ARCHIVED REPORTS_XR0011962 - Laserfiche WebLink

Home Browse Search

Soil Vapor Extraction and Air Sparge Feasibility Evaluation Work Plan University Park September 15,2004 Page 6 its TABLE 1 Laboratory Ana! tical Methods for Vapor Samples ` CONSTITUENT METHOD DETECTION LIMIT BTEX 8020 0.5 mg/m3 OXYGENATES/ADDITIVES 8260 0.5 mg/m3 TPH-G 8015M 20 mg/m3 Unit Conversions: Analytical mg/m':milligrams per cubic meter BTEX=benzene,toluene,ethyl benzene,and total xylenes. TPH-G=total petroleum hydrocarbons,quantified as gasoline. OXYGENATES/ADDITIVES include methyl tertiary-butyl ether(MTBE),ethanol, tertiary-butanol(TBA),di-isopropyl ether(DIPE),ethyl tertiary-butyl ether(ETBE), tertiary-amyl methyl ether(TAME), 1,2-dibromoethane(EDB or 1,2-DBA),and 1,2- dich[oroethanc(1,2-DCA) 5.0 AS PILOT TEST This section describes the proposed AS pilot test to be conducted at the site. An oil-less air compressor capable of providing a minimum of 25 scfm of air at 25 pounds per square inch (psi) will be used for the pilot test. A pilot test will be performed on the AS well to determine the optimum air pressure and flow rate for the AS well, the radius of influence at the optimum air pressure and flow rate, and the effects of mounding resulting from the injection of air into the saturated zone. Data collected during the pilot tests will also be used in sizing the components to be used in the AS system. Condor will notify the SJCEHD ti.. at least 48 hours prior to implementation of the pilot test. 5.1 AS PILOT TEST PROCEDURES Helium gas will be used as a conservative tracer to aid in determining subsurface airflow pathways. A 20 percent mixture of helium gas in air will be used for the pilot test. The compressed air and helium gas flow line will be equipped with appropriate pressure regulators, throttle valves, pressure indicators, and a. flow rate indicators. Sparged gas samples will be collected from observation wells MW-1, MW-2, MW-3, and the three SVE wells. The depth to water will be measured in the AS well being tested and the observation wells prior to the start of the test. Groundwater samples will be collected from each of these wells for field analysis for dissolved oxygen (DO). A vacuum pump will be used to evacuate three casing volumes of vapor from the a.. observation wells, then a vadose zone gas sample will be collected in a Tedlar bag for the field measurement of organic vapors and helium. s Compressed air will be introduced to the AS well at a pressure equal to the head of water from the top of the well screen to the water table. The air pressure will be gradually increased until breakthrough is achieved and air begins flowing through the well. The pressure will be increased until the lowest desirable flow rate is achieved. The first test will be performed at this flow rate. Helium gas will be introduced to the well at the same pressure as the compressed air. During the test, the air and helium flow rates, the pressure at the AS well, and the depth to water in the observation wells will be monitored. Vadose zone gas samples will be collected for the field measurement of organic vapors and helium. Saturated zone gas �6_ samples will be collected for the field measurement of helium. After the helium concentration in the gas samples collected from the observation wells stabilizes, the test - will be stopped. The depth to water in the AS well and the observation wells will be measured. Vadose }t. 4M �.� CONDOR LW