Denver has had this for decades. I’m not sure how much it reduces pollution, though. And the bay area doesn’t exactly get cold in the winter, so I wonder how many people use a fireplace anyway.
I guess my $1100 heating bill last January was because of all my computers running day and night. True, it’s not seriously cold like in Minnesota or somewhere, but people use their fireplaces all winter. On a still day with no wind, there is a blue haze hanging over the valleys from all the wood smoke. It’s always seemed very ironic to me that the same liberals who want to ban smoking, are oblivious to the pollution from their precious fireplaces. This is one law I would like to see passed.