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i �3/1712000 also included a soil bore and monitoring well(MW#4)to be installed in the sidewalk on the north side ofLafayette Street.This soil bore was not completed as planned.An unknown underground storage tank was encountered in the direct path of the soil bore. As a result of this encounter,the soil ;. bore was abandoned and the local agencies were notified. CPT43 was installed on June 13,2000 in the Caltrans right of way.This CPT is northeast of the site, and the data gathered is in the report issued for that work. All monitoring wells have been sampled quarterly, and a recap of the findings is attached. A Work Plan to expand the horizontal definition of the contamination plume was approved in December of 2000.This Work Plan called for the installation of three new CPT's within the Caltrans R/W to the north of the project site. These CPT's were completed on March 8,2001 and soil and water samples were extracted to a depth of 125 feet. Also, included in the Work Plan of December 2000 was the installation and testing offour new monitoring wells,(MW-8S,MW-8D,MW-7,MW-9) to be placed on the project site or the adjacent property. These monitoring wells were completed on April 11,2001. Procedure On September 19,2001, Del Tech Geotechnical Support Services secured water samples from all of the monitoring wells on the above stated property.The work was supervised by Foothill Engineering. All monitoring wells were in good condition and samples were taken using the standard recommended procedures.All samples were extracted using the tube with check valve pump system.Purge volumes were+/- 1 g.p.m. and the physical properties of the groundwater can be found in the Del-Tech Field Report. The replacement and original monitoring wells were sampled for analysis and the original monitoring . wells(MW-1,MW-2,MW-3)were used to establish groundwater elevation and hydraulic gradient. All samples were transported under chain of custody to Sherwood Labs of Hilmar, California for analysis by EPA methods 602 and 503018015. All water sample analysis and groundwater elevations are summarized in the attached tabular recap sheet.Copies of the original Laboratory data sheets from this sampling event are also attached and are a part of this report., Findings The groundwater elevation in the wells has lowered+/-0.6 feet for both the shallow and deep wells from the last sampling date of June 28,200 1. MW-1 continues to have the highest concentration of gasoline contamination(TPHg)at 203,000 ppb.which is higher than 133,000 ppb.of the last sampling event. MW-8S has recorded a major change with a drop in TPHg to non-detect(Report limit of 50 ppb),from a high of 14,000 ppb.for the first groundwater sample from this well.Please review the recap sheet that is attached. The groundwater hydraulic gradient was calculated at S=0.0026 with the down slope in the Southeast direction. This gradient applies to the shallow well data only(see a site map attached). Conclusions The hydraulic gradient for this monitoring event has changed from the traditional hydraulic gradient direction of northeast to a bearing of South75East. This direction change may account for the major drop in gasoline contamination in monitoring well MW-8S. The slope of the hydraulic gradient has increased to 5=.0026 for this event, from 5=.0015 of the last event. 2