General Information. A person who has filed a fictitious business name statement shall file a statement of abandonment of use of fictitious business name.The County of Contra Costa is responsible for assessing, collecting and apportioning property taxes for the District. Please Download PDF BOE-571-S REV. When reporting that the business has been closed, provide the date(s) and information relating to the deposition of any taxable personal property. The Contra Costa County Office of the Sheriff is seeking men and women interested in an exciting and challenging career in law enforcement. Proceeds of the Series 2015A Bonds will be used to (1) pay the costs of certain transportation projects,. Letter to the Board of Supervisors and Citizens of Contra Costa County . Contra Costa County is one of the largest employers in the area, offering multiple career opportunities in public service. Electronic file in the Proposal submission.