Appendix I - Hazardous Materials Documentation - VTA

4.1.1.2 Hot Spot Characterization
Contaminant Management Plan, SVRT/BART Extension
The preliminary reconnaissance characterization may identify certain samples with unexpectedly high
contaminant concentrations. The unexpectedly high concentration samples may indicate an area represented
by either a single sample or a relatively small number of samples. When these concentrations threaten to
adversely affect the final design and/or construction, these results will be considered a potential indicator of a
“hot spot”. In such circumstances, additional sampling and analysis will be performed to further characterize
the hot spot.
The approach to additional sampling and analysis will be dependent on the specific concentrations and
relative locations of the unexpectedly high concentration samples. “Step-out” sampling will continue until the
extent is defined to the limits of proposed construction. Hot spot characterization may be performed during
either the final engineering design or the construction phases of the project.
Once the vertical and horizontal extent of the hot spot is defined, this material will be removed during the
construction phase. Hot spot material will be managed in accordance with the guidance provided herein,
though handled separately from the surrounding excavated soils or ballast.
4.1.1.3 Discovery of Unknown Impact
Care will be taken during construction activities to note any stained, discolored, or odorous soils. If such soils
are encountered, work will be stopped and the environmental engineer or geologist will be consulted. In the
case of discolored soils, if the engineer or geologist decides that there is significant cause, the soil will be
sampled for TPH-d (or any other suspected contaminant). In the case of strong odors or visual indications, the
soil will be sampled for TPH-g, TPH-d, volatile organic compounds (VOCs), and/or SVOCs. No further work
will be conducted with the impacted soil until analytical results have been received and reviewed, and either
the soil has been found not to contain hazardous substances or engineering controls have been implemented to
protect worker health and safety. During characterization, site control measures will be implemented to
minimize exposure to potential hazardous substances.
4.1.1.4 Waste Disposal Characterization
Soil and ballast that contain chemical constituents at levels that are above the corresponding reuse
concentrations (see Section 4.2) will be properly disposed off-site. Other material may also be disposed offsite
at VTA’s discretion, such as soil that is not appropriate for reuse due to geotechnical or other
characteristics, or excess material. As part of this process, all material to be disposed off-site will be
characterized for final disposition while still on-site.
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