Usage of Fly Ash in National Highway Construction

The Ministry of Environment, Forest and Climate Change (MOEF&CC) has mandated the usage of fly ash/pond ash through various notifications and amendments since 1999. However, the stipulations were only partly adhered to in national highway construction owing to issues such as non-execution of MOUs for the usage of fly ash between thermal power plants and contractors, conditional contracts executed by agencies of the ministries or ambiguous interpretation of contract provisions.

The NHAI therefore issued another order dated September 26, 2023, clarifying the provisions of the notifications applicable to national highway projects for which bids were received between January 25, 2016, and December 31, 2021.

Key provisions of the prior notifications, as reproduced in the order, pertain to the mandatory requirement of adherence to the guidelines issued by the Indian Road Congress regarding the use of fly ash when constructing roads or flyover embankments with top soil within a radius of 300 kms of a Thermal Power Plant (TPP). It shall further be the responsibility of the State Authorities approving construction to ensure that an MOU or any other legally binding agreement is established between the TPP and the contractors for the utilisation of fly ash or fly ash-based products.


In addition, TPPs were required to transport the ash free of charge to the construction site of asset creation programs of the government which have been clarified to include National Highway Projects.

The order further clarifies that MORTH shall share a list of road projects for which bids were received from 2016 to 2021 with MoP along with the quantity of ash required. In addition, a Standard Operating Procedure (SOP) has been provided that requires TPPs to provide ash, if available, according to the provisions stated in the MoEF&CC’s 2016 Notification. However, if available ash has been auctioned and no issuable ash is remaining, TPPs may issue No Availability Certificate so alternative arrangements may be explored. TPPs supplying ash free of cost but not bearing the transportation cost are directed to bear it. MoP shall take action against IPPs/state plants not adhering to these statutory obligations. MORTH shall also explore measures to address the issue of excessive billing for ash transportation that is provided free of charge including route identification, geo-tagging etc.

However, the mandatory use of fly ash shall not be insisted upon by the MORTH or the NHAI if:

  • No Availability Certificate of fly ash is obtained from TPPs situated within 300 km of the site.
  • The Highest Technical Officer of the Authority approves deviation as per para 1(5) of the MOEF&CC notification dated 25.01.2016.

The contractor is obligated to carry out due diligence of the project during the bidding phase to determine if fly ash is available from nearby TPPs. The Authority may accordingly permit the use of alternative materials such as soil, sand, etc. that are arranged by the contractor on their own. The Authority (MORTH/NHAI/ NHIDCL/ BRO/ PWDs) shall not be responsible for covering the expenses related to fly ash, alternate material, transportation, etc. Further, the unavailability or slow supply of fly ash for the project will be considered a non-political event under the force majeure clause of the agreement.