Spatial Data Analysis

Delta-H provides a high-level spatial analysis (using GIS) of large groundwater datasets which includes proximity analysis and identifying influencing factors on borehole productivity such as geology, geomorphology and lineaments (e.g. dykes and faults). The combination of multivariate statistical methods and spatial analysis of geochemical data sets provides useful assessment of controls over water composition and assists in the identification of possible anthropogenic influence.

Training

Delta-H staff is actively involved in the lecturing of groundwater modelling and geochemistry courses at Universities in South Africa and Germany. We also offer training to the public, private and mining sector.

Expertise and Services

Hydrogeological Modelling

Numerical groundwater models are the best tools available to quantify groundwater and mass balances, which can then be used to inform decision making related to environmental impact assessments or the optimisation of engineering designs. The project team is competent in both finite element (SPRING) and finite difference modelling codes (Modflow, including various interfaces). These internationally accepted modelling packages are used in a variety of applications like numerical flow modelling to estimate mine inflow rates and associated impacts, to define aquifer vulnerability and aquifer protection zones around abstraction boreholes or to predict contaminant transport rates from various source types. The finite element modelling code SPRING allows also simulating discrete fractures, undergrounding mine workings, heat exchange as well as unsaturated flow and transport processes. For more information on the software package SPRING visit:

Seepage Modelling

The Delta-H team is competent in developing two- and three-dimensional seepage models for Tailings and other Mine Residue Facilities as well as contaminated soils using the finite element software SPRING. The developed seepage models typically consider material properties, installed drains, as well as interactions with the underlying aquifer. The output of a three-dimensional seepage models can thereby be coupled with regional groundwater flow and transport models to enable a realistic representation of the entire system and inform management decisions.

Groundwater Management

Delta-H has vast experience in supporting clients with effective management and protection of groundwater resources. Groundwater resources are subject to human impact in many ways and the exploitation of groundwater is increasing everywhere. Delta H provides specialist input into Environmental Impact Assessments (EIA) and Feasibility Studies. These services include: • Groundwater management plans • Groundwater resource delineation (and availability assessment) • Groundwater balance • Aquifer characterisation • Conceptual groundwater model development • Cumulative groundwater impact assessment

Geochemistry

The main purpose of geochemical assessments is to predict the likely drainage and seepage water quality associated with Mine Residue Deposits (MRD). This information is used as inputs into groundwater flow and transport models to assess the potential pollution plume associated with the MRD. Delta H offers mine site geochemical investigations including Acid Rock Drainage (ARD) risk assessments and management plans, as well as geochemical modellinge:

Hydraulic Plume Containment

The scavenger well system is designed to hydraulically control the movement of polluted groundwater in order to prevent continued expansion of the polluted zone, i.e. to capture and remove polluted groundwater. The implementation of a scavenger well system is driven by a sound understanding of the migration of pollutants and hydrogeological parameters of the groundwater flow path (conceptual model) and supported with a site-specific numerical flow and transport model. Delta-H is experienced in the design, implementation and management of both conventional vertical scavenger wells as well as horizontal scavenger wells.. A single horizontal well could in theory be more effective than a number conventional scavenger wells.

Groundwater Supply

Delta-H applies conventional geophysical survey methods as well as retrieved knowledge of the hydrogeological setting to determine optimal drilling targets for water supply boreholes. Delta-H have developed a respectable working relationship with drilling contractors and pumping test teams to provide service of high quality. With the assistance of project partners Delta-H caters for all pumping and infrastructure requirements as well as the commissioning of water supply boreholes and wellfields.