SITE INFORMATION AND CORRESPONDENCE

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the location for the split sample, and possibly the duplicate sample, will be from the uppermost screened interval in the Lower Tulare (at a depth of 512 to 523 feet based on Figure 3) . 4 . Section 5. 0 . 1, page 9 Section 5 . 0. 1 states that the field activities will include a "lead paint evaluation. " The purpose for this evaluation is not given. • The plan should clarify the purpose, sample collection procedure and analysis method for the lead paint evaluation. 5 . Section 5. 1.2, page 10 Section 5. 1 .2 indicates that the use of packers during sampling or performance of a spinner test prior to sampling may be appropriate, if "flow into the well is preferential ." This section also states that the sampling and abandonment procedures may be modified, based on results of the pump removal and geophysical logging. • The plan should clarify under what conditions it will be appropriate to use packers or perform the spinner test. The plan should explain what potential modifications of the sampling and abandonment procedures are going to be considered. 6 . Section 5 .3 . 1, page 11 Section 5 . 3 . 1 states that the purge volume will be three times the submerged-casing volume of water. However, for this production well, this purge standard is not appropriate for sampling to help evaluate potential downward flow of contaminants along the well casing. • A sample should be collected from water along the well casing, not from the aquifer itself. The plan should be modified to minimize the required purge volume. It should state the expected purge and sampling rates . Low flow rates are preferred. The use of a double-packer system during purging and sampling would be appropriate. 7 . Section 6 . 1.3, page 13, and Section 3 .2 .1 The plan states that samples will be shipped within 48 hours to the lab. However, Table 1 indicates that the holding time for nitrates and orthophosphate is 48 hours . epa/rMju 94 2