DEEP: Quality Assurance and Quality Control

Quality Assurance and Quality Control

 Data Quality Assessments & Usability  RCPs for Laboratory Analytic Methods
 Modification of RCP Forms  Final Discontinuation of EPA 418.1 Method
 QA/QC Documents  Questions or Comments

Data Quality Assessment and Usability

The Remediation Standard Regulations, sections 22a-133-1 to 22a-133k-3 of the Regulations of Connecticut State Agencies (RSRs) Appendices A through F include numeric criteria used to determine if a potential risk to human health or the environment may exist.  The results of analyses performed on environmental media are used to determine if remediation is needed. Because of the nature of environmental media, limitations of analytical methods, characteristics of analytes, and human error, the results of environmental analysis may contain an element of uncertainty and, in some cases, may be significantly biased, and therefore, may not be representative of the actual concentrations of the analytes in the environmental media.  Thus, an evaluation of the quality of the analytical data in relation to its intended use is important in order for the environmental professional to make decisions which are supported by data of known and sufficient quality.

To assist responsible parties and environmental professionals in evaluating the quality of analytical data in relation to its intended use, the Department is providing these guidance documents:

  • Laboratory Quality Assurance Quality Control Reasonable Confidence Protocols, effective November 2007 and revised December 2010, provides information on laboratory quality control and quality control assurance and the Reasonable Confidence Protocols (RCPs).  The RCPs are analytical procedures that include specific laboratory Quality Assurance and Quality Control (QA/QC) criteria that produce analytical data of known and documented quality.  RCPs have been developed for twenty of the most commonly used analytical methods and RCPs may be developed for other methods in the future.

  • Laboratory Quality Control Assurance and Quality Control, Data Quality Assessment and Data Usability Evaluation Guidance Document  (DQA/DUE Guidance), effective May 2009 and revised December 2010 - There are many ways to evaluate the quality of analytical data in terms of precision, accuracy, representativeness, comparability, completeness and sensitivity in relation to the intended use of the data.  Precision, accuracy, representativeness, comparability, completeness, and sensitivity are collectively referred to as the PARCCS parameters.  This guidance document describes a DEEP- accepted, two-step process for data evaluation.  The first step consists of an assessment of data quality.  The second step is an evaluation to determine whether the data can be used to support the decisions that will be made using that data. Use of this guidance provides consistency in evaluation and presentation of data quality information that will facilitate review.  If an alternative process is used, that process and the rationale for its use should be well documented and may involve a commitment of significant resources to demonstrate that the data is of known and sufficient quality and is usable relative to its intended purpose.

  • Importance of Communication Between the Environmental Professional and the Laboratory During the DUE/DQA Process, effective March 2017.  DEEP expects responsible parties and environmental professionals to ensure that the analytical data generated during environmental investigations conducted in accordance with the Site Characterization Guidance Document are of a known and appropriate quality.  DEEP also expects responsible parties and environmental professionals to ensure that the analytical data generated during remediation projects meet the same standards for quality.  In 2007, DEEP created the Reasonable Confidence Protocols (RCPs) in coordination with the Connecticut Department of Public Health to facilitate the generation of laboratory data of known quality.  The RCPs are described in the DEEP RCP Guidance Document.  The procedures for assessing the quality of analytical data and evaluating the data in a project-specific context are presented in the Data Quality Assessment and Data Usability Evaluation Guidance Document.  DEEP, with the assistance of a workgroup comprised of representatives from DEEP and licensed environmental professionals, prepared this guidance document based on the two guidance documents mentioned above and focuses on the DQA/DUE of analytical data generated using RCP analytical methods and the importance of clear communication between the environmental professional and the laboratory throughout a project.
Modification of Reasonable Confidence Protocol Certification Forms
It has come to the attention of the Remediation Division of the Connecticut Department of Energy and Environmental Protection that several laboratories had modified the “Reasonable Confidence Protocol Laboratory Analysis QA/QC Certification Form” (“RCP Certification Form”), dated November 2007.  The RCP Certification Form must not be altered.  These modifications to the form included adding not applicable (“N/A”) as a response to questions 2 to 7.  At the request of DEEP, these laboratories have returned to using the RCP Certification Form.
The primary purpose of the RCP Certification Form is to standardize the questions that the laboratory must answer when determining if a data set meets the requirements for Reasonable Confidence.  When Reasonable Confidence is achieved for a particular data set, the environmental professional will have Reasonable Confidence that the laboratory has followed the Reasonable Confidence Protocols, has described non-conformances, if any, and has adequate information to make judgments regarding data quality.  If Reasonable Confidence is not achieved for an analytical data set, use of such a data set may involve a commitment of significant resources to demonstrate that the data is of known and sufficient quality and is usable relative to its intended purpose.

