FINAL SITE INSPECTION REPORT

847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878 The reported munitions used at this AOC are practice munitions only; The munitions used at this target used relatively insensitive explosive components; The area is used for farming, undergoing yearly tillage to depths of approximately 18inches without MEC discovery; The unfenced area is not frequented by the public and only farm workers or PGE workershave access to the area; and No MEC has ever been reported or found.4.4 Munitions Constituents EvaluationPotential MC include metals associated with steel, sheet metal, paint, and other components ofmunitions (chromium, copper, iron, lead, molybdenum, and nickel), and black powder(potassium nitrate, sulfur, and charcoal). Perchlorate was not identified as a potential MC atTarget No. 1. Nonetheless, discussion of perchlorate analytical results from surface water andgroundwater samples collected from Target No. 1 during the PA/SI is included in the followingevaluation for completeness.4.4.1 Terrestrial PathwayTerrestrial receptors may be exposed to MC because soil may have been directly affected by thecorrosion of metals from the bomb bodies or explosives used. One surface soil sample (NWO-030-0001) was proposed and collected at Target No. 1. The location was near the center of theformer target. The sample location is shown in Figure 4-2. The samples were analyzed forselect metals (chromium, copper, iron, lead, molybdenum, and nickel) by EPA Method 6020. Inaddition, samples were analyzed for aluminum and manganese for potential use in evaluatingnaturally occurring concentrations of metals in soil using the method of Myers and Thorbjornsen(2004). The sample was also analyzed for explosives including nitroglycerin by EPA Method8330A. The explosives were added at the request of the ODEQ to confirm than no explosiveswere present.Detected soil analytical results and comparison to soil background and human health andecological screening values are shown in Table 4-1. The results of the comparison to soilbackground and human health and ecological screening values are shown pictorially on Figures4-2 (metals) and 4-3 (explosives).4.4.1.1 Comparison to Background DataThe analytical results were compared to the Boardman AFR site specific background values.There were no background exceedances for metals and no detections of explosives.Boardman AFR Final SI Report.doc 4-3 Contract No. W912DY-04-D-0010 Delivery Order No. 003September 2007