“Participating entity” means a city or county that has entered into an agreement with the district pursuant to subdivision (b) of Section 102100.3, but only during the period in which the agreement is in effect. “Participating entities” means all those cities and counties.
Source:
Section 102026, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PUC§ionNum=102026..