An UST is “any one or combination of tanks, including pipes connected thereto, that is used for the storage of hazardous substances and that is substantially or totally beneath the surface of the ground.” (Health and Safety Code 25281(y)) 

Public Works permits and inspects the USTs within the unincorporated areas of Los Angeles County and 77 cities. 

Public records can be found using our Online File Review system. For further assistance, please email us at 

Permit Applications

UST permits are required prior to installing new USTs, modifying UST systems, permanently or temporarily closing USTs, and upon UST ownership change. Please refer to the UST Permits page for more information. 

Please submit UST permit applications to for review and processing. You can also mail submissions to: 

Los Angeles County Public Works
Environmental Programs Division
900 South Fremont Avenue
Annex Building, 3rd Floor
Alhambra, CA 91803