Being mindful of the environment we live in is one of the many responsibilities we have as conscientious human beings. We should always work towards achieving a lifestyle that sustains our environment in the long run. The resources of our mother earth are limited and depleting, and the only way we can nurture them is by living an eco-friendly lifestyle.
Privately dug up wells are an excellent water resource. However, if these wells are left abandoned without the needed decommissioning, they become hazardous. A water well is considered abandoned if the well gets permanently discontinued. It is in a state that its usage for groundwater is impossible, or is a safety or health hazard. Abandoned wells pose a safety threat since there have been numerous reported cases of children accidentally falling into such wells. They also pose a health hazard by contaminating the deeper grounds’ aquifers.
For these reasons, sealing an abandoned well is imperative. It is essential to keep in mind that appropriately sealing a well as crucial as sealing the well. The Water Well Drillers License Act issues fundamental guidelines and procedures on how you should effectively discharge a well at the end of its life. The following rules are considered the bare minimum that you need to follow in the absence of stricter laws.
Characterizing The Well:
So the first step towards an effective decommissioning process is to know the hydrogeology and the structure of the well. It becomes crucial to know the features of the well thoroughly when there is an increase in the risk of aquifer contamination, or there is a greater complexity in the construction of the water source.
The Bureau of Topographic and Geologic Survey (BTGS) owns a record of all the wells drilled since 1966. They have an extensive Water Well Inventory System database that holds all the files. There are also several reports issued by BTGS and USGS (United States Geological Survey) that can explain the construction and geological formation of a well.
Furthermore, there are a few instruments that can help you measure the water levels and the depth of a well. Such devices include a weighted tape measure or water well sounder. A downhole camera or borehole geophysics can also assist in determining the structure of a well.
Do The Necessary Prepping:
Before the final well abandonment and plugging, the professionals need to clear the well up for any hindrances. There may be pipes, airlines, wires, and pumps inside the well, which will require pulling out. The professionals need to ensure that the borehole stays intact during the process of pulling out the casing.
Telescoped or nested casing strings can make the abandonment process a bit more complicated. Removal of these strings becomes necessary, and where this is not possible, they need to either vertically split or cut them. This step is essential to ensure that the water well is filled sufficiently without any gaps.
- The Final Plugging:
There are a few materials and methods used to plug an abandoned well that we discuss in the following paragraphs:
- Sealants: These include bentonite clay, portland cement-based grouts, or a mix of these materials. You can use sealants to give a watertight blockade to the water traveling in the wellbore, in the fractures and openings adjacent to or in the annular spaces of the wellbore.
Additives are added into these materials to enhance or reduce some of the properties such as shrinkage, setting time, viscosity, or strength.
Various types of sealants available for use are:
- Concrete grout;
- Grout additives;
iii. Neat cement grout;
- High-solids sodium bentonite;
- Chip bentonite.
- Aggregate: These are the substances that eradicate the open space and hazards of the borehole but do not stop the wellbore’s water flow. Materials that fall in this category include crushed stone, sand, etc. Aggregates need to be clean of any adulterations and have a consistent size to ensure an appropriate settlement. Certain situations may require the usage of aggregates which include:
- A caving hole;
- Lack of a need to seal or penetrate fractures, joints or other openings;
iii. No requirement for a watertight seal;
- The interval does not enter more than one aquifer;
- The range does not enter a confined aquifer.
- Bridge Seals: Often constructed by fitting an expandable wood, pneumatic, or neoprene plug, a bridge seal has various uses. You can use it to separate two producing zones inside the well, provide structural reliability, or segregate vast sections of a well.
Water Well abandonment and plugging is an essential step in wells creation. If you plan to get a well dug up privately for your use, you need to make sure you consider the costs and processes you would require for decommissioning it later. Failing to seal a well at the end of its life adequately has several risks, which means it is essential that wells get properly plugged and not just casually deserted.