Laserfiche WebLink
Appendix B <br /> Groundwater Velocity Calculations (Deep Zone) <br /> Apache Plastics <br /> 2050 East Fremont Street <br /> Stockton , California <br /> Assumptions : <br /> • The following calculations assume that there is no dispersion or diffusion and that <br /> groundwater is flowing in a steady state . <br /> • Groundwater elevation data used for the calculations was derived from the most <br /> recent full/complete event for site. <br /> • Hydraulic gradient used to calculate the groundwater velocity in the shallow zone <br /> was based on results from the most recent groundwater monitoring event <br /> performed the site (Figure 5) ; the greatest calculated gradient (0 . 006 foot per foot <br /> [ft/ft]) was used to perform the calculations . <br /> • The screening intervals for deep groundwater wells MW-8 (screened 96 to 105 <br /> feet below surface grade [bsg]) and MW-9 (94 to 104 feet bsg) were used to <br /> determine the cross sectional heights . To calculate the groundwater velocity in <br /> the deep zone an average height of 9 .5 feet was used to determine the deep <br /> groundwater velocity. <br /> • The width of the deep zone plume was used to determine the thickness of the <br /> aquifer in which groundwater flows (Figure 6) . <br /> • The rate of flow, or hydraulic conductivity value, was determined by field <br /> lithologic observations . For the deep zone, the hydraulic conductivity value for <br /> silty sand 1 centimeters per second [cm/sec] or 10 gallons per day per square <br /> foot [gpd/ft ) was used to calculate the groundwater velocity in the deep zone. <br /> • Darcy Velocity was calculated using the following formula : <br /> V= Q/A <br /> V: Darcy velocity <br /> Q : Rate of flow for used hydraulic conductivity <br /> A: Cross-Sectional Area <br />