Appendix I - Hazardous Materials Documentation - VTA

• RWQCB ESLs for Human Health, Commercial/Industrial land use;
Contaminant Management Plan, SVRT/BART Extension
• RWQCB ESLs for Groundwater Protection, Commercial/Industrial land use;
• US EPA Region 9 Industrial PRGs; and
• Ten times the STLC.
Screening levels for each chemical under the Stations and Facilities Scenario are listed in Table 5 by source,
as well as the selected resulting screening value for each chemical.
4.2.4.4 Right-of-Way
Under the Right-of-Way Scenario, material must meet acceptable standards for reuse where relatively low
exposure frequency is anticipated (such as maintenance of rail road right-of-ways), but not within the MPZ or
areas which are part of a riparian fringe habitat. The Right-of-Way Scenario is modeled by two exposure
scenarios, a reduced exposure frequency industrial exposure scenario to model on-site workers and
passengers, and a residential scenario to model off-site residents’ exposure to dust disturbed by trains passing
over the reused material. SSRA values for both of these exposure scenarios will be included in the screening
value selection.
Right-of-Way Scenario screening levels are either background levels or the most conservative of the
following:
• SSRA values calculated for the reduced exposure frequency industrial exposure scenario;
• SSRA values calculated for off-site residents’ exposure to dust disturbed by trains passing over the
reused material;
• RWQCB ESLs for Human Health, Commercial/Industrial land use;
• RWQCB ESLs for Groundwater Protection, Commercial/Industrial land use;
• US EPA Region 9 Industrial PRGs; and
• Ten times the STLC.
Screening levels for each chemical under the Right-of-Way Scenario are listed in Table 6 by source, as well
as the selected resulting screening value.
4.2.4.5 Encapsulation
Under the Encapsulation Scenario, material may be reused on-site under barriers or other structures (and
covered on all exposed sides by at least a 6-inch thickness of clean material), though these will not be placed
within the MPZ or areas which are part of a riparian fringe habitat. The Encapsulation Scenario is modeled by
construction exposure scenario, as post-construction exposures will be negligible due to the construction of
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