A bipartisan group of 34 US senators is urging the US Environmental Protection Agency (EPA) to increase the volumes of advanced biofuels for 2018 and biomass-based diesel for 2019 in the Renewable Fuel Standard (RFS).

In a 16 October open letter to EPA administrator Scott Pruitt, the senators said the agency’s proposal to decrease the advanced biofuel volume for 2018 to 4.24bn gallons and hold the biomass-based diesel volume for 2019 stagnant at 2.1bn gallons did not reflect the existing potential for the biodiesel and renewable diesel industries.

“Reducing volumes ­– and especially those Renewable Volume Obligations (RVOs) that were previously finalised – is disruptive, unprecedented and troubling. These volumes do not meet the actual biodiesel production capacity in the USA and could have a negative impact on jobs and economies in rural communities across the nation,” the letter read.

On 26 September, the EPA sought comments on potential reductions in RVOs that it had previously proposed in July. Back then, the EPA had called for a total of 19.24bn gallons of renewable fuels to be blended into the US fuel supply for 2018, down from 19.28bn gallons in 2017.

In its 26 September call for public comment, the EPA cited the expiration of the US$1 per gallon biodiesel tax credit and a recent preliminary determination by the US Department of Commerce that it would be appropriate to place countervailing duties of 41%-68% on imports of biodiesel from Argentina and Indonesia as factors that could impact the cost and supply of advanced biofuels.

The National Biodiesel Board (NBB) has backed the senators, saying in a statement that it had serious concerns over the EPA’s recent actions and that it had made these concerns known to the Senate in an earlier testimony.

According to the NBB, the proposed cuts to the fuel volumes threatened rural jobs, negatively affected companies who had invested to comply with the law and undermined the energy security goals of the RFS programme.

“EPA should seeks comment on factors that warrant higher advanced biofuel and biomass-based diesel volumes in order to achieve the Congress’ goals of diversifying our fuels supply, supporting rural jobs and enhancing US energy security,” said NBB chief operating officer Doug Whitehead.

“Instead, the recent request for comment from EPA flaunts these objective with the potential to eradicate jobs and bankrupt farmers,” he added.