I might have to call 311 on my neighbors soon for something similar.
According to DPW’s page on bulk trash collection — http://dpw.dc.gov/DC/DPW/Services+on+Your+Block/All+Services/Bulk+Trash+Collection — when you call for bulk trash pickup, an appointment is usually available within 7-10 days. So I guess I’ll give the neighbors another 9 days (in case they did actually schedule a bulk trash pickup) and then call.
There are other people on my street who don’t seem to be aware that yard waste is supposed to go in the same spot as regular trash (see http://dpw.dc.gov/DC/DPW/Services+on+Your+Block/All+Services/Yard+Waste+Collection ). They leave it in front of their houses and it just sits there.