10/01/2018
Developed countries encourage the use of ash, slag and gypsum from thermal power plants which meet technical regulations and standards for construction materials, cement additives, bitumen, ground levelling and road construction. In Việt Nam, some studies on using thermal power plants’ ash, slag and gypsum for non fired bricks, cement additives, bitumen and transport works. However, at present, most of the power plants have not taken measures for reuse and treatment of ash, slag and gypsum, causing negative environmental impact.
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| Cement and construction material manufactures need to increase the use of ash from thermal power plants, chemical and fertilizer production as their production input |
Environmental impact by ash, slag and gypsum from thermal power plants
At present, nationwide 26 thermal power plants are operating with capacity of 13,810 MW, consuming about 47,8 million tons of coals per year and producing 16.4 million of tons of ash, slag and gypsum and gypsum. It is estimated that by 2020, there will have been 15 coal fired thermal power plants more with the capacity of 24,370 MW and the consumption of 60 million of tons of coals per year. Many power plants are discharging ash, slag and gypsum directly to the environment with potential pollution risks. In particular, a large ash, slag and gypsum storage site can cause leachate (wet ash, slag and gypsum), polluting soil and water. The amount of ash, slag and gypsum is increasing while storage capacity is limited. In addition, dust (PM2.5 and PM5) generated during storage and transport can cause air pollution if not properly controlled. Many plants have not finished ash and gypsum transport and storage as regulated, causing pollution. In addition, many plants have not proactively implemented ash usage plans to reduce storing areas and have not cooperated with entities to receive and recycle ash as production input.
In fact, the main reason for over stock of ash and gypsum in thermal power plants is a lack of technical regulation guidance for using ash and gypsum in ground levelling and construction materials. Some plants produce low quality ash which has met technical regulations issued by Ministry of Construction.
Related regulations on management and usage of ash, slag and gypsum
According to Article 40, Government’s Decree 24a/2016/ND-CP on construction material management, owners of thermal power plants, chemical, fertilizer, cement production, metallurgy factories which produce ash, slag and gypsum and gypsum are responsible for classification and pre-processing to meet technical regulations. In case the facility owners are incapable of doing the job by themselves, they shall hire competent agencies for classifying and processing ash, slag and gypsum to meet standards of construction materials. At present, some plants are studying and constructing factories for classifying and preprocessing ash, slag and gypsum to meet standards for cement and construction materials.
To promote the use of ash, slag and gypsum of thermal power plants as construction materials, on September 23, 2014, Prime Minister issued Decision 1696/QD-TTg on some measures for treating ash, slag and gypsum and gypsum from thermal power, chemical and fertilizer plants. This regulation stipulates that the use of fly ash and artificial gypsums as construction materials shall follow national technical regulations on construction material products and goods. On 12/4/2017, Prime Minister issued a program for promoting treatment and use of ash and gypsums from thermal power, chemical and fertilizer plants as regulated in Decision 452/QD-TTg. According to this document, ash, slag and gypsum, FGD gypsum, PG gypsum (before or after being treated) meeting technical regulations for construction materials are considered as construction material goods and products and comply with regulations on products and goods.
At present, most of plants having ash have got certification from Construction Material Institute, Ministry of Construction) for using ash as input for cement production and transferred the ash to cement manufacturers. Owners of facilities discharging ash, slag and gypsum and those who treat and use ash, FGD gypsum and PG gypsum as construction materials shall comply with Article 40, Decree 24a/2016/ND-CP. In case ash and FGD and PG gypsums cannot be treated and used as construction materials, they shall be treated as solid wastes which are not recyclable. In addition, to minimize ash pollution, Law on Environmental Protection in 2014, Government’s Decree 38/2015/ND-CP dated 24/4/2015 regulate that ash generated from thermal power plants shall be classified and follow MONRE’s guidance on normal industrial solid waste. Reuse and recycle of solid waste, including the use of ash as production inputs are encouraged by LEP and Decree 38/2015/ND-CP. Recently, MONRE has issued documents to provide guidance for thermal power plants to implement these activities.
In case thermal power, it is impossible for chemical and fertilizer plants to carry out reuse, recycling and treatment of their ash within their own territories, they shall transfer the waste to competent authorities for transporting and treating normal industrial waste as regulated in Decree 38/2015/ND-CP as well as MONRE technical guidance documents. When transport the ash, the authorities shall not litter, create dust, odor or leachate to the environment and use record for delivery and receiving. Transporting entities shall be responsible for signing contracts and hand over all ash to receiving entities for proper treatment.
