Laserfiche WebLink
Mr. Jeff Goold � • • <br /> - 2 - 16 February 2005 <br /> columns for methanol and ethanol and is not consistent with Table 3 of the Annual <br /> Report, which provides the fuel oxygenate sampling data. Furthermore, Shell needs to <br /> add new monitoring well MW-36 to the Well Construction Detail table. <br /> 3. The Letter reviews the fuel oxygenate sampling results, compares those results to the <br /> MRP, and proposes fuel oxygenate sampling in a table based on the wells that have or <br /> have not met the requirements to eliminate fuel oxygenate sampling. Based on the review <br /> of the analytical data provided in Table 3 of the Annual Report and the table provided <br /> with the Letter, Regional Board staff concurs with the proposed fuel oxygenate sampling <br /> for 30 of the 36 monitoring wells. The following are the six wells that Regional Board <br /> staff does not concur with the proposed sampling and why: <br /> MW-10: Ethanol sampling is no longer required for this well <br /> MW-16, MW-20, &MW-24: Ethanol sampling is no longer required for these wells, <br /> but methanol sampling must continue until it is reported <br /> as non-detectable at the PQL, which is 50 micrograms per <br /> liter(ug/1) in the MRP. Some of the methanol samples <br /> are reported as less than 0.5 ug/l,but Regional Board staff <br /> believes these entries to be errors in Table 3 <br /> MW-23: Quarterly sampling of tertiary amyl methyl ether is still <br /> required because there have not been four consecutive <br /> quarters of non-detectable results at the PQL after a <br /> reported detection as required by the MRP <br /> MW-29: Quarterly sampling of methyl tertiary butyl ether is still <br /> required because there have not been four consecutive <br /> quarters of non-detectable results at the PQL after a <br /> reported detection as required by the MRP <br /> Additionally, Table 3 does not include the analytical method used for the fuel oxygenate <br /> sampling. If the samples were analyzed by an analytical method other than USEPA <br /> Method 8260B (such as methanol by 8015), then the fuel oxygenate sampling must <br /> continue because USEPA Method 8260B is required by the MRP. <br /> Based on the current trends at the site and to simplify the sampling schedule,we have attached a <br /> draft revised MRP. By 18 March 2005,please provide comments on the draft revised MRP and <br /> provide a figure showing all site wells that is labeled as Figure 1. Note that dissolved lead has <br /> been added to the MRP. The tables in the Annual Report do not show results for lead sampling. <br /> If this sampling has been conducted, please provide the results along with any other comments on <br /> the draft revised MRP. If sampling occurs prior to the issuance of the new MRP, fuel oxygenate <br /> sampling may still be eliminated based on the requirements of MRP No. 5-01-815. If you have <br /> any questions, you may contact me at (916) 464-4719 or dlewis@waterboards.ca.gov. <br /> DEVRA LEWIS <br /> Environmental Scientist <br /> Attachment <br /> cc: See Page 3 <br />