EPA, CARB to Review SCR Policies

The Environmental Protection Agency and California Air Resources Board have agreed to begin a “thorough review” of their policies regarding the operation of selective catalytic reduction-equipped heavy-duty diesel engines when diesel engine fluid tanks run dry.

The review outlined in legal settlements disclosed in federal and state court documents filed earlier this month, are the result of lawsuits filed last year against EPA and CARB by engine maker Navistar Inc.

Navistar is the only major engine manufacturer who is using exhaust gas recirculation technologies to reduce emissions in its 2010 engines.

Navistar has alleged in court documents and public statements that when DEF tanks are empty, SCR engines do not shutdown as required, but continue to run even though their pollution system is no longer working properly to reduce nitrogen oxide emissions.