contains an USDW.

Common method to cleanup the ground water is known as “Pump & Treat” process. During this process, Pumping & Treating activity is repeated until contaminated concentration are required and additional removal becomes impossible.

Class V UIC Wells – Injection 

Class V UIC Wells ranges from simple shallow wells to complex experimental injection technologies and are used to inject Non-hazardous Fluids underground. The Fluids are injected either into or above an USDW. These wells, include any UIC well that is not classified as Class I, II, III, IV or VI well. Most Class V UIC wells are “Low Tech” and depend on gravity to drain fluids directly below the land surface including Dry Wells, Cesspools, Septic System Leach Fields. “Low Tech” Class V UIC Wells that typically rely on gravity drainage include:

Gas Stations where service floor drains lead to septic system.

Apartment bulidings that use septic systems for sanitary waste disposal.
Municipalities where storm water flows into dry wells.
Strip malls where business such as dry cleaner discharge sanitary waste and process chemicals into septic systems.
Office buldings that inject water passed through heat exchanges to cool the buildings.
Carwashes where waste water enters a floor drain that leads to a dry well or septic systems.
Some examples Class V UIC Wells include:

Deep brine injection wells.
Experimental wells used for slurry injection of Municipals Waste.
Wells that are used for the injection of drinking water treatment residuals.
Class VI UIC Wells: Injection wells for Geologic Sequestration / Carbon Dioxide:
For the purpose of reduced CO2 emission into the atmosphere, to mitigate climate change, for Enhanced Oil Recovery (EOR) and for Enhanced Gas Recovery (EGR), a long-standing practice of constructing wells to inject CO2 into deep rock formations is used. This long-term underground storage is called Geologic Sequestration (GS). 

So, GS may be referred to as the process of injecting CO2, captured from an Industrial (e.g: steel & cement production) or energy related sources (e.g: power plant or natural gas processing facility), into deep surface rock formation for long term storage. This is part of process frequently referred to as “Carbon Capture & Storage (CCS)”. Class VI Well requirements are designed to protect USDW, addressing:

Siting
Construction
Operations: Mechanical Integrity Testing (MIT) & Monitoring
Testing
Monitoring
Closure

Well means: A bored, drilled, or driven shaft whose depth is greater than the largest surface dimension; or, a dug hole whose depth is greater than the largest surface dimension; or, an  or, a subsurface fluid distribution system.