Context: Recently, the Centre government drafted the New fly ash utilisation rule for Thermal Power Plants(TPPs).
Key highlights

• It is mandatory for  Thermal Power Plants(TPPs) to ensure 100% utilisation of fly ash within three to five years. 
• Existing provisions allow TPPs to fully utilise fly ash in a four-year cycle in a staggered manner. 
• It also introduced fines of Rs 1,000 on non-compliant plants under the ‘polluter pays principle’, taking into account utilisation targets from April 1 next year.
• The 'polluter pays' principle is the commonly accepted practice that those who produce pollution should bear the costs of managing it to prevent damage to human health or the environment.

Under this,the collected fines will be deposited in the designated account of the Central Pollution Control Board (CPCB). 

• The fine collected by CPCB from the TPPs and other defaulters shall be used towards the safe disposal of the unutilised ash.
• It also deals with unutilised accumulated ash (legacy ash) where TPPs will have to utilise it within 10 years from the date of publication of final notification in a staggered manner.
• If the utilization of legacy ash is not completed at the end of 10 years, a fine of Rs 1000 per tonne will be imposed on the remaining unutilised quantity which has not been fined earlier.

Objectives and Need 

• Fly ash utilisation in India has increased from nearly 10% in 1996-97 to the highest level of over 83% during 2019-20, unutilised ash gets dumped in an environmentally hazardous manner, polluting air, water and soil.
• It aims to deal with environmentally hazardous fly ash generated from coal and lignite based thermal power plants (TPPs).

Fly Ash

• Fly ash is a byproduct of burning pulverized coal in thermal power plants.
• During combustion, mineral impurities in the coal (clay, feldspar, quartz, and shale) fuse in suspension and float out of the combustion chamber with the exhaust gases. As the fused material rises, it cools and solidifies into spherical glassy particles called fly ash. 
• The low-grade coal used in thermal power generation carries 30-45% ash content. The high-grade imported coal has a low ash content of 10-15%. 
• Since most of the coal used in thermal plants is low-grade, it generates a large quantity of ash which requires a large area as landfill or ponds for disposal.
• All fly ashes exhibit cementitious properties to varying degrees depending on the chemical and physical properties of both the fly ash and cement.

Composition

• Fly ash includes substantial amounts of silicon dioxide (SiO2), aluminium oxide (Al2O3), ferric oxide (Fe2O3) and calcium oxide (CaO).

Usage

• It is an excellent material for making construction materials such as bricks, mosaic tiles and hollow blocks. 
• Bricks made of fly ash can help conserve soil to a great extent.
• There are several eco-friendly ways to utilise fly ash so that it does not pollute air and water.
• It includes the use of fly ash in the manufacturing of cement, ready-mix concrete; constructing roads, dams and embankment, and filling of low-lying areas and mines.

Issues 

• Fly ash contains toxic and heavy metals. 
• The ponds where fly ash is usually dumped are poorly managed. Fly ash becomes dry as temperature increases and gets airborne. 
• Thus, it becomes one of the major sources of air and water pollution. 
• Air in areas around coal-fired power plants is polluted with fly ash.
• Apart from causing various diseases, it also leads to reduction in the recharging of groundwater. 

Initiatives Taken

Optimum utilization of fly ash: To facilitate 100% ash utilization by all coal based thermal power plants, a web portal for monitoring of fly ash generation and utilization data of Thermal Power Plants and a mobile based application titled “ASHTRACK” has been launched by the Government. 

• Ash-park has developed, and awareness programme for utilisation of fly ash and its products conducted at various platforms.. 

Roles played NTPC: National Thermal Power Corporation (NTPC) has developed an infrastructure to transport fly ash from power plants in bulk to cement plants, at a cheaper cost.

• NTPC intends to transform the fly ash it produces into a revenue-generating by-product.
• It has developed geopolymer and nano aggregates from residual fly ash for use in the construction of roads and houses is a manifestation of this.

Road Ahead

• Promoting R&D for increasing the efficiency of power plants will also help in reducing ash generation. Proper management of fly ash is important for the environment and also for power plants as it occupies a  lot of land space.