TAG reports: Volume 3, Number 1; February,2001
Phase III Remedial Investigation Report:
Summary
Over the past year, the Glynn Environmental Coalition received from the Environmental Protection Agency two Feasibility Study plans for the Brunswick Wood Preserving Superfund Site. Unfortunately, neither provides accurate estimates of the length, width and depth of the Operable Units. Because of this, it is not practical to understand how extensive the cleanups may be, or even where they may occur on the site. Recently the GEC received the two volume Final Report Phase III Remedial Investigation, Brunswick Wood Preserving Site December 2000. These new documents describe a series of field studies conducted over the last several months. These follow-up studies do succeed in confirming some soil contamination borders, and show that off-site groundwater plumes are wider than previously shown. The studies confirm the accuracy of some earlier observations relating to organic contaminants. Further, the studies show that off-site contamination along Burnett Creek can occur. The new studies omit some areas the community is concerned about; for example, there is little new information regarding the now blocked outfall pipe that emptied into Burnett Creek. However, the central question is: “Does Region 4 EPA now have enough information to define Unit 1 or 2 and plan a cleanup?” Unfortunately, that answer appears to be “no” since important studies relating to ponds IM4 and IM5 did not furnish complete data. It seems that the central issues of cleanup borders and volumes are not completed by these studies.
Discussion:
Located in western Glynn County Georgia, the Brunswick Wood Preserving Site is a former wood treatment company. When in operation, the company treated wood products using chemical slurries. Considerable amounts of chemicals leached into soils and groundwater around the area and persist to this day. Dioxins, organic carcinogens, and arsenic, along with many other chemicals, are all found in toxic amounts. Although the site has been the target of both federal and state Emergency Cleanup efforts to stabilize the area and remove the toxins, the site still releases to the environment through groundwater. Much of the soil is still toxic to humans and wildlife.
The current thrust of EPA’s efforts on this site is the treatment of the remaining site soils. Although Region 4 EPA has no overall strategy for the site, or at least has not shared their plans with the community, it appears the direction of the cleanup is to stabilize site soils and monitor to see if groundwater is then cleaned by passive dilution. Many in the community prefer a more ambitious cleanup that returns the site to safety and usefulness.
The purpose of the Remedial Investigation is to provide useful data to model a cleanup Feasibility Study. To accomplish this, it is essential to know what chemicals are present, and their concentrations and distributions. The type of chemical present is important in determining the cleanup. The chemical concentrations and distributions are used to create a map that directs the cleanup. Unless the cleanup map is complete, the cost of the cleanup cannot be determined. The overall size of the cleanup may affect decisions on the technology. Removal or mounding, for example, may both become impractical if the volumes are too large.
At BWP there are two draft Feasibility Studies for areas named Operable Unit 1 (OU1) and Operable Unit 2 (OU2). The Final Feasibility Study –OU1, dated October 1999, describes an area encompassing the IM1 ponds area in conjunction with the “CCA cell,” a mound of toxins left over from the earlier emergency cleanup actions. However, these two areas are not contiguous—roads and heterogeneous areas of contamination separate them. The boundaries and volumes of OU1 were unclear from that document. A second Feasibility Study draft; described as the Feasibility Study Technical Memorandum for Operable Unit 2 dated December 1999, was also received. This document describes OU2 as being just about any area, other than OU1, that has pollutants affecting groundwater. How cleanup volumes were calculated for OU2 was very unclear; the authors merely made some guesses. There are no maps or graphs showing the borders of either OU1 or OU2. Unfortunately, the Remedial Investigation III provides very little new insight into the cleanup process.
