Energy Resilient Municipal Water and Wastewater Operations—A One Water System Review

The small, medium, and large municipal water and wastewater systems serve the populations from less than 1,000 to more than 1,000,000 in the U.S. (and worldwide), where the municipalities operate with stringent financial resource(s) to conduct water systems. The One Water concept of an integrated water management (IWM) at municipal operations would include resource water (surface water and/or groundwater); drinking water treatment; metered, potable water distribution; wastewater (sewage, I/I, stormwater, pre-treated industrial, and the leachate-wastewater and septage, as locally applicable) collection; wastewater treatment and resource recovery; water-reuse; and the permitted disposal of treated effluents back to watershed. The total energy use for effective operation of municipal water infrastructure (MWI) is significant; an estimated U.S.-wide average of (approximately) 4.75E+06 J/m³ (5,000 kWh per a million-gallon) water-processed is expended. This energy use can be reduced or conserved via an effective design (or a rehabilitation) of various water-systems including the application(s) of renewable energy-systems; thus, the water-systems can be made operating with net-zero-to-net-positive-energy into the future. Author has accomplished energy resilient water-systems at various municipal water operations. This paper includes identification and explanation of various elements of municipal water infrastructure; energy-use by the components of water systems; energy efficient and environmentally compliant design of unit and process operations; recommendation on effective application(s) of renewable energy systems; the net-zero-energy design and making the water systems net-positive-energy into the future; discussion of a few case studies; and resulting cost-effective and environmentally sound operation of a Municipal One Water System (MOWS) into the circular-economy.