Center for Biological Diversity

For Immediate Release, October 26, 2015

Contact: Lisa Belenky, (415) 385-5694,

Settlement Will Protect Air Quality in Southern California's Imperial Valley

Road Paving Plan Would Have Increased Pollution, Imperiled Wildlife

EL CENTRO, Calif.— The Center for Biological Diversity today reached a settlement with Southern California’s Imperial County Air Pollution Control District under which the district will withdraw a flawed emissions-exchange plan it adopted in May 2015. The rule would have awarded credits for paving unpaved roads — which primarily reduces only large dust particles — to be used to offset increased emissions of smaller particles from diesel exhaust and other sources. The Center challenged the rule because it could lead to an increase in the smallest particulate emissions, which are particularly dangerous to human health.

“We’re pleased the air district agreed to withdraw this rule, which could have increased the most dangerous kinds of air pollution in Imperial County — a place where residents already suffer from some of the worst air quality in the nation,” said Ileene Anderson, a senior scientist at the Center. “Paved roads increase roadkill and damage wildlife habitat by fragmenting it so animals can’t get where they need to go. If the county wants to pave more roads, it needs to properly study these harms.”

The road-paving plan would also have hurt imperiled flat-tailed horned lizards, a species that is particularly vulnerable to impacts from roads. Along with increasing habitat fragmentation and roadkill, expanding paved roads spreads invasive weeds and increases roadside pollution. Flat-tailed horned lizards are currently candidates for protection under the California Endangered Species Act, and their long-term survival depends on protection of remaining habitat in Imperial Valley.  

Under the settlement the district also agreed that if it proposed any similar rule in the future, it would have to prepare a full environmental impact report in order to adequately assess environmental impacts to air quality, public health and wildlife in the area. 

The case was filed in Imperial County Superior Court under the California Environmental Quality Act, challenging the district’s lack of adequate environmental review before it adopted the rule. The Center was represented in the case by Doug Carstens at the law firm of Chatten-Brown and Carstens.  

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 900,000 members and online activists dedicated to the protection of endangered species and wild places.

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