Does East St. Louis, IL need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, East St. Louis is Category D. High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. Rank it against the rest of the country and East St. Louis sits at the 84th percentile for seismic hazard among 4,875 US cities.

East St. Louis by the numbers

The raw figures: peak ground acceleration 0.269g, short-period spectral response 0.465g, 1-second spectral response 0.163g. Among 330 Illinois cities in this dataset, East St. Louis ranks 26 for seismic hazard, the 92th percentile within the state. About 17,808 people live in East St. Louis, Illinois.

Retrofit economics for East St. Louis

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Illinois. 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 East St. Louis address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced East St. Louis'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.