In 1987, three sand-filled fractures were created at the Elda Landfill in Cincinnati as part of the research projects funded by the US EPA. These fractures were created in glacial till that was mined eventually by the landfill operators for daily cover. However, prior to mining, trenches were dug to permit closes observation of the fractures.
Fracture Excavation Site
The plan of the three fractures is shown below. Fractures 1, 2 and 3 were nucleated 5 ft, 7 ft and 9 ft below surface from the same injection location, "EL6". We note that these fractures are elliptical in plan and extend several meters around the injection point from which they were created.
Plan of example fractures
The photo below is looking along trench "B" from approximately the location of injection well "EL6". The regular white lines are horizontal strings while the white sand appears as the approximately parallel trace along the face of the trench. The white dot on the middle fracture is a coin.
Exposed hydraulic fractures
A closer perspective shows that the fracture maintains a relatively uniform aperture along its length.
