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Aiming for Net Zero Water Utilities

Water and wastewater utilities use a substantial amount a municipality’s energy. The pumping stations, treatment facilities, and other infrastructure required takes a massive amount of energy to run. As cities work to become climate change resilient, reducing carbon emissions is key. Lowering the energy use of a city’s water utilities can help municipalities reach their carbon reduction goals.


There are many steps a city can and should take when it comes to reducing carbon emissions from water utilities, and in improving energy efficiency. The first steps a city should take, before investing in any new buildings or facilities are laid out by the EPA:


  • Track their energy use
  • Prioritize energy-saving opportunities
  • Identify funding options
  • Develop communication networks
  • Evaluate renewable energy options
  • Develop near- and long-term plans for energy management


Once done, there are many actions cities should take to improve utility efficiency. Cities can start with simple improvements such as lightbulb replacement to LEDs, and light timers. Heavier lifts include improving pumping stations and timing pumping to be most efficient, and updating or adding meters for ratepayers to help detect leaks and other water conservation programs laid out by ACEEE. Efficiency at all levels is important, so installing water meters to help detect leaks for ratepayers and for municipal buildings, and then securing those leaks, should be priorities.


An action plan that leads to these changes are the first steps towards reducing energy use. From there you can implement efficiency in existing facilities and infrastructure, and then consider what new ones you might need to build.


One of the more visible options is the construction of biodigesters. These facilities are often seen as a big investment, but they can also yield big returns. These facilities convert a city’s waste and wastewater into biogas, which is then syphoned off with the gas and used to power the facility itself. These facilities could potentially end up fully powering themselves, becoming net zero energy producers.


There is danger for cities to overreach in their investment by going too big too soon, by building to become an energy producer instead of net-zero energy, your utility or city might put themselves in a situation where the facility is not cost effective. Instead, best practices suggest that cities should look for grants and state funding, and invest in a facility that can partially power itself with the goal of eventually fully powering itself and your water utilities, leading to net zero energy production. A good example of this comes from Grand Rapids MI, which in 2018 broke ground on a $38 million digester, is a good example of a new facility approach to this issue. Only through careful planning and scaling should selling back electricity become a goal for these facilities. Stevens Point WI, is a prime example of retrofitting and scaling older facilities to bring them up to date and aid in reducing energy use for wastewater facilities.

The Water Reuse Roadmap Primer, Water Environment Federation, November 17th, 2016.

Net-zero water management: achieving energy-positive municipal water supply, James D. Englehardt, Tingting Wu, Frederick Bloetscher, Yang Deng, Piet du Pisani, Sebastian Eilert, Samir Elmir, Tianjiao Guo, Joseph Jacangelo, Mark LeChevallier, Harold Leverenz, Erika Mancha, Elizabeth Plater-Zyberk, Bahman Sheikh, Eva Steinle-Darlingm and George Tchobanoglous, Environmental Science Water Research & Technology, June 15th, 2016.

Increasing Participation in Utility Energy Efficiency Programs, ACEEE, August 1st, 2015.

A Survey of Energy Use in Water Companies, Rachel Young, ACEEE, June 1st, 2015.

Public Water Energy Efficiency, Andrew Fishbein, Journal of Science Policy & Governance, June 1st, 2014.

Water and Wastewater Companies for Climate Mitigation Carbon Emissions Assessment & Monitoring tool, Water and Wastewater Companies for Climate Mitigation.
The Energy Performance and Carbon Emissions Assessment and Monitoring (ECAM) tool is a free web-based tool that is designed for assessing the carbon emissions that utilities can control within the urban water cycle

Climate Smart Water, Climatesmartwater.org.
The way to carbon neutrality for water utilities Low-carbon, low-energy solutions in the water sector that make economic sense

The Energy Roadmap Primer, Water Environment Federation, 2011.

Local Technical Assistance Toolkit: Energy Efficiency in Water and Wastewater Facilities, ACEEE.

Energy Efficiency in Water and Wastewater Facilities, EPA, 2013.

Grand Rapids, MI broke ground in the winter of 2018 on a $38 million biodigester. This is part of a much larger process to make themselves an “all-renewable-powered city,” making water utility efficiency and reduction of carbon use a major component. This facility is one piece, but on that will go a long way to reducing the carbon use of their waste water and improving water utility energy efficiency, easing the way for alternative energy sources to power the city- which includes the biodigester itself. And actually, breaking ground on a new facility ended up saving Grand Rapids money over expansion of an old facility.


The City of Stevens Point, WI has long invested and upgraded their wastewater treatment plant to be one of model efficiency, and through a series of upgrades they’ve been able to build a model biodigester facility.


Downer Groves Sanitary District, in Illinois, built cost effective net-zero energy wastewater treatment plant. Through diverse investments over the past 10 years they were able to create this facility and converted what was an energy user into an energy resource.


April 2015 Gresham, Oregon was able to achieve net zero energy status for their wastewater plant, making it one of the first in the USA to achieve this status. They were able to do this through an active mayor and utility director.


For larger metropolitan areas, DC Water is a great example of how to improve efficiency within water and wastewater utilities. They became the first city in “North America to generate clean and renewable energy from wastewater.”


East Bay Mud Municipal Utility District is another great example of how to build, upgrade, and maintain a cost-effective digester facility. Through efficiency and creating a direct line from high biowaste producers to their facility, they’ve been able to create an increasingly efficient plant.


Matthew Braunginn

View all materials, including presentations and briefing book materials, from the Summer 2018 Meeting panel on Net Zero Utilities here.