During the 13th Five Year Plan period, China's soil pollution control has achieved positive results. In order to establish a comprehensive prevention and control pilot area of soil pollution as the starting point, we explored the source prevention, risk management and control, governance and remediation, regulatory capacity-building and other aspects, and solved a number of prominent problems of soil pollution control.

Policies and regulations escort the construction direction of the pilot zone is more clear

In May 2016, the State Council issued and implemented the "soil pollution prevention and control action plan" (hereinafter referred to as the "ten soil articles"), which has become the program of the national soil pollution prevention and control work in the 13th five year plan and even for a longer period.

It took three years to solicit the opinions of relevant departments and units of the Central Committee and the State Council five times, solicit the opinions of the people's governments of various provinces (autonomous regions and municipalities) three times, and revise more than 50 times. Aiming at the current prominent soil environmental problems that harm people's health, the "ten articles on soil" put forward 10 articles, 35 items and 231 specific measures focusing on agricultural land and construction land, pointing out the direction for the prevention and control of soil pollution in China. At this point, the "pure land defense war" officially began.

At the end of 2016, the construction of the six pilot areas started rapidly. Taizhou, Zhejiang Province, Huangshi, Hubei Province, Changde, Hunan Province, Shaoguan, Guangdong Province, Hechi, Guangxi Province and Tongren, Guizhou Province shoulder the mission and expectations and take the lead in making progress.

Make clear the basic principles, objectives and requirements of the construction of the pilot area——

In August 2017, the former Ministry of environmental protection and the Ministry of Finance jointly issued the guiding opinions on strengthening the construction of pilot areas for comprehensive prevention and control of soil pollution (hereinafter referred to as the opinions), which determined six aspects of infrastructure conditions and eight aspects of quantitative construction indicators. The opinions have become an important guide for the construction of pilot areas.

The "opinions" guide each pilot area to carry out demonstration in the aspects of soil pollution source prevention, risk control, treatment and remediation.

It is the first time to formulate special laws to regulate the prevention and control of soil pollution and provide legal protection——

On August 31, 2018, the law of the people's Republic of China on the prevention and control of soil pollution was officially passed, with a total of 7 chapters and 99 articles. This law makes it clear that the prevention and control of soil pollution should adhere to the principles of prevention first, protection first, classified management, risk control, pollution responsibility and public participation.

In January 2019, the "law on the prevention and control of soil pollution" was officially implemented, which is an important step in the prevention and control of soil pollution according to law and the implementation of the "ten articles on soil pollution".

Increase the special funds to support the construction of the pilot area, and ensure stable capital investment——

The construction of comprehensive prevention and control pilot area of soil pollution is an important task at present, and it is also the key direction supported by the central special fund for soil pollution prevention and control. During the 13th Five Year Plan period, the central government allocated 28.5 billion yuan of special funds for soil pollution prevention and control, of which 3.34 billion yuan was allocated by the central government to increase support for the construction of pilot areas, accounting for 11.7% of the total special funds for soil pollution prevention and control.

Prevent from the source, cut off the way of industrial pollution into the soil in an all-round way

"According to the experience of soil pollution prevention and control in developed countries in Europe and the United States, the investment ratio of soil pollution source prevention, risk management and control, treatment and restoration is approximately 1 ∶ 10 ∶ 100, and the implementation of soil pollution source prevention is the key to avoid large investment in later treatment and restoration." Li Zhitao, temporary head of the comprehensive business department of the soil and agricultural and rural ecological environment supervision technology center of the Ministry of ecological environment, said.

Adhere to the principle of prevention first, protection first and risk management and control, which is the clear requirement of the law on the prevention and control of soil pollution. It is also the primary task of the construction of the pilot areas to strengthen the prevention and control of the source and not to owe new accounts.

Huangshi Economic Development Zone, known as "central Silicon Valley", has a large scale of circuit board production capacity, high degree of agglomeration, and obvious environmental sensitivity and vulnerability. The circuit board production process is complex, there are many links of production and emission, and there are many kinds of potential pollutants with high concentration, mainly including copper, nickel, silver, tin and so on. In addition, a variety of hazardous chemicals, high concentration wastewater and solid waste involved in the production process, once mismanaged, will easily cause soil and groundwater pollution.

In order to speed up the elimination of backward production capacity, Huangshi Economic Development Zone has established a "cage for bird" forced mechanism and implemented the park cluster development. While improving the industry access threshold, we should focus on introducing industry leading enterprises, encourage enterprises to adopt new technologies and new processes, reduce the generation of pollutants from the source, and promote the green development of the circuit board industry.

Taizhou, Zhejiang invested more than 6 billion yuan to move all 38 waste metal dismantling enterprises into Taizhou metal resources recycling industry base. At present, the recycling rate of the base dismantling is more than 95%, the amount of garbage produced only accounts for 1.9% of the total annual dismantling amount, and the amount of hazardous wastes such as waste circuit boards only accounts for 1.79 ‰, so as to prevent the dismantling garbage from flowing out of the park and causing pollution.

In recent years, Taizhou city has demolished more than 3000 illegal work sheds, nearly 1 million square meters of buildings involved in dismantling industry, cleared 250000 tons of dismantling waste, and the rectification rate of off-site dismantling has reached 100%, with an additional green area of more than 6000 mu, thoroughly clearing the "cancer" of off-site illegal dismantling.

