California cities are paying high costs to clean up water pollution running off parking lots. Environmental groups say the state needs to hold businesses accountable.

The president said he will invoke Cold War-era emergency powers to direct a nearly $700-million investment into the waning coal industry, including construction of a West Coast coal export terminal in Oakland.

After the Eaton and Palisades fires devastated Southern California, a highly toxic metal stayed in the air much longer and probably traveled much farther than expected, according to a new study.

A new dashboard makes public for the first time heat-related deaths and emergency room visits in near-real time.

Can Silicon Valley solve California’s mosquito problem? Google is seeking federal approval to unleash millions of bacteria-infected, non-biting mosquitoes in the Golden State.

A biologist discovered a decomposing bighorn sheep tangled in concertina wire recently strung in Imperial County, part of an effort to deter illegal immigration. Advocates had warned of danger to migrating animals.

Residents of Monterey Park voted overwhelmingly to ban data centers, making the San Gabriel Valley city the first in the nation to do so by public vote.

With energy demand already straining infrastructure, AI players are reimagining the data center from the ground up.

Local governments in a few U.S. towns and cities have banned data centers, but Monterey Park could be the first city to ban them by popular vote.

Tests of a new desalination technology in a reservoir near Westlake Village were a success. Next comes an ocean trial off Southern California.