California Code, Penal Code - PEN § 1210.16

(a) The chief probation officer may administer continuous electronic monitoring pursuant to written contracts and appropriate public or private agencies or entities to provide specified supervision services. No public or private agency or entity may operate a continuous electronic monitoring system as authorized by this section in any county without a written contract with the county's probation department. No public or private agency or entity entering into a contract may itself employ any person who is a participant in continuous electronic monitoring surveillance.

(b) The county board of supervisors, the chief probation officer, and designees of the chief probation officer shall comply with Section 1090 of the Government Code in the consideration, making, and execution of contracts pursuant to this section.