. Mercury was used as a catalyst in the production – although that practice was discontinued in 1950. In the late 1970s, a DuPont construction team noticed high mercury levels in the soil around the factory. The next year, the Virginia Department of Health issued a fish consumption ban for more than 100 miles of stream bank stretching from Waynesboro to Front Royal. In the 1980s, the ban was shifted to an advisory. Experts thought that over time the level of mercury in fish tissue would improve on its own. It didn’t. The problem?
LIBERATI: There’s a continuing source of mercury input into the river.
Now, they’re trying to fix it.
[Sound of the river]
Construction began here the first week of November. Liberati says the project is expected to take two to three months to complete -- much less time than it took for all the stakeholders to approve the plan.
JAMES SHAW: I think the earliest proposals -- we were kind of startled -- in that they called for a lot of excavation of soils along the riverbanks.
SHAW: Ultimately I think our concerns were several-fold – one was the loss of riparian buffers and established tree stands and the effect that it would have on aquatic habitat and that sort of thing on the river as well as the aesthetic impact on the river.
Waynesboro is trying to reinvent itself from an industrial town to a tourist town. So Shaw says preserving existing assets like the urban trout fishery and boat access points is extremely important to officials – especially because physical contact with the contaminated soil isn’t that big of a deal from a health perspective – it’s really just the fish.
VINCE MAIDEN: So that’s our ultimate goal is to reduce the levels in fish until that risk has been eliminated or significantly reduced.
That’s Vince Maiden, RCRA Corrective Action Project Manager for the Virginia Department of Environmental Quality. RCRA is a program that investigates and oversees the cleanup of hazardous waste.
MAIDEN: Since we became involved it’s been fast-moving from a regulatory perspective, and we’re happy to see some action on the river and some steps being taken to remove the contamination and protect human health and the environment.
But local officials eye the huge clean-up with a mixed sense of approval and caution.
SHAW: I think our concern at some level gets to be that we recognize the mercury contamination has had effect on habitat...But we are also concerned -- is the cure worse than the disease at some level?
Shaw is referring to the scale of the project and the impact that it will have on the beauty of land that encompasses both private and public property.
[Sound of construction]
This is the first stage of construction on the remediation project. About 70 feet of riverbank are being excavated here because this is where the pollution is most pronounced.
LIBERATI: The excavated area will be backfilled, first with a layer of biochar…
LOFTON: What is that?
LIBERATI: It’s a hardwood that has been fired at low temperature to form something akin to charcoal...We’ve done a lot a lot of research on it, and we’ve found that it has properties to attenuate and to lock in mercury. It’s kind of like a belt-and-suspenders approach in that while we are excavating the majority of the mercury, any residual mercury that may be there will be tied up by the biochar.
They will then use a capping technique that includes replanting the riverbank with native vegetation. This capping technique will be used on the rest of the banks without excavation.
The land they are currently working on is actually still owned by DuPont. As they move down river they will have to work with the city and private landowners to be granted access to the banks. Such a large scale private-public remediation partnership, Maiden says, may be unique in Virginia.
*Update, Thursday, Dec. 15: DuPont has agreed to a proposed $50 million settlement with the Commonwealth of Virginia and the Departments of Justice and the Interior. In a statement by the Department of Justice, the settlement will [quote] "compensate the public for the natural resource injuries and losses in ecological and recreational services." In addition to a cash payment of just over $42 million, DuPont will fund significant renovations at the Front Royal Fish Hatchery, estimated to cost up to $10 million. The settlement terms are outlined in a proposed consent decree filed in federal court in Harrisonburg on December 15.