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• collect groundwater samples from LM-60 was made due to the previously sampling which showed no detectable PCE or TCE. Based on our review of tabulated data in WCC (1991a) , LM-60 has had consistently non-detectable levels of all analytes. • Since the well is accessible for purging and sampling, it would be prudent to retrieve a sample prior to abandonment, due to previously discussed levels of contaminants in wells in close proximity to LM-60. Page 3-4 , Section 3 .4 20. Section 3 .4 .2 states that "data precision will be assessed as percent relative standard deviation of duplicate/replicate samples. " This is the only place in the Work Plan that field duplicates are mentioned. • State whether a field duplicate/replicate be retrieved for each sample. • Explain the protocol for collection of these duplicates/replicates. (NOTE: According to Regional Water Quality Control Board (RWQCB) policy, post- sampling purging is required between initial sampling and the duplicate/replicate retrieval events. ) Pages 3-5 to 3-7 , Section 3 . 5 21. All data, whether "rejected" or "nonconforming" but "amenable to corrective action" should be presented to EPA for review. Any decision to reject data should be documented in presentations to EPA. Pages 3-7 to 3-10, Section 3 . 6 22 . EPA should receive copies of all Engineering Reports and Analytical Submittals, Minutes of Meetings, Correspondence, and Monthly Progress Reports. EPA and the state are again missing from the listing of governmental agencies to receive copies of all reports and technical documents. • Explain in the text how EPA and the state receive their copies. Page 4-1, Section 4 . 1 23 . As previously discussed, Section 4 . 1. 2 states the intention to drill the "sand backfill" out to total well depth for Wells No. 1 and 2 , using a 14-inch bit. This creates the possibility of damage to the 12-inch casing at the bottom of the Well No. 1. 7 of 12