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Senan Group LTD (formerly SenanGroup Liberia)
Senan Group LTD (formerly SenanGroup Liberia)
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GEOTECHNICAL INVESTIGATION

Introduction: Groundwater exploration is the investigation of underground formations to understand the hydrologic cycle, know the groundwater quality, and identify the nature, number, and type of aquifers. A surface geophysical method is one of the groundwater investigation methods.

The use of geophysics for both groundwater resource mapping and water quality evaluations has increased over the years in large part due to the rapid advances in microprocessors and associated numerical modeling solutions.

Procedure: To locate groundwater accurately and to determine the depth of water several techniques must be used. As a first step geologic maps and cross sections showing the distribution and positions of the different kinds of rocks, both on the surface and underground are reviewed.

Types of Geotechnical Survey:

Electrical Resistivity Survey, Seismic Survey, Seismic-electric Survey, Ground Penetrating Radar

Objectives

  • 1. To investigate the aquifer characteristics, thickness, layer-wise soil type, groundwater quality (by conductivity value), and water table depth using the Vertical Electrical Sounding (VES) resistivity survey technique.
  • 2. To determine the geoelectric and hydrogeologic characteristics of the aquifer present in the study area.
  • 3. Detecting and mapping water-saturated layers in various types of shallow as well as deep aquifers.

Senan Resources

Senan has a wide range of VES tools and equipment including GER Detect for Ground Water Detector, to carry out the groundwater survey. We have a qualified team, and a great resource to carry out successful geological surveys for all our clients.

GEOTECHNICAL SURVEY EQUIPMENT

CASINGS

SOLAR PUMPING SYSTEMS

Ground Water Detector – Fresh Result 2 Systems Device

COMPRESSOR

TRUCK AND COMPRESSOR

BOREHOLE DRILLING AND DEVELOPMENT:

1. Geological Survey

A Geological survey accesses the geographical landscape and composition of your ground and ascertains the location and depth at which the water drilling should take place.

2. Drilling Equipment Mobilization

Mobilization of the Drilling Equipment Once payment has been settled, our drilling equipment is mobilized from our operations site to the drilling site.

3. Drilling and Installation

Upon reaching the site, our rig locates the area identified by the hydrogeologist as suitable for drilling. The machine uses a bit and a hammer to penetrate the ground and rods which further push the head of the drill toward the ground.

The penetration continues until the drill reaches the required depth. The drill usually passes through a water-bearing formation as it is drilling. A casing of the borehole is usually done after the required depth is reached.

4. Testing

This stage is crucial as it conducts a chemical analysis of the water to determine its suitability for use. This is usually a 24-hour process.

5. Securing the borehole

Top Slabs are inserted, and a cap is usually put on the borehole

6. Water Collection

As per the client’s requests, we can also put up steel/plastic tanks and a water tower along with the required piping.

BOREHOLE REHABILITATION SERVICES

There are several potential causes for reduced yield from a domestic or commercial water borehole. These may include, but are not limited to:

Mechanical Blockage: mechanical blockage occurs when small soil particles or by-products from the well-wall build up and cause blockages or reduced flow.

Chemical Encrustation: essentially the chemical version of a mechanical blockage, chemical encrustation occurs when chemical deposits build up on the good screen or gravel pack and restrict the flow of water.

Bacteriological Plugging: Bacteria and other microorganisms can also clog a borehole.

To rehabilitate a borehole will vary depending on the nature of the cause for the blockage or reduced flow, the following steps constitute a brief overview of the traditional steps borehole rehabilitation could or would necessitate:

A survey of the borehole will be undertaken first – the surveyor may ask you questions such as depth, yield, diameter, and tests.

The pumping mechanism and/or other removable parts will be cleaned with a chlorine solution.

The borehole will be drained of all water and will be thoroughly cleaned of all sediment and debris.

Any damage to the inside of the borehole will be repaired. If the damage is too extensive, the borehole may be re-lined as opposed to simply repaired/patched.

The well itself will now be cleaned with chlorinated water.

Should the borehole/well require chemical cleaning it will take place at this juncture. If the well needs to be chemically cleaned the process could take anywhere from 1 to 3 days and will mean the well needs to be dewatered thereafter to remove the chemicals and chemical residue.

The well/borehole will be disinfected. Chlorination is the most common method of disinfection undertaken.

Post chlorination the well/borehole will need to be dewatered. The water will be tested until chlorine levels are back below 0.5mg per liter.

The well/borehole will be resealed.

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INSTALLATIONS – PUMPS, STORAGE

The kind of pumping system and piping installed in your new domestic water borehole will largely depend on the intended use of the borehole water.After the test pumping is complete, we shall know what kind of Submersible Pump that can be installed in the borehole. If the water quantity is low the recommended pump will be a small sized i.e. 2m 3 to 4m3 and if the water quantity is high the pump that will be recommended shall be from 5m3 to 10m3 or more.

The overhead water tank can be installed per the client’s request if they want a steel tank, plastic tank, or concrete tank.

Let us know how we can be of service to you today. Send us a message.

PROVISION OF DRILLING ACCESSORIES

Featured Products

Products here…

GROUNDWATER MANAGEMENT

  • Environment Assessment Services
  • Environmental Compliance

CAPACITY BUILDING

  • Local Resource Training (I.e Water systems, Pumping)
  • Awareness of WASH Services (Water, Sanitation, and Hygiene)

CONSULTANCY/ ADVISORY SERVICES

  • Geotechnical Investigation
  • Borehole Drilling
  • WASH Management
  • Environmental Compliance Advisory Services.

Let us know how we can be of service to you today. Send us a message.