Engine Manufacturers Association v. South Coast Air
Quality Management District 541 U.S. 246 (2004)
Los Angeles was worried about air quality, so they
instituted a requirement that private owners of large vehicle fleets had
to purchase "clean fuel" vehicles.
The Federal Clean Air Act §209 preempts States and
localities from introducing their own air quality standards.
However, California is exempt and can develop their own
standards. The only requirement is that California applies for a waiver
whenever they institute a standard that is different from the Federal
Los Angeles did not apply for a waiver because they felt
that the new rule was a purchasing requirement and not an emissions
standard and was therefore not covered by the Clean Air Act.
The Engine Manufacturers' Association (EMA) sued, saying
that Los Angeles' rule was preempted by the Clean Air Act §209.
The Trial Court found that the new regulation was legal.
The Trial Court found that "where a State regulation
does not compel manufacturers to meet a new emissions limit, but rather
affects the purchase of vehicles, as the Fleet Rules do, that regulation
is not a standard."
The Appellate Court affirmed. EMA appealed.
The US Supreme Court reversed and threw out the new
The US Supreme Court looked to the language in §209
and found that in the past, the word "standard" had been
interpreted by the Trial Court to include only regulations that compel
manufacturers to meet specified emissions limits.
The Court found that the word "standard" should
be defined more broadly to include commands made to purchasers to buy
vehicles based on emissions characteristics.
The case went back to the Trial Court, who decided that
the part of the regulation that was directed towards vehicles owned and
operated by the City of Los Angeles was not covered by §209 and was
The basic reason that there is a preemption doctrine
in the Clean Air Act is that if there wasn't, each State could have
their own draconian emissions standards and car manufacturers would have
to make 50 different vehicles, which wouldn't be efficient.
However, that worry isn't applicable here, so what's the