A scientific investigation into well construction practices will help ensure groundwater is safe to drink, thanks to research by government agencies, the Nebraska Well Drillers Association, the University of Nebraska, industry suppliers of drilling and grout products, and several consultants. Through the NGWREF’s McEllhiney Lecture Series in Water Well Technology, this research will be shared first-hand with the water well construction community throughout 2011, perhaps leading to jurisdictions beyond Nebraska revising their water well construction codes. The study he will present the findings from began as a demonstration of how a well is properly constructed. Transparent Schedule 40 PVC casing allowed for well construction above and below the water table to be videoed from inside the casing of 168 water wells. For the first time, researchers could view actual grout conditions over time, documenting the ability of grout to stabilize the well within the borehole and maintain a contaminant seal. More than 800 hours of videotape documented the progression of the sealing properties of all types of well grouts over 16 months in three distinctly different geologic regions of Nebraska. The materials the study looked at included bentonite slurry grouts less than, equal to, and greater than 20 percent solids; non-slurry chip bentonite; and various cement grout slurries that incorporated sand, water, and other additives. The researchers found that all grouts performed differently than what was expected and what has been assumed by the groundwater industry for decades. The visual documentation of grouts provides the industry with a clearer insight of what is needed for adequate groundwater protection.

1.5 CEPs