Deep Well Injection

Deep well injection is a method of disposing of liquid waste, placing treated or untreated liquid waste into geologic formations that prevent the migration of contaminants into potential potable water aquifers. A typical injection well will extend several thousand feet down from the surface level into highly saline, permeable injection zones such as deep sandstone or limestone, remaining below an impermeable layer. Examples of contaminant groups for deep well injection are hazardous industrial waste products (often organic compounds), wastewater/process water from oil, gas and mining operations, as well as for sequestering CO2. 

There is no one filtration recommendation possible due to the wide variation of the strata in the injection zone. These sites require state and or federal permits which includes requires among other things, geologic characterization and reservoir evaluation to determine the nature of the formation zone. The nature of this zone coupled with the contaminant characteristics of the injected fluid determine what level of filtration may be required to preserve the porosity of the injection zone.