ARCHIVED REPORTS_REPORTS - Laserfiche WebLink

Home Browse Search

• • • • SECTION 5.0 RESULTS • • grove.The ammonia concentration at piezometer TG-2 has decreased from a maximum of • 83 mg/L in 1999 to 17 mg/L in August 2011. • Ammonia was detected at concentrations ranging from 0.074 to 22 mg/L at the remaining • locations.Time-series concentration plots and regression analyses of ammonia concen- trations for monitoring wells KP-2,KP-3,and KP-4 and piezometers TG-2 and TG-4 are • shown with groundwater elevations on Figure 5-8.The regression analyses for monitoring • wells KP-2 and KP-4 and piezometers TG-2 and TG-4 indicate that the trend of ammonia • concentrations is gradually decreasing.The regression analysis for Monitoring Well KP-3 indicates that the trend of ammonia concentrations is gradually increasing. • The Mann-Kendall statistical trend test was used to verify trends indicated by the regression • analyses on Figure 54.Using groundwater data collected from 2000 through 2011,the • Mann-Kendall test concluded that there is a statistically significant downward trend in • ammonia concentrations in piezometers TG-2 and TG-4,and a statistically significant upward trend in monitoring well KP-4 and piezometer TG-3.The significance level used • was 0.05.The calculated probabilities of a downward trend were 100 percent and . 99.4 percent for piezometers TG-2 and TG-4,respectively.The calculated probabilities of an upward trend for monitoring well KP-4 and piezometer TG-3 were 96.8 percent and • 97.1 percent,respectively.The Mann-Kendall test results for data collected from 2000 • through 2011 indicate that there is not enough evidence to support a statistically significant trend in monitoring wells KP-2(93.6 percent probability of a decreasing trend) and KP-3 • (91.3 percent probability of an increasing trend). • Ammonia concentrations in grab groundwater samples collected in the former bagging • plant area are presented on Figure 5-5 and in Table 5-2. Concentrations of ammonia ranged • from 0.034 to 83.8 mg/L in grab groundwater samples.The highest concentration of ammonia in groundwater(83.8 mg/L)was collected from sample location K11-06.The next • highest concentration of ammonia in groundwater was 9.65 mg/L,from location K11-02. • • 5.2 Soil Sampling Results 5.2A Ten-year Soil Sampling Results • The results of soil sampling performed in 2000(baseline),2006 (5-year),and 2011 (10-year) are presented in Table 5-3.The soil sampling locations for the Ten-year Evaluation(1K • through 7K) are presented on Figures 4-1 through 4-4. Original Test Grove and Turnaround Area • Soil sampling area 2K in the turnaround area and soil sampling area 6K in the original test • grove are shown on Figure 4-1.At soil sampling area 2K in the turnaround area,nitrate • concentrations range from 0.53 J to 15.3 mg/kg.These results indicate that concentrations have stabilized compared to the baseline concentrations in 2000 (763 to 966 mg/kg) and the • 5-year concentrations in 2006 (6.4 to 41 mg/kg).Soil sampling at soil sampling area 6K was • not initiated until 2006;however,concentrations of nitrate-N decreased in the 0 to 2 and 2 to • 4 feet bgs sample intervals between 2006 and 2011.Nitrate-N concentrations increased in the 4 to 6 feet bgs sample interval between 2006 and 2011 (111 to 201 mg/kg,respectively). • • • R00/112370001(CPH5003.00M 5.7 esoersnazroavoo • • -