2346 21st Ave, San Francisco, CA 94116

The two-unit residential building at 2346 21st Avenue in the Parkside neighborhood, owned by Shirley M Tan, is a two-story flats and duplex structure constructed in 1946. The property has undergone several significant renovations, most notably in 2004-2005 when substantial improvements were made including the addition of two bathrooms and a laundry facility on the ground floor, along with electrical upgrades featuring new lighting, switches, receptacles, and the installation of two new 100-amp services.

The building has a concerning history of sewer-related issues, with eight documented incidents between 2009 and 2024, including multiple sewage backups from the 4-inch side sewer vent and one occurrence involving street drainage. The most recent incident in August 2024 was resolved through field work by the PUC Sewer Operations team.

Prior to this, there were three consecutive sewage backup incidents in January 2022, one of which was reported just two days after a similar incident. While the building has received necessary infrastructure upgrades over the years, the recurring nature of the sewer problems, especially in recent years, is notable and represents the most significant pattern of maintenance issues on record for this property.