ARCHIVED REPORTS_REPORTS - Laserfiche WebLink

Home Browse Search

• • • SECTION 5.0 RESULTS • • plus nitrate-N)at two sampling depth intervals(2 to 4 feet bgs and 4 to 6 feet bgs)at soil • sampling area 1K remain below 200 mg/kg.The concentrations of TKN plus nitrate-N at the • remainder of the soil sampling intervals at soil sampling areas 1K and 7K appear to be • decreasing or have stabilized.The pH of soil samples from the stormwater pond area were generally more alkaline than soil samples collected from other soil sampling areas and from • previous soil samples collected from this area,with an approximate range of 8 to 9. • 5.2.2 Former Bagging Plant Area Investigation • The results of soil samples collected in the former bagging plant area during the 2011 • investigation and Ten-year Evaluation are presented in Table 5-4,with selected results also • presented on Figure 5-9.The results generally indicate higher concentrations of nitrate-N in the former bagging plant area than other parts of the Koppel Stockton Terminal site.For soil • samples collected in the former bagging plant in 2011,24 of the 30 soil samples,excluding • duplicates,had nitrate-N concentrations greater than 50 mg/kg. In comparison,only 2 of • the 15 samples,excluding duplicates,collected outside the former bagging plant area had nitrate-N concentrations greater than 50 mg/kg.Nitrate-N concentrations in soil samples • from the former bagging plant area ranged from 0.033J mg/kg(4K,0 to 2 feet bgs) to • 521 mg/kg (K11-07,4 to 6 feet bgs). • As discussed,total soluble ammonia/ammonium-N were analyzed from a saturation paste • extract(ASTM Type I deionized water) and analyzed in the laboratory as ammonia-N plus ammonium-N.The lab uses the measured pH of the soil along with the pKa to calculate the • relative amounts of soluble ammonia-N and soluble ammonium-N from the total soluble • ammonia/ammonium-N.When pH is neutral to acidic,most of the total soluble ammonia/ ammonium-N measured are in the form of soluble ammonium-N. Because the pH values of • all the soil samples collected from the former bagging plant area were neutral to acidic,the • concentrations of calculated soluble ammonia/ammonium were below the laboratory • detection limit. Concentrations of calculated soluble ammonia/ammonium ranged from below the laboratory detection limit to 69.4 mg/kg.The highest concentrations of calculated • soluble ammonium-N were from the samples collected from the three depth intervals at soil • sampling location 3K(11.9 to 69.4 mg/kg). Concentrations of calculated soluble • ammonium-N from the remaining locations in the former bagging plant area ranged from below the laboratory detection limit to 2.3 mg/kg.Exchangeable ammonium concentrations • in soil samples collected in the former bagging plant area ranged in concentration from • 0.568 to 475 mg/kg,with the highest concentrations detected in the samples collected from the three depth intervals at soil sampling location 3K(89.3 to 475 mg/kg). Concentrations of • exchangeable ammonium from the remaining locations in the former bagging plant area • ranged from 0.568 to 19.1 mg/kg. • The concentrations of TKN in soil samples collected from the former bagging plant area • ranged from 237 to 2,140 mg/kg.The pH of soil samples from the former bagging plant area generally ranged from acidic to slightly alkaline,approximately 4 to 8.The pH values of • most of the soil samples were slightly acidic, approximately 4 to 7.The lowest pH(3.84)was • measured at soil sampling area 3K in the 4 to 6 feet bgs sample. • • • • 5-12 R0O1112370001(CAH5003.00CX) • EM82511MV@ D • • •