Reports from residents near Raleigh-Durham International Airport describe an outlandish scene – workers roaming in white, full-body hazmat suits while a billowing plume rises in the sky.
This steady activity is in fact a sign of progress on the Environmental Protection Agency’s clean-up at the former Ward Transformer facility located off of Mount Herman Road. The 11-acre lot is on the federal Superfund list, making it one of the nation’s worst toxic waste sites.
While crews are busy cleaning the site and plan to clean up three tributaries near Ward Transformer, the EPA says it will not cleanup downstream where community and environmental groups say many of the contaminants have gone. The EPA says it will monitor Brier Creek Reservoir, Lake Crabtree and Lower Crabtree Creek, but does not plan to clean those waterways.
Since clean-up began in the summer of 2008, crews have demolished the buildings which housed Ward Transformer offices. The EPA’s contracted team continues to excavate, test and clean thousands of pounds of tainted soil in an effort to remove the main contaminant, polychlorinated biphenyls (PCBs).
Until 2006, The Ward Transformer facility repaired and reconditioned transformers and other types of electrical equipment at its location in northwest Raleigh. The company’s indiscriminate disposal of PCBs, a compound commonly used as lubricants in transformers prior to 1977, led to the site’s contamination, eventually seeping into surrounding areas and more than 30 miles of local waterways.
In 1977, the manufacture of PCBs was banned after studies revealed they build up in the environment and can cause harmful health effects. PCBs likely cause cancer, skin conditions and liver damage in humans, according to the EPA and the International Agency for Research on Cancer.
Last October The News & Observer reported that the pollution was far worse than projected, with the first phase of clean-up lasting through mid-2009.
According to Luis Flores, site project manager for the EPA, the project’s timeline for the PCB removal action completion will be pushed into late-summer or early-fall.
To date, the team has already processed more than 200,000 tons of material and will likely reach 300,000 tons, said Flores. The EPA had originally estimated the need to excavate roughly 150,000 tons of contaminated soil. According to the agency’s 250-page decision, outlining the clean-up strategy, some areas of the Ward Transformer site contain the highest levels of PCBs ever detected in soil.
The removal action currently taking place is the first phase of the clean-up plan, an effort to contain and remove the source of the pollution. This measure “must be taken to eliminate immediate and near-term threats to human health and the environment,” according to the EPA’s Superfund Site Progress Profile.
“Cleaning up PCBs is tricky business because they don’t break down easily and are not easy to clean up,” said Dr. Peter DeFur, an environmental consultant who provides technical services on contaminated site clean-up. “Going after the source is a key first step.”
The chosen method for eliminating PCBs from excavated soil at the Ward site is a process known as low temperature thermal desorption. During this process, the contaminated soil is excavated and then heated up to 1900 degrees Fahrenheit. Because PCBs are volatile at high temperatures, it separates from the soil in a gas stream, is routed to a thermal oxidizer and destroyed with additional heat.
The PCB-free gas stream is then cooled with water and discharged out of a steam stack. The rising plume seen for miles around RDU is the steam generated from this cooling process. According to Flores, federal regulations require the system to achieve more than 99.99 percent PCB destruction. This process is a typical solution for Superfund sites like Ward, deFur said, and is often viewed in communities as a better alternative to the incinerators.
According to Alissa Bierma with the Neuse Riverkeeper Foundation, recent tests have revealed PCB contamination in fish throughout Crabtree Creek. The contamination extends into a three-mile section of the Neuse River, Bierma said.
The current plan for clean-up downstream of the former transformer facility involves excavating contaminated sediment and soil from three tributaries near the Ward site as well as lower Brier Creek. The EPA will stop active clean-up there, outlining Monitored Natural Recovery (MNR) for waterways further downstream, including the Brier Creek Reservoir, Lake Crabtree and Lower Crabtree Creek, where contamination is reported to be below the allowable limit of 1 part per million. Meanwhile, Wake County has ordered the public not to take or eat any fish in these areas.
The clean-up remedies selected by the EPA depend on the varying levels of contamination. According to Flores, excavation and clean up will occur in areas with PCB contamination concentrations above 1 milligram per kilogram. Other areas with residual PCBs (less than 1 milligram per kilogram) will be monitored to ensure natural recovery, Flores said.
DeFur insists that the available data doesn’t add up, given the extent of fish contamination in these bodies of water. “They need to know where the PCBs are coming from,” deFur said, adding that additional sampling and testing may be needed to determine if there are any “hot spots” of contamination.
As the name implies, MNR leaves the site as-is, relying on natural processes to reduce the risk of contaminated sediments. This process involves assessments, modeling and continued monitoring of a contaminated area. Both Bierma and deFur contend that there is no positive evidence that demonstrates MNR as an effective solution. “I have never seen it work,” deFur said.
Bierma said she hopes that the EPA will weigh other options and implement a more aggressive strategy, adding that clean-up plans are amended often. “It is not set in stone that monitored natural recovery is the way to go,” Bierma said. “We don’t have enough information to even select an option right now,” she added.
“EPA believes that the overall remedy as described in the ROD [Record of Decision] is the most feasible alternative to address the PCB contamination related to the Ward Transformer site and is not considering any other alternatives at this time,” Flores said.
Bierma’s main concern is for minority populations who often practice subsistence fishing in Lake Crabtree and Crabtree Creek. “People are still taking PCBs home, especially with the downturn in the economy.” She is currently working to communicate the activities surrounding the Ward site contamination. Updates on the issue can be found on the Riverkeeper’s Web site.
The Ward Transformer site has been on the EPA’s radar since the late 1970’s. In 1978 and the following year, collected samples on-site revealed PCB contamination in the area soil, storm water impoundment and water and sediments in an unnamed tributary nearby and Little Briar Creek. However, the EPA did not revisit the site until 1993, when it conducted a removal investigation, finding no contaminants above levels that would call for a removal action in the investigated area.
In 1994, a North Carolina Superfund Section assessment recommended an expanded site inspection, which revealed further and more serious contamination. Almost a decade later, the Ward site was added to National Priorities List of toxic sites, launching a phased investigation from April 2003 to Aril 2007.