Is the laboratory s pledge or declaration of the quality of the results produced. to produce data compliant with the Safe Drinking Water Act (SDWA)

Transcription

1 QA/QC

2 Is the laboratory s pledge or declaration of the quality of the results produced. to produce data compliant with the Safe Drinking Water Act (SDWA)

3 Is a description of the policies, procedures, techniques and references to other documents used to meet the pledge or declaration, usually found in a Quality Assurance Manual (QAM) Every laboratory should have a QAM, If your laboratory does not, here a couple sources of information to get started.

4 Manual for the Certification of Laboratories Analyzing Drinking Water, Fifth Edition, Chapter III, Section 11. Standard Methods For The Examination of Water & Wastewater, 21 st Edition, Part 1000, 1020 A.1.

5 Is the use of Standard Operating Procedures and the implementation of method defined criteria and other regulatory limits to determine if analytical data meets the laboratory s quality pledge. U.S. EPA Methods and many other approved methods in the Code of Federal Regulations define the required quality control in the body of the method.

6 Later versions of Standard Methods define the required quality control in three different places. Part general description of quality control techniques. In the body of the method - quality control specific to the method. In the introduction to the Parts ( ,000) contains the quality control limits for the methods in the Part.

7 1. Demonstration of Capability (DOC) 2. Method Detection Limit (MDL) 3. Dynamic Range (DR) 4. Calibration Minimum of three standards Range Factors Order of magnitude Correlation Coefficient 0.995

8 5. Calibration Verification A midpoint calibration standard analyzed after calibration, recovery must be within %. 6. Quality Control Sample (QCS) Second source, recommended with each new calibration.

9 7. Method Blank (MB) Frequency: with each set of 20 or fewer samples. Reagent water run as a sample, recovery should be < MDL. 8. Laboratory Fortified Blank (LFB) Run with all sample preparation techniques (i.e. digestions). Frequency: with each set of 20 or fewer samples.

10 9. Duplicates For relative percent difference calculations, sample duplicates or spike duplicates may be used. Frequency: with each set of 20 or fewer samples. 10. Laboratory Fortified Matrix samples (Spikes). Frequency: with each set of 20 or fewer samples. Spike addition should be less than 5% of volume.

11 Internal standards Surrogate standards Tracers for radiochemistry Corrective Actions Control charts Where mandated and when quality control criteria is not specifically defined.

12 Certification is required to analyze microbiological samples for compliance purposes. Focus on sample collection Sample collectors - training records

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15 6.5 Sample information Form Name of system WSSN number if available) Sample identification (if any) Sample site location Sample type (e.g., routine distribution, repeat sample, raw or process water, special purpose. Date and time of collection Analysis requested Disinfectant residual Name of sampler Any remarks

16 8.3 Data should be recorded in ink with any changes lined through such that original entry is visible. Changes should be initialed and dated Sample information form, from 6.5 above Date and time of sample receipt by the laboratory Name of laboratory person receiving the sample Any deficiency in sample condition. - exceeded hold time - Presence of disinfectant in sample is noticed (e.g., odor) - Evidence of freezing - Use of a container not approved by the laboratory - Insufficient sample volume (e.g., <100 ml) - Presence of interfering contaminant - Sample temperature exceeds the maximum allowable

17 Deficiency: The laboratory is not checking and taking necessary corrective action if the sample chain of custody form is received with incomplete, improperly recorded or illogical information. Specifically, on the sample information sheet, The date and time of sample collection was improperly corrected by the sample collector. Incomplete, improperly recorded or illogical data on a chain of custody form is considered a deficiency in the condition of the sample at receipt and corrective action must be taken.

18 Not performing or documenting all chemistry quality control measures required by Standard Methods, Section 1020 and in the introduction to each chapter. Incorrect data changes The laboratory is not following the correct procedures for all data changes. Specifically, he laboratory s records contained written over data. All data corrections must be made by drawing a single line through the incorrect entry, writing in the correct result, and dating and initialing the correction.

19 Gregg Lundy Laboratory Certification Officer MDEQ-RRD-LSS (517)