Wisconsin Administrative Code
Department of Natural Resources
NR 100-199 - Environmental Protection General
Chapter NR 149 - Laboratory Accreditation
Subchapter VII - Quality Systems
Section NR 149.48 - Quality control requirements for chemical testing

(a) A laboratory shall establish a quality control program that includes the analysis of appropriate quality control samples and quality control procedures that define their practices. These quality control procedures shall be used to assess all the following:

(b) A laboratory may not adjust or correct the sample results by the recoveries of associated quality control samples or surrogates unless otherwise allowed by method, regulation, or covered program. A laboratory may not subtract analyte concentrations found in method blanks from sample results unless otherwise allowed by method, regulation, or covered program.

(c) A laboratory shall document deviations from the laboratory's quality system or exceedances of quality control samples. To the extent the department's data systems allow, the deviations shall be communicated with the results.

(d) A laboratory shall establish procedures for identifying and documenting preparation batches that facilitate determining compliance with the frequencies of quality control samples required under this chapter.

(a) A laboratory shall determine the LOD for all tests performed except for any of the following:

(b) A laboratory shall determine the LOD of an analyte annually by 40 CFR Part 136, Appendix B. All sample-processing steps of a method shall be included in the determination of a LOD.

Note: Links to the 40 CFR Part 136, Appendix B can be found on the Wisconsin department of natural resources laboratory accreditation program website.

(c) The LOD shall meet the regulatory limits required by the covered programs.

Note: Exemptions to LOD requirements for specific compounds are provided on the Wisconsin department of natural resources laboratory accreditation program website.

(d) The LOD shall be adjusted when the sample amounts used are different than those used for the LOD determination.

(e) For tests exempted from performing an LOD under par. (a), the laboratory shall establish a reporting limit, or an estimate of a test's sensitivity based on the intended use of the data for a given application.

(f) The LOD shall be determined each time there is a change in a method or instrumentation that affects the sensitivity of an analysis.

(g) For HRGC/MS technology, the estimated detection limit is defined in SW-846 8290A and is equivalent to the LOD.

(a) A laboratory shall establish the LOQ for all tests performed except for those exempted from an LOD under sub. (2) (a).

(b) The LOQ shall meet the regulatory limits required by the covered programs.

Note: Exemptions to LOQ requirements for specific compounds are provided on the Wisconsin department of natural resources laboratory accreditation program website.

(c) Except for ICP and ICP/MS single point initial calibrations, the LOQ shall be established as 10/3 the LOD or at the concentration of the lowest standard in the initial calibration. For ICP and ICP/MS, when single point initial calibrations are utilized, the LOQ shall be established as 10/3 the LOD or at the "lower limit of quantitation."

Note: The "lower limit of quantitation" is referenced in SW-846 6010C, 6010D, 6020A, and 6020B.

(d) The LOQ shall be greater than the LOD.

(a) Reporting limits are reserved for those analytes exempted under sub. (2) (a) and shall be established based on a test's sensitivity and the intended use of the data.

(b) For biochemical oxygen demand and carbonaceous biochemical oxygen demand, the minimum reporting limit is 2 mg/L which is based on a 300 mL sample volume. When no dilution is equal to 300 mL, the reporting limit shall be adjusted based on the lowest dilution reported.

(c) For total suspended solids, the reporting limit shall be determined using the following formula: Reporting Limit (mg/L) = 1000 / (sample volume filtered in mL).

(a) The laboratory shall process method blanks along with and under the same conditions, including all sample preparation steps, as the associated samples in a preparation batch.

Note: Method blanks are not required for analysis of pH, alkalinity, acidity, conductivity, and solids determinations.

(b) The laboratory shall process method blanks at a frequency of at least one per preparation batch up to 20 environmental samples. When samples are analyzed by methods that do not require a preparation step before analysis, a method blank shall be analyzed at the frequency of one per analytical batch up to 20 environmental samples.

(c) Whenever the concentration of the method blank contains analytes of interest greater than the LOD, the laboratory shall evaluate the nature of the interference and its effect on each sample in a preparation batch.

(d) The acceptance criteria for method blanks are analyte and sample specific and are established based on the highest of any of the following:

(a) Unless otherwise exempted by this subsection, the laboratory shall process an LCS at a frequency of at least one sample per preparation batch up to 20 environmental samples, along with and under the same conditions as the associated samples in a preparation batch. These conditions shall include all sample preparation steps, except for leaching procedure extractions.

Note: TCLP leachates for metals analysis are fortified after the leaching step is completed and before acid preservation.

(b) The laboratory shall fortify the LCS for the biochemical oxygen demand and carbonaceous biochemical oxygen demand tests with a mixture of glucose-glutamic acid as specified in approved methods of analysis. The LCS shall be processed at a frequency of at least one sample per analytical batch for a laboratory that analyzes more than 20 samples per week. A laboratory that analyzes fewer than 20 samples per week shall analyze one LCS per week.

(c) The laboratory is not required to process an LCS for tests for which analyzing a fortified sample is impossible or impractical.

Note: An LCS need not be analyzed for the following tests: pH, solids determinations, chlorophyll a, and color.

(d) The LCS shall be fortified with the analytes specified by method, regulation, or covered program or all reported analytes, except as allowed in par. (e).

(e) For analyses of polychlorinated biphenyls, the laboratory shall fortify an LCS with at least one aroclor per preparation batch. For other tests that determine analytes with responses that encompass more than one chromatographic peak, as in the case of toxa-phene and chlordane, the laboratory may fortify an LCS with a single multi-peak analyte per preparation batch. The laboratory shall ensure that all multi-peak analytes detectable by a method are fortified in an LCS at least once every year that any of those analytes are reported at a detectable concentration.

(f) When the method, regulation, or covered program do not specify control limits, the laboratory shall evaluate LCS recoveries and generate in-house control limits, following exclusion of outliers with a statistical technique and using the mean plus or minus 3 times the sample standard deviation. Annually, the laboratory shall review its generated in-house control limits and update those limits whenever the performance characteristics change.

(g) In lieu of using generated in-house control limits for the LCS, the laboratory may opt to use the CCV standard limits.

(a) The laboratory shall develop and document acceptance criteria, which consider retention time shifts, for chromatographic retention time windows.

(b) The laboratory shall document acceptance criteria for mass spectral tuning.