Circular No. 28/2019/TT-BTNMT stipulates technical procedures for evaluating dredged materials and determining disposal areas for such materials in Vietnam's marine zones.

CIRCULAR

TECHNICAL REGULATIONS ON THE ASSESSMENT OF DREDGED MATERIALS AND THE IDENTIFICATION OF SITES FOR DISPOSAL OF DREDGED MATERIALS IN VIETNAMESE MARINE AREAS

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Pursuant to the Law on Marine Resources and Environment 2015;

Pursuant to the Law on Environmental Protection 2014;

Pursuant to Decree No. 40/2016/NĐ-CP dated May 15, 2016 of the Government detailing certain provisions of the Law on Marine Resources and Environment;

Pursuant to Decree No. 159/2018/NĐ-CP dated November 28, 2018 of the Government on the management of dredging activities in port water areas and inland waterways;

Pursuant to Decree No. 38/2015/NĐ-CP dated April 24, 2015 of the Government on waste management;

Pursuant to Decree No. 40/2019/NĐ-CP dated May 13, 2019 of the Government amending and supplementing some articles of decrees detailing and guiding the implementation of the Law on Environmental Protection;

On the basis of Decision 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;

At the proposal of the Director General of the Vietnam Administration of Seas and Islands, the Head of the Science and Technology Department, and the Head of the Legal Department,

The Minister of Natural Resources and Environment promulgates this Circular on technical regulations for assessing dredged materials for disposal at sea and identifying sites for disposal of dredged materials in Vietnamese marine areas.

PART I
GENERAL PROVISIONS

Article 1. Scope of Regulation

This Circular stipulates technical regulations for assessing dredged materials for disposal at sea and identifying sites for disposal of dredged materials in Vietnamese marine areas.

Article 2. Applicability

This Circular applies to state administrative agencies, organizations, and individuals, both domestic and foreign, involved in the assessment of dredged materials for disposal at sea and the identification of sites for disposal of dredged materials in Vietnamese marine areas.

Article 3. Principles for Applying Monitoring, Analytical, and Assessment Methods for Dredged Materials for Disposal at Sea and Identification of Sites for Disposal of Dredged Materials

Clause 1. The application of monitoring, analytical, and assessment methods for dredged materials for disposal at sea and identification of sites for disposal of dredged materials must comply with the methods prescribed in this Circular and current national technical standards and regulations.

Clause 2. In cases where international standard methods, regional standard methods, or foreign standard methods not specified in this Circular have equivalent or higher accuracy, they may be considered and accepted for use.

Clause 3. In cases where the monitoring, analytical, and assessment methods for dredged materials for disposal at sea and identification of sites for disposal of dredged materials prescribed in this Circular are amended, supplemented, or replaced by new methods, the new methods shall be applied.

Article 4. Definitions and Abbreviations

The terms and abbreviations in this Circular are defined as follows:

Point 1. Dredged material for disposal at sea (hereinafter referred to as dredged material) is the material obtained from dredging operations under the seabed in inland waterways, port water areas, and Vietnamese marine areas that need to be disposed of at sea.

Point 2. Bioavailability level of pollutants in dredged material is the ratio of pollutants in dredged material absorbed by a particular species of organism through different contact routes.

Point 3. Biological accumulation of pollutants in dredged material is the increase in pollutant concentration in the body of organisms over time.

Point 4. Ecological niche is an ecological space where environmental conditions determine the indefinite existence and development of individuals and species.

Point 5. Adjacent area is the nearby marine area around the dredging site, the disposal site of dredged material, and affected by hydrodynamic processes and material dispersion due to dredging, transportation, and disposal of dredged material at sea.

Point 6. QCVN: National Technical Regulation.

Point 7. ASTM: abbreviation for "American Society for Testing and Materials," the United States Association for Materials and Testing.

Point 8. USEPA: abbreviation for "United States Environmental Protection Agency," the United States Environmental Protection Agency.

Point 9. OSWER: abbreviation for "Office of Solid Waste and Emergency Response," the Office of Solid Waste and Emergency Response under the United States Environmental Protection Agency.

