Quality Assurance and Quality Control (QA/QC) Guidance
Overview
The CTDEP expects responsible parties and environmental professionals to ensure that the analytical data generated during environmental investigations conducted in accordance with the CTDEP’s Site Characterization Guidance Document (SCGD), dated September 2007, are of a known and appropriate quality. CTDEP also expects responsible parties and environmental professionals to ensure that the analytical data generated during remediation projects are of a known and appropriate quality.
To assist responsible parties and environmental professionals in evaluating the quality of analytical data, the CTDEP Remediation Division Laboratory Quality Assurance and Quality Control Work Group (the Work Group), developed the Reasonable Confidence Protocols (RCPs). The Work Group is comprised of licensed environmental professionals, data validators, and representatives from private laboratories, the Connecticut Department of Public Health, the United States Environmental Protection Agency, and the CTDEP. 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 eighteen of the most commonly used analytical methods, and RCPs may be developed for other methods in the future. The RCPs are available below. Improvements in analytical data quality and consistency will help environmental professionals and responsible parties make sound technical decisions regarding data quality and usability. These improvements will also promote CTDEP’s acceptance of the analytical data, thereby reducing the need for additional sampling and analysis to support and/or confirm the analytical data and the environmental professional’s decisions.
For samples collected on or after September 1, 2007, the CTDEP expects that any associated analytical data will be generated using the RCP (or methodologies that contain a level of quality control and documentation at least equivalent to the RCPs). The environmental professional is advised that the use of non-RCP methods for samples collected on or after September 1, 2007 may involve the commitment of significant resources to demonstrate an equivalency with the RCPs. Submittals to the CTDEP of data generated by methods other than the RCPs should be accompanied by adequate documentation and opinions as to how the methods are equivalent to, or exceed, the level of quality control documentation in the RCP methods. Please see the Policy Letter dated April 18, 2007 for additional information.
The guidance document titled
Laboratory Quality Assurance Quality Control Reasonable Confidence Protocols , dated November 2007, provides information on laboratory quality control and quality control assurance and the Reasonable Confidence Protocols.
In May 2009, the Laboratory Quality Control Assurance and Quality Control, Data Quality Assessment and Data Usability Evaluation Guidance Document (DQA/DUE Guidance) was finalized. The DQA/DUE Guidance will act as a supplement to the CTDEP’s SCGD, and will aid the environmental professional in ensuring that analytical data used for environmental investigation and remediation projects are of a known and sufficient level of quality. The guidance document describes a two-step process for evaluating the quality of analytical data to determine whether the data are of sufficient quality for the intended purpose. The first step in the process 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 and conclusions that will be made using that data.
On Tuesday, May 19 and again on Wednesday, May 20, 2009 the Work Group held a DQA/DUE training workshop for environmental professionals. The workshop consisted of reviewing the overall concepts of the DQA/DUE, and then two case studies were presented to further explore the process.
Reasonable Confidence Protocols
The Reasonable Confidence Protocols (RCPs) are enhanced laboratory quality assurance and quality control (QA/QC) procedures for laboratories that have been developed to provide guidelines for the type of QC documentation that will be expected for analytical laboratory data that is used by environmental professionals. The RCPs include method-specific performance and reporting criteria. The RCPs were developed because SW-846 methods do not require specific QA/QC standards; therefore, QA/QC practices vary widely by laboratory. Issues identified by the work group included lack of documentation of QA/QC practices, inconsistency in QC deliverables, and inconsistency in laboratory performance.
Included, as part of the RCPs, is the concept of "Reasonable Confidence." When Reasonable Confidence is achieved for a particular data set, the environmental professional will have 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. Reasonable Confidence will form the basis for the review of the analytical data by the environmental professional to determine if the data is acceptable for the intended purpose.
Other components of this guidance include a Reasonable Confidence Protocol Laboratory Analysis Certification Form, Project Communication Form, and a Reasonable Confidence Protocol Equivalency Determination Form.
The Reasonable Confidence Protocol Laboratory Analysis QA/QC Certification Form (PDF) will be used to document compliance with the RCPs. This form will be used to indicate if the analytical data meets the requirements for Reasonable Confidence.