For ash receiving and using facilities, they need to comply with the following detailed regulations: receipt and use of ash shall follow the contents in approved environmental impact assessment reports, certified environmental protection plans or equivalent documents, and measures shall be taken to ensure that the ash reuse and recycling shall not create negative impact on the environment components of surface water, groundwater and air.
In addition, MONRE has provided guidance for dealing with the ash which do not meet technical standards for construction materials issued by Ministry of Construction or related agencies. According to regulations at Point a, Clause 12, Article 32 and Clause 2, Article 33 of Decree 38/2015/ND-CP, facilities wishing to expand their operations to include treatment of normal industrial wastes and not being subject to environmental impact assessment requirements shall draft action plans and submit to MONRE for approval before carrying out the plans. At present, MONRE has guided some provinces to assess and approve proposals on using ash as inputs for non-fired brick and cement production.
Measures for managing and using ash and trash
For ministries and sectors
Ministry of Construction shall study and issue technical regulations and standards for treatment and use of ash and trash from thermal power plants as input for construction material production; direct cement factories to use ash and trash as substitutes for other convention production inputs. In the meantime, the Ministry of Construction shall publicize the list of thermal power plants producing suitable ash and trash for construction material production as well as the amount of ash and trash which have been used by cement, bitumen and other construction material manufacturers.
Ministry of Industry and Trade directs project owners and emitters and thermal power plant owners to draft ash treatment and management plans to submit to Ministry of Industry and Trade for approval. It is planned that by 2020, the area of landfills is not higher than the average production of two years. More specifically, existing plants shall submit plans by December 31, 2018 and proposed plants shall prepare and submit plans before starting operation. In the meantime, the Ministry shall urgently review the 7th master electricity plan to draft a road map for closing, phasing out and removing ineffective, outdated and polluting thermal power plants, in the meantime, carrying out research and development renewable and clean energy alternatives, reviewing and removing outdated and polluting technologies.
For other ministries: Ministry of Transport shall complete and develop standards, technical guidance and regulations on ash, trash and gypsums for materials for road construction. Ministry of Agriculture and Rural Development shall complete standards, guidance and technical regulations on use of ash, trash and gypsums as materials for irrigation works as well as for other agricultural infrastructure works. MONRE shall review and develop standards, technical guidance and regulations for ash treatment. In case ash cannot be reused and recycled, the ministry shall guide the ash generating and receiving facilities to comply with environmental protection requirements. It shall refuse environmental impact assessment reports if thermal power plants fail to present plans for ash treatment and disposal as regulated in Prime Minister’s Decision 452/QD-TTg. Ministry of Science and Technology shall study and issue standards and technical regulations on thermal power plant technologies to scrutinize outdated and polluting technology import.
Provincial people’s committees shall lead and cooperate with Ministry of Industry and Trade and other concerned agencies to confiscate landfill areas over two year storage capacity. They shall direct project investment owners using local state budgets to prioritize the use and ash, trash and gypsums. They shall cooperate with line ministries to inspect, supervise and timely deal with violators of regulations on management and use of ash, trash and gypsum as construction materials and works, timely taking measures to respond to obstacles.
For thermal power plants
Existing thermal power plants shall comply with Prime Minister’s Decisions 1696/QD-TTg and 452/QD-TTg dated 12/4/2017. The plants shall proactively seek options for treatment and consumption ash and gypsums as construction materials. Proposed thermal power plants shall be requested to develop plans for ash treatment and consumption with a principle that ash and trash are resources. Measures for mitigation of ash impact shall be taken such as water spraying, ash compacting, water infiltration prevention, tree planting as well as other environmental protection measures, notably autonomous environmental monitoring and wastewater treatment.
For cement production, construction material manufactures and building investors
Cement production, construction material manufactures and building investors shall increase the use of ash which are certified to meet technical standards and regulations QCVN 16:2014/BXD- national technical regulations on construction material products) as inputs for cement and bitumen production. They shall need to meet water monitoring requirements.
Nguyễn Thượng Hiền, Director
Nguyễn Thành Lam
Department of Waste Management and Environment Promotion
Vietnam Environment Administration
