McEllhiney Revisited: Annular Space Research and Chemical Rehabilitation of Wells

In following up on the initial research published in the Nebraska Grout Study, Nebraska has been researching how to retroactively insert grout material in the annular space of existing irrigation and some municipal wells to block pathways for contaminates. The Department is part of the Nebraska Annular Space Task Force which is currently developing methods to effectively perforate and inject the grout materials studied in the grout research project. There have been some early successes and several challenges to overcome have been identified. Tom Christopherson and his team are addressing wells that are cased with concrete, transite, PVC, and stainless steel casing. His current research is addressing these contaminates: nitrate, selenium, arsenic, and uranium.

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The 2002 McEllhiney lecture "Chemical Rehabilitation of Wells” focused on understanding the chemistry and microbiology of well systems to improve maintenance efforts. While our organization continues our work in these areas, the interplay of chemistry and microbiology on the well structure, with regards to corrosion, is one of the more important steps forward we’ve taken.

As part of a brief update, John Schnieders, Ph.D. will present a “true picture of iron in produced water”. His team has documented many wells that have a reported iron problem with no definable iron presence in the aquifer or identified iron bacteria present in the well. There are numerous chemical and biological parameters that can impact the well design, produced water, as well as the subsequent use and treatment of the water. In brief, John Schnieders will discuss some of the chemical and bacteriological parameters which often are the major cause of corrosion and that lead to iron in the water. Some diagnostic and operational procedures will be included; however, a more complete coverage will be available in a soon to be published book.