Citing concerns about possible pension liability, Larkspur officials this week took the first step toward severing the city’s membership in the Central Marin Sanitation Agency, a wastewater organization it helped form in the late 1970s. The Larkspur City Council agreed Wednesday to give up the city’s seat on Central Marin’s six-member board of directors, which governs the infrastructure that treats sewage collected from Larkspur and other nearby areas. The council will vote on formal resolutions declaring the city’s severance at future meetings. But Larkspur’s voice won’t be completely flushed down the drain when the withdrawal is finalized, one of the...