SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Mr . Gordon Boggs RWQCB - Central Valley Region November 8, 1988 Page 3 Phase II pumping would be balanced at 5 gpm injected and 5 gpm withdrawn (see figure 2 ) . Dr . Calvin Chein of DuPont, who developed the groundwater mode for this site, has assured me the balanced system would not result in a significant change in groundwater clean-up flow and that the original clean--up strategy presented to the Water Board is still valid . 4 ) The monitoring system which will be used to monitor the groundwater clean-up: Initial Monitoring : There are two sets of monitoring wells : interior wells within the area of contamination and exterior wells which are outside the contamination zone and used to demonstrate that nutrient flow is under control (Figure 3 and 4 ) . These two sets of wells will be sampled under different regimes . Monitoring during the initial addition of nutrients will be performed three times per week until the breakthrough of tracers is detected in the recovery wells . Monitoring will then be performed twice a week until concentrations of the nutrients at the recovery wells have stabilized . The exterior wells will be monitored every two weeks initially and monthly later to assure that nutrient solutions do not escape the site . Microbial analyses will be done initially on a bi-weekly basis . Routine Monitoring: Groundwater from selected wells will be sampled bi-weekly to monthly as appropriate, to evaluate the progress of the remediation. Analyses for benzene, toluene, and xylenes and for total petroleum hydrocarbons will be performed monthly. Dissolved oxygen, pH, Eh, conductivity, and temperature will be measured in the field by probes . Wet chemical analyses will be performed for ammonia, phosphate, chloride, and, as necessary, nitrate .