PORT TOWNSEND — Next month, civil engineer Kathryn Neal will present an illustrated discussion on Port Angeles’ bluff erosion near its now-closed landfill site.

Her talk will be at 4 p.m. Saturday, Dec. 3, at the Quimper Unitarian Universalist Fellowship hall at 2333 San Juan Ave., Port Townsend.

Sponsored by the Jefferson Land Trust Geology Group, the talk is free and open to the public, although a $5 donation is appreciated to defray expenses.

The city of Port Angeles created a 25-acre dump in 1947 on a blufftop near its western shoreline, between Ediz Hook and the Elwha River.

Throughout the next 60 years, the site evolved into a 70-acre landfill with numerous waste containment cells. It was closed in 2007.

Wave action at this beach site had been continuously eroding the 135-foot-high bluffs.

In June 2011, a small exposure of garbage from one of the landfill cells was hanging over the edge of the bluff.

Further erosion could easily have resulted in a large release of garbage onto the beach below, because there were only 11 to 15 feet of bluff and native vegetation between the eroded bluff face and a 60-foot-deep pit of municipal solid waste.

Neal will review the geologic setting, bluff retreat rates and sediment contribution from the bluffs to Ediz Hook, the history of public works construction at the site, wave energy and beach morphology studies that the city conducted, and summarize design alternatives that the city considered before deciding to relocate the whole landfill.