Circular 52: Regulations on the Assessment of B-class mining reserves in Vietnam

Circular 52: Regulations on the Assessment of B-class mining reserves in Vietnam (Internet image)

Circular 52/2014/TT-BTNMT stipulates the requirements for the evaluation of geology, hydrogeology, water quality, and water reserves of B-class mining reserves in Vietnam.

1. Requirements for the evaluation of geology and hydrogeology:

- Determine the geological structure of the mineral water-bearing layer;

- Identify the hydraulic relationship between mineral water, natural hot water, and water in other layers and surface water;

- Approximately identify the origin of the formation of mineral water and natural hot water reserves;

- Monitor water dynamics for a minimum of one (01) hydrological year.

2. Requirements for water quality evaluation:

- Water quality must be sampled and analyzed accurately and comprehensively for all indicators of chemical, physical, biological, and radioactive components; the analysis and evaluation results must clearly determine that water quality remains stable over time within permissible limits; the discrepancy in indexes of chemical, physical, biological, and radioactive components must be a maximum of twenty percent (20%) compared to the average value of the initial three sample analysis results in the exploratory phase, which has been verified and controlled by the competent state management agency.

- Before, during, and after each water extraction experiment; comprehensive samples must be collected and analyzed, including source water samples, trace element samples, chemical samples, microbial samples, physical samples, and radioactive samples.

3. Requirements for the evaluation of water reserves:

- Mineral water and natural hot water extraction reserves are generally evaluated using hydraulic methods. For Category I mines, a combination of hydraulic and hydrodynamic methods is used;

- B-class mining reserves are calculated and determined by the actual flow rate of individual boreholes (for single water collection works) or the total flow rate of a group of boreholes (for group water collection works).

- In cases of concurrent experimental water extraction or extraction-experiments achieving stable dynamics of hydrodynamics, hydrochemistry, gases, and temperature. For Category I mines, the continuous minimum experimental water extraction period is three (03) months; for Category II mines, a minimum of six (06) months; and for Category III mines, a minimum of twelve (12) months;

- For mineral water and natural hot water naturally outcropping on the surface, B-class mining reserves are calculated and determined by the minimum daily flow rate of outcropping points during a one (01) year monitoring cycle. For extraction using natural outflow works, calculation and determination are based on the average flow rate of those outcropping points.

For more details, refer to Circular 52/2014/TT-BTNMT which comes into effect in Vietnam from October 27, 2014.

Ty Na

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