The suit left the court's jurisdiction when the Environmental Protection Agency approved California's plan to reduce emissions, including the rules for trucks and buses that will go into effect Jan. 1, U.S. District Judge Morrison C. England in Sacramento ruled Wednesday.
If the Upland-based California Construction Trucking Association wants to continue pursuing the case against the California Air Resources Board, it will have to include the EPA as a party in the litigation in a court of appeals, Morrison wrote.
CCTA spokesman Lee Brown said an appeal is being discussed and is likely. The group brought the lawsuit against state regulators to prevent implementation of the legislation, which was first adopted in 2008.
The 2008 rule was eased in 2011, in recognition that compliance costs were difficult to manage in the flailing economy. The regulation began being phased in with the 2012 calendar year, after the judge denied motions for injunctions to halt its implementation.
As of Jan. 1, a new phase of regulations will kick in requiring many heavy duty trucks and buses from model years 2000 to 2004 to install diesel soot filters, as needed. The 2012 phase had similar requirements for 1996 to 1999 models.
The National Resources Defense Council, an environmental protection group, applauded the court's ruling, saying it would ensure that roughly 1 million aging diesel vehicles will be retrofitted to reduce pollution.
"Older diesel trucks and buses have little or no emissions controls," NRDC attorney Melissa Lin Perrella said in a statement. "We have the technology to make these large vehicles cleaner for the people riding inside and for those who breathe their exhaust."