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SummerHill Apartment Communities 10391.000.000 Rollins Road—Carolan Avenue, Burlingame November 19, 2014, Revised January 14, 2015 8.0 SOIL MANAGEMENT The Pre-Demolition Environmental Summary identified areas of concern on the Site that will require additional characterization and attention prior to Site development. These include pre- 1940 undocumented fill, the former lumber planing and coal storage areas, former underground and above-ground storage tanks, and data gaps discussed in an earlier section of this plan. 8.1 CONSTRUCTION ACTIVITIES The proposed soil mitigation consists of the removal of impacted soil, if any, encountered during demolition/construction that exhibits concentrations exceeding the noted ESLs. TPH-diesel and TPH-motor oil RAOs of 100 mg/kg, as well as TPH-gasoline and BTEX RAOs around the former UST area. These conservative activities will address potential concerns regarding potential groundwater impact and successfully reduce potential human health risk to acceptable levels for future residents and workers. Primarily, visual and olfactory evidence will be used for soil screening; however, a photo- ionization detector (PID) will also be used to further screen soils for potential contaminates, as well as ambient air during excavation work. The specific locations of air monitoring will be field-adjusted based on potential access and safety limitations, but will generally include within the excavation area, along with the perimeter of the excavation. PID readings will generally be taken at least every hour and whenever suspect material is encountered. PID screening of soil sampling will be conducted using the following methodology: • A minimum of five samples will be recovered from suspect areas using one-gallon ziplock bags. • Each bag will be allowed to equilibrate in direct sunlight, if possible, to allow for headspace accumulation. • The PID probe will be placed into the bag and headspace VOC readings will be recorded • Samples exhibiting highest PID reading will be submitted to the laboratory in stainless steel tubes and Encore samplers. With regard to ambient air screening, any PID reading for volatile organics that is 10 ppm above background for more than 3 minutes will result in a stop work order. Background will be determined at the beginning of the day prior to excavation activities. Work will not continue until PID readings have attenuated below the action level. The PID will provide real-time data on the presence of potentially hazardous compounds to provide for proper selection of Personnel Protection Equipment (PPE). The initial PPE will be Level D (modified) which includes safety glasses, hard hat, steel-toed boots, gloves, hearing EhGEO —Expect Excellence