If you locate unlawful language, you may complete the Restrictive Covenant Modification form, and submit it to our office for review and recording. Contra Costa County.Employment and Human Service Department. Contra Costa County - Martinez Employment Lawyer. One of 58 counties in California, Contra Costa County has the 11th largest public-school student population in the state (approximately 169,394 students). Contra Costa County is recruiting to fill multiple Social Service Program Assistant I vacancies in the Employment and Human Services Department (EHSD).