Multi mode exploration of safe use of agricultural land to ensure that the masses eat at ease

Food is the priority of the people, and food safety is of great importance. Therefore, the targeted classification management and safe use of agricultural land has become a new idea for pollution risk control and remediation in many pilot areas.

Wenling City, Taizhou, Zhejiang Province, has carried out fine classification of polluted farmland and achieved good results. On the one hand, Wenling City strictly controls the use of heavily polluted cultivated land. First, it delimits the forbidden production area of agricultural products according to law, transfers the land comprehensively, and forbids the planting of edible agricultural products. It reduces the degree of soil pollution by adjusting the planting structure, agricultural engineering measures, biological treatment and restoration. On the other hand, Wenling tried out the "positive and negative" crop list system for lightly and moderately polluted farmland to guide farmers' scientific layout, encourage low-risk crops such as rape, soybean and corn to replace high-risk crops such as taro and ginger, help farmers "clear the land" while teaching them how to revitalize "land".

Tongren, Guizhou Province, in exploring the remediation and safe use of contaminated farmland, resolutely avoided and prevented excessive remediation and governance, combined with the actual regional agricultural production, and walked out of the new soil pollution control mode of "ecological governance of heavy metal contaminated soil + ecological industry + ecological poverty alleviation". The farmland polluted by Mercury will be used as a base for agricultural adjustment and construction of edible fungi. The work of changing paddy field into dry land will be carried out in an all-round way. The focus will be on the development of black fungus, Lentinus edodes, Pleurotus ostreatus and other non soiled edible fungi industries. While directly benefiting 782 people from 260 poor households, the rebound of high-risk agricultural production mode of rice planting will be effectively prevented.

Changde, Hunan Province, established an inter Bureau joint conference system for the safe use of Contaminated Farmland to manage the contaminated agricultural land. In Shimen County and other places, through plant extraction + crop intercropping, passivation + plant barrier and other measures to promote the safe use of land, in realgar mining area, through the adjustment of planting structure, the development of improved citrus varieties that are not easy to absorb arsenic, and the use of Citrus centipede intercropping technology for risk management and control have achieved significant benefits.

Strictly control the risk of construction land to ensure the people's peace of mind

"In the early days, European and American countries used high energy consumption technologies such as digging, burying and burning to treat contaminated land, which often led to excessive treatment of soil pollution. Nowadays, with the deepening of public and regulatory understanding, it is becoming more and more mainstream to set remediation goals according to the function and use of soil. This is obvious in soil management and control of construction land. " Gu Qingbao, deputy director of the Institute of soil and solid waste environment of the Chinese Academy of Environmental Sciences, said.

East steel plant of Hubei Xinye Steel Co., Ltd. was shut down due to excessive arsenic, cadmium, lead and other heavy metal pollution. However, this plot was later planned as a cultural and educational land, shouldering a relatively arduous remediation project of contaminated soil.

Due to the long production process of iron and steel plant, the production tasks of each region are different, and the pollutants, pollution degree and underground conditions are different. Therefore, for the cross area of reserved buildings and demolished buildings, Donggang determined the remediation idea of risk control for the contaminated soil within 4 meters near the wall of the reserved buildings; for the contaminated areas that do not need to retain buildings, the technology of combining shallow contaminated soil remediation with deep pollution risk control is adopted. In view of the heavy metal pollution area, more than 30 foundation pits were excavated in the construction process. The method of "one pit, one policy" was adopted. According to the specific situation, different chemicals and temperatures were used for treatment.

In order to prevent the migration of pollutants and control the risk of ecological environment, Shaoguan, Guangdong Province, actively creates the management and control mode of temporarily undeveloped contaminated plots, continuously promotes the ecological restoration of key mining areas without covering soil, establishes the linkage supervision process of soil environmental departments for the development and utilization of construction land, and explores the "Shaowei" formula of soil prevention and control.

A remote mountain depression in Lihu Township, Nandan county, Hechi County, Guangxi Province, used to be an arsenic factory. The concentration of arsenic, cadmium and other pollutants in the waste residue exceeded the standard. Now it is the site of demonstration disposal project of arsenic residue. In the treatment process, Nandan county adopted the scheme of rigid landfill for high-risk pollutants, stabilization for medium risk pollutants and high leaching risk contaminated soil, combined with barrier landfill method for disposal, and barrier landfill for low-risk pollutants and low leaching soil.

The comprehensive prevention and control of soil pollution has been carried out in the first place, and the model, experience and effect have been achieved. The road construction in five years has achieved remarkable results. At present, there is no case of exceeding the standard of agricultural products pollution caused by agricultural land soil pollution, and there is no case of adverse social impact caused by improper redevelopment and utilization of contaminated land.

Standing at the important node of the 14th five year plan, the prevention and control of soil pollution in China has entered a new stage. China will continue to explore the experience that can be replicated and popularized in soil pollution prevention and control, so as to provide a new model and experience for the national soil pollution prevention and control work, so that the people can "rest assured of food and housing" at a higher level.

Source: China Environment News