You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553. An incomplete application packet may disqualify an applicant.Contra Costa County is seeking talented and qualified individuals to fill clerical vacancies throughout the County! The supplemental job information questionnaire should be prepared from the qualifications listed in the job announcement. All notices related to County recruitments for which you have applied will be sent via email. In your cover letter and responses to the Supplemental Questions, please address minimum and Desirable Qualifications. The Welfare-to-Work (WTW) Program is a comprehensive Employment and Training Program designed to promote self-sufficiency. For further information or questions, please contact the Contra Costa County Office Of The Sheriff Recruiter. Frequently Asked Questions. What do I do if my provider is not in CCHP's network, but I want to continue to see them?