Chapter II

TECHNICAL REGULATIONS ON THE ASSESSMENT OF DREDGED MATERIALS FOR DISPOSAL AT SEA

Article 5. Content of dredged material evaluation

1. Evaluation of the characteristics, physical properties, and pollutant content in the dredged material.

2. Evaluation of the sedimentation and precipitate-forming ability of pollutants in the dredged material.

3. Evaluation of the biological availability level of pollutants in the dredged material.

4. Evaluation of the toxicity of pollutants in the dredged material.

5. Evaluation of the biological accumulation potential of pollutants in the dredged material.

Article 6. Steps for evaluating dredged material

1. Collecting, investigating information, documents, and data related to the evaluation of dredged material.

2. Sampling dredged material.

3. Establishing and implementing a sample analysis plan.

4. Analyzing and testing dredged material:

a) Evaluating the characteristics, physical properties, and pollutant content in the dredged material;

b) Evaluating the sedimentation and precipitate-forming ability and the level of biological availability of pollutants in the dredged material;

c) Evaluating the toxicity of pollutants in the dredged material;

d) Evaluating the biological accumulation potential of pollutants in the dredged material.

5. Synthesizing the results of the dredged material evaluation.

Article 7. Collection and investigation of information, documents, and data related to the evaluation of dredged material

1. The contents of information, documents, and data to be collected and investigated include:

a) Information, documents, and data on the location, coordinates, depth, topography of inland waterways, port waters, seabed of the dredging area;

b) Information, documents, and data on natural conditions, meteorological, hydrological, marine, and environmental characteristics of the dredging area;

c) Information on the purpose of dredging; the area, volume, quantity, depth, and time of dredging; equipment serving dredging activities;

d) Information on the history of dredging (if any), including: location, area, volume, quantity, and time of dredging; results of previous dredged material evaluations;

đ) Information, documents, and data on the exploitation and utilization of the dredging area; economic and ecological values of natural resources in the dredging area; issues related to resource exploitation, utilization, and environmental pollution that have occurred in the dredging area;

e) Other relevant information (if any).

2. Sources of information, documents, and data for evaluating dredged material:

b) Information, documents, and data from strategic environmental assessment reports and environmental impact assessment reports of projects and dredging activities;

c) Other information, documents, and data related to dredging activities provided by competent state agencies according to regulations;

d) Monitoring data on natural resources and the environment from the global, regional, national monitoring systems, and those of Ministries, sectors, and localities;

đ) Results of provincial, ministerial, and national scientific research programs that have been accepted;

e) Information, documents, and data from surveys, investigations, and scientific research activities in the dredging area.

3. Information, documents, and data related to the evaluation of dredged material collected and investigated according to Clause 1 and Clause 2 of this Article shall be used for synthesis, evaluation, and sampling of dredged material as stipulated in Article 8 of this Circular.

a) The project or activity has a dredging area that does not change;

b) The quantity of dredged material does not exceed 10% of the quantity of dredged material previously permitted;

c) After synthesizing and evaluating the information, documents, and data collected and investigated according to Clause 1 and Clause 2 of this Circular, it is found that there are no new sources of pollution, no changes in environmental and ecological conditions in the dredging area and its vicinity.

Article 8. Sampling dredged material

1. Selection of parameters for sampling dredged material:

a) Assess and determine sources and activities that have the potential to cause pollution and adversely affect the environment in the dredging area based on the results of compiling and evaluating information, documents, and data related to the assessment of dredged material as stipulated in Article 7 of this Circular;

b) Determine parameters for sampling dredged material, including:

Physical parameters: including the particle size distribution of dredged material to the dredging depth; water and solid content in dredged material; specific gravity of dredged material;

Chemical and radioactive parameters: including pollutant parameters in dredged material specified in Appendix 01 issued together with this Circular;

Biochemical and biological parameters: including parameters for assessing toxicity and bioavailability of pollutants in dredged material.

2. Develop a sampling plan for dredged material with the following main contents:

a) Brief description of the dredging area, dredging depth, volume of dredged material, volume of dredged material to be disposed of;

b) Evaluate the history of the dredging area and adjacent areas; assess physical and marine environmental factors that may affect the spread of pollutants in dredged material and the implementation of the sampling plan;

c) Scientific and practical basis for determining sampling locations and sampling location network diagrams;

d) The number of sampling locations determined according to the volume of dredged material, as prescribed in Appendix 03 issued together with this Circular;

đ) Determine the sampling location network diagram as prescribed in Clause 3 of this Article;

e) Sampling depth; sample volume ensuring analysis and evaluation of dredged material; number of samples required at each sampling location, as prescribed in Clause 4 of this Article;

g) Requirements for sampling, processing, storage, preservation, and transportation of samples, as prescribed in Clause 5 of this Article;

h) Means of transport and other necessary equipment for sampling, preservation, and transportation of samples to the laboratory;

i) Emergency response plan in case of adverse weather conditions, serious mechanical or equipment failure; measures to ensure health and safety;

k) Organization and implementation methods for the sampling plan.

