Williamsport's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Williamsport in Seismic Design Category A: Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Nationally, Williamsport ranks above 14% of the 4,875 cities in this dataset for seismic hazard - the 14th percentile.

Williamsport by the numbers

USGS's underlying values for Williamsport: 0.048g peak ground acceleration, 0.099g at short period, 0.04g at 1 second. Within Pennsylvania alone, Williamsport ranks 178 of 193 cities by seismic hazard - the 8th percentile in-state. Williamsport has a population of about 27,628.

Retrofit economics for Williamsport

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 Williamsport 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 Williamsport's figures come from

Williamsport's Category A 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 A does and doesn't tell you about Williamsport.