Appendix I - Hazardous Materials Documentation - VTA

Contaminant Management Plan, SVRT/BART Extension
• Unrestricted Off-site Reuse, in which soil and ballast excavated from the project can be reused in any
off-site situation without restriction, including residential uses, or near a stream or shallow
groundwater.
• Unrestricted On-site Reuse, in which soil and ballast excavated from the project can be reused in any
on-site area. This includes areas within a MPZ.
• Stations and Facilities, in which soil and ballast excavated from the project can be reused in areas
where there is anticipated to be relatively frequent potential exposure, like stations and maintenance
facilities, but not within a MPZ.
• Right-of-Way, in which soil and ballast excavated from the project can be reused in areas where there
is anticipated to be relative infrequent potential exposure, like along the BART tracks and right-ofway,
but not within a MPZ or areas which are part of a riparian fringe habitat.
• Encapsulation, in which soil and ballast excavated from the project can be reused under barriers or
other structures (and covered on all exposed sides by clean material). Encapsulations will not be
placed within a MPZ or areas which are part of a riparian fringe habitat.
Soil and ballast that contains chemical constituents at levels greater than the acceptable reuse concentrations
for any of these five reuse scenarios will be disposed of off-site at an appropriate disposal facility in
accordance with Section 4.4.
4.2.3 Reuse Scenario Selection Process
This section describes the process of classifying soil and ballast into one of the reuse scenarios listed in
Section 4.2.2. In order to be eligible for a reuse scenario, a data population (Section 4.1.3.1) will have to meet
the most restrictive of the reuse criteria for that scenario, as listed in subsequent sections. The reuse criteria
are a combination of two types of values: 1) the site-specific risk assessment (SSRA) values for that chemical
and exposure scenario (from Section 3), and 2) the screening values from existing regulatory agency
guidance. For each reuse scenario, both SSRAs and regulatory agency screening values are developed
specifically for that chemical and exposure scenario.
In order to determine the reuse scenario in which a data population should be classified, the designer for each
project segment will compare the EPCs (either 95 percent UCLs or maximum values, as described in Section
4.1.3.3) to the SSRAs values and the screening values derived herein. Whichever is the least restrictive reuse
scenario for which the data population satisfies all the requirements will be the classification received by that
data population.
4.2.4 Screening Values
Screening values were obtained from a variety of sources, particularly existing regulatory agency screening
values. Depending on the various exposure scenarios, separate screening values were selected for different
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