It's mostly Yiddish, from our significant Jewish contingent.

However, dreck has been in English for a while; Merriam-Webster claims since 1922.

I'll give you a quick list of such words that appear outside areas with large Jewish concentrations:

bupkes* - nothing
chutzpah* - brazenness
farklempt (largely due to a schetch on Saturday Night Live) - choked up
kosher - proper
kvetch* - complain
Mazel Tov - congratulations
mensch - salt of the earth
meshuggina - crazy person
mishmash** - hodgepodge
nosh* - eat, snack
plotz - burst
schlemiel - person who does stupid things (mostly from the Laverne and Shirley TV show theme)
schlemozzel - unlucky person (also mostly from the Laverne and Shirley TV show theme)
schlep* - carry
schvitz - sweat, steambath
schmutz - dirt
tuchis** - butt

The ones with asterisks are probably the most common and might be used without thinking about them being Yiddish. The double-asterisked ones might be used unaware that they're Yiddish.