SITE INFORMATION AND CORRESPONDENCE

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Ms. Nancy Bishop - 2 - 13 September 2001 WFS did conduct a capture zone analysis as required by the permit. The corresponding report evaluates the area of influence seen during pumping periods of 50 to 223 minutes, the maximum period permitted due to on-site water storage limitations. All five monitoring wells showed an influence from pumping. From this data, GeoSyntec predicts that if continuous pumping was available, groundwater beneath most of the site would be captured. Quarterly Monitoring Reports The quarterly monitoring reports are well written and brief, show the status of contaminant distribution in groundwater, and the effectiveness of the carbon treatment system. The reports show that upgradient monitoring wells contain nitrate ranging from 6 to 12 mg/l, and ammonium ranging from 0.2 to 1.5 mg/l. Operations area monitoring wells (MW-2 and MW-3) contain nitrate between 50 and 500 mg/l, and ammonium between 200 and 600 mg/1. The off-site downgradient monitoring well (MW-5) consistently contains nitrate ranging from 15 to 20 mg/1 and ammonium from 5 to 10 mg/l. The other major groundwater contaminant of concern at this site is 1,2-dichloropropane (1,2-DCP). The apparent source area is in the northwestern portion of the facility, since MW-2 in this operations area contains between 10 and 40 µg/1 1,2-DCP, but the other operations area well (MW-3) does not contain 1,2-DCP. The off-site downgradient monitoring well (MW-5) contains declining concentrations of 1,2-DCP, from a high of 3 µg/1 in late 1998 to about 1 µg/1 in 2001. WFS extracts groundwater for use in its fertilizer formulations seasonally (about April through September) from an extraction well near MW-3 in the southeast portion of the site, which is treated in a carbon adsorption system prior to use. The monthly water quality monitoring from the influent and effluent ports show that about 9 mg/l nitrate and 30 mg/l ammonium are consistently moved through the system into the fertilizer production process. Volatile organic compounds and fumigants are not detected in the influent (including 1,2-DCP, ethylene dibromide and dibromochloropropane), although carbamates are occassionally detected. WFS requests that staff revise Monitoring and Reporting Program No. 97-808 (MRP) to reflect a Board staff approved change from nitrate analyses using EPA Method 300.0 to EPA Method 353.2 which includes nitrate and nitrite. This is a reasonable request, and we ask that you resubmit this request and any additional MRP revision proposals in the third QMR which is due 30 October 2001. Approval Of Work Plan In the work plan, GeoSyntec proposes to conduct a field-scale pilot test injecting Hydrogen Release Compound® (HRC) one time into the shallow aquifer at 23 discrete points within a 640 square-foot grid. Six pounds of HRC per vertical foot of shallow aquifer(about 24 to 48 feet below ground surface) are proposed to be injected at each point. GeoSyntec also proposes to install a small diameter monitoring well (MW-6) in the center of the grid, and monitor the progress of the pilot test quarterly from MW-6 and MW-2, which is immediately downgradient from the injection grid. GeoSyntec will additionally obtain baseline groundwater samples prior to injection and annually after injection from MW-4, MW-6, MW-2, and downgradient MW-5.