You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553. List experience that relates to the qualifications as required on the job announcement.How to fill out the Contra Costa County Employment Application Form? 1. Read the instructions carefully. 2. We can help you discover rewarding career paths, find a job, write your resume and cover letters and even get ready for interviews. An incomplete application packet may disqualify an applicant. Hello, I applied to be an Experienced Clerk for the County. My first assigned interview is for the County Counsel. It's been 3 weeks and I haven't received an email or a phone call, nothing. Does anyone know how long on average the county takes to reach out to you?