3. The sampling location network diagram is established in the following sequence:

a) Based on the number of sampling locations determined in Point d Clause 2 of this Article and the schematic or map of the dredging area, divide the dredging area into square grids with the condition that the total number of grid cells is at least five times the number of sampling locations;

b) Select sampling locations within grid cells using a random method combined with an assessment of the degree and uniformity of polluted areas or areas potentially containing high levels of pollutants;

c) Display the coordinates of sampling locations on a topographic map of the dredging area at a scale of 1:5,000 or larger, established based on current regulations on surveying and mapping.

4. Sampling depth, sample volume, and number of samples required at each location:

a) Sampling depth is the dredging depth;

b) Sample volume is determined based on the groups of analytical parameters specified in Appendix 04 issued together with this Circular;

c) The number of samples required for each location is determined according to the sampling depth, the parameters to be analyzed and tested, and the sample volume according to the characteristics of the analysis already determined as prescribed in Point b Clause of this Article.

5. Requirements for sampling, processing, storage, preservation, and transportation of samples are implemented in accordance with Circular No. 24/2017/TT-BTNMT dated September 1, 2017 of the Minister of Natural Resources and Environment on environmental monitoring techniques (referred to as Circular No. 24/2017/TT-BTNMT); Circular No. 57/2017/TT-BTNMT dated December 8, 2017 of the Minister of Natural Resources and Environment promulgating technical regulations for comprehensive investigation and survey of marine resources and environment at depths of 20 meters or more by ship.

1. The analysis sample plan includes the following main contents:

a) Determining the level of quality assurance for the entire sampling, storage, and analysis work consistent with the used analytical methods;

b) Contents related to sample preservation conditions, sample division methods, mixing methods, sample volume, and corresponding laboratory equipment based on the selection of analytical methods;

c) Specific quality assurance programs and requirements that need to be reflected in the analysis report;

d) Time, expected progress, and other requirements related to the implementation of the analysis plan.

2. In cases where biological analysis and testing are required for dredged material, apply a separate quality assurance and quality control program with the following main contents:

a) Parameters to be analyzed or monitored and statistical assurance levels according to requirements;

b) Operating procedures for standardized and published tests for analysis and testing purposes;

c) Testing conditions including temperature, pH, DO, salinity, hardness, and other water quality parameters or sediment quality parameters;

d) Observing positive reactions of organisms to pollutants in test tanks to determine abnormal reactions of species when exposed to pollutants; observing negative reactions of organisms to pollutants (organisms in normal condition not exposed when contacting with pollutants present in dredged material);

đ) Control charts to record the time and concentration of pollutants when abnormal reactions of organisms occur.

Article 10. Evaluation of the characteristics, physical properties of dredged material, and pollutant content in dredged material

1. Evaluate and determine the particle size distribution of dredged material by depth up to the dredging depth; the amount of water and solids in dredged material; the specific gravity of dredged material.

3. Compare the results of pollutant content analysis in dredged material with the pollutant content thresholds specified in Appendix 01 issued together with this Circular.

a) In cases where the pollutant content in dredged material is lower than the thresholds specified in Appendix 01 issued together with this Circular, compile the results and include them in the Submarine Disposal Project content;

b) In cases where the pollutant content in dredged material exceeds the thresholds specified in Appendix 01 issued together with this Circular but is lower than the values prescribed in QCVN 43:2017/BTNMT on sediment quality issued pursuant to Circular No. 78/2017/TT-BTNMT dated December 29, 2017 of the Minister of Natural Resources and Environment (referred to as QCVN 43:2017/BTNMT), conduct tests to evaluate the settling and sedimentation capacity of pollutants in dredged material and the biological availability of pollutants in dredged material as stipulated in Article 11 of this Circular.

Article 11. Evaluation of sedimentation and deposition capacity of pollutants in dredged material and evaluation of the bioavailability level of pollutants in dredged material

1. Testing for the sedimentation and deposition capacity of pollutants in dredged material and testing for the bioavailability level of pollutants in dredged material aims to assess the proportion of pollutants in the dredged material that can be absorbed by living organisms.

