A job offer letter is a document that a Canadian employer gives you (as a temporary worker). It explains the details of your job.You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553. Your job offer has to include an LMIA number or a copy of the LMIA. An incomplete application packet may disqualify an applicant. Hiring employees in Canada? Equal Employment Opportunity. The District is an equal opportunity employer and actively encourages applications from all qualified and outstanding applicants. Diablo Valley College (DVC) is one of three publicly supported two-year community colleges in the Contra Costa Community College District. As jobs become available, they are posted at the respective Job Placement Center on each campus.