Valle Lindo High School Expansion Site, No. 2

Valle Lindo High School Expansion Site, No. 2

The Removal Action Work Plan (RAW) proposes to excavate approximately 3,900 total cubic yards of contaminated soil up to 7.5 feet. The contaminant of concern is a metal, arsenic. Arsenic concentrations range from 0.27 mg/kg to 178 mg/kg. Impacted soil will be removed for disposal off-site. Confirmation samples will verify the site-specific cleanup goal for arsenic has been achieved. In order to prevent any potential exposure to the chemical of concern by adjacent faculty, staff, students, residents and site personnel, students and staff and a start work notice will be issued to adjacent residents requesting that they keep their windows closed during the field activities, and the excavation areas will be controlled to avoid dust generation with physical barriers and soil wetting. Additionally, airborne dust monitoring will be conducted using real-time, data-logging aerosol monitors, to verify and document the effectiveness of dust suppression in the work zone and the immediate perimeter, including the fence-line of the nearest receptors, during the field activities. No excavation will be conducted in times of high wind conditions. The site will be secured using temporary chain-link fencing with locked gates to restrict unauthorized access to the stockpiles and work area. The RAW provides additional field provisions to be put in place, in the event of adverse weather, to control run-off, ponding or erosion. Excavation, confirmation sampling, waste soil characterization sampling and off-site disposal activities for the impacted soil, and backfill and site restoration are expected to take approximately 35 calendar days to complete. Excavated soil will be placed in a temporary staging area until soil profiling is complete and the uncontaminated soil is used as backfill, and the remaining stockpiles are transported off-site for disposal. The soil will be stockpiled on impermeable material and covered with tarps to prevent run-on and/or dust generation and bermed to contain any run-off, or placed in covered roll-off bins. The excavated soil is estimated to require removal by approximately 300 trucks, covered, and transported under proper manifest to the pre-approved facilities for disposal. All vehicles will be decontaminated prior to exiting the loading area. Transportation of contaminated soils will be on arterial streets and/or freeways, minimizing any potential impact on the local neighborhood. Trucks will be staged to avoid impacts on the local streets. Transportation will be timed to avoid rush traffic hours. Transport of the material will be conducted in accordance with the transportation plan included in the RAW, prepared under the Cal-EPA DTSC Transportation Plan Preparation Guidance for Site Remediation, 1994. This will minimize potential health, safety, and environmental risks resulting from the movement of material and/or equipment during site cleanup.

El Monte

Los Angeles