Construction and demolition debris (CDD) fines are a byproduct of mechanized CDD recycling. Fines contain soil, wood, gypsum drywall, concrete, paper, and plastic and they often contain trace chemicals that exceed regulatory thresholds. We examined water washing as a means of CDD fines beneficiation to lower trace contaminants levels and achieve acceptable physical properties for road base use applications. Nine sources of CDD fines from across the US were processed to remove the finer and floatable fractions and retrieve a coarse aggregate. The targeted material, washed coarse aggregate, was on average 30% (10–49%) by mass. The concentrations of arsenic, lead, benzo(a)pyrene (BaP), and sulfate in nearly all samples decreased following washing, while the bulk density and specific gravity increased. A comparison of washed coarse aggregate samples’ chemical concentrations to risk thresholds yielded varied results; in some samples the lead and arsenic concentrations significantly decreased lower than the most strict thresholds. In other samples although the BaP concentrations decreased they were still higher than the least strict thresholds. The physical properties of the washed coarse aggregate (specific gravity, density, and absorption) were compared and found like recycled concrete aggregate (a commonly used road base material). However, the washing process removed the fine fraction from the aggregate matrix resulting in a poorly graded material for road base/structural fill. Washing as a treatment method to reduce trace contaminants is promising for recycling decision makers aiming to more sustainably manage their fines, however, more physical property testing are needed to confirm its structural suitability.