2. The number of sampling locations, sampling methods, and frequency of sampling are specified as follows:

a) The minimum number of sampling locations for testing the sedimentation and deposition capacity of pollutants in dredged material and testing the bioavailability level of pollutants in dredged material is stipulated in Appendix 5 issued together with this Circular.

In cases where the dredging area includes sub-regions selected for testing and assessment of pollution levels, these sub-regions must be chosen as sampling locations.

If there are test results on the sedimentation and deposition capacity of pollutants in dredged material within three years from the time of dredging, and these results are representative of the dredging area without new sources of pollution, such results may be used for evaluation. If not, samples should be taken again at representative areas using random sampling combined with stratified random sampling methods and the sedimentation and deposition capacity of pollutants in dredged material should be tested according to the provisions of Clause 3 of this Article.

b) Sampling methods and frequency of sampling shall be carried out in accordance with the provisions of Circular No. 24/2017/TT-BTNMT.

3. Testing for the sedimentation and deposition capacity of pollutants in dredged material shall be conducted in the following sequence:

a) Mix the dredged material sample with seawater collected from the proposed disposal site at a ratio of 1:4 (one part of the dredged material sample with four parts of seawater). Shake thoroughly at room temperature laboratory conditions for 30 minutes and allow the sample to settle for one hour.

b) Separate the supernatant obtained after settling according to the provisions of Point a of this Clause to evaluate the concentration of dissolved pollutants, the concentration of pollutants in suspended solids, and the total concentration of pollutants in the solution. Analytical parameters to evaluate the concentration of pollutants are specified in Appendix 2 issued together with this Circular.

Analysis of the concentration of dissolved pollutants in the solution is conducted after centrifuging or filtering with a filter membrane size of 0.45 micrometers within one hour based on the selection of the sedimentation and deposition capacity testing method for pollutants in dredged material according to the current national standard. In cases where the sedimentation and deposition capacity testing method for pollutants in dredged material is not included in the current national standards, USEPA-503/8-91/001 guidelines shall be applied.

c) Evaluate the concentration of pollutants based on comparing the analysis results according to the provisions of Point b of this Clause with the values prescribed in QCVN 10-MT/2015/BTNMT on seawater quality issued by Circular No. 67/2015/TT-BTNMT dated December 21, 2015 of the Minister of Natural Resources and Environment (referred to as QCVN 10-MT/2015/BTNMT).

If the concentration of pollutants is lower than the values prescribed in QCVN 10-MT/2015/BTNMT, conduct testing for the bioavailability level of pollutants in dredged material according to the provisions of Clause 4 of this Article.

If the concentration of pollutants is higher than the values prescribed in QCVN 10-MT/2015/BTNMT, compile the results and incorporate them into the Submarine Disposal Project content.

4. Evaluation of the bioavailability level of pollutants shall be conducted in the following sequence:

a) Pollutants requiring evaluation of their bioavailability level are specified in Appendix 1 issued together with this Circular.

b) Based on the pollutants identified in Point a of this Clause, select the method to conduct the evaluation of the bioavailability level of pollutants in dredged material according to the current national technical standards and regulations. In cases where the method to conduct the evaluation of the bioavailability level of pollutants in dredged material is not included in the current national standards, apply the guidelines of US EPA 910/R96-002, US EPA 9200.1-86, OSWER 9285.7-77, OSWER 9200.3-51.

c) Based on the results of evaluating the bioavailability level of pollutants in dredged material according to the methods specified in Point b of this Clause, compare with toxicity assessment requirements and conduct evaluation according to the provisions of Article 12 of this Circular.

Article 12. Evaluation of Toxicity of Pollutants in Dredged Material

1. The evaluation of toxicity of pollutants in dredged material shall be conducted with selected organisms based on the following factors:

a) Organisms that frequently come into contact with sediment in the proposed disposal area; sensitive to pollutants present in dredged material;

b) Capable of tolerating physical and chemical conditions of dredged material;

c) Suitable for exposure methods and toxicity endpoints; compatible with standardized procedures and quality assurance protocols to allow comparison of results between laboratories;

d) Able to be sampled from cultivation areas or field sites; easy to preserve in laboratory conditions; easily identifiable; have short to medium life cycles;

e) Of ecological and economic value; wide geographic distribution; native species or have similar habitats to those of interest in the proposed disposal area.

2. The method for conducting toxicity tests of pollutants in dredged material shall be selected according to the national technical standards and regulations currently in effect. In cases where such methods are not specified in current national technical standards and regulations, the guidelines ASTM E1367-99, ASTME1525-02, ASTM E1391-03, ASTM E1706-05, ASTM E1367-03 shall be applied.

3. The level of toxicity of pollutants in dredged material shall be evaluated as follows:

a) If the number of affected individuals is less than or equal to 10% of the total number tested, biological accumulation testing of pollutants in dredged material shall be conducted as stipulated in Article 13 of this Circular;

b) If the number of affected individuals exceeds 10% of the total number tested, the results shall be compiled and included in the Submarine Disposal Project content.

Article 13. Evaluation of Biological Accumulation Capacity of Pollutants in Dredged Material

1. The method for evaluating the biological accumulation capacity of pollutants in dredged material shall be selected according to the national technical standards and regulations currently in effect. In cases where such methods are not specified in current national technical standards and regulations, the guidance ASTM E1688-00a(2007) of the American Society for Testing and Materials shall be applied.

2. Based on the results of the evaluation of biological accumulation capacity and toxicity tests of pollutants in dredged material as stipulated in Article 12 of this Circular, the results shall be compiled and included in the Submarine Disposal Project content.

Chapter III

TECHNICAL PROVISIONS FOR DETERMINING SUBMARINE DISPOSAL AREAS FOR DREDGED MATERIAL IN THE SEA

Article 14. Content of Determining Submarine Disposal Areas for Dredged Material

1. Evaluate the physical, chemical, and biological characteristics of proposed submarine disposal areas for dredged material.

2. Assess the impact of dredged material disposal activities on marine resources, environment, ecosystems, and socio-economic, defense, and security activities in the proposed disposal areas and adjacent regions.

3. Determine the coordinates of boundary lines and areas of marine zones used for submarine disposal of dredged material.

Article 15. Steps to determine areas for disposal of dredged materials

1. Collecting, compiling information, documents, data to serve the determination of potential areas for disposal of dredged materials.

2. Proposing feasible areas for disposal of dredged materials.

3. Conducting detailed evaluations of proposed areas for disposal of dredged materials.

4. Comparing, selecting, determining potential areas for disposal of dredged materials.

1. Information, documents, data to serve the determination of potential areas for disposal of dredged materials must meet the following requirements:

a) Collected from official statistical sources recognized legally, ensuring reliability and accuracy;

b) Updated to the latest available at the time of determining potential areas for disposal of dredged materials.

2. Sources of information, documents, data to serve the determination of potential areas for disposal of dredged materials:

a) Information, documents, and data from the Statistical Yearbook of the General Statistics Office, Ministries, sectors, and Provincial Statistics Offices;

b) Information, documents, data from environmental impact assessment reports, strategic environmental assessment reports of projects, activities involving dredging and disposal of dredged materials in the sea;

c) Other relevant information, documents, data related to dredging and disposal of dredged materials in the sea up to the time of determining potential areas for disposal provided by competent state agencies according to regulations;

d) Monitoring information, documents, data on natural resources and environment from global, regional, national monitoring systems and monitoring systems of ministries, sectors, localities;

đ) Results of provincial, ministerial, and national-level scientific research programs that have been accepted;

e) Information, documents, data from research, surveys, investigations to serve the determination of potential areas for disposal of dredged materials.

3. Information, documents, data to be collected and compiled:

a) General information about potential areas for disposal of dredged materials including: location, coordinates of the area, distance to the coast, islands, and the dredging area, area size, depth;

b) Characteristics of the water body in potential areas for disposal of dredged materials and adjacent areas, including: depth; seasonal stratification characteristics and other weather conditions; wave, wind, tide, marine current characteristics; temperature, salinity, pH, and dissolved oxygen variation with depth; suspended solids, turbidity or clarity of the water body;

c) Information, documents, data on seabed characteristics including: seabed topography; sediment grain size distribution; seabed mud and sand transport, deposition, erosion characteristics; sediment chemistry; representative seabed images, videos of the area;

d) Information, documents, data on ecosystems in potential areas for disposal of dredged materials and adjacent areas including: general information on species of flora and fauna in potential areas for disposal of dredged materials; soft-bottom and hard-bottom mollusk communities; soft-bottom and hard-bottom fish communities; distribution of certain special ecosystems including coral reefs, seagrass beds;

đ) Current environmental status of potential areas for disposal of dredged materials;

e) History of disposal of dredged materials; information on equipment and means of transporting dredged materials to disposal sites;

g) Marine resource exploitation and utilization activities in potential areas for disposal of dredged materials and adjacent areas;

h) Other relevant information, documents, data.

Article 17. Proposing feasible areas for disposing dredged materials

1. The marine areas proposed for use in disposing dredged materials must meet the following requirements:

a) Not causing harmful impacts on human health, the country's economic potential; minimizing negative effects on the environment, marine ecosystems, and fishery resources in accordance with the law;

b) Not affecting the safe use of port facilities and maritime routes, oil and gas structures, submarine cables, electrical cables along the coast, and the activities of organizations implementing co-management in protecting fishery resources and other lawful exploitation and utilization of natural resources by organizations and individuals as stipulated by the law;

c) Not impacting national defense, security, sovereignty, jurisdictional rights, and national interests at sea.

2. Proposing feasible areas for disposing dredged materials based on the following factors:

a) Ensuring harmony between the costs of disposal, benefits obtained, and the goal of protecting the marine environment;

b) Marine weather conditions by season and types, technical specifications of vessels and equipment used for transporting and disposing dredged materials;

c) Current maritime safety regulations;

d) Transportation and construction costs for disposing dredged materials;

đ) Administrative boundaries and relevant maritime boundaries;

e) The ability to monitor, inspect, and observe the disposal area of dredged materials.

3. The boundaries and area of the marine zone proposed for disposing dredged materials are determined by a closed line consisting of straight segments connecting specific coordinate points and are depicted on a seabed topographic map with appropriate scale.

Article 18. Detailed assessment of proposed areas for disposing dredged materials

1. Assessing the characteristics and physical, chemical, and biological properties of the areas proposed for disposing dredged materials, as specified in Article 19 of this Circular.

2. Evaluating the degree of impact of the disposal of dredged materials on resources, the environment, marine ecosystems, and socio-economic, defense, and security activities in the proposed areas and adjacent regions, as specified in Article 20 of this Circular.

Article 19. Assessment of the characteristics and physical, chemical, and biological properties of the areas proposed for disposing dredged materials

1. General information about the proposed area for disposing dredged materials includes:

a) Administrative geographic location; coordinates, boundaries, and area of the proposed disposal zone;

b) History of dredged material disposal activities in the proposed area and adjacent regions;

c) Resource exploitation and utilization, environmental activities already occurring or currently taking place in the proposed disposal area and adjacent regions that may affect sediment quality;

d) Characteristics or activities in the proposed disposal area that could influence sediment dispersion and movement;

đ) Information, documents, and data on oil spills and toxic chemical incidents in the proposed disposal area and adjacent regions.

2. Physical, chemical, and biological characteristics of water masses in the proposed disposal area and adjacent regions include:

a) Detailed seabed topography in the proposed disposal areas and adjacent regions;

b) Forecast of water temperature and salinity during the disposal period and seasonal variations over time;

c) Forecast of bottom turbidity, dissolved oxygen, and natural fluctuations of these characteristics at the disposal time; temporal and seasonal variations of these characteristics;

d) Seasonal flow patterns, tidal characteristics, wave regime, and water rise and fall characteristics in the proposed disposal areas and adjacent regions; evaluation of the dispersal capacity of dredged materials in these areas and adjacent regions;

đ) Living areas and spatial and temporal changes of marine species in these areas;

e) Description of fishery resources including known sensitive species, habitats in the dredging area, proposed disposal area, and adjacent regions.

3. Physical, chemical, and biological characteristics of sediments in the proposed disposal area and adjacent regions include:

a) Particle size distribution, moisture content, and total organic carbon;

b) Contaminant levels in sediments according to current national technical standards for sediment quality;

c) Benthic community characteristics in the proposed disposal area and adjacent regions;

d) Bioaccumulation of heavy metals, persistent organic compounds, pesticides, and other contaminants.

Article 20. Evaluation of the degree of impact of disposal activities on dredged materials on resources, environment, marine ecosystems, and economic, social, defense, and security activities in proposed disposal areas and adjacent regions.

1. Establish scenarios for disposing of dredged materials including the following factors:

a) The maximum total amount of dredged material expected to be disposed of in the proposed disposal area, measured in tons or meters.³;

b) The rate of disposal of dredged materials over time, measured in tons/hour or meters/hour;³/hour;

c) Duration of each disposal operation and frequency of such operations over time;

c) Duration of each disposal session and frequency of disposal sessions over time;

d) Average speed of the equipment used for disposing of dredged materials, measured in nautical miles/hour or kilometers/hour;

đ) Disposal route within the scope of the proposed disposal area;

2. Evaluate the impacts of disposal activities on dredged materials on resources, environment, marine ecosystems, including:

a) Impacts on the seabed, seawater masses, and marine ecosystems in the proposed disposal area and adjacent regions according to the characteristics and features specified in Point b, c, d Clause 3 Article 16 of this Circular;

b) The evaluation and forecasting of impacts and effects of disposal activities on dredged materials may use models simulating the dispersion, transmission, transformation, and conversion of pollutants in dredged materials and their impacts on marine and island resources and the environment according to the disposal scenarios determined under Clause 1 of this Article;

The application of simulation models is regulated in Article 21 of this Circular.

3. The evaluation of the degree of impact of disposal activities on dredged materials on economic, social, defense, and security activities in proposed disposal areas and adjacent regions for each economic, social, defense, and security activity is stipulated in Appendix 06 issued together with this Circular.

Article 21. Application of simulation models for the process of dispersion, transmission, transformation, and conversion of pollutants in dredged materials and their impacts on marine and island resources and the environment.

1. Based on specific calculation and simulation requirements, conditions for applying models, and practical information and data available for analysis and selection of simulation models for the process of transmission, transformation, and conversion of pollutants in dredged materials and their impacts on marine and island resources and the environment.

2. Procedure for applying models:

a) Prepare information and data for calculations;

b) Process topographic data to establish models;

c) Develop computational domains and grids;

d) Set boundary conditions;

đ) Set initial conditions;

e) Set basic model parameters;

g) Connect hydraulic dynamic models with simulation models for the process of transmission, transformation, and conversion of pollutants in the marine and island environment;

h) Calibrate and determine parameter sets for the model;

i) Test and evaluate the reliability of model results;

k) Develop, calculate, and simulate scenarios;

l) Prepare reports on calculation results.

3. Evaluation of the accuracy and suitability of models

The evaluation of the accuracy and suitability of models must be conducted when calibrating and determining parameter sets for the model; testing and evaluating the reliability of model results as stipulated in Point h and Point i Clause 2 of this Article shall follow the procedure below:

a) Visual assessment through comparison of actual measurement data series and calculated and simulated data series according to the model; compare the synchronization between the two data series;

b) Calculate and determine the correlation level between actual measurement data series and calculated and simulated data series according to the model;

c) Calculate the model efficiency coefficient according to the following formula:

Where:

E: model efficiency coefficient;

N: length of the characteristic data series calculated and simulated in the model;

O: actual measured value of the characteristic calculated and simulated in the model;

O_tb: average value of the actual measurement data series;

S: calculated and simulated characteristic values;

đ) Conduct expert consultation before deciding to use the model in calculating and simulating scenarios as stipulated in Point k Clause 2 of this Article.

Article 22. Comparison, selection, determination of areas that may be used for disposal of dredged materials

1. Based on the results of assessing the degree of impact of the disposal of dredged materials on natural resources, the environment, marine ecosystems, and socio-economic, defense, and security activities in proposed disposal areas and adjacent regions, comparisons shall be made to select areas that may be used for disposal of dredged materials according to the following requirements:

b) The degree of impact of the disposal of dredged materials on natural resources, the environment, and marine ecosystems in the proposed disposal area and adjacent regions;

c) The degree of impact of the disposal of dredged materials on socio-economic, defense, and security activities in the proposed disposal area and adjacent regions;

d) The suitability of the proposed disposal area for dredged materials with existing infrastructure and technical equipment serving the disposal activity;

đ) The ability to meet future disposal requirements;

2. Compile the results, specifically determine the coordinates, boundaries, and areas of marine zones used for disposal of dredged materials, and include them in the contents of the Disposal Project.

Chapter IV

IMPLEMENTING PROVISIONS

Article 23. Effectiveness of Implementation

This Circular takes effect from February 18, 2020

Article 24. Implementation Organization

1. Ministries, ministerial-level agencies, government agencies, provincial People's Committees under the central city, and organizations and individuals related to this matter are responsible for implementing this Circular.