Laserfiche WebLink
Victoria Taylor <br /> Page 2 <br /> August 23,2002 <br /> 5. Rationale for Determining Step-Out Locations. As discussed, the rational for the <br /> location of the temporary piezometers for groundwater chemistry and groundwater <br /> gradient assessment will be as follows: <br /> • Day 1 <br /> - Gradient. Four piezometers will be installed at 200 feet from the center of the <br /> former soil excavation area, to the north,south,east,and west,respectively. <br /> - Chemistry. Six piezometers will be installed at 25 feet from the center of the <br /> former soil excavation area at an even spacing and then sampled. <br /> • Day 2 <br /> - Gradient. The four piezometers will be shot for elevation,and the gradient will <br /> be determined. <br /> - Abandonment. The ten piezometers will be abandoned. <br /> The results will be provided to the RWQCB,including recommendations for additional <br /> work. Additional work will be performed,if necessary,after discussion with the <br /> RWQCB about the results and the scope of that work. <br /> 6. TPG-D Container Volume/Preservative Requirements. The container and preservative <br /> requirements for analysis of total petroleum hydrocarbons as diesel(TPH-d)were <br /> verified with the lab,Alpha Analytical,and are correct. The methodology using this <br /> smaller volume is approved by the State DHS. The preservative is not necessary,and <br /> will not be added. See Table 1 for analytical method,container,preservative,and <br /> holding time requirements. <br /> 7. Signature by Registered Professional. The signature for this addendum will satisfy the <br /> signature requirement by a registered professional for both this addendum and the June <br /> 27,2002 work plan. <br /> Also,a revised project schedule is attached as Figure 1. Note that this is the same schedule <br /> submitted with the June 27,2002 letter,but pushed back to reflect the date of this <br /> addendum. <br /> Please call me at 805-371-7817 ext.23 if you have any questions or comments about the <br /> proposed work described in this letter. <br /> Sincerely, <br /> CH2M HILL <br /> Mark uttig,RG No. 6820 <br />