Officials on Friday said they have expanded the incident area for a massive sewer spill in the northern part of Clearlake as a precautionary measure. Sunday will mark three weeks since a Lake County Sanitation District-owned force main rupture triggered the Robin Lane sewer spill, which released nearly three million gallons of raw sewage into streets and across private properties. On Monday, the city of Clearlake began managing the recovery phase of the incident in unified command with the Lake County Sheriff’s Office of Emergency Services. … By Friday, the unified command said that, based on continued evaluation of groundwater conditions related to the spill, the incident area was expanded as a precautionary measure to ensure the protection of public health.