Excavating Contractors
Napa Valley, San Francisco North Bay, Ca. USA

Underground Service Alert (USA) is an organization that provides information about underground utilities at proposed excavation sites in California, Nevada and Hawaii as a free service. Simply call 811 Homeowners, excavators and professional contractors who are digging, blasting, trenching, drilling, grading, or excavating regularly use USA's services. Sites marked for investigation will often have a recognizable "USA" in spray paint on pavement, or be labeled in some other way.

USA began operation in 1975 and incorporated as a Non Profit Mutual Benefit Corporation in 1986. USA receives planned excavation reports from public and private excavators and transmits those reports to participating members of USA. USA members include private companies and public agencies that have underground lines or facilities. The USA members will either mark or stake their facility, provide information or give clearance to dig.