In August of 1910 the United Association granted a charter to form a local union for work in the San Gabriel Valley of Southern California. Local 398 began dispatching from what was then the dusty farm town of Pomona (population 10,000) half a day’s journey from downtown Los Angeles on the Southern Pacific rail line. More than a century later
Local 398 is still dispatching plumbers and fitters from the Local’s offices in Rancho Cucamonga. 

The Local’s jurisdiction stretches from the peaks of the San Gabriel Mountains to the lowlands of the basin, including more than twenty major towns, among them heavily populated Corona, Rancho Cucamonga, Ontario, Pomona, and Pasadena.   

Moving into its second century of service, the goal of this Local remains the same: Help our contractors grow, train men and women for well paying honorable jobs.