Bridgeton's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Bridgeton 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 Bridgeton sits at the 82th percentile for seismic hazard among 4,875 US cities.

Bridgeton by the numbers

USGS's underlying values for Bridgeton: 0.202g peak ground acceleration, 0.369g at short period, 0.144g at 1 second. Within Missouri alone, Bridgeton ranks 51 of 135 cities by seismic hazard - the 63th percentile in-state. Bridgeton has a population of about 11,301.

What a retrofit costs in Bridgeton

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Missouri specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Missouri.

Insuring against this, not just retrofitting

A Bridgeton homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Bridgeton's figures come from

Bridgeton's Category D and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category D does and doesn't tell you about Bridgeton.