ARCHIVED REPORTS XR0011229 - Laserfiche WebLink

Home Browse Search

' Site Background Information K & S Gas & Grocery Page 5 of 5 low pore pressures,however, a pore pressure dissipation test conducted at CPT-4 suggests that the hydraulic conductivity is low in this sand interval (between 2X10'5 and 4X10"' centimeters per second cm/s) ' Hydrogeologic Unit 3 (HU3) - HU3 extends from 85 feet to between 95 feet and 100 feet bsg, it consists of predominantly fine-grained material, except for two thin cemented sand lenses (each approximately 1 foot thick) at the western edge of the survey area This zone is characterized by ' variable pore pressures,though moderate to high pore pressures are evident in more clayey intervals, and low pore pressures in stiffer fine-grained intervals Hydrogeologic Unit 4 (HU4)- HU4 extends from 95 feet to 100 feet to approximately 120 feet bsg and consists of approximately 10 feet of fine-grained sediment overlying approximately 10 feet of ' sand, the lower half of the sand interval is gravelly sand HU4 is characterized by very low to low pore pressure 1 Hydrogeologic Unit 5 (HU5) - This unit extends from approximately 120 feet to approximately 135 feet bsg It is a predominantly fine-grained interval, silts and a 2-foot thick sand lense in the western half of the survey area transition to silty clay in the eastern half The lateral variation in soil ' types is reflected in the pore pressures, which tend to be dominantly low in the western half and moderate to high in the eastern half of the area ' Hydrogeologic Unit 6 (HU6) - This unit extends from approximately 135 feet to 150 feet bsg and interval consists predominantly of sand and gravelly sand, and is characterized by very low to low ' pore pressure Hydrogeologic Unit 7(HU7)-Beginning at 150 feet bsg,HU7 is evidenced as a black clay recovered at total depth in wells MW-8 and MW-9 1 ' REFERENCES Maxey, G B , 1964, Hydrostratigraphic units Journal of Hydrology, v 2, pp 124-129 tRobertson,P K , Campanella,R G ,Gillespie,D and Greig,J , 1986, Use of piezometer cone data Proceedings of the ASCE Specialty Conference in Situ 86, Use of In Situ Tests in ' Geotechnical Engineering, Blacksburg,p 1263-1280 Sanders, L L , 1998,A manual of field hydrogeology, Prentice-Hall, Inc ,New Jersey, 381 p 1 Advanced GeoEnvironmental,Inc