There are several quality control (QC) considerations that apply when using the methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM). Having data of known and documented quality is critical so that public officials can accurately assess the activities that may be needed in remediating a site and determine effectiveness following remediation. Information regarding EPA's DQO process, considerations and planning is available at Quality Management Tools - Systematic Planning. Having such data requires that laboratories: (1) conduct the necessary QC to ensure that measurement systems are in control and operating correctly; (2) properly document results of the analyses; and (3) properly document measurement system evaluation of the analysis-specific QC. Ensuring data quality also requires that laboratory results are properly evaluated and the results of the data quality evaluation are included within the data report when transmitted to decision makers. See: Quality Management Tools - Systematic Planning.

The level or amount of QC needed often depends on the intended purpose of the data that are generated. Various levels of QC may be required if the data are generated during contaminant presence/absence qualitative determinations versus confirmatory analyses. The specific needs for data generation should be identified. QC requirements and DQOs should be derived based on those needs, and should be applied consistently across laboratories when multiple laboratories are used. For example, during rapid sample screening analyses, minimal QC samples (e.g., blanks, duplicates) and documentation might be needed to ensure data quality. Implementation of the analytical methods for evaluation of environmental samples during site assessment through site clearance, such as those identified within the Selected Analytical Methods for Environmental Remediation and Recovery (SAM) document or on this website, might require increased QC frequency.

Some method-specific QC requirements are described in many of the individual methods that are cited in this manual. QC requirements will be referenced in analytical Protocols developed to address specific analytes and sample types of concern. Additional information regarding QC requirements specific to radiochemical methods is included in the MARLAP manual. Individual methods, sampling and analysis protocols, or contractual statements of work also should also be consulted to determine any additional QC that may be needed. See: MARLAP Manual.

QC samples are required to assess the precision, bias, and reliability of sample results. All QC results are tracked on control charts and reviewed for acceptability and trends in analysis or instrument operation. QC parameters are measured as required per method at the prescribed frequency. QC of laboratory analyses using radiochemical methods includes ongoing analysis of QC samples and tracking QC parameters including, but not limited to the following:

• Method blanks
• Calibration checks
• Sample and sample duplicates
• Laboratory control sample recoveries
• MS/MSD recoveries and precision
• Tracer and/or carrier yield

Please note: The appropriate point of contact identified on the Technical Contacts page of this website should be consulted regarding appropriate QA/QC procedures prior to sample analysis. These contacts will consult with the EPA ERLN or WLA coordinator responsible for laboratory activities during the specific event to ensure QA/QC procedures are performed consistently across laboratories. EPA program offices will be responsible for ensuring that the QA/QC practices are implemented. See: SAM Technical Contacts.

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