In a letter to Carol M. Browner, Administrator of the EPA, the organisation asked the EPA to withdraw and reconsider its diesel sulphur reduction proposal, currently under review by the Office of Management and Budget.

Claiming it is committed to reducing diesel engine emissions, the NPRA says the EPA’s proposal could reduce the supply of diesel fuel, heating oil and even petrol. Last year, the NPRA used the same argument against proposed reductions of sulphur levels in petrol (see related story).

The EPA proposal calls for a reduction of the on-road diesel sulphur cap from 500 parts per million (ppm) to 15 ppm in 2006. The NPRA say this is not feasible, either from an energy supply or environmental standpoint.

Environmentalists do not expect the NPRA’s letter to produce a withdrawal of the proposal. “It would be very close minded of them to oppose the proposal altogether,” Angie Farleigh, a US Public Interest Research Group (PIRG) Clean Air advocate told edie. “They may get some compromise from the EPA – maybe a regional approach or extended timelines. But opposing the standard outright – no.

“Ultimately, the NPRA members are going to have to clean up and spend money doing it, ” says Farleigh. “It’s clear the benefits to public health outweigh the costs of more expensive diesel.”

The NPRA’s letter claims that EPA has not released any compelling data to support its sulphur standard or schedule and has not made a study of the impact of the proposal on diesel supply. “EPA should refrain from taking actions that are without sound technical justification and that could impose severe costs and supply impacts on diesel consumers,” the letter says.

Petroleum refiners support a 90% cut in diesel sulphur to no less than 50 ppm from the current onroad sulphur cap of 500 ppm. The refiners propose that this should occur on top of a 90% reduction in sulphur in petrol during roughly the same period. The NPRA says these two regulatory changes alone will present formidable technical, financial and logistical challenges to US refiners.

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