Circular No. 75/2017/TT-BTNMT on the protection of underground water during drilling, excavation, exploration, and extraction activities

CIRCULAR

PROVISIONS ON THE PROTECTION OF UNDERGROUND WATER IN DRILLING, DIGGING, EXPLORATION AND EXTRACTION ACTIVITIES OF UNDERGROUND WATER

Pursuant to the Water Resources Law 2012;

Pursuant to Decree No. 36/2017/NĐ-CP dated April 4, 2017 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;environment;

Pursuant to Decree No. 201/2013/NĐ-CP dated November 27, 2013 of the Government detailing the implementation of certain provisions of the Water Resources Law;

At the proposal of the Director of the Water Resources Management Department and the Head of the Legal Department;

The Minister of Natural Resources and Environment promulgates this Circular on the protection of underground water in drilling, digging, exploration, and extraction activities of underground water. 1. This Circular provides for the protection of underground water in drilling, digging, exploration, and extraction activities of underground water, including the following activities: exploration and extraction of underground water, geological survey drilling, geological exploration, exploration and extraction of minerals, foundation treatment of construction works, mine dewatering, and other drilling and digging activities related to underground water.

Article 1. Scope of Regulation

2. Drilling and exploration of oil and gas are not within the scope of regulation of this Circular.

This Circular applies to state management agencies for water resources and organizations, individuals, and households (hereinafter referred to collectively as organizations and individuals) related to the protection of underground water in drilling, digging, exploration, and extraction activities of underground water.

Article 2. Applicability

Article 3. Principles of Underground Water Protection

1. Protection of underground water shall prioritize prevention, focusing on protecting underground water sources in areas over-exploited or severely degraded, prohibited zones, restricted exploitation zones, areas supplying domestic water, urban areas, industrial zones, export processing zones, craft villages, concentrated residential areas, water-scarce regions, areas at risk of underground water depletion, pollution, and intrusion of saline water, and areas at risk of land subsidence and collapse.

2. Protection of underground water must be linked with the rational, economical, and efficient exploitation and utilization of underground water resources; it must also be linked with surface water protection, environmental protection, forest protection, and natural resource conservation.

3. Protection of underground water must be considered and implemented from the planning stage of relevant plans concerning the exploitation and utilization of water resources. For investment projects involving exploration, extraction, or use of underground water, or drilling and digging activities affecting the quantity and quality of underground water, underground water protection must be carried out during the project investment planning phase.

Article 4. General Requirements for the Protection of Underground Water in Well Drilling Design and Construction

Organizations and individuals designing and constructing wells (hereinafter collectively referred to as wells) in exploration and extraction activities of underground water, geological survey drilling, geological exploration, mineral exploration and extraction, foundation treatment of construction works, mine dewatering, and other drilling and digging activities related to underground water must implement the following requirements for the protection of underground water:

1. Implement the provisions of Circular No. 59/2015/TT-BTNMT dated December 14, 2015 of the Minister of Natural Resources and Environment on technical drilling, assessment, and exploration of underground water.

2. Install a natural clay or equivalent impermeable material casing around the well walls and temporary support pipes. Within a minimum radius of one meter around the well opening, reinforce and elevate with natural clay or other waterproof materials to prevent contaminated water from the surface flowing directly into the well or seeping through the well walls into the aquifer.

3. Do not use wastewater, contaminated water, water containing oil or harmful chemicals as drilling fluid or mix them with drilling fluid to inject into the well; do not allow fuel or oil leakage into the surrounding environment of the well site.

4. Ensure the stability of the surrounding soil environment during drilling and when conducting research and testing work inside the well or during the use of the well.

5. For wells expected to operate for two (2) years or more, ensure that pipe lining and isolation grouting are performed to prevent surface water from infiltrating into the aquifers or allowing different quality water from different aquifers to flow through the well walls.

6. In case of accidents such as land subsidence or other unusual incidents during construction or operation of the well, immediately stop construction or use, promptly address and rectify the incident, compensate for losses (if any), and promptly report to the People's Committee of the commune, ward, town (hereinafter referred to as the People's Committee of the commune) and the Department of Natural Resources and Environment of the province or centrally-administered city (hereinafter referred to as the Department of Natural Resources and Environment) where the incident occurred.

7. For unused or damaged wells during construction or operation, they must be treated and plugged according to the laws on water resources.

7. For unused or damaged wells during construction or use, they must be treated and plugged in accordance with the laws on water resources.

Article 5. Requirements for the design and construction of wells for extracting underground water

Organizations and individuals extracting underground water must comply with the provisions set forth in Article 4 of this Circular and the following specific requirements:

1. The design of wells for extracting underground water must be carried out by the person primarily responsible for technical matters of organizations or individuals holding a drilling license for underground water or by the technical supervisor of organizations or individuals providing consultancy services to prepare proposals and reports included in the application for permission to explore and extract underground water.

2. The construction of wells for extracting underground water must be performed by organizations or individuals holding a drilling license for underground water in accordance with the laws on water resources.

