2020-02-26_REVISION - M2002004 - Laserfiche WebLink

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Title: Sampling and Analysis Plan for Environmental Control Number: Revision Date: page 15 of 30 Groundwater Monitoring PUE.EN.D.026.04 2/19/2020 The RPD(Relative Percent Difference) is calculated with the following equation: RPD(%)=(S1-S2)/[(S1+S2)/2] * 100 where: S 1 and S2 are the two duplicated values or the highest and lowest values if more than two sample duplicates are analyzed. Duplicated sample results that do not meet the above criteria and are not consistent with historical results are flagged.Flagging is not required when fewer field duplicates than required are collected, but a QA memo is filed with the data and the incident is noted in the data transmittal for the sampling event. 5.2.2 Laboratory Data Verification Laboratory data reports are reviewed for appropriate QA/QC procedures and data qualifiers. Applicable U.S. Environmental Protection Agency (EPA) analytical methods encourage laboratories to develop in-house QA/QC limits, and require adherence to in-house limits for data reporting, qualifying and corrective actions. Verification of appropriate laboratory flagging is conducted during data validation. Although it is the laboratory's responsibility to ensure that its results meet minimum internal QA/QC standards and are properly flagged, the data validation process also includes the following checks: • Confirm that all sample sites and constituents are reported and that there is an explanation for a missing data point. • Review the data report and confirm that titles, labels, column headings, and footnotes are accurate and complete. Confirm that constituents are reported in proper units. • Review values reported as Non-Detected. Confirm that the analytical detection limits are low enough to accomplish project goals. Confirm that all values are either reported as values or less than the detection limit. Confirm that the detection limit is used consistently on all samples. • Ensure that the required quality control tests (i.e., preparation and calibration blanks, laboratory control standards, matrix spikes and duplicate samples) were performed at the required frequency. If quality control results cannot be obtained from the laboratory, all associated data are qualified or invalidated. • Ensure that initial calibration verification and reference sample test results were within laboratory specified control limits. Any data reported with associated initial calibration verification or reference standards that are outside of control limits are invalidated. • Confirm that the laboratory properly qualified(flagged)the data. • Review data for internal consistency.Confirm that values have a logical relationship to one another.Confirm that values are within the historical range of data for a given well and constituent. Confirm that values vary logically according to known geologic conditions.