Findings:
Groundwater
Overall, these new studies do provide a better understanding of groundwater underlying the site, especially regarding the nature and extent of groundwater plumes. From the data, it appears that there are two groundwater plumes moving to the west from the site, crossing under Perry Lane Road towards Burnett Creek. One plume comes from the IM1 pond area; the same area associated with the Burnett Creek outfall pipe that was finally closed this past summer. The other plume runs from the IM4 and IM5 pond areas. Deep well testing does not show contamination moving across the creek, or moving deep into groundwater supplies. However, the characterization studies indicate that a layer of clay mentioned in earlier reports does not completely protect groundwater across the site. The fact that the plume is wider than thought indicates there might be more sources affecting groundwater than previously known. The principle chemicals affecting the groundwater are the cancer hazards benzene and PAH. In the summer of 2000, in response to public debate and congressional inquiry, the EPA blocked a pipe that fed oily pollutants directly to Burnett Creek. Note that the sources to this pipe were not treated, and the toxins will accumulate in groundwater and contribute to future plumes. There is not enough information to model these new pollutant plume effects, and it is not clear if the present water well testing system is sufficient to monitor the increased discharge to groundwater.
Off-site soils
and sediments
Longtime residents tell of fume-clouds that were frequently moving from the site across nearby property during past plant operations. There were fires and apparently explosions also releasing chemicals into the air. The lower levels of site chemicals that are found in the top soil all around the site are most likely from these past events, and not from present-day runoff. Unfortunately, EPA did not perform thorough off-site soil studies until fairly recently, so it is not possible to know if the levels are declining. At this time there does not appear to be a specific acute hazard from the chemicals along the immediate perimeter of the site.
Site chemicals affect both the creek banks and sediments. This is not surprising since the creek received effluent from the start of operations (about 1959) until the summer of 2000. At this time, there are too few studies to be confident the creek or its banks are safe. Many tons of toxic effluents were dumped from the site to the creek. The stream does not flow swiftly enough to remove all of the material to the ocean, and these compounds have half-lives that are too long to be completely broken down. More studies are definitely needed to fully account for Burnett Creek pollution.
Site Soils
These new studies confirm the nature and levels of contaminants leftover from the Emergency Removal Action. Areas around the containment mounds were resampled and shown to still contain high levels of dioxins, carcinogens, and toxins. The IM4 and IM5 pond areas were retested but the extent of contamination was inconclusive. This is unfortunate since cleanup volume estimates cannot be accurately gauged at this time, and the effects of a cleanup on groundwater plumes remains unpredictable. To be fair, the pond soils are a difficult material to study. Since the ponds are dry part of the year, Region 4 EPA was hoping to study the material as if it were soil rather than pond sediment. Soil has different testing parameters than pond sediment. The cleanup levels (level of chemical concentration) can also be different—usually more restrictive-- for sediments. The actual testing encountered a mixture of groundwater and soil very near the “soil surface” which did not allow accurate estimates of toxin depth. This failure is significant. Without this data, it is not likely that estimations of total cleanup volumes can be accurately calculated. Further, it seems unlikely that the pond “soils” can be included in an operable unit that is aimed at surface soils.
To handle the pond “soils” as true soils, it will be necessary to dewater the areas in some way. The two obvious methods are inserting physical barriers upgradient between the groundwater source and the ponds, or continuously pumping all of the groundwater in the area out of the ponds through a pump field. Neither alternative is cheap. Note that, based on the information provided by EPA so far, it is not clear if the IM4/5 pond area is included in either OU1 or OU2. Overall, it appears the current studies show that the ponds cannot be considered soil for the purposes of remediation in Operable Unit 1.
Finally:
The Final Report Phase III Remedial Investigation, Brunswick Wood Preserving Site December 2000, consists of an executive summary and sections on site groundwater, soils, off-site areas and the banks and sediments of Burnett Creek. Although there is a section labeled “Purpose of Report” the description provides no insight into how this Phase III Report fits into the remedial process at Brunswick Wood Preserving. Surface and subsurface areas associated with OU1 are confirmed, but no new information is presented that would clarify the two different areas (OU1 and everything else - OU2) for remedial volume calculations. The Phase III report does not provide information or models on the IM1 pond hydrology or the short or long-term groundwater plume effects from plugging the outfall pipe. It remains unclear if the IM4 and IM5 ponds that contribute to one plume are to be included within OU1 or OU2 or if they will comprise a third operable unit. Further, the depths, and therefore the cleanup volumes, cannot be reliably estimated using this data. It appears that either additional testing or a clarifying report is still needed before either a Feasibility Study can be undertaken or a remedy proposed.
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