Cal. Gov. Code § 31680.01

As used in Section 31680 service rendered as a member of a governing board of a joint agency created by two or more counties, under the authority of Chapter 5 (commencing with Section 6500) of Division 7, Title 1 of this code, shall not be deemed service rendered a county or district, provided that the county from whose service the employee was retired is a party to the agreement creating the joint agency.