WORK PLANS - Laserfiche WebLink

Home Browse Search

groundwater gradient is to the southwest. URSG will contract Gregg Drilling of Martinez, California to advance four soil borings at the Nelson site to a depth of 25 feet by hollow-stem-auger drilling. One boring will be advanced at each end of the diesel UST excavation pit. An additional boring will occur downgradient of the gasoline UST. The fourth borehole will be advanced at the terminal point of the septic system. The proposed boring locations are presented in Figure 2, and are subject to change based on the results of utilities surveys. The borings will be labeled SB-1 through SB-4, and soil samples will be collected from each boring at 5-foot intervals from 5 to 25 feet bgs. URSG will continuously log each borehole according to the Unified Soil Classification System. In addition, URSG will collect a grab groundwater sample from within 5 feet of the water table at each location. 2.3 Surface Soil Sampling Figure 2 presents the general areas in which surface soil samples will be collected. Exact sample locations will be determined based on field observations such as stained soil, stressed vegetation, and surface topography. URSG will collect up to 15 samples from 6 inches bgs in former agricultural areas to the southwest and northeast of the SR 99/Jack Tone Road intersection. These samples will be numbered AS-1 through AS-15. URSG will also collect up to five samples from 6 inches bgs along the SPRR line; these samples will be numbered RR-1 through RR-5. Finally, URSG will collect up to 20 samples from 6 inches bgs within the interchange right-of- way; these samples will be numbered IS-1 though IS-20. 2.4 Sample Collection Sample collection will proceed in accordance with the U.S. Environmental Protection Agency (EPA) document, Test Methods for Evaluating Solid Waste Physical/Chemical Methods (EPA Reference SW-846). Borehole soil ` samples will be collected in brass sleeves, and the ends sealed with teflon tape and polyethylene caps. URSG will use dedicated trowels to collect surface soil samples in 8-ounce glass jars. Grab groundwater samples will be collected using a stainless-steel bailer through a HydroPunchTM, and 40 ml VOA vials or 1-liter amber glass bottles, depending on the analysis (see Section 2.5). All soil and groundwater samples will be labeled with the sample number, date of collection, and analysis required. Chain-of-custody seals will be placed on each container. In addition, the samples will be put in a plastic bag, placed in a cooler with ice, and maintained at 4°C to preserve sample integrity during shipment to the laboratory. All sampling equipment will be decontaminated between sampling locations using a detergent wash, tap water rinse, and a final deionized water rinse. PSI Soil sampling Plan Page SR99./lack one Load Interchange Project I