At this time, the Department is not requiring that laboratories issue new RCP Certification Forms for data sets that were reported using modified RCP certification forms.  If the form had been previously altered, then, because the achievement of Reasonable Confidence is based on questions 1, 1A and 1B, modification of the responses to questions 2 to 7 on the form will not prevent the achievement of Reasonable Confidence.

A response of “N/A” to questions 2 to 7 on the form may not provide the environmental professional with the narrative information needed for a data quality assessment and data usability evaluation.  Any nonconformance of the RCP criteria should be described in the laboratory narrative.

If the environmental professional has questions regarding the impact of a modified form on data assessment and usability, the environmental professional should contact the laboratory or DEEP for assistance. 

DEEP has sent an email to laboratories reminding them that the RCP Certification Form may not be altered.

QA/QC Documents

Laboratory Quality Assurance Quality Control Reasonable Confidence Protocols  - effective November 2007 and revised December 2010 (PDF)
Additional Worksheets: RCP and DQA Worksheet 1 (Word) / RCP and DQA Worksheet 2 (Excel)
Reasonable Confidence Protocols for Laboratory Analytical Methods
Method 1311 TCLP - December 2006 (PDF)
Method 1312 SPLP - December 2006 (PDF)
Method 6010  Trace Metals - July 2006 (PDF)
Method 6020  Trace Metals - July 2006 (PDF)
Method 7000  Metals - July 2006 (PDF)
Method 7196 Hexavalent Chromium - July 2006 (PDF)
Method 7470/7471 Mercury - July 2006 (PDF)
Method 8021 Volatile Organics - July 2006 (PDF)
Method 8081 Pesticides - July 2006 (PDF)
Method 8082 PCBs - July 2006 (PDF)
Method 8151 Chlorinated Herbicides - July 2006 (PDF)
Method 8260 Volatile Organics - July 2006 (PDF)
Method 8270 Semivolatile Organics - July 2006 (PDF)
Method 9010/9012/9014 Total Cyanide - July 2006 (PDF)
Method TO-13 PAHs in air - December 2006 (PDF)
Method TO-15 Volatile Organics in air - December 2006 (PDF)
Method TO-17 Volatile Organics - December 2006 (PDF)
Method ETPH Extractable Petroleum Hydrocarbons - July 2006 (PDF)
Final Discontinuation of the EPA 418.1 Method for Samples Collected After June 30, 2009

In the December 31, 2005 Federal Register, the EPA Office of Water proposed to revise 40 CFR 136 and withdraw all analytical methods that use Freon 113 as a solvent.  The methods affected are 413.1, 413.2 and 418.1.  The final rule was published in the March 12, 2007 Federal Register and the Freon-based methods were withdrawn. 

In an effort to help bring about the end of Freon use in Connecticut and to be consistent with Federal Law, the DEEP will not accept analytical data derived by EPA Method 418.1 for samples collected on or after June 30, 2009.

The Environmental Laboratory Certification Program of the Connecticut Department of Public Health (CTDPH) stopped offering certification for EPA Method 418.1 as of September 30, 2009 and after this deadline laboratories may not use EPA Method 418.1.

Data derived using the ETPH Method will continue to be accepted by the Department.  In addition, the Department has provided further information regarding analytical methods used to characterize petroleum releases .

Questions or Comments?
Questions or comments regarding quality assurance and quality control may be directed to Peter Hill or by calling (860) 424-3705.

Content Last Updated October 18, 2019

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