OSHA requires washing facilities when your crew handles contaminants that can harm them, not toilets alone for every job. Under 1926.51(f), employers must provide adequate washing facilities for employees in operations where contaminants may be harmful, and those facilities have to sit near the worksite so people can remove the stuff. Concrete, wet cement residue, and treated lumber chemicals count. Your auditor is citing that sanitation rule, not inventing something outside the standard.
1926.51(c) covers toilet counts by crew size. For 35 workers you already need more than one standard unit under the toilet table. That toilet rule does not replace washing. A seat and tank alone do not meet the washing requirement when contaminant exposure is present.
On a six-week foundation job with concrete and treated lumber daily, put a dedicated handwash station with soap and rinse water next to the toilets, and keep it on the same servicing route so water and waste get swapped. Built-in sanitizer gel on a unit helps between uses, but auditors want real wash capability when concrete and wood preservatives are in play.
