You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553. Open examination -- Any persons qualified for the position may apply for the examination.Hello, I applied to be an Experienced Clerk for the County. My first assigned interview is for the County Counsel. A cover letter of 300 words or less, explaining why you are the ideal candidate for the students at Contra Costa College. When replying to a job offer letter via email, you'll want to express your gratitude for the offer and confirm your acceptance of the position. The Workforce Development Board of Contra Costa County offers a variety of services to help job seekers looking for employment and career opportunities. An outline of the employment process in this District appears below; each letter corresponds to a step in the process.