New Features of the EPA’s Unified Guidance

Water Law Resource
June 12, 2012 — 1,166 views  
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The U.S. Environmental Protection Agency (EPA) released the "Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities" in March 2009. The Unified Guidance replaced the 1989 Interim Guidance and the 1992 Addendum with a more complete and updated document.


The Unified Guidance provides suggested direction for groundwater statistical analysis and monitoring data at RCRA facility units under the influence of 40 CFR Parts 264 and 265 and 40 CFR Part 258. According to the EPA, the Unified Guidance document solves issues found in earlier installments.


The overall purpose of the manual is to provide the information necessary for determining if groundwater has been tainted with hazardous materials. Therefore, RCRA regulations, situation examples, background information and the processes and formulas for groundwater statistical analysis are described in detail.


EPA state departments and professional boards provided input over a decade to develop the March 2009 Unified Guidance. It includes new methodologies and strategies developed from the mid-90s and later, as well as the necessary RCRA permits for testing. The developers of the outline suggest a systematic detection methodology to reduce the chance for errors and retain high credibility.


In the guidelines portion of the document are testing procedures, performance criteria, sample requirements and information on how to identify and measure groundwater protection standards. In addition, it also includes new statistical methods for predicting limits, and measuring outliers, normality, autocorrelation and non-detect data diagnostic evaluations.


The guidance works to streamline groundwater statistical analysis procedures. Due to the fluctuating habits of groundwater and geochemical interaction, the right approaches and applications are critical. Broken up into four parts and with multiple chapters, the Unified Guidance is an inclusive and detailed document containing a variety of new industry standards. Suggestions offered defer to EPA and state regulatory needs. The purpose of the groundwater statistical analysis is to ensure the protection of the public and the environment.


Mathematical equations developed for the purpose of evaluating and predicting the habits of groundwater can increase the success of maintaining safe chemical concentrations. Water and environmental professionals seeking to maintain safe groundwater quality standards and implement programs to improve conditions use the guidance outlined in this document. It offers scientists a peer-approved standard of analysis to add credibility to a cause. A full and complete copy of the text is provided by the EPA.

Water Law Resource