No statement contained in this chapter shall be construed as prohibiting any special agreement between the Village and any person or between the Commission and any person whereby an industrial waste of unusual strength or character may be admitted to the Village sewerage system, either before or after pretreatment, provided that there is no impairment of the functioning of the wastewater treatment facilities by reason of the admission of such wastes and no extra costs are incurred by the Village or by the Commission without recompense by the person. All special agreements between the Village and any person which affect the wastewater treatment plant shall be reviewed by the Commission; similarly subject to Village review. The user charge system established through this chapter takes precedence over any preexisting agreements between the Village, Commission and any person which may be inconsistent with the governing regulations of this program.