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• • STANDARD OPERATING PROCEDURE— DIRECT PUSH BORINGS SOIL CORING AND SAMPLING PROCEDURES Prior to drilling,all boreholes will be hand dug to a depth of 4-5 feet below ground surface(bgs)to check for underground utility lines. Soil and groundwater samples are collected for lithologic and chemical analyses using a direct driven soil coring system. A hydraulic hammer drives sampling rods into the ground to collect continuous soil cores. As the rods are advanced, soil is driven into an approximately 2.5-inch- diamter sample barrel that is attached to the end of the rods. Soil samples are collected in sleeves inside the sample barrel as the rods are advanced. After being driven 4 to 5 feet into the ground, the rods are removed from the borehole. The sleeve containing the soil core is removed from the sample barrel, and can then be preserved for chemical analyses, or used for lithologic description. This process is repeated until the desired depth is reached. A soil core interval selected for analyses is cut from the sleeve using a hacksaw. The ends of the tube are covered with aluminum foil or Teflon liner and sealed with plastic caps. The soil-filled liner is labeled with the bore number, sample depth, site location, date, and time. The samples are placed in bags and stored in a cooler containing ice. Soil from the core adjacent to the interval selected for analyses is placed in a plastic zip-top bag. The soil is allowed to volatilize for a period of time, depending on the ambient temperature. The soil is scanned with a flame-ionization detector (FID) or photo-ionization detector (PID). All sample barrels, rods, and tools are cleaned with Alconox or equivalent detergent and de-ionized water. All rinsate from the cleaning is contained in 55-gallon drums at the project site. GROUNDWATER SAMPLING FROM DIRECT PUSH BORINGS After the targeted water-bearing zone has been penetrated,the soil-sample barrel is removed from the borehole. Small-diameter well casing with 0.010-inch slotted well screen maybe installed in the borehole to facilitate the collection of groundwater samples. Threaded sections of PVC are lowered into the borehole. Groundwater samples may then be collected with a bailer, peristaltic pump, or WaTerra pump until adequate sample volume is obtained. Groundwater samples are preserved, stored in an ice-filled cooler, and are delivered, under chain- of-custody, to a laboratory certified by the California Department of Health Services (DHS) for hazardous materials analysis. BOREHOLE GROUTING FOR DIRECT PUSH BORINGS Upon completion of soil and water sampling, boreholes will be abandoned with neat cement grout to the surface. If the borehole was advanced into groundwater, the grout is pumped through a grouting tube positioned at the bottom of the borehole.