For future uploads, could you make sure that quality checks are done before uploading? The OSM database is not the right place to dumb any messy data and hope that somebody else will clean it up later.  The various QA tools already generated thousands of errors and warnings because of this upload which in turn keeps other mappers busy checking what is going on here. 

Btw, if you say "the task has been set up", this seems to be some sort of mapping within a larger group? In that case there are some guidelines to follow: https://wiki.osmfoundation.org/wiki/Organised_Editing_Guidelines