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Appendix D Direct Push Boring Investigation Phase II ESA Multi-Modal Station`Six-Block Project' January 6,2003 Page 2 of 15 • Detection borings were Installed along the E Miner Avenue, E Channel Street, N Grant Street, and N Aurora Street public right-of-ways and on the Union Pacific Railroad right-of-way to evaluate possible site sources that might have moved off site or from one of the six blocks "Perimeter" detection borings were Installed along N Stanislaus Street and E Weber Avenue (where underground utilities permitted) In order to evaluate if off site sources had Impacted the site The Geoprobc boring procedures consisted of coring through hard surface material such as concrete or asphalt, followed by advancing the borings with a hand auger to five feet bgs to check for the presence of buried utilities Once the bonngs had been advanced to five feet with a hand auger, the direct push sampling equipment was lowered into the holes Continuous soil cores were collected from five feet to 15 feet bgs and retained for soil sample collection The detection boring procedures were identical to the Geoprobe procedures to a depth of 15 feet bgs Between 15 feet and 35 feet bgs, the detection bonngs were advanced with the soil sampler tip closed At 35 feet bgs, the soil sampler tip was opened and continuous soil cores were collected from 35 to 45 feet bgs and retained for soil sample collection and geologic logging After advancement of the detection bonngs to a depth of 45 feet bgs, a temporary well casing was installed in the open boring to allow groundwater depth measurement and to facilitate groundwater sample collection If field observations indicated that contamination was present, the Geoprobe borings were advanced beyond 15 feet bgs and continuous soil cores collected through the extent of impacted soil Continuous cores were also collected between 15 and 35 feet bgs in the detection borings if contamination was noted . at 15 feet bgs If contamination was noted in detection borings at 45 feet bgs, continuous cores were collected beyond 45 feet bgs through the extent of impacted soil A limited number of hydropunch bonngs were ,,idvanced to evaluate the potential presence of groundwater contamination at selected locations The hydropunch borings were generally coupled with a detection or Geoprobe boring The hydropunch boring procedures consisted of direct push advancement to approximately 40 to 45 feet bgs, unless otherwise noted, and a five to 10-foot retraction of the push rods to allow groundwater Influx and sample collection After completion of the Geoprobe, detection and hydropunch boring advancement and associated sampling activities, all bonngs were backfilled to grade with a neat cement grout Dye was added to the grout as necessary to match the pre-existing surface completion at each boring location 3.1 SOIL SAMPLING PROCEDURES AND LABORATORY ANALYSES Continuous core soil samples were collected from 5 to 15 feet bgs for laboratory analyses from the Geoprobe and detection borings The soil samples were collected in clean acetate sleeves installed in five- foot long macro core samplers Three soil samples, each approximately four inches long, were cut trom the acetate liners at depths of approximately 5, 10, and 15 feet bgs The ends of the acetate liners were covered with Teflon' sheeting and capped with plastic end caps The samples were labeled for identification and placed in a cooler chilled with ice The remainder of the acetate liner was opened for lithologic logging and other observations A grab sample of soil from each recovered acetate liner was placed in a re-sealable plastic bag for headspace screening of volatile organic vapors with a phototonization detector (PID) •