The department shall, upon request of a facility subject to the regulations concerning operation under a permit-by-rule for treatment of wastes which are hazardous solely due to the presence of inorganic metals listed in paragraph 2 of subdivision (a) of Section 66261.24 of Title 22 of the California Code of Regulations, allow the facility to use the technologies specified for aqueous wastes on a mixture of aqueous wastes and wastes which are nonaqueous solely due to the presence of nonhazardous suspended solids at concentrations greater than 1 percent, unless

the department determines under the circumstances that the treatment would not qualify for the lower risk status to which permit-by-rule is intended to apply.