ARCHIVED REPORTS XR0001845 - Laserfiche WebLink

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The monitoring wells were developed on October 15 and 16,2003 in order to remove disturbed water that results from the drilling and well construction The result of the development is to increase the filtration capability of the filter pack which will increase the groundwater yield and reduce total suspended solids Development was accomplished with a surge block and by bailing approximately 10 to 20 well volumes from each wellbore Water was bailed from the well until mostly clean, clear water was recovered After development, the well retained a slight brownish discoloration due to suspended fine gramed material The well was developed using the finest screen possible(0 010 inches)and a fine sand filter(Monterey#212)but this was unable to filter all solids from entering the wellbore during development Approximately 50 to 100 gallons of water were removed from each of the wellbores All development water was placed in a series of six 55-gallon drums which were labeled as purge water The purge water in the drums will be disposed of at a licensed hazardous waste disposal facility after samples have been collected and analyzed to determine concentrations of petroleum hydrocarbons in the water After development, a clear, acrylic bailer was used to visually inspect the water column for a free product layer or sheen None of the monitoring wells indicated any physical evidence of petroleum product layer or sheen to be present iThe six monitoring well casing locations and elevations surveyed on October 22,2003 using a Pentax PX- 06D theodolite and electronic distance measurement instrument immediately after completion of each well Elevations were tied to the City of Lodi Bench mark #608 located on the east side of Cherokee Lane immediately north of the intersection of Murray Street and on the curb surrface This benchmark has a reported elevation of 53 00 feet msl and is tied to the North American Vertical Datum, 1988(NAVD, 1988) according to Ms Jeanne Matsumoto, City of Lodi Public Works specialist The top of casing elevation and top of traffic box elevation at each well was surveyed On October 29,2003 the individual wellheads were resurveyed using a global positioning system(GPS)to confirm each well head horizontal coordinates at the 521 North Cherokee Lane site A Trimble 4000 base station and 5700 receiver/rover unit were used to determine the horizontal and vertical coordinates of all of the wells at the site Horizontal coordinates were reported in California State Plane Coordinate System Zone 2, North American Datum 1927 (NAD27) coordinates along with latitude and longitude coordinates in WGN84 spheroid A summary of coordinates for each of the wells is provided in Table 6 Mam\D 1Env"uvie tWWamwTex=o\ReponASAR1203 wpd Page 16