GEOSCIENCE AND ENVIRONMENTAL SERVICES

 

water protection

treatment, supply and conservation

1
1

Groundwater Resource Development and Management

All over the world, groundwater resources have become an invaluable resource for socio-economic development. They are a primary source for drinking water, industrial, and agricultural development. MEK staff have been involved in groundwater resource development and management in various parts of the world and thoroughly understand the inherent challenges and effective and technical solutions for addressing them.

Groundwater Resources Management

The main purpose of groundwater resource management is to limit the adverse impacts of severe abstraction and contaminant loads. This can be realized by continuously monitoring the well’s response and water quality over the long run. Effective groundwater management should ensure that the quantity and quality required for domestic, commercial, industrial, agricultural, and environmental usage is not compromised. Furthermore, groundwater resource management is necessary to prevent land subsidence of both private and public infrastructures.

In general, groundwater monitoring data can be used to estimate the amount of groundwater that can safely be withdrawn from an aquifer without severe environmental impacts. Information obtained from the groundwater level can also be useful in forestalling a severe decline in groundwater level that may arise from acute abstraction. This could ultimately lead to a prohibitive cost of providing potable water and even have adverse impacts on groundwater quality. Furthermore, groundwater level data can be very helpful in establishing the interaction between surface and groundwater systems.

Our hydrogeologists have excellent experience in the entire spectrum of groundwater resource management, which consists of two components: groundwater monitoring and groundwater quality monitoring, as described below.

In general, groundwater monitoring can be carried out at three levels to accomplish different objectives:

  • i.   Primary Groundwater Monitoring

In primary groundwater monitoring, the focus is to analyze trends in groundwater water levels due to land use and climatic change as well as to changes in recharges, flows, and diffuse contamination.

  • ii.   Secondary Groundwater Monitoring

In secondary groundwater monitoring, the focus is on the protection of groundwater resources, wellfields, land subsidence, and groundwater-dependent ecosystems against potential environmental impacts.

  • iii.   Tertiary Groundwater Monitoring

MEK’s tertiary groundwater monitoring program is designed to provide early warnings of adverse environmental impacts to groundwater resources that could arise from intensive agricultural land use, industrial and mining activities, and waste disposal (landfill).

Continuous groundwater level monitoring is required to ensure reliable groundwater supply and to protect its quality. In developing an effective groundwater monitoring network, the MEK team will carefully analyze and evaluate the geological, hydrogeological, land, and water use settings carefully before selecting the location of monitoring wells. Furthermore, we will carefully consider trends in land and water use in residential, industrial, agricultural, and environmental settings and incorporate our findings into the final monitoring program designs.

From the groundwater level data, our hydrogeologists will develop two- and three-dimensional groundwater flow models that clearly depict the groundwater flow patterns and recharge and discharge zones within the monitored region. Furthermore, using multi-temporal groundwater-level data, our team can accurately predict seasonal and long-term changes in the groundwater flow patterns over an entire region.

Because water is a good solvent, it can easily become contaminated due to the dissolution of one or of several contaminants. Groundwater contamination usually results from one of the following:

  •   Contamination from naturally occurring chemicals in soil and rock formation (e.g., dissolution of naturally occurring toxic arsenic and selenium in rocks);
  •   Contamination as a result of agricultural, commercial, and industrial activities; and
  •   Leakage from underground storage tanks into the soil and groundwater systems.

MEK has a full-fledged groundwater sampling protocol tailored in line with the World Health Organization and Canadian Environmental Protection Agency protocols. The protocol contains quality control/quality assurance (QA/QC) measures to ensure that water samples collected from the field and submitted to the laboratory are representative of the sampled groundwater. This implies that groundwater samples are stored in appropriate containers together with other QA/QC samples under approved temperature conditions and submitted in a timely manner to an accredited laboratory for analysis.

Upon receipt of the laboratory analytical results, MEK staff will perform in-house due diligence by analyzing the results to affirm their accuracy and precision.

Based on the laboratory results, MEK can determine spatial variation in groundwater quality over the region under study. Long-term spatial variations in water quality are identified from multi-temporal groundwater quality data. This latter analysis also enables our staff to affirm the encroachment or mobility of pollutants into the aquifers of interest.

Groundwater Resource Development

We have the expertise and technical know-how to select, drill, design, and construct prolific and sustainable water well sites in igneous, sedimentary, and metamorphic terrains. We have used different tools in well site selection, and we are guided by our understanding of hydrogeology, which is derived from our terrain assessment studies. In very difficult hydrogeological terrains, we collect information from satellite images to help define or demarcate areas with high potential for groundwater resource development. Once these areas are located on the ground, we refine the likely locations of aquifers using our structural geological knowledge of the area together with geophysical techniques to select prospective well sites. Using this methodology, our team has consistently realized improvements of between 20 to 85 percent in well drilling success rates compared to other drilling campaigns in the same or similarly difficult hydrogeological terrains. Additionally, our approach has resulted in much higher water well yields. We have been involved in the completion of more than 1000 water wells in different parts of the world, ranging from shallow hand-dug domestic and community water wells to high-yielding municipal and industrial water wells.

Our water wells are designed based on information derived from well logs, sieve analysis results, pumping and aquifer test data, water chemistry, and the anticipated water demand. Additionally, factors that will enhance well efficiency, reduce operational cost, and ensure the long-term sustainability of the wells are taken into consideration in the well design and construction.

The company has the expertise and the state-of-the-art facilities to embark on full-scale groundwater exploration and development activities for individual homes (domestic), rural water supply programs (districts/county), and for commercial and industrial purposes for our clients.

Our water well drilling campaigns are carried out in the following chronological order:

  •   Review of available geological and hydrogeological literature on the terrain conditions and previous drilling campaigns, if any;
  •   Analysis and interpretation of remotely sensed data (processed satellite imagery) and stereo aerial photographs;
  •   Terrain evaluation;
  •   Geophysical surveys and interpretation of results;
  •   Drilling of well;
  •   Sieve analysis;
  •   Well design and construction;
  •   Well development;
  •   Well chlorination;
  •   Pumping and aquifer tests; and
  •   Pump installation.

Additionally, we have vast experience and technical know-how related to the construction of hand-dug wells in loose and highly weathered to semi-consolidated rock formations. We have constructed hundreds of hand-dug wells and lined them with concrete rings and/or PVC plastic sheets, some to depths in excess of 20 meters (Plate 8). Our full service consists of:

  •   Selection of the most favorable well sites;
  •   Digging of the wells;
  •   Lining of the excavated wells through the lowering of concrete rings;
  •   Backfilling the annular space between the concrete rings and the well’s natural embankment with sand;
  •   Conducting water-quality tests;
  •   Chlorinating the wells;
  •   Covering the wells with concrete slabs;
  •   Constructing aprons and drainage gutters around the wells; and
  •   Installing pumps in completed wells.