What must be done to a permanently abandoned well according to best practices?

To properly abandon a well according to best practices, it is essential to fill it with sealing material up to within 3 feet of the surface. This process, known as well sealing or well plugging, prevents contaminants from entering the groundwater and protects the aquifer by minimizing the risk of pollution from surface runoff or other sources. The sealing material is typically a combination of bentonite clay, cement, or other appropriate materials that create a barrier to groundwater flow.

It is important that the seal reaches a depth of at least 3 feet below the surface to ensure that it is adequately isolated from any potential contamination sources. Moreover, this practice helps prevent any collapse or hazards associated with open wells, thereby enhancing public safety.

Keeping casings at the surface, allowing water to remain in the bore, or leaving the well open for future use do not align with the recommended guidelines for well abandonment and can lead to significant environmental hazards or legal issues. Proper sealing is crucial to safeguarding groundwater resources and ensuring compliance with regulatory standards.