Use the tabs below to locate a significant guidance document by environmental topic.  We sorted the documents by topic to help you find the appropriate document more quickly; however, we did not necessarily list a document under every topic mentioned in it.  Instead, documents are grouped according to their major themes.  Some documents may be listed multiple times while others may appear under just one topic.

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Technical Guidance Manual (TGM)
for Hydrogeologic Investigations and Ground Water Monitoring

TGMThe TGM identifies technical considerations for performing hydrogeologic investigations and ground water monitoring at potential or known ground water contamination plumes and source areas. The TGM’s purpose is to promote the collection of representative hydrogeologic data that meeting project data quality objectives by sharing Ohio EPA’s technical recommendations with the regulated community. The TGM helps ensure regulatory consistency across the regulated community and within Ohio EPA, as well as informing the regulated community of the scientific bases for Ohio EPA’s technical recommendations.

Under Ohio EPA’s Voluntary Action Program, phase II property assessment sampling activities investigating ground water contamination need to follow the TGM per OAC 3745-300-07(F)(6)(d)(viii)(b). For Ohio EPA’s other regulatory programs, the TGM provides guidance to help the regulated community comply with laws, rules, regulations and policy.

Guidance describes recommended practices and is used to support regulatory decisions regarding compliance. A regulated entity may use alternate methods to collect information and data to satisfy a regulatory program. However, Ohio EPA may require the regulated entity to demonstrate that the alternate methods produce information and data that meet pertinent regulatory requirements. Ohio EPA recognizes that the procedures used to meet data quality objectives should be designed to address applicable regulatory requirements, project needs and site-specific conditions or circumstances.

The TGM consists of a series of chapters that were originally published in 1995. The chapters are periodically updated, and the most current versions can be downloaded from “Technical Guidance Manual Chapters” below. Current versions include a summary of the major changes from the last revision date. All previous versions are available for reference (see “Archives” section below).


Technical Guidance Manual Chapters

Note: Chapter 1 (Introduction) and Chapter 2 (Regulatory Authority) are no longer part of the TGM series of documents. Chapter 1 provided a list of authorities for various pollution sources. This information can be found in Ohio EPA’s fact sheet "Getting to Know Ohio EPA." Chapter 2 provided a regulatory overview of Ohio EPA’s programs that may require ground water monitoring and/or hydrogeologic investigations. Information regarding Ohio EPA’s regulatory programs and ground water related rules and guidance are available on the DDAGW, DERR and DMWM internet pages.

**See U.S. EPA’s Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities-Unified Guidance, March 2009 for ground water statistical guidance.

TGM Supplements


Archived versions of the Technical Guidance Manual for Hydrogeologic Investigations and Ground Water Monitoring (TGM)

This page provides links to older versions of the TGM are provided in the event that they are applicable to a particular program rule. For example the TGM is cited in the following rule; therefore, the TGM version available at the time when the rule was promulgated is associated with that rule.

Archived TGM Documents

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