Injection of hydraulic fracturing and shale gas produced wastewater along with the mechanics of aquifer systems have an extensive and unique terminology, most with well-defined meanings. The practicing fracking engineer, manager, operator, or student of fracking should know the concepts; otherwise, it will be difficult to practice or understand the injection of produced wastewaters. Groundwater is found in saturated layers called aquifers under the Earth's surface. A confined aquifer is sandwiched between two impermeable layers that block the flow of water. The water in a confined aquifer is under hydrostatic pressure. In soil mechanics, consolidation is the adjustment of a saturated soil in response to increased load, involving the squeezing of water from the pores and a decrease in void ratio. Application to liquid wastes began during the 1930s but did not achieve a significant status until the introduced of comprehensive Federal water pollution control laws and regulations in the 1960s and early 1970s.