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On May 2 and 3,2000 the soil borings for both M W#5 and MW#6 were made as described in the Work <br /> Plan of 3/1712000. Monitoring wells were installed in both of these soil bores. The Work Plan of <br /> • 3/17/2000 also included a soil bore and monitoring well(MW#4)to be installed in the sidewalk on the <br /> north side ofLafayette Street.This soil bore was not completed as planned.An unknown underground <br /> storage tank was encountered in the direct path ofthe soil bore.As a result of this encounter,the soil <br /> bore was abandoned and the local agencies were notified. <br /> CPT43 was installed on June 13, 2000 in the Caltrans right of way. This CPT is northeast ofthe site, <br /> and the data gathered is in the report issued for that work. <br /> All monitoring wells have been sampled quarterly, and a recap of the findings is attached. <br /> A Work Plan to expand the horizontal definition ofthe contamination plume was approved in December <br /> of 2000.This Work Plan called for the installation of three new CPT's within the Caltrans R/W to the <br /> north of the project site. These CPT's were completed on March 8, 2001 and soil and water samples <br /> were extracted to a depth of 125 feet. Also, included in the Work Plan of December 2000 was the <br /> installation and testing offour new monitoring wells,(MW-8S,MW-8D,MW-7,MW-9) to be placed <br /> on the project site or the adjacent property. These monitoring wells were completed on April 11,2001. <br /> In Januaryof2002 the owners of this property removed the apartment house structure on the east side <br /> of the property.At the time of this report that portion of the property is clear without any structures or <br /> other improvements. <br /> Procedure <br /> On February 8,2002,Del Tech Geotechnical Support Services secured water samples from all of the <br /> imonitoring wells on the above stated property.The work was supervised by Foothill Engineering.All <br /> monitoring wells were in good condition and samples were taken using the standard recommended <br /> procedures.All samples were extracted using the tube with check valve pump system.Purge rates were <br /> +1-.5 g.p.m.and the physical properties ofthe groundwater can be found in the Del-Tech Field Report <br /> which is attached and part of this report. <br /> The replacement and original monitoring wells were sampled for analysis.The original monitoring wells <br /> (MW-1,MW-2,MW-3)were used to establish the groundwater elevation and hydraulic gradient.All <br /> samples were transported under chain of custody to Sherwood Labs ofHilmar,California for analysis <br /> by EPA method SW8020. All water sample analysis and groundwater elevations are summarized in <br /> the attached tabular recap sheet (see attached recap sheets). Copies of the original Laboratory data <br /> sheets from this sampling event are also attached and are a part of this report. <br /> Findings <br /> The groundwater elevation in the wells has raised+/-0.2'feet for both the shallow and deep wells from <br /> the last sampling date of December 14,2001. MW-1 continues to have the highest concentration of <br /> gasoline contamination forTPHg at 127,000 ppb.which is lowerthan 196,000 ppb.ofthe last sampling <br /> event.In general,all ofthe monitoring wells indicated lower levels of TPHg from the last sample period. <br /> The groundwater hydraulic gradient was calculated at S=0.003 with the down slope in the northeast <br /> direction,which is very similar to the direction of flow for the last period. This gradient applies to the <br /> shallow well data of MW-1, MW-2, and MW-3 only (see a site map attached). <br /> Conclusions <br /> • The hydraulic gradient for this monitoring event is in the more traditional hydraulic gradient direction <br /> of northeast. The slope of the hydraulic gradient is S=.003 for this event, the same as the last event. <br /> 2 <br />