(1) All sanitary sewage from new or expanded uses shall be discharged into a public sewage collection and treatment system when such facilities are currently available or can reasonably be made available at the lot line and have adequate capacity to handle the projected waste generation.

(2) If the public collection system is not at the lot line, but can be extended in the public right-of-way, the collection system shall be extended by the owner and the new or expanded use connected to the public system. Such extension shall be required if the public system is within 100 feet of a new use with a design sewage flow of less than 500 gallons per day or within 300 feet of a new use with a design sewage flow of 500 or more gallons per day and the system has adequate capacity to accommodate the additional flow. The Planning Board may waive this requirement if the use is already served by a properly functioning subsurface disposal system that is properly sized for the projected flows, provided that connection to the public system shall occur if and when the subsurface system needs to be replaced.

(3) If the public system cannot serve or be extended to serve a new or expanded use, the sewage shall be disposed of by an on-site sewage disposal system meeting the requirements of the Subsurface Waste Water Disposal Rules.

(4) When two or more lots or buildings in different ownership share the use of a common subsurface disposal system, the system shall be owned and maintained in common by an owners' association. Covenants in the deeds for each lot shall require mandatory membership in the association and provide for adequate funding of the association to assure proper maintenance of the system.

(5) Industrial or commercial wastewater may be discharged to public sewers in such quantities and/or of such quality as to be compatible with sewage treatment operations. Such wastes may require pretreatment at the industrial or commercial site in order to render them amenable to public treatment processes. Pretreatment includes, but is not limited to, screening, grinding, sedimentation, pH adjustment, surface skimming, chemical oxidation and reduction and dilution. The pretreatment standards shall be determined by the Portland Water District.