ARCHIVED REPORTS_XR0012624 - Laserfiche WebLink

Home Browse Search

Ga } i characteristics. Soil borings will be advanced at least 10 feet below the level at which groundwater is first encountered in order to assure i an ample quantity of water for sample collection.2 Locations of utilities on the former tank site were identified previously before proceeding with the soil investigation. Other nearby utilities are identified in Figure 2-2. SOIL SLING Soil samples will be taken at 5 foot intervals beginning at 5 feet below the ground surface. All samples will be examined in the field for evidence of contamination. Soil samples will be submitted for laboratory analysis only if visual examination or odor indicate that the samples are contaminated. Soil borings will be made by a mobile truck mounted drill rig using hollow stem augers. Soil samples will be taken with a California modified split-spoon sampler fitted with brass tube liners. i All brass liners will be steam cleaned prior to use. All augers, bits, and split spoon samplers will be steam cleaned prior to beginning work and between all borings. Soil samples will be collected by inserting the sampler into the augers and hammering it into the soil to the desired depth. The sampler wilI then be removed from the augers and the brass liner containing the sample will be removed from the sampler. The soil sample will be examined for evidence of contamination. Any brass tubes I containing samples exhibiting evidence of contamination will be covered with Teflon tape and capped with plastic caps to make airtight seals. The brass tube will be labeled with the boring number, 4 sample interval depth, sampler's initials, date, time, location, and a analysis required. The sample will be logged on a chain-of-custody form and in the field book, and noted on the boring log. The sample will be placed in a water-tight plastic bag and stored in a cooler w containing ice. Once all the samples have been collected, the samples will be delivered to the laboratory along with the accompanying chain-of-custody forms. 2 Groundwater levels have leen steadily dropping in the San Joaquin Valley in 4 recent years due to increased agricultural use. However,the relatively close 916 proximity of the investigation site to the Stockton Deep Water Channel and Mormon Slough will minimize the impact on the groundwater level that the �. agricultural drawdown is having in the agricultural zones. This should prevent the monitoring wells from going dry as agricultural use of groundwater continues to lower area groundwater levels. 2-5