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the last soundings on 08/31/00 The hydraulic gradient of the water table has changed to a North direction The original direction of flow gradient was South 75 degrees East, where as on 10/19/98 it was almost due East the 411199 gradient is down slope North 80 degrees East with S=0 002 The 9109199 soundings show the down slope gradient to be North 79 degrees East with S=0 0016 Soundings for 12/21/99 indicate the down slope gradient was at North 83 degrees East with S=00023 For the event of 3/31/2000 the soundings resulted in a gradient with a bearing of South 88 degrees East with S-0 002 For the 08/3 1/00 event the groundwater gradient is North 50 degrees East For this sampling event the gradient has changed from a generally easterly direction to nearly true north Pump rates for purging continue to be between 10 gpm and 2 0 gpm WATER SAMPLE ANALYSIS FINDINGS In general, monitoring well samples taken on 03/09/01 were very similar to previous samples Analysis by EPA Test Method 8260 was not repeated,as the 4/1/99 samples were non-detect MW- 3S is the only monitoring well with BTEX compounds determined by EPA Method 602 and 5030/8015(M) TPHg in MW43S is down 30% from the last March, 2000 sampling event Forthis event,compound 1,2-Dichloroethane is present in low concentrations in wells MW-1,MW- 2D, MW-3S, and MW-31) (see recap of data attached) CONCLUSIONS BTEX compounds for this event in the MW#3S moved to lower concentrations from past spring events This monitoring well is receiving the highest impact of all the wells due to TANK#1 (the Stoddard's Solvent tank), which is usually up gradient and Northwest of MW#3S . Halocarbon compounds are present in low concentrations in all monitoring wells with the exception of MW#4S In general, llalocarbon concentrations in all water samples are at the same concentrations as the last sampling period RECOMMENDATIONS The author requests that all monitoring wells continue to be sampled in semiannual events to conserve financial resources In response to your verbal request for the installation of a new monitoring well on the East side of California Street,this author will develop a work plan to install the new monitoring well in the city owned right of way Please contact this office at 209/368-9381 if any questions arise from this report I Respectfully submitted, QFEssra Foothi ng R1 FE Ervin Ri en rg, Exp �a t� cc Mrs Helen Higgins, prgi place 416, Stockton CA 95219 41 2