Coatesville, PA: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Coatesville is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Coatesville in the 58th percentile nationally for seismic hazard - higher than 58% of the 4,875 US cities USGS was checked against here.

Where Coatesville sits in Pennsylvania

USGS's underlying values for Coatesville: 0.11g peak ground acceleration, 0.193g at short period, 0.048g at 1 second. Within Pennsylvania alone, Coatesville ranks 2 of 193 cities by seismic hazard - the 99th percentile in-state. Coatesville has a population of about 13,390.

Retrofit economics for Coatesville

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 Pennsylvania 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 Pennsylvania.

Insuring against this, not just retrofitting

A Coatesville 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 Coatesville's figures come from

Coatesville's Category B 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 B does and doesn't tell you about Coatesville.