ARCHIVED REPORTS XR0001488 - Laserfiche WebLink

Home Browse Search

C A M B R I A i the directive to submit a work plan This work plan was issued August 26, 1999 In preparing this work plan Cambria considered the comments mentioned in PHS/EHD's May 26, 1999 letter The comments we were asked to consider were not presented in the May 26, 1999 PHS/EHD letter as "site-specific requirements " Cambria considered preparing flow nets, fence diagrams, and rose diagrams for this site, as requested by PHSIBHD We felt flow nets and fence diagrams were not warranted for this site but did propose to prepare a rose diagram and to update cross-sections in our August 26, 1999 work plan We did not include rose diagrams in our quarterly monitoring reports submitted after our work plan because the work plan had not been approved by PHS/EHD The May 26, 1999 PHS/EHD letter stated in Paragraph 2 "The workplan must he approved and implemented within 90 calendar days from the date of this letter " This statement indicates we need to get PHS/EHD approval of our work plan prior to implementing it This statement also suggests that we would get approval or review of our work plan from PHS/EHD within 90 days of PHSIEHD's May 26, 1999 letter Since we did not receive approval or comments on our work plan until April 17, 2000 we have not performed tasks proposed in our work plan • Additional Soil Borings PHS/EHD recommends in the April 17, 2000 letter that at least four continuously cored soil borings be drilled in two different locations "PHS/EHD now recommends the installation of at least four continuous core boreholes given the strength of the plume documented near MW-11 Two horeholes should he placed near SB-3/VW-4, and Iwo off-site near AfW-11 " We do not see a need to continuously core two borings adjacent to each other at two different locations Perhaps PHS/EHD was just recognizing that when drilling with Cone Penetrometer Testing (CPT) equipment, multiple boreholes are needed at each drilling location to log the soil and to collect soil and groundwater samples Different tool heads need to be put on the tip of the CPT rods for different operations There is a tool for logging the soil, there is a different tool for collecting soil samples, and there is yet a different tool for collecting groundwater samples Typically we first drill with the CPT soil logging tool to log the soil types beneath the site Then a second boring is drilled adjacent to the first with the soil sampling tool affixed to the CPT rods to allow collection of soil samples Then a third boring is drilled adjacent to the first two with the groundwater sampling tool to collect groundwater samples Our work plan addendum, presented below, proposes two soil boring locations in agreement with the recommendation of PHS/EHD More details on these borings are provided below 1399 3