Connecticut Department of Energy & Environmental Protection

Quality Assurance and Quality Control

The Remediation Standard Regulations (RSRs) 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 (e.g. soil, water, air) are used to determine if remediation is needed to minimize risk to human health and the environment or if remediation has been completed. Because of the complex 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. Therefore, data may not always be representative of the accurate concentrations of the analytes in the environmental media.  It is necessary to evaluate the quality of analytical data in relation to its intended use in order for the environmental professional to make decisions that are supported by data of known and sufficient quality. It is important that both environmental professionals and analytical laboratories implement Quality Assurance and Quality Control (QA/QC) methodologies.

The use of QA/QC parameters provide a level of confidence in the quality of the acquired data. DEEP refers to this level of data confidence as “Reasonable Confidence”. “Reasonable confidence” is achieved when the laboratory has followed the Reasonable Confidence Protocols (RCPs), has described non-conformances, if any, and has provided adequate documentation for a particular dataset to allow the environmental professional or responsible party (i.e., data users) to make judgements regarding data quality for its intended purpose.  The concept of Reasonable Confidence and the Reasonable Confidence Protocols are further supported by RCSA section 22a-133k-1(h)(1)(B).

Data users have the option to use non-RCP analytical methods and/or methods that have no published RCP. However, it is important that data users consider the resources that may be required to demonstrate an equivalency with the RCPs. Pursuant to RCSA 22a-133k-1(h)(1)(C), when a non-RCP method is used for demonstrating compliance, the methods and/or protocol must be submitted to DEEP for review and evaluation. DEEP has provided a Demonstration of Equivalency form in the document list below that may be used to provide the necessary information including the laboratory-generated QC data that support the accuracy, precision, and sensitivity of the data.

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

QA/QC Documents

Reasonable Confidence Protocols for Laboratory Analytical Methods

For a general review of the primary changes made to the RCPs, DEEP has provided a summary table  of the changes to be used as a quick reference guide.  See the table below for both the current and revised RCPs.

Characterization of Petroleum Releases

See analytical methods used to characterize petroleum releases for additional information.

Questions or Comments?

Questions or comments regarding quality assurance and quality control may be directed to Veronica Tanguay or Allison Forrest-Laiuppa.

 Content Last Updated May 29, 2024