Key nodes and supervision points in the whole process of drilling construction

Key nodes and supervision points in the whole process of drilling construction

As an owner, effective supervision of drilling construction is the core to ensuring that you ultimately obtain a well with sufficient water volume, good water quality, and long life. You don’t need to be technically proficient, but you must grasp a few key points that determine success or failure and confirm them on-site.

1. Preparation stage for starting construction: lay the “foundation”

On-site disclosure and plan confirmation: Confirm the well location with the person in charge of the construction party on-site to ensure that it is far away from pollution sources such as septic tanks and sewage ditches (a horizontal distance of more than 30 meters is recommended). Clarify the target well depth, well pipe material (such as thickened PVC), diameter and approximate cost composition.

On-site acceptance of materials (key!): This is the first step of supervision.

Well pipes (casings) and water filter pipes (flower pipes): Check whether the pipes on site are new materials and thickened pipes as agreed in the contract, and have no cracks or deformation. The pores of the water filter pipe should be uniform.

Filter material (gravel) and sealing material: The filter material should be clean, uniform quartz sand or rice stone, not soil or construction waste. The sealing material must be high-quality clay balls or professional bentonite, and cannot be replaced by ordinary soil.

2. Core supervision points in the drilling process

Request and view "stratigraphy records": The construction party is required to simply record the soil layers excavated at different depths (such as clay layer, sand layer, pebble layer, rock layer depth). You need to check it out in person and take photos for your records. This record is the only scientific basis for judging the location of the aquifer and determining the depth of the water filter pipe.

Supervise the quality of the wellbore: observe whether the drilling is stable and whether the wellbore is approximately vertical. You can simply observe whether the proposed drill pipe is severely bent.

3. Well-forming process stage (must be on-site for supervision throughout the entire process)

This is the core of determining the quality of water wells, and all three steps are indispensable.

Lower management supervision:

Key: Ensure that the water filter pipe section is accurately lowered to the previously recorded water-bearing sand layer position, and the actual pipe section corresponds to the aquifer.

Inspection: Observe whether the well pipe connection is firm and straight, and whether the lowering process is smooth.

Gravel filling (lower filter material) supervision:

Key: The annular space between the well pipe and the well wall must be filled evenly and continuously with clean filter material to form an effective filter layer to prevent the entry of fine sand.

Prohibited: Backfilling with excavated soil is strictly prohibited.

Packaging (cementing/water stop) supervision (vital!):

Key: After the filter material is filled to a predetermined height, high-quality clay balls or bentonite must be used to seal it tightly and firmly above it until it is close to the ground.

Purpose: Permanently isolating surface sewage and shallow low-quality water from seeping down along the outer wall of the well pipe is a core step to ensure drinking water safety.

4. Well cleaning and acceptance stage

Supervise thorough well cleaning: After the pipe is filled with gravel, the well must be cleaned with an air compressor or a large pump for a long time and with great intensity until the pumped water is completely clear and contains no sand. Incomplete well cleaning is the main reason for long-term turbidity of water wells.

On-site water test acceptance:

Measuring static water level: After stopping pumping, measure the depth when the water surface is stable.

Do a pumping test: Carry out stable pumping for several consecutive hours (such as 4-6 hours) to evaluate whether the water output is sufficient and stable, and how quickly the water level recovers after it drops.

Check the water quality: Use a clean container to collect the water. It should be clear and transparent by visual inspection, with no visible impurities and no peculiar smell.

5. Payment and data transfer

It is recommended to pay in installments: Link the project payment to key nodes (for example: 30% for the start of construction, 30% for the arrival of materials, and 40% for the final payment after passing the well test).

Request completion data: The construction party is required to provide a simple "well completion report", which at least includes: well depth structure diagram, stratigraphic brief description, static water level, and list of materials used. This is the "ID card" of the well.

Summary: On-site confirmation, process certificates, and payment based on performance

The weapons of your supervision are "on-site witness" and "process photography". The core task is to guard the four gates of “materials, records, gravel filling and isolation of lower pipes, and well cleaning acceptance.” A clear installment payment method is the most effective way to protect your right to speak. A rigorous supervision will result in a worry-free and reliable well in the next ten years.