10179096_2103 S. GRAND - Plan (2)

Home Browse Search

Former Circuit One 2103 S. Grand Avenue, Santa Ana, California Proiect No. 11-0106 backfill material shall not contain chemicals above United States EPA Preliminary Remedial Goals. A geotechnical field technician will provide observation and testing services during backfill operations. The clean backfill material will be moisturized as needed by hose or water truck prior to placement, or else mixed as the fill material is being placed. Fill will typically be placed in 6-inch lifts and compacted. In situ density tests will be performed to determine when a minimum relative compaction rate of about 90 percent has been achieved relative to the maximum dry density of the soil. A compaction report will be submitted to the City of Santa Ana Building Department in accordance with the grading permit. During excavation activities, depending on soil conditions, there is potential to generate airborne dust. Dust control measures will comply with the local Air District feasible control measures to protect on-site and off-site receptors from chemicals in soil and nuisance dust.Dust suppression will be performed by lightly spraying or misting the work areas such as the excavation and soil handling areas with water. Misting may also be used on soil placed in the transport trucks. Efforts will be made to minimize the soil drop height from the excavator's bucket onto the soil pile or into the transport trucks. The excavator will be positioned so as to load or stockpile soil from the leeward side. After the soil is loaded into the transport trucks, the soil will be covered to prevent soil from spilling out of the truck during transport to the disposal facility. Additionally, soil stockpiles and truck beds containing soil will be covered to minimize the potential for dust generation. If precipitation is anticipated, engineering controls will be implemented to minimize the collection of rainwater in the soil stockpile area. While on the property, all vehicles will maintain slow speeds for safety purposes and for dust control measures. Before exiting the job site, the vehicle's tires will be inspected and brushed, if necessary, to ensure that impacted soil remains on-site. This cleanup/decontamination area will be established as close to the excavation and/or loading areas as possible to minimize spreading the impacted soil. 4.4 Confirmation Soil Sampling and Testing Four side wall and two bottom confirmation soil samples will be collected from each of the two excavation areas. The samples will be collected by using clean trowels. The soil will be transferred from the trowel into eight ounce jars that will be provided by an analytical laboratory. The samples will be labeled, logged on a chain of custody form and placed in a chilled ice chest for shipment to an analytical laboratory. Before each use, the sampling trowel will be cleaned in a solution of phosphate-free detergent and potable water followed by double rinsing with potable water. The samples will be sent to a State of California certified laboratory and tested for copper using EPA Method 6010B and for its STLC using EPA Method 6010B STLC Citrate. If the samples do not meet the cleanup goal, the excavation trench will be extended until the remaining soil has copper STLC less than 25 mg/L. 4.5 Waste Disposal of Contaminated Soil Off-site disposal will be conducted based on the soil stockpile analytical results under appropriate documentation and in accordance with applicable federal, state, and local regulations. REMEDIATION SCIENCES 7