3. The casing pipes and filter pipes installed in wells for extracting underground water must be specialized pipes designed for such wells, meeting the following requirements: clearly marked with symbols, model numbers, standards, and manufacturer names; having thickness and physical, chemical properties suitable for the geological characteristics, depth, diameter, duration of use, and chemical corrosion properties of the soil and water at the installation site; ensuring the stability of the well during its entire period of use.

4. In cases where the mouth of the well is placed above ground level, the top of the well pipe must be installed higher than the ground surface or pump room floor by at least 0.3 meters or higher than the average annual flood level in areas frequently affected by floods.

In cases where the mouth of the well is placed below ground level, the pump chamber must be waterproofed to isolate it from surface water sources; the ground surface within a minimum radius of 1.5 meters around the well mouth must be raised to the same level as the surrounding ground and reinforced with concrete, brickwork, or cement mortar to prevent contaminated water from infiltrating the aquifer through the extraction well.

5. There must be a design drawing of the well structure and a construction plan for the well that includes the following contents:

a) Name of the well owner and the organization or individual designing the well;

b) Geological column and description of the geological layers, depth distribution of each layer of rock at the drilling location; type, diameter, thickness, and depth of each section of casing and filter pipes; size and position of the centering devices for the casing columns (if any);

c) Depth, thickness, type, and size of the filtration material for each water collection section;

d) Depth, thickness, and type of isolation material for each section around the well casing. The isolation work around the well casing must be carried out in accordance with Clause 6 of this Article;

đ) Extraction flow rate and estimated static and maximum dynamic water levels; layout of extraction equipment and monitoring equipment for water levels and extraction flow rates of the well;

e) Size of the concrete protection around the well mouth and the elevation of the well mouth;

g) Clearly specify the construction methods for each layer of filtration material, isolation sections, and inspection and control procedures during well construction.

6. The isolation work around the well casing specified in point đ Clause 5 of this Article must meet the following requirements:

a) A minimum depth of five (05) meters from the ground surface must be sealed with cement grout;

b) The next section up to the roof of the aquifer being extracted or the top of the filtration material layer must be sealed with cement grout or cement grout mixed with natural clay or bentonite;

c) In addition to the requirements stipulated in points a and b of this clause, if the well diameter exceeds 250 millimeters compared to the outer diameter of the installed casing or if the extraction well has a casing diameter less than 60 millimeters and a well depth not exceeding thirty (30) meters, natural clay pellets smaller than 0.25 times the thickness of the sealing layer may be used as sealing material;

d) If the extraction well draws water from two (02) or more non-contiguous aquifers simultaneously, the sealing work for the section between these aquifers must be carried out according to point b of this clause;

đ) The sealing layer must have a minimum thickness of thirty (30) millimeters for casings with a diameter less than sixty (60) millimeters or a minimum thickness of fifty (50) millimeters for other cases.

7. During the construction of extraction wells, temporary casing pipes must be installed with a minimum depth of three (03) meters from the ground surface; the top of the temporary casing must be at least 0.2 meters higher than the surrounding ground surface of the well mouth and must be protected and maintained throughout the well construction process.

8. Materials used for installing wells must not contain harmful chemicals or disease-causing bacteria and must be stored in dry places away from potential pollution sources. In cases where chemicals are used to soak or clean wells, the chemicals used must belong to the list of permitted chemicals under the law, ensuring they do not cause environmental or water pollution.

Article 6. Requirements for the design and construction of exploration, investigation, assessment wells for underground water resources, geological survey for engineering purposes, geological exploration, mineral exploitation, foundation treatment of structures, mine dewatering, and excavation wells.

Organizations and individuals designing and constructing drilling wells must comply with the provisions set forth in Article 4 of this Circular and the following specific requirements:

1. For exploration, investigation, and assessment wells for underground water resources:

a) In cases where the drilling well is to be used as a groundwater extraction well, long-term monitoring well, or a well expected to be in use for two (02) years or more, it shall comply with the provisions of Article 5 of this Circular;

b) Drilling wells not falling under the circumstances specified in point a of this Clause must be sealed off from the surface of the well to the top of the aquifer layer or to the top of the filter material layer.

2. For geological survey for engineering purposes, geological exploration, mineral exploration, foundation treatment of structures, and mine dewatering wells:

a) In cases where the drilling well is expected to be in use for two (02) years or more, it shall comply with the well sealing-off regulations stipulated in Clause 6 of Article 5 of this Circular;

b) Drilling wells not falling under the circumstances specified in point a of this Clause must be sealed off from the surface of the ground to a depth of at least five (05) meters.

3. For excavation wells:

a) The location of the well must ensure a distance of ten (10) meters or more from animal shelters, toilets, garbage pits, and other potential pollution sources;

b) The well wall must be constructed of brick, stone, or concrete and must be at least half a meter (0.5m) above ground level to prevent surface water from flowing into the well.

Article 7. Requirements for protecting underground water during testing in drilling wells

Organizations and individuals conducting construction and using drilling wells for testing must ensure the following requirements:

1. The methods and procedures for testing in drilling wells must be fully reflected in project proposals, research projects, scientific study topics, and technical construction files. During the testing process, they must be subject to inspection and supervision by competent state management agencies.

