Does Seneca, SC need an earthquake retrofit?

Seneca carries Seismic Design Category C under USGS's ASCE 7-16 model. Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. Nationally, Seneca ranks above 78% of the 4,875 cities in this dataset for seismic hazard - the 78th percentile.

How Seneca compares

The raw figures: peak ground acceleration 0.23g, short-period spectral response 0.37g, 1-second spectral response 0.101g. Among 66 South Carolina cities in this dataset, Seneca ranks 21 for seismic hazard, the 69th percentile within the state. About 9,202 people live in Seneca, South Carolina.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for South Carolina. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Seneca address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Seneca's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.