Final Second Five-Year Review Report Fort Ord Superfund Site ...

• Drilling 23 borings to depths of 15 to 20 feet bgs on an approximate 50-foot grid
• Collecting 69 surface and subsurface soil samples for lithologic characterization and chemical and
physical analysis
• Analysis of soil samples for explosive compounds and priority pollutant metals.
The findings of the field investigations at Range 36A indicated the following:
• The explosive compounds cyclotetramethylenetetranitramine (HMX) and RDX were present at low
levels (maximum concentrations of 1.84 and 16.5 mg/kg, respectively), were generally limited to
shallow soil, and were below PRGs. The PRG for HMX is 803 mg/kg and the PRG for RDX is 4.4
mg/kg.
With the exception of beryllium detected at a maximum concentration 0.89 mg/kg in shallow soil, metals
in soil at the site were below background or PRG concentrations. The Fort Ord PRG for beryllium is 0.39
mg/kg. The most recent EPA Region 9 PRG for beryllium is 150 mg/kg.
Additional sampling was conducted in 2004 to investigate the areas used after the previous investigations
and to verify the presence of RDX above the PRG. At the request of DTSC, dioxins and perchlorate were
also analyzed. The following items summarize the 2004 investigation:
• Ten soil samples were collected.
• RDX was detected in one sample but at a concentration less than the PRG of 4.4 mg/kg.
• Perchlorate was not detected in any of the soil samples.
Dioxins were detected at low levels (less than the 2,3,7,8-Tetrachlorodibenzo-p-dioxin [TCDD] PRG of
3.9E-06 mg/kg) in each of the surface samples. One dioxin congener was detected at soil sample
collected at a depth of 5 feet but at a concentration was less than the 2,3,7,8-TCDD PRG. Additionally,
all calculated TCDD-TE concentrations for dioxins detected in the soil samples were less than the
2,3,7,8-TCDD PRG.
Status Report
The Final RCRA Closure Plan, Range 36A, Former Fort Ord, California (Solid Waste Management Unit
FTO-016) (MACTEC, 2005) was submitted in 2005. This plan was amended after geophysical
investigation revealed widespread metal debris across the whole site. In the amended plan, the Army
proposed to excavate and investigate additional areas to demonstrate with a reasonable probability that
MEC are unlikely to be found at Range 36A. These amended closure procedures will provide sufficient
information to determine whether Range 36A meets the closure performance standards or additional MR
is warranted.
The amended closure activities were completed in February 2007. No MEC was found. The final closure
certification report was submitted in June 2007.
18.1.3 Solid Waste Management Units (SWMUs)
Background
In support of Fort Ord’s RCRA Part B permit application, the Army Environmental Hygiene Agency
identified 58 Solid Waste Management Unit (SWMUs) in 1988. All but two of these 58 SWMUs were in
areas investigated during the RI/FS or were previously identified as Operable Units. In 1996, the Army
identified 14 additional SWMUs. The Draft Field Investigation and Data Review, Solid Waste
Final
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FORMER FT ORD 5YR REVIEW 2007_FINAL United States Department of the Army