This was a first. I’ve never seen dense pack cellulose in a basement. The sills had been netted and packed with cellulose. The netting and been pulled down in some places but the packed cellulose remained. This may not have been a problem if not for the surrounding swamp.
The house had essentially been built in a marsh. The moisture was saturating the foundation and wicking up into the sills. Lotsa moisture plus lotsa mold food (plant cellulose) equals lotsa mold. *Yech*
(Sorry about the dark photo…flash had died on the camera).