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Review Comments for Revised Site investigation Work Plan-June 2015 <br /> Former Helena Chemical Facility <br /> Page 5 <br /> Clarifications were made.The other samples will be discarded. <br /> 6. Figure 2: Please revise the figure to show that a groundwater sample (GW 13) will be collected <br /> from boring B41. <br /> The correction was made. <br /> 7. Appendix C, Table Listing Constituents of Concern, Screening Levels, and Proposed <br /> Laboratory Reporting Limits for Groundwater; Please address the following comments: <br /> a. The units of concentration are shown in the table as u/L rather than ug/L. Please correct <br /> this typographical error. <br /> The correction was made. <br /> b. The proposed laboratory RLs and MDLs for total petroleum hydrocarbons as gasoline, <br /> diesel, motor oil, and kerosene (TPH-G, TPH-D, TPH-MO, and TPH-K); benzene, <br /> toluene, ethyl benzene, and xylenes (BTEX); and methyl tert-butyl ether(MTBE) are not <br /> included in the table.The Work Plan should be revised to include the proposed RLs and <br /> MDLs for these constituents. <br /> Reporting limits were not included on the table for groundwater because analysis for <br /> hydrocarbons in groundwater was not proposed in the original work plan or the first <br /> revision of the work Dian. <br /> c. The proposed laboratory RLs and method detection limits (MDLs) for some chemical <br /> constituents listed in Appendix C (e.g. cadmium, lead, 1,2,3-trichloropropane [TCP], <br /> 1,2,- dibromo-3-chloropropane, disulfoton, aldrin, chlordane, dieldrin, kepone, and <br /> toxaphene) are greater than their respective WQO values. Please ensure that the selected <br /> laboratory can perform analyses using the lowest commercially available and achievable <br /> RLs,to provide quantification of constituents for evaluation with respect to WQOs. <br /> Please refer to discussion above regarding the available reporting limits. <br /> d. The water quality assessment thresholds (WQATs) listed for several constituents (zinc, <br /> chlorpyrifos, diazinon, disulfaton, aldrin, alpha-BHC, beta-BHC, delta-BHC, gamma- <br /> BHC, chlordane, DDD, DDE, DDT, dieldrin, endosulfan, endrin, heptachlor, and <br /> methoxychlor) are for inland surface water or estuary, rather than for groundwater.Please <br /> revise the Work Plan to list the correct groundwater WQATs for these constituents. <br /> WOATs have been changed to the groundwater values. <br /> e. The Federal and State MCLS listed for simazine are incorrect. The Federal and State <br /> MCL for simazine is 4 ug/L and not 40 ug/L.Please revise accordingly. <br /> The correction has been made. <br /> f. Region 2 ESLs should be deleted from the table because they are not applicable for the <br /> Site,as noted in General Comment No. 1 above. <br /> References to Region 2 ESLs have been removed. <br /> as <br /> IW CONDO <br />