Results
The site description in the Remedial Investigation is deficient since it
uses old data on surrounding development and demographics. This is significant
since much of the long-term planning for remediation is based on the site's
influence on the general population. If the site description is invalid, then
the choice of remediation alternatives can be biased. The site description
provided in the RI is a "snapshot" of the site as things were in the
mid-1980's. The area actually exhibits high growth of residential and commercial
developments that does not appear to be factored in to remedy selection. Some
estimates place the local population at near 1 million residents by the time
this site is remediated. However, the site description is that of a rural
area development not an urban area. Also, the Anclote River description
in the RI is limited to that of a commercial waterway and sport fishing
recreation area. Actually, both sides of the river are used as residential
frontage.
Ponds
Much of the material was found to be harmless soils separated from the
phosphorus; however, elevated levels of arsenic, barium, cadmium, chromium, lead
and zinc were detected in soil borings. In addition, organics such as PCB were
found in low levels in former pond sediments. Soil boring logs report
construction debris and metallic junk in addition to chemicals. The logs also
indicate disturbed soils in the lagoons to depths below the water table. The
ponds closest to the Anclote River were tidally influenced. Although
predominantly dry now, these ponds were likely conduits for contamination
to the Anclote River during plant operations.
Elemental Phosphorus
Five main concentrations of elemental phosphorus were detected. Near the
"powerhouse" at pond 44, within pond
49 near Brady Road, Ponds 48 and 49 in the center of the lagoon area, and
around the perimeter of pond 46 near the Anclote River. Well water studies
indicate that elemental phosphorus is not migrating with the surficial aquifer.
Surface and Subsurface Soils
The Northeast Property nearest the Elementary school shows levels above
the background soils for cadmium and arsenic. Subsurface soils show arsenic as
deep as 6 feet near pond 39.
The 1988 study was not a systematic analysis of the site. There were
insufficient soil analysis, and the subsurface soils were merely an afterthought
of well placement activities. With the exception of the elemental
phosphorus/buried drum hunt none of the surface or subsurface
investigations were very methodical or logically planned.
The EPA's selected remedy for
the site is primarily based on consolidation and capping. Only a few percent of
the basement material will be stabilized following the EPA's recommendations.
Since much of the understrata will be left in contact with the water table it is
essential that all areas containing toxins be located and stabilized prior to
placement of the consolidated materials.
The amount of effort on site in the demobilization and processing of the
site prior to the initiation of site studies raises concerns that the surface
soils present at the time of sampling are not representative of actual site
conditions. Surface soils may not be truly indicative of industrial activity if
the site has been covered over with fill material in the course of demolishing
buildings and removal of the railroad beds and processing equipment.
This effect would not show up in these studies. Most of the soil borings
were in the pond bottoms or from drilling activity for monitor wells. Only one
study, in 1990, looked at subsurface soils in the processing areas and rail
beds, and these examined composite samples at two feet or deeper. Other
subsurface testing was conducted at depths of 4 feet or deeper.
It is not clear from the data provided if the areas requiring in
situ stabilization are well defined.
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