At an active open-pit gold mine in Finland, the operator needed to understand its groundwater — where the water table sits and which structures carry water — to manage dewatering and pit stability. Working entirely from the surface across 15 virtual boreholes, ADR mapped a coherent water table at around 75 metres and traced its step-down toward the pit, matching the drawdown you’d expect from active dewatering — an independent sign the interpretation was tracking real hydrology. It’s a fast, non-invasive first model of the subsurface water, meant to guide where to focus monitoring and drilling rather than replace them.
Mapping groundwater from surface
A 15-borehole subsurface water and dewatering model, built entirely from surface Atomic Dielectric Resonance (ADR) — at an active mine in Finland.
See before you drill.
VEXRAD mapped the subsurface water regime at an active mine in Finland without drilling a single hole. Fifteen ADR virtual boreholes and three 100-metre profile scans, acquired from surface, were combined into a four-parameter model — conductivity, dielectric permittivity, E-Gamma reflectivity and energy density — that resolved a common water table at roughly 75 m, a step-down toward the north pit, a main water-bearing zone, and a fluid classification from freshwater to saline with depth. From that model, a dewatering assessment ranked candidate extraction sites by modelled yield. This is a capability demonstration: the water model is an interpretation from surface geophysics, reported here as such, not a drill-confirmed result.
Four parameters, no drilling
Fifteen virtual boreholes and three 100-metre profile scans were acquired from surface in a single field campaign. ADR returns a depth profile of the subsurface’s material-property response; here four parameters were used together to fingerprint water. Dielectric permittivity rises with water content, conductivity acts as a proxy for fluid type (freshwater, partially saturated, saline), E-Gamma marks layer boundaries and faults, and energy density tracks the combined response.
A water table, from surface
Combined across the four parameters, the survey delineated a coherent water-bearing zone and a common water table. The main zone sits toward the north of the survey; the interpreted water table lies at roughly 75 m and steps down from about 72 m to about 100 m toward the north pit.
Every finding below is an interpretation from surface ADR. Under VEXRAD’s four-tier standard these sit at Candidate — real, coincident signals across parameters, but not yet confirmed by drilling.
| Feature ADR mapped | Indication | Evidence tier |
|---|---|---|
| Common water table | ~75 m depth across the site, from a shared change in multiple parameters | Candidate |
| Water-table step-down | From ~72 m to ~100 m toward the north pit | Candidate |
| Main water-bearing zone | North of the survey — coincident conductivity and dielectric highs | Candidate |
| Fluid zonation | Freshwater near surface → partially saturated → saline with depth | Candidate |
| Dewatering candidates | Highest modelled yields at three sites (Darcy Q = K·i·A) | Candidate |
From water model to well placement
Classifying each depth by conductivity showed the section grow more saline with depth — freshwater near surface, mixed and then saline below. A dewatering assessment then estimated yields with a Darcy approximation (Q = K·i·A), ranking candidate extraction sites and depths against geological risk read from the E-Gamma response.
What this doesn’t claim
- This is a capability study, not a validation: there is no independent drill ground-truth here, so the water model is an interpretation, not a confirmed result.
- The water table is inferred from a common change in values across datasets; the flow-direction interpretation is explicitly tentative, given the limited spread of scans.
- Dewatering yields are order-of-magnitude Darcy approximations — useful for ranking sites, not a substitute for a pumping test.
We report these plainly. A result is only worth as much as the honesty around it.
What it means for mine operators
For a working mine, water is both an asset and a hazard, and drilling to find it is slow and costly. This survey shows ADR building a whole-site water and dewatering picture from surface, non-invasively, in a single campaign — enough to rank where to drill, dewater or manage water before committing to a rig. On a live project the picture sharpens further: calibrate ADR against one or two of the operator’s existing holes, and the interpreted model becomes a validated one.
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