Well Plugging & Rehabilitation
Contamination of our groundwater is most common through old abandoned wells or poorly constructed wells. The groundwater moves through the soil and any well that taps into this vital resource is a potential channel for pollution. Many abandoned wells are not covered adequately and small animals are often found floating in the water. This polluted well has direct contact with the water others are using everyday for drinking and bathing. Poorly constructed wells are also a channel for pollution, and some wells can be rehabilitated to produce good water The Grants To Counties Program provides cost share assistance plug or correct well construction problems that may allow contaminants to enter the well and the groundwater supply.
Many abandoned wells are large diameter brick wells that allow contamination to enter at all levels of the well.
Standing water is pumped from the well prior to filling to eliminate the mess of overflow, and to reduce the risk of bridging.
Fill sand is used in large diameter wells to reduce settling that occurs over time. The bottom layer of sand is brought up to the static water level.
Bentonite clay is used to create a seal or plug in the well to prevent surface water from following the pathway of the abandoned well to the groundwater.
In wells with a diameter of four feet or more, the bentonite is replace with concrete. On small diameter wells, a bentonite or concrete slurry is used to flow into limited space.
More sand is added after the sealing material is in place.
When the well has been filled up to about four feet below the natural grade, the casing is knocked in and soil may be used to fill to the top.