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Mr. Chris Dressel SB1072.400.0002 January 27, 2014 Page 3 Should any potentially complete vapor intrusion exposure pathways be identified, depending upon the nature and extent of the potential vapor intrusion i%H, Hu®V\f+vLFHVP Dy InFOO-i V1H I R(MwwlnJ W".. a. Task 1: Enaineerina review of facility systems at current or future structures: This task would primarily consist of an in -depth review of available structural documentation, including architectural and mechanical design /construction documentation. b. Task 2a• Interview current operations & mainWMDnFH V491 I DnG RwnHr'V rHSrHV+\DNb1 -V This task would include interviews of any designers, staff, and /or appropriate maintenance service providers to clarify current or proposed heating, ventilation, and air conditioning (HVAC) system operations.. C. Task 2b• Validate current or proposed HVAC control conditions: This task may include an evaluation of the proposed HVAC system, or functional tests of an existing HVAC system to evaluate technical details such as air supply and exhaust quantities. d. Task 2c• Measure and validate existing HVAC airflow quantities: If appropriate for an existing HVAC system, for this task, Hull may measure, through industry standard procedures, the facility outside air and exhaust airflow quantities. e. Task 2d• Measure and validate existing_ building pressures: If appropriate for an existing structure, this task would entail detailed evaluations such as measurement of current building pressure relative to the outdoors at both minimum and maximum outside air operational conditions. f. Task 2e• Determination of Beneficial Outside Air n uantity: If data collected during Task 2d at an existing structure suggest that an HVAC system may be enhanced to maintain an industry accepted positive building pressure, Hu ®P Dy FRP S(EWt' 7D\N 2H DVVM &LWV discretion. Hull will conduct Tasks 1 and 2a. through 2d. above in a step -wise manner to control costs and realize efficiencies where feasible. Hull will initially complete Tasks 1 and 2a above, should any potential current or future vapor intrusion issues be identified. Next, as deemed appropriate, Hull will conduct Task 2b above, should the results gained from the completion of Tasks 1 and 2a suggest that Task 2b will provide meaningful results. Finally, Hull will complete Tasks 2c, 2d, and 2e above should they be deemed necessary and meaningful, and only subject to specific prior written authorization by the City. Should they be identified as necessary, Hull offers that the costs to complete Tasks 2c, 2d, and 2e concurrently could result in relatively significant savings by realizing efficiencies from a single mobilization, reduced per diem costs, etc. Should it be deemed that Tasks 2c, 2d, and 2e are necessary, Hull commits to evaluating the most reasonable, cost - effective, and meaningful approach with the City prior to seeking authorization for Tasks 2c, 2d, and 2e. Task 3 Install Temporary and Permanent Groundwater Sampling Points This Task will begin with a Site visit to evaluate the presence and condition of all on -site monitoring wells, as well as to mark boring locations before public utility locators are contacted. Additional on -Site groundwater sampling (through the installation of permanent monitoring wells, as presented below) to evaluate the potential impact from COCs associated with the former Studebaker operations is required. Also, as we have discussed, an evaluation of the extent to which off -Site sources may have impacted groundwater underlying the Site is necessary. The installation and sampling of a series of temporary groundwater monitoring points in the vicinity of the area generally bounded by hendall Street (and alley to the west), Edward Street, Scott Street, and Indiana Avenue south and west of the Site (i.e., across the upgradient sectlRn RI J rRunGwDWIF I nW%lnJ V1H 61]WV\Ru\%H`MDrFH (PwIJ(MIJG1n