You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553. No. You must submit a completed application for each position you are interested in.Each case is given individual consideration, based on job relatedness. We can help you discover rewarding career paths, find a job, write your resume and cover letters and even get ready for interviews. Contra Costa County is seeking talented and qualified individuals to fill clerical vacancies throughout the County! Welcome to Contra Costa County's on-line application process! The Workforce Development Board of Contra Costa County offers a variety of services to help job seekers looking for employment and career opportunities. Eligibility: Any employer in Contra Costa County seeking to fill a job that comes with salary (not a commission-only job). How do I get started?