SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

r � t(enncdr Jen'•:s Chilton Mr. Tom Terrill Reynolds and Brown 26 January 1987 Page Two the boundary between metal tanks and soil ) . Radio waves are transmitted and received by a skid-mounted transducer. A strip chart records radar wave reflections during the survey so that results can be evaluated in the field as they are obtained. The ground penetrating radar survey was performed on 23 December 1986 by Norcal Geophysical Consultants. Ground penetrating radar could not define the location or depth of the underground storage tanks. Survey results are presented in Attachment A. The technique was apparently successful, however, in detecting reflectors that could be interpreted as shallow metal pipes. Ground penetrating radar transects were performed over proposed p boring locations to determine whether they were likely to be underlain by metal pipes or other metallic objects. No reflec- tors interpreted as pipes or other obstacles were detected at any of the borehole sites selected. TANK INSPECTION on the day of the ground penetrating radar survey field work, the filler cap on the south tank was removed (see Figure 1 for loca- tion) . The tank bottom was found, by probing, to be about 11 . 3 feet below ground surface. The south tank contained an undeter- mined amount of petroleum product. The steel plate covering the submersible pumps at the west end of the tank ( see Figure 1 ) was removed, revealing a concrete slab between eight and nine inches thick which overlay loose, medium grained sand. € DRILLING AND SOIL SAMPLING _ E A commercial concrete coring service was used to dri11 boreholes through the surface concrete since it was thicker than antici- pated during the planning of this investigation. Concrete coring was performed on 31 December 1986. Drilling and sampling of three soil borings and one monitor well was performed on 5 .and 6 January 1987. The drilling was performed by the Tlater Develop- ment Corporation under observation by a Kennedy/Jenks/Chilton field scientist. Locations of the borings are shown on Figure 1 . Drilling was performed using a CME-55 truck-mounted auger rig. All augers were steam-cleaned prior to use and after each subse- quent use to minimize the cross-contaminating of samples. All cuttings generated by drilling were collected into covered steel drums . These drums are ?teeing stored onsite pending appropriate 1 disposal by Reynolds and Brown.