I heard that it was effectively a hasmat site for quite some time with spills of several nasty things including mercury. Also I have fond memories from I popped in there to get some random tech things in the 1990s.

Surplus stores have been replaced by online auctions.[1] If you have something really obscure, you might find a buyer on online. Piling the stuff up locally means most of it sits there for years.

Weird Stuff Warehouse. Haltek. HSC. All gone. Excess Solutions moved online. Jameco took down their "open to public" sign. Anchor Electronics [2] is perhaps the only remaining electronics surplus place in Silicon Valley you can visit in person.

[1] https://svdisposition.com

[2] https://anchor-electronics.com/