Does Mount Pleasant, SC need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Mount Pleasant in Seismic Design 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. Nationally, Mount Pleasant ranks above 97% of the 4,875 cities in this dataset for seismic hazard - the 97th percentile.

Mount Pleasant by the numbers

USGS's underlying values for Mount Pleasant: 0.783g peak ground acceleration, 1.217g at short period, 0.36g at 1 second. Within South Carolina alone, Mount Pleasant ranks 9 of 66 cities by seismic hazard - the 88th percentile in-state. Mount Pleasant has a population of about 95,604.

Retrofit economics for Mount Pleasant

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 South Carolina 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 South Carolina.

What this means for insurance

A Mount Pleasant 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 Mount Pleasant's figures come from

Mount Pleasant'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 Mount Pleasant.