Laserfiche WebLink
Date September 29,2003 <br /> Report Assessment 2003 <br /> ATTACHMENT D <br /> FIELD AND LABORATORY PROCEDURES <br /> Exploratory Drilling and Soil Sampling <br /> The monitoring wells were drilled using 8-inch hollow-stem auger drilling equipment A URS geologist logged the <br /> borings using the Unified Soil Classification System Soil samples were collected from the borings at 5-foot intervals <br /> using a California modified split spoon sampler Well MW-13D was logged continuously below 40 feet bgs The <br /> sampler was driven a maximum of 18 inches using a 140-pound hammer with a 30-mch drop Soil samples for chemical <br /> analysts were retained in brass liners,capped with Teflon®squares and plastic end caps, and sealed in clean zip-lock <br /> bags The samples were then placed on ice for transport to the laboratory accompanied by chain-of-custody <br /> documentation Down-hole drill mg and sampling equipment were steam-cleaned following the completion of each soil <br /> boring Down-hole sampling equipment was washed in non-phosphate soap and deionized water solution between <br /> samples <br /> Groundwater Monitoring Well Installation <br /> The groundwater monitoring wells were constructed of 2-inch schedule 40 PVC blank casing and 0 020-mch machine <br /> slotted well screen with flush threads A#3-sand filter pack was installed in the annulus from the bottom of the borehole <br /> to at least 2 feet above the top of the well screen, followed by a transition seal consisting of a 2-foot-thick hydrated <br /> bentonite plug,which in turn was overlain by neat cement grout to ground surface The wells were secured with locking <br /> expandable well caps and fitted with traffic-rated well boxes set in concrete <br /> Soil Sampling from Drummed Soil <br /> Soil samples were collected by advancing 2-inch-diameter brass sample liners into the soil drum, after removing <br /> approximately 6 inches to 1 foot of surface material in the sample location One composite was collected per drum Sot] <br /> samples for chemical analysis were retained in the brass liners,labeled,and capped with Teflon®sheets and plastic end <br /> caps The samples were then sealed in zip-lock bags,placed on ice,and transported to the laboratory accompanied by the <br /> appropriate chain-of-custody documentation <br /> Laboratory Analysis of Soil Samples <br /> Soil samples are analyzed for TPHg,BTEX,fuel oxygenates,and lead scavengers by EPA Method 8260B Drummed <br /> soil samples are analyzed for TPHg and BTEX by EPA Methods 801518021,lead content is analyzed by EPA 6000/7000 <br /> Series Methods <br /> Groundwater Sampling Procedures <br /> Sampling equipment is thoroughly cleaned prior to each sample The sampling procedure for each well includes <br /> measuring the water level and checking for the presence of separate-phase hydrocarbons(SPH),using either an electronic <br /> indicator and a clear Teflon®bailer or an oil-water interface probe if the measured water leve]in the well is below the <br /> top of screen elevation, the well may be sampled without purging For non-purge wells, one set of water quality <br /> parameters are collected and the well is sampled with a disposable bailer Wells not containing SPH that do not qualify as <br /> non-purge wells are purged of approximately three casing volumes of water(or to dryness)using a submersible pump, <br /> centrifugal pump,gas displacement pump,or bailer The equipment and purging methods used for the current sampling <br /> K\wprocessl15 BP ARCa10602012003 Assessment16020 Assessment&SCM 2003 doc <br /> Page D-1 <br />