Dry cleaners do not require a permit for the discharge from their washing machines if they do not use their washing machines to wash industrial, hospital/clinic, or commercial uniforms, wipers, mats, or mops; industrial, hospital/clinic, or commercial linens; diapers; or carpets, but may not discharge cleaning solvents (e.g., perchloroethylene), including solvents in their cooling water discharge.
360 CMR, § 10.007