400645 - FORE MAJ Colio 26 Kov 78 FACT SHELT SUBJECT: Enjrbi Subsurface Contaminatlon PURPOSE: To provide current status of Enjebi (Janct) subsurface contamina- tion. BACKGROUND: a. On 27 Sep 77, DOE-ERSP outlined to CJTG a ground zero (Easy - X Ray and Item sites) subsurface exploration plan for Enjebi. The plan was to verify NVO-140 data by backhoe soil profile sampling. b, On 5 Oct 77, CJTG directed soil sampling priority to Lujor, boken, Aomon and Runit. It was implied by CJTG that the Enjebi subsurface was secondary to characterizing surface TRU contamination. This prioritization was IAW the mission and personnel safety considerations inasinuch as subsurface contamination presents less of an immediate hazard than surface contamination. ec. On 16 Aug 78, almost one year later, DOE-ERSP extracted 740 soil’. samples in the Easy - X Ray and Item Ground Zero sites, using sidewall sam- pling in backhoe trenches to a depth of 120 en (4 £t). d, On 30 Sep 78, DOE~ERSP reported to CJTG that two areas in the NW quadrant of Enjebi had subsurface TRU greater than 160 pCi/g, thereby exceeding Condition D. The assumed depth of'cut to excise the approximate 1307 cy of subsurface TRU contamination was 100 cm (3.3 ft). DISCUSSION: sms We ale stan ee” STATUS: None The Enjebi subsurface excision is scheduled to begin o/a 27 Nov 78.