Contaminant-investigation report, Bandelier National Monument

Rhombus Environmental Group

This report presents the results of a contaminant investigation performed by Rhombus P .A. Inc. at Bandelier National Monument near Los Alamos, New Mexico. Figure I depicts the location of Bandelier National Monument in New Mexico. For the purpose of the contaminant investigation, the National Park Service (NPS) separated the investigation site into three separate zones. The NPS designated these zones Area 1, Area 2, and Area 3 as shown on Figure 2. Rhombus P .A., Inc. (Rhombus) performed the investigation on behalf of the NPS to delineate the extent of soil contamination by dichlorodiphenyl-trichloroethane (DDT) and other hazardous substances in the environment at the site. The contaminant investigation consisted of the following phases of work: • Preliminary Sump Investigation - October and November, 1993; • Area 2 and Area 3 Investigation- November, December 1993 and September, 1994; and, • Phase II Sump Investigation - March 1994. The Preliminary Sump Investigation and the Area 2 and 3 Investigation were performed in accordance with the Sampling and Analysis Plan (SAP) prepared by Rhombus and approved by the NPS in August 1993 (revised October, 1993). Rhombus structured each of these investigations in general accordance with procedures noted in the Guidance for Performing Site Inspectjons Under CERCLA developed by the EPA for CERCLA sites (EPA, 1991)1, Management of Investigation-Derived Wastes During Site Inspections (EPA, 1991)2, Guidance for Performing Preliminary Assessments Under CERCLA (EPA, 1991)', and 40 CFR Parts 300 to 399 (Revised July I, 1991}'. The Phase II Sump Investigation Work Plan, dated February 15, 1994, was based primarily upon the results of the Preliminary Sump Investigation. The NPS also reviewed and approved the Phase II Sump Investigation Work Plan. The following subsections provide a description of the site conditions, the regulatory framework which covers the investigation and future n:mediation, and the investigation objectives. Section 2.0 summarizes the results of previously reported investigations which include the Fletcher Investigation results (a study performed by the NPS during 1989 and 1990) and the Preliminary Sump Investigation results (completed by Rhombus during October and November 1993). Section 3.0 presents the Field Procedures utilized during the Area 2 and 3 Investigation/Phase ll Sump Investigation. The results of these tasks as well as the conclusions and recommendations are presented in Sections 4.0, 5.0, and 6.0 respectively.