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WASTE DISCHARGE REQUIREMENTSORDER NO. R5-2003-0020 -18- <br />FOR COUNTY OF SAN JOAQUIN <br />FOR CONSTRUCTION, OPERATION, CLOSURE AND EVALUATION MONITORING <br />FOOTHILL SANITARY LANDFILL, MUNICIPAL SANITARY LANDFILL <br />SAN JOAQUIN COUNTY <br />equipment used by the lab, rather than simply being quoted from USEPA analytical method <br />manuals. In relatively interference -free water, laboratory -derived NIDLs and PQLs are <br />expected to closely agree with published USEPA NIDLs and PQLs. <br />13. If the laboratory suspects that, due to a change in matrix or other effects, the true detection <br />limit or quantitation limit for a particular analytical run differs significantly from the <br />laboratory -derived MDL/PQL values, the results shall be flagged accordingly, along with <br />estimates of the detection limit and quantitation limit actually achieved. The NIDL shall <br />always be calculated such that it represents the lowest achievable concentration associated <br />with a 99% reliability of a nonzero result. The PQL shall always be calculated such that it <br />represents the lowest constituent concentration at which a numerical value can be assigned <br />with reasonable certainty that it represents the constituent's actual concentration in the <br />sample. Normally, PQLs should be set equal to the concentration of the lowest standard <br />used to calibrate the analytical procedure. <br />14. All QA/QC data shall be reported, along with the sample results to which they apply, <br />including the method, equipment, analytical detection and quantitation limits, the percent <br />recovery, an explanation for any recovery that falls outside the QC limits, the results of <br />equipment and method blanks, the results of spiked and surrogate samples, the frequency <br />of quality control analysis, and the name and qualifications of the person(s) performing the <br />analyses. Sample results shall be reported unadjusted for blank results or spike recoveries. <br />In cases where contaminants are detected in QA/QC samples (i.e., field, trip, or lab blanks), <br />the accompanying sample results shall be appropriately flagged. <br />15. Unknown chromatographic peaks shall be reported, along with an estimate of the <br />concentration of the unknown analyte. When unknown peaks are encountered, second <br />column or second method confirmation procedures shall be performed to attempt to <br />identify and more accurately quantify the unknown analyte. <br />16. The statistical method shall account for data below the practical quantitation limit (PQL) <br />with one or more statistical procedures that are protective of human health and the <br />environment. Any PQL validated pursuant to §20415(e)(7) of Title 27 that is used in the <br />statistical method shall be the lowest concentration (or value) that can be reliably achieved <br />within limits of precision and accuracy specified in the WDRs for routine laboratory <br />operating conditions that are available to the facility. The Discharger's technical report, <br />pursuant to §20415(e)(7) of Title 27, shall consider the PQLs listed in Appendix IX to <br />Chapter 14 of Division 4.5 of Title 22, California Code of Regulations, for guidance when <br />specifying limits of precision and accuracy. For any given constituent monitored at a <br />background or downgradient monitoring point, an indication that falls between the NIDL <br />and the PQL for that constituent (hereinafter called a "trace" detection) shall be identified <br />and used in appropriate statistical or nonstatistical tests. Nevertheless, for a statistical <br />method that is compatible with the proportion of censored data (trace and ND indications) <br />in the data set, the Discharger can use the laboratory's concentration estimates in the trace <br />