Sustainable Water Infrastructure

Energy Efficiency for Water Utilities

For many municipal governments, drinking water and wastewater plants typically are the largest energy consumers, often accounting for 30 to 40 percent of total energy consumed. Overall, drinking water and wastewater systems account for approximately 2 percent of energy use in the United States, adding over 45 million tons of greenhouse gases annually.

As much as 40 percent of operating costs for drinking water systems can be for energy. 

By incorporating energy efficiency practices into their water and wastewater plants, municipalities and utilities can save 15 to 30 percent, saving thousands of dollars with payback periods of only a few months to a few years.

EPA Webinars on Energy Efficiency for Water and Wastewater Utilities

Determining Energy Usage

As a utility manager, understanding how your water or wastewater utility uses energy and how your electricity provider structures rates will help you better manage both costs and your facility’s operations. The first step is to determine your facility’s baseline energy use. Another important step is to understand what impact energy-intensive processes such as pumping and aeration have for your facility and how you can prioritize improvements.

You can determine baseline energy use using third-party energy audits or self-assessments. Both water utility professionals and technical assistance providers can benefit from the resources provided below.

Tools and Guidance for Water Industry Professionals

Paying for Energy Efficiency Audits

Cutting Energy Usage and Costs

Energy Management

Energy costs often make up 25 to 30 percent of a utility's total operation and maintenance (O&M) costs. They also represent the largest controllable cost of providing water and wastewater services.  EPA works with utilities to manage and reduce costs, using the steps described in its Energy Management Guidebook for Wastewater and Water Utilities. The Guidebook takes utilities through a series of steps to analyze their current energy usage, use energy audits to identify ways to improve efficiency, and measure the effectiveness of energy projects.

EPA's regional offices are working with over 150 utilities to help develop energy management programs using the Guidebook and develop case studies of benefits seen by utilities.

Best Energy Practices

Once you know your baseline energy use and where you are consuming the most energy, you can identify and prioritize energy conservation opportunities resulting in meaningful cost savings.

Case Studies


  • The ENERGY STAR program’s Portfolio Manager includes wastewater and drinking water treatment facