HJ 740-2015Technical guideline for environmental risk assessment of tailings pond (English PDF)

4.1 Characteristics of pollutant control requirements

Characteristics of pollutants control the implementation of the EIA approved the relevant requirements, EIA approved after the country or local to develop more stringent pollutants Emission standards, the implementation of new emission standards, emission standards and environmental impact assessment are not specified in the project, with reference to other relevant standards Quasi-execution.

4.2 Assessment of Environmental Risk Receptor Survey

4.2.1 Investigation of water environment risk receptors Assessment. The lower reaches of tailings are not less than 10 km.

4.2.2 Other types of environmental risk Receptor survey Scope of assessment.

A) valley type, near mountain type, cut river type tailings. downstream of not less than 80 times the dam height.

B) other types of tailings. downstream of not less than 40 times the dam height.

4.2.3 The actual operation can be based on the actual situation to expand the scope of assessment.

4.3 Working procedures

4.3.1 Overall process

Tailings reservoir environmental risk assessment procedures (see Figure 1), by the tailings reservoir environmental risk assessment preparation, tailings reservoir environment Risk prejudgment, tailings reservoir environmental risk classification, tailings reservoir environmental risk analysis and reporting preparation of four stages.

Figure 1 Working Procedure for Environmental Risk Assessment of Tailings

4.3.2 Preparation of tailings bank environmental risk assessment

The main contents of the preparatory work include the collection of relevant information and information.

4.3.3 Pretreatment of environmental risk of tailings

From the type, size, the surrounding environment sensitivity, safety, historical events and environmental violations of the five aspects of the tailings Library environmental risk to predict, to determine whether it is a key environmental supervision tailings, whether the need for further environmental risk assessment estimate.

4.3.4 Classification of Environmental Risk Classification of Tailings

The use of AHP, environmental hazards from the tailings (H), the surrounding environment sensitivity (S), the control mechanism can be Reliability (R) three aspects of the classification, the use of environmental risk classification model, the key environmental supervision tailings reservoir environmental risk Divided into major, large, general three grades, according to the rules of environmental risk level characterization.

4.3.5 Environmental risk analysis and reporting of tailings

For key environmental supervision tailings, in the tailings reservoir environmental risk assessment preparation, risk prediction, risk classification of the base on the basis of the development of tailings reservoir environmental risk analysis and tailings reservoir environmental safety hazard investigation and management of relevant documents; and record tailings Library environmental risk assessment to carry out the process, summed up the tailings reservoir environmental risk assessment of the relevant work content, the preparation of tailings reservoir environmental wind Risk assessment report. For non-key environmental supervision tailings, only record environmental risk forecasting process.

7.1 Index System of Environmental Risk Classification of Tailings

The use of AHP, environmental hazards from the tailings (H), the surrounding environment sensitivity (S), the control mechanism can be (R) three aspects (Figure 2) tailings reservoir environmental risk level division.

Figure 2 tailings reservoir environmental risk classification index system

7.2 Environmental Hazard (H)

Using the scoring method, the type, nature and scale of the three (Table 1) indicators were scored (the index scoring method See Appendix B) with Accumulated Sum, Assessment of Tailings Environmental Hazard (H).

Table 1 tailings reservoir environmental hazards (H) equal division index system

No. Indicator Item Index score Tailings ring Dangerous environment Type Mineral Type/Solid Waste Type/Tailings (or Tailings) Composition Type 48 nature Characteristic contaminants Indicator concentration situation Concentration multiple of pH 8 3 the maximum concentration of the index 14 4 times the concentration of more than 3 times the number of indicators and 6 5 scale present situation capacity 24 (H) is divided into H1, H2, and H3 according to the environmental hazard classification of the tailings pond (Table 2) Three equal.

Table 2 tailings reservoir environmental hazards (H) equal division table

Tailings reservoir environmental hazard score (DH) tailings reservoir environmental hazard equivalent code DH > 60 H1 30 3 surrounding environmental risk receptors Peripheral environment function class Other circumstances Water Environment Downstream water body - surface water 5 - sea water

6 Groundwater 6

Soil Environment

8.1 Environmental risk analysis of tailings pond

This paper analyzes the environmental risk prejudgment of the tailings pond, the results of the environmental risk classification of the tailings and the risk characteristics, (Appendix B and Appendix D) for the reliability of the hazard and control mechanisms, and the score will be greater than Equal to 1 indicator, as a risk factor for sudden event events in tailings and marked in the planking plan. According to reality the other indicators or content can also be used as a risk factor for sudden events in tailings.

According to the investigation and analysis of the status quo of tailings, combined with the effectiveness of existing environmental risk prevention and control measures, the environmental events were analyzed and the corresponding countermeasures were put forward.

8.2 Environmental safety hazard investigation and management related documents

Based on the analysis of the environmental risk of the tailings, the summary of the tailings in the tailings reservoir control mechanism reliability index Sudden environmental events risk factors, the formation of tailings reservoir environmental safety hazard checklist; in accordance with the principles of classification, the preparation of the environment Safety hazard management plan; combined with hidden trouble investigation and day-to-day management work, the preparation of tailings reservoir environmental safety hazards management for the program. For general environmental risk tailings, you can only prepare excerpts and schedules.

8.3 Preparation of tailings bank environmental risk assessment report

Record the development process of environmental risk assessment of tailings pond, summarize the risk assessment of risk of tailings, risk classification, risk Analysis and other tailings reservoir environmental risk assessment of the relevant work content, the preparation of tailings reservoir environmental risk assessment report, the report outline see Appendix E.

Standard Implementation and Supervision this standard shall be supervised by the administrative department of environmental protection of the people's government at or above the county level.

Appendix A

(Normative appendix) Risk Assessment of Environmental Risk of Tailings Meet one of the following circumstances, included in the key environmental supervision tailings related instructions Types of Type of ore (including main ore, ancillary)/tailings (or tailings) Composition Type Solid waste type 1. Hazardous chemicals listed in the Catalog of Hazardous Chemicals for Hazardous Chemicals are used in the relevant production process.

Heavy metal minerals. copper, nickel, lead, zinc, tin, antimony, cobalt, mercury, cadmium, bismuth, arsenic, thallium, vanadium, chromium, manganese, molybdenum 3. Precious metal minerals. gold, silver, platinum group (platinum, palladium, iridium, rhodium, osmium, ruthenium).

4. Light non-ferrous metal mineral. aluminum (bauxite), magnesium, strontium, barium.

5. - rare earth elements of minerals. yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium.

6. - non-ferrous metal mineral. tungsten, titanium.

7. - non-metallic mineral. chemical raw materials or chemical ore.