In the event a customer of the Municipal Sewer Department discharges an unusually large amount of waste daily, an unusually large amount of grease or oil, or waste with an unusually high biochemical oxygen demand the chief sewer official may require the said customer to install interceptors or other preliminary treatment equipment to reduce the objectionable characteristics of the waste to within such maximum limits as he shall prescribe subject to the review of the Governing Body. All preliminary treatment facilities shall be purchased and maintained continuously in satisfactory and efficient operation at the customer's expense. Nothing herein shall be construed to prohibit a special agreement or arrangement between the Governing Body and an industrial concern whereby an industrial waste of unusual strength or character may be accepted by the Municipality for treatment subject to additional rental fees or other charges.