Ohio EPA Issues Revised Ground Water Sampling Chapter of Technical Guidance Manual for Review and Comment


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Ohio EPA Issues Revised Ground Water Sampling Chapter of Technical Guidance Manual for Review and Comment

By: Steve Williamson, CPG

Published in the May 2020 Focus on the Environment Newsletter

On May 20, 2020, Ohio EPA Division of Environmental Response and Revitalization (DERR) Geologist Group announced that they have posted a draft revision of the Ground Water Sampling chapter (Chapter 10) of the Technical Guidance Manual (TGM) for Hydrogeologic Investigations and Ground Water Monitoring. The DERR Geologist Group maintains Ohio EPA’s TGM and provides support for geologic and ground water issues related to the investigation and cleanup of contaminated sites, including:  

  • Resource Conservation and Recovery Act (RCRA) Subtitle C facility corrective actions and closures
  • Comprehensive Environmental, Response, Compensation and Liability Act (CERCLA or Superfund) sites and federal facilities
  • State-lead remedial response sites, properties regulated under Ohio’s Voluntary Action Program (VAP) and brownfield properties

The Ohio EPA TGM was first finalized in 1995 and subsequently updated in February 2006 (Revision 1) and May 2012 (Revision 2). This guidance document represents an update (Revision 3) to Chapter 10 (Ground Water Sampling). Listed below are the technical changes from the 2012 version of Chapter 10.

  • Updated formula for calculating water volume in a one-foot section of well casing and associated table.
  • Updated sampling mechanisms and associated table.
  • Added general information related to sampling PFAS.
  • Updated Field Conditions section for additional conditions that could affect sample representativeness.
  • Updated water level measurements section and associated table.
  • Updated existing references and added new references.

The Ohio EPA will accept comments on the revised chapter until June 19, 2020. Comments should be emailed to Doug.Switzer@epa.ohio.gov


Steve Williamson is a Senior Scientist with Cox-Colvin & Associates, Inc. He holds a BS degree in Environmental Health and an MS degree in Hydrogeology from Wright State University. Mr. Williamson has over 30 years' experience working on brownfields, solid and hazardous waste, and groundwater contamination projects in Ohio and the Midwest.