Old Moccasin Powerhouse Hazard Mitigation

The San Francisco Public Utilities Commission plans to demolish the Old Moccasin Powerhouse, a structurally deficient facility located on a 1.3-acre site near the junction of State Route 49 and State Route 120 in the unincorporated town of Moccasin, Tuolumne County, approximately eight miles east of Groveland. The structure poses a significant risk to public health and the environment due to the presence of hazardous materials and the potential for catastrophic failure, which could release debris into the air and contaminate the adjacent Moccasin Reservoir and Moccasin Creek. Prior to demolition, site preparation and hazardous material abatement will be conducted to mitigate these risks. The demolition process will involve complete removal of the building, filling of the basement, and leveling of the site, followed by restoration activities including cleanup and the placement of compacted gravel to stabilize the area. The project is scheduled to take place over a six-month window beginning as early as 2028, with all work confined to the existing footprint to minimize environmental disruption. The project is being managed by the City and County of San Francisco, with primary coordination handled by Timothy Johnston, Senior Planner, and supported by project applicant Sue Chau and consultant Sally Johnson.