2. In case of accidents such as subsidence, cracking of houses and surrounding buildings, or other unusual incidents during testing, operations must be immediately halted, timely measures taken to address and rectify the situation, and compensation provided if necessary; timely notification must be made to the People's Committee of the commune and the Department of Natural Resources and Environment where the incident occurred.

3. Chemicals and radioactive materials used during testing must be included in the list of permitted chemicals and radioactive materials according to the law, ensuring that they do not cause environmental pollution or contamination of water sources.

4. Measures must be taken to prevent and stop wastewater containing toxic substances from entering the drilling well.

5. In cases of testing involving pumping water, in addition to complying with the provisions of Clauses 1, 2, 3, and 4 of this Article, the following requirements must also be met:

a) Water pumped up must be collected and directed away from the wellhead by at least ten (10) meters, ensuring no flooding or adverse impact on the surrounding environment;

b) It must not lower the water level excessively and adversely affect the extraction activities of nearby groundwater extraction facilities;

c) If the pumped-up water shows abnormal signs or causes the death of animals or plants in the area, pumping must be immediately stopped, timely measures taken to address and rectify the situation, and compensation provided if necessary; timely notification must be made to the People's Committee of the commune and the Department of Natural Resources and Environment where the incident occurred.

Article 8. Protection of underground water during exploitation

1. The owner of the underground water exploitation works shall be responsible for maintaining hygiene around the exploitation wells and implementing measures to prevent, control, and prevent pollution of underground water through drilling exploitation wells.

2. The owner of the underground water exploitation works serving the purpose of supplying domestic water must establish a sanitary protection zone for the works in accordance with the provisions of the law on natural resources.

3. The owner of the exploitation works that require a permit for exploitation and use of underground water must organize the installation of equipment and arrange personnel to carry out monitoring of flow rate, water level, and water quality at the exploitation wells and observation wells of the works to ensure parameters, forms, and monitoring regimes to provide and update data into the system for supervising the exploitation and use of natural resources managed by state agencies in accordance with the provisions of the law on natural resources.

Monitoring of water levels at the observation wells of the exploitation works must be carried out at least at one well for underground water exploitation works with a flow rate from 3,000 m³/day-night up to less than 5,000 m³/day-night; at least at two wells for underground water exploitation works with a flow rate from 5,000 m³/day-night to less than 10,000 m³/day-night; at least at three wells for underground water exploitation works with a flow rate from 10,000 m³/day-night or more.

4. Detecting, handling, and rectifying abnormal phenomena and incidents regarding water quality and water levels during exploitation and other incidents caused by their exploitation activities; in case of incidents, they must immediately stop exploitation, promptly handle and rectify the incidents, compensate for losses (if any), and promptly report to the People's Committee of the commune where the incident occurred and the Department of Natural Resources and Environment of the locality where the incident occurred, and report to the agency issuing the exploitation and use permit for underground water.

Article 9. Protection of underground water in activities related to investigation, assessment of underground water resources, geological survey of construction, geological exploration, mineral exploration and exploitation, foundation treatment, and mine dewatering

1. Organizations and individuals conducting investigations, assessments of underground water resources, geological surveys of construction, geological exploration, mineral exploration and exploitation, foundation treatment, and mine dewatering with drilling and excavation components in wells must, in addition to complying with relevant technical regulations, standards, and norms, fully implement requirements for protecting underground water as stipulated in Articles 4, 6, and 7 of this Circular.

2. Organizations and individuals engaged in foundation treatment may only use materials permitted under the law; they must not use wastewater, dirty water, or water containing oil for foundation treatment.

3. For pumping water operations to dewater mines, the provisions of Clause 4, Article 26 of the Law on Water Resources 2012 shall apply.

4. For reservoirs, ponds, or areas storing wastewater, tailings, and other liquid waste generated during mineral exploitation, they must comply with environmental protection regulations, requirements, and laws on minerals and natural resources to ensure that they do not cause pollution of underground water.

Article 10. Effective Date

1. This Circular takes effect from February 12, 2018.

2. Chapter III, Chapter IV, Chapter V, and Article 21 of Chapter VI of Decision No. 15/2008/QĐ-BTNMT dated December 31, 2008 issued by the Minister of Natural Resources and Environment on the regulations for protecting underground water resources shall cease to be effective from the date this Circular takes effect.

Article 11. Implementation Organization

1. The National Water Resources Management Agency shall be responsible for guiding and inspecting the implementation of this Circular.

2. Ministries, ministerial-level agencies, government agencies, People's Committees at all levels, Departments of Natural Resources and Environment of provinces and centrally-administered cities, and organizations and individuals concerned shall be responsible for implementing this Circular.

3. During the implementation of this Circular, if there are difficulties or obstacles, the relevant agencies, organizations, and individuals are requested to reflect these issues to the Ministry of Natural Resources and Environment for research, amendment, and supplementation to make it appropriate./.