State of Ohio Ohio Water Resources Council State Coordinating Committee on Ground Water REGULATIONS AND TECHNICAL GUIDANCE FOR SEALING UNUSED WATER WELLS AND BOREHOLES March 2015 John R. Kasich, Governor Mary Taylor, Lt. Governor STATE OF OHIO REGULATIONS AND TECHNICAL GUIDANCE FOR SEALING UNUSED WATER WELLS AND BOREHOLES Ohio Water Resources Council State Coordinating Committee on Ground Water March 2015 (Revision of 1996 document titled “Technical Guidance for Sealing Unused Wells”) Table of Contents Table of Contents ................................................................................................................................................ i List of Tables ..................................................................................................................................................... iii List of Figures ..................................................................................................................................................... iv Acknowledgements ........................................................................................................................................... v Well Sealing Workgroup Members ............................................................................................................................. v State Coordinating Committee on Ground Water Member Agencies .......................................................... v Preface .................................................................................................................................................................. vi Introduction ........................................................................................................................................................ 1 Overview of the Regulations .......................................................................................................................... 2 Reasons to Properly Seal an Unused Well ................................................................................................. 3 Eliminate Physical Hazard .............................................................................................................................................. 4 Prevent Ground Water Contamination ..................................................................................................................... 5 Minimize Further Loss of Confining Pressure ....................................................................................................... 5 Deciding Who Should Perform Well Sealing ............................................................................................ 7 Types of Wells as Defined by Method of Construction .......................................................................... 7 Dug Wells ............................................................................................................................................................................... 7 Driven Wells ......................................................................................................................................................................... 8 Drilled Wells ......................................................................................................................................................................... 9 Auger .................................................................................................................................................................................................... 9 Cable Tool ........................................................................................................................................................................................ 10 Rotary ................................................................................................................................................................................................ 10 Vibratory .......................................................................................................................................................................................... 11 Types of Wells as Defined by Aquifer Characteristics ........................................................................ 13 Preparation for Sealing ................................................................................................................................ 13 Well Information ............................................................................................................................................................. 13 Well Inspection ................................................................................................................................................................ 18 Water Quality .................................................................................................................................................................... 18 Access to Well ................................................................................................................................................................... 18 Past Land Uses .................................................................................................................................................................. 18 Procedure Planning ........................................................................................................................................................ 18 Sealing Materials............................................................................................................................................. 19 Cement–Based Grouts ................................................................................................................................... 20 Cement Properties .......................................................................................................................................................... 20 Cement Types ................................................................................................................................................................... 21 Neat Cement Grout ......................................................................................................................................................... 23 Concrete Grout ................................................................................................................................................................. 23 Commercially Packaged Concrete Sack Mixes .................................................................................................... 24 Cement Additives ............................................................................................................................................................ 24 i Bentonite-Based Grouts ............................................................................................................................... 27 Clay Mineral Properties ................................................................................................................................................ 27 Properties of Bentonite Grout ................................................................................................................................... 27 Bentonite Grout Products ............................................................................................................................ 28 Powdered Bentonite/Clay Grout .............................................................................................................................. 29 Granular Bentonite Slurries ........................................................................................................................................ 29 Coarse Grade Bentonite ................................................................................................................................................ 30 Pelletized Bentonite ....................................................................................................................................................... 30 Other Fill Materials ........................................................................................................................................ 31 Procedures for Sealing the Well ................................................................................................................ 31 General Sealing Procedures ........................................................................................................................................ 31 Specific Well Sealing Procedures ............................................................................................................................. 36 Sealing Dug Wells ......................................................................................................................................................................... 36 Sealing Bucket Auger Wells ..................................................................................................................................................... 39 Sealing Driven or Small Diameter (2 inches or less) Wells ........................................................................................ 40 Sealing Water Supply Wells .................................................................................................................................................................... 41 Sealing Environmental