https://www.mercurynews.com/2020/06/28/coronavirus-as-bay-area-reopens-counties-turn-to-social-bubbles-to-slow-the-spread/

Susan Bergmann spent her 61st birthday swimming in the Bay and eating pizza and cupcakes. Despite COVID-19, she wasn’t alone: she was surrounded by her husband, daughter and the half-dozen friends who have become her “pod” over the past few months. They swim and bike together, a strict group whose members have agreed not to come into social contact with anyone outside of the pod.

As the Bay Area begins to reopen, some counties are codifying the kind of system Bergmann’s group has been using since the beginning of the pandemic. In Alameda, Contra Costa, Marin and San Mateo Counties, public health officials are now allowing for “social bubbles,” which come with strict guidelines but a lack of enforcement.