The Project Communication Form (PDF) can be used to communicate all information required by the laboratory. Communication between the environmental professional and the laboratory is recognized as an important component of the success of the enhanced QA/QC procedures. This information includes but is not limited to analytical methods, contaminants of concern, regulatory criteria, project-specific QA/QC requirements, required report deliverables, and scheduling. The use of the laboratory communication form is optional and may be modified by the user to facilitate communication with the laboratory.
The Reasonable Confidence Protocol Equivalency Determination Form (PDF) must be submitted for environmental investigation and remediation projects when a laboratory uses a non-RCP method for an analysis for which there is an existing RCP method. This form is not required for methods for which no RCP method has been published. This form must be submitted to the CTDEP with the analytical data, appropriate documentation, and opinions as to how the method(s) used are equivalent to, or exceed, the level of quality control and documentation required by the RCPs.
Final Reasonable Confidence Protocols for Extractable Petroleum Hydrocarbons (EPH) and Volatile Petroleum Hydrocarbons (VPH)
The Reasonable Confidence Protocol (RCP) for Volatile Petroleum Hydrocarbons (VPH) and Extractable Petroleum Hydrocarbons (EPH) do not report total petroleum hydrocarbons (TPH). The EPH and VPH RCPs evaluate petroleum hydrocarbons by reporting the results for specific carbon ranges found in petroleum hydrocarbons.
The RSRs include criteria for TPH "by EPA Method 418.1 or another EPA-approved method acceptable to the Commissioner." After discontinuation of EPA Method 418.1, compliance with the Remediation Standard Regulations Sections 22a-133k-1 through 22a-133k-3 (the RSRs) can be achieved by either:
- The State of Connecticut, Department of Public Health, Extractable Total Petroleum Hydrocarbon RCP Method ("CTDPH ETPH"), because it is both EPA accepted in Quality Assurance Project Plans and acceptable to the Commissioner; or
- The use on a site-specific basis of the EPH and VPH methods accompanied with an alternative criteria for specific carbon ranges for petroleum hydrocarbons (as an alternative to the RSR’s TPH criteria). Parties performing remediation who opt to use EPH and VPH methods will need to apply to the Commissioner for an alternative criteria under the RSRs. Applications for alternative criteria must use the Transmittal Form (Word / PDF/ Instructions) to accompany such application.
CTDEP intends to publish, as guidance, optional alternative criteria for the specific carbon ranges for petroleum hydrocarbons. If applying for alternative TPH criteria, a party may either apply to use such optional alternative criteria from such future DEP guidance when available (which could be approved quickly), or may develop and apply to use a different alternative criteria for specific carbon ranges for petroleum hydrocarbons.
Training on the EPH and VPH methods will be provided to environmental professionals in the Fall/Winter of 2009. Data derived using the ETPH Method will continue to be accepted by DEP.
The DEP recommends the use of the RCP Methods for EPH and VPH for the following reasons:
- Both the EPH and VPH methods allow for risk based evaluation of TPH data. This will allow for a more accurate evaluation of TPH contamination and its effect on public health and the environment.
- The VPH method, which uses the purge and trap technique for sample introduction to the instrumentation, also captures the volatile hydrocarbon fraction currently lost by the ETPH Method or Method 418.1.
- The EPH and VPH methods have been in place several years in Massachusetts and have been adopted by other states for use in their environmental programs.
Final Discontinuation of the EPA 418.1 Method for Samples Collected After June 30, 2009
In an effort to help bring about the end of Freon use in Connecticut, DEP will not accept analytical data derived by EPA Method 418.1 for samples collected on or after June 30, 2009. Data derived using the ETPH Method will continue to be accepted by DEP. CTDEP has provided responses to public comments on the discontinuation of EPA 418.1 Method.
Questions or Comments?
Questions or comments regarding quality assurance and quality control guidance may be directed to Peter Hill or by calling (860) 424-3912.
QA/QC Documents
Content Last Updated June 10, 2009
