Case Studies: Full-Scale Operations and Delivery Systems - Stabilization and Solidification of Hazardous, Radioactive, and Mixed Wastes - page 350

TABLE 13.3
Summary of Treatability Study Results for Soil Core Samples in
Case Study #2

Performance Evaluation

Preliminary

Stabilized and
Unstabilized

Unstabilized Stabilized

Volatile
Organic Compound

TCLP
(mg/L)

Total
(mg/kg)

TCLP
(mg/L)

Total
(mg/kg)

TCLP
(mg/L)

Vinyl chloride < 0.009 < 0.009 < 0.009 < 0.15 < 0.002

1,1 - Dichloroethylene < 0.007 < 0.007 < 0.007 < 0.12 < 0.002

Methylene chloride < 0.006 < 0.006-0.012 < 0.006 < 0.10 < 0.004

Trans - 1,2 - Dichoroethylene < 0.007 < 0.007 < 0.007 < 0.12 < 0.002

1,1 - Dichloroethane < 0.006 < 0.006 < 0.006 < 0.10 < 0.001

Chloroform < 0.007 < 0.007 < 0.007 < 0.12 < 0.002

1,1,1 - Trichloroethane < 0.012 < 0.012-0.054 < 0.012 < 0.20-0.44 < 0.003

Carbon tetrachloride < 0.009 < 0.009 < 0.009 < 0.15 < 0.003

1,2 - Dichloroethane < 0.006 < 0.006 < 0.006 < 0.10 < 0.002

Trichloroethylene < 0.013 < 0.013-0.059 < 0.013 < 0.22 < 0.003

were performed according to EPA SW-846 Method 8260. Total uranium was analyzed
according to CNES Science and Technology Division Method 90284 using a laser
kinetic phosphorimeter. Total technetium was analyzed according to method EC 206
for soils, and EC 038 for waters, both MMES methods.
A summary of results is shown in Table 13.3. Only three of the ten target
compounds were detected in samples. Methylene chloride and TCE were detected
at levels just above the analytical detection limit in two untreated core samples.
Neither was detected in the treated samples. Also, 1,1,1-trichloroethane was detected
at levels just above the analytical detection limit in one untreated core sample, but
was detected at elevated levels in the total volatiles analysis of two of the treated
core samples. This appears to be an anomaly, since these results are 5 to 10 times
higher than the total VOC results of the untreated samples. Previous experience
suggests that “hot spots” (small localized areas in the soil that contain elevated levels
of volatile organics) could be present in the soil and cause this type of response.
The TCLP results suggest that the admixture handled these elevated levels. However,
proof of reagent effectiveness is uncertain from these treatability study results,
because total analysis results indicate significant losses during mixing of the small
core samples, an inherent problem when working with VOCs. The in situ system
for the field demonstration likely resulted in less loss from mixing, although verifi-
cation proved difficult, as attested to in Section 13.4.2.5. No uranium was detected
in the untreated and treated samples (detection limit of 20 ppm). Small amounts of
technetium (up to 1.7 pCi/g) were present in the untreated samples. No technetium
was detected in the TCLP extract of the treated samples, but this could be from
dilution.