Old Tappan's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Old Tappan in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Old Tappan ranks above 66% of the 4,875 cities in this dataset for seismic hazard - the 66th percentile.

Where Old Tappan sits in New Jersey

USGS's underlying values for Old Tappan: 0.186g peak ground acceleration, 0.299g at short period, 0.062g at 1 second. Within New Jersey alone, Old Tappan ranks 2 of 194 cities by seismic hazard - the 99th percentile in-state. Old Tappan has a population of about 6,342.

What a retrofit costs in Old Tappan

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 New Jersey 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 New Jersey.

What this means for insurance

A Old Tappan 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 Old Tappan's figures come from

Old Tappan'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 Old Tappan.