Station 119 of the Los Angeles County Fire Department covers part of Walnut, Diamond Bar, and Rowland Heights. It is…More located near the intersection of Pathfinder and Brea Canyon Cutoff in Rowland Heights, near the south-easternmost border between Diamond Bar and Rowland Heights.</p> <p>This station serves the southern portion of Diamond Bar.</p>

The South Coast Air Quality Management District manages air-pollution regulations and policy for all of Orange County…More and urban portions of Los Angeles, Riverside and San Bernardino counties. The AQMD shares a building with Diamond Bar City Hall and has an auditorium that provides public-meeting space.</p> <p>In 2004, the AQMD facilities became the state's first to have a fueling station for hydrogen cars. A solar array adjacent to the building provides electricity for a number of electric vehicles in the AQMD fleet.</p>