Fort Irwin Drying Bed Rehabilitation Project By admin | On April 10, 2014 | in Fort Irwin, High Desert Underground, Sewer Treatment, Underground Rehabilitation with Comments Off on Fort Irwin Drying Bed Rehabilitation Project Sewer Sludge Drying Bed Re-construction – CH2M Hill – 2011 Additional Information: Rebuilt 21 sewer sludge drying beds. Re-habilitation included plumbing, sub-liner & liner installation, rock, and sand filter.