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GEOMATRIX <br /> monitoring wells MW-16 and MW-17 should be moved further upgradient. The monitoring wells will <br /> be installed using hollow-stem auger methods unless subsurface conditions dictate otherwise. Actual <br /> ' locations may be adjusted based on the results of the exploration activities described above. These <br /> locations have been selected to provide background monitoring points upgradient of the Facility (near <br /> 1 MW-16 and MW-17); monitoring points downgradient of the Facility in the shallow, intermediate, and <br /> deeper zones; and monitoring points cross-gradient(south) of the Facility. <br /> We anticipate that the shallow zone wells will be screened from approximately 10 to 25 feet bgs, the <br /> intermediate zone monitoring well will be screened from about 70 to 85 feet bgs, and the deeper zone <br /> monitoring wells will be screened from about 110 to 130 feet bgs. The actual completion intervals will <br /> be based on subsurface conditions observed in the field. After a minimum of 24 hours following <br /> ' installation, the monitoring wells will be developed by bailing and surging to remove sediments <br /> accumulated during well installation and to enhance the hydraulic communication between the target <br /> zone and the well. Development fluids will be placed in barrels on-site pending final disposition. <br /> ' 3.5 Monitoring Well Survey <br /> ' Following installation, the northings and eastings of the existing and newly installed monitoring wells <br /> and exploration borings will be surveyed by a State-licensed surveyor. In addition,the measuring point <br /> elevation of each monitoring well relative to mean sea level will be recorded. <br /> ' 3.6 Monitoring Well Sampling <br /> The newly-installed monitoring wells will be included in the next trimesterly groundwater monitoring <br /> event. Following well installation and development,the trimesterly monitoring event will be conducted <br /> in accordance with the existing sampling and analysis plan(SAP)for the Facility (TreaTek, 1996a). As <br /> ' /quality control <br /> described in the SAP, the groundwater samples and associated quality assurance <br /> (QA/QC) samples (including replicate samples, equipment blanks, and MS/MSD samples) will be <br /> ' submitted to a State-certified laboratory for analysis using the following analytical procedures: <br /> • Halogenated Volatile Organic Compounds(VOCs)- EPA SW846 Method 8010 <br /> • Fumigant Pesticides-DBCP and EDB -EPA SW846 Method 8011 <br /> • Carbamate Pesticides- EPA SW846 Method 8321 <br /> ' • Organochlorine Pesticides-EPA SW846 Method 8080 <br /> • Organophosphorus Pesticides- EPA SW846 Method 8140 <br /> ' . Triazine Herbicides- EPA SW846 Method 8141 <br /> • Phenoxy Herbicides- EPA SW846 Method 8150 <br /> ' Nitrates as N,Nitrites as N,Chloride, and Sulfate-EPA Method 300.0 <br /> ' • Ammonia- EPA Method 350.1 <br /> cvaortrnaumnau�rvr.�xssa�a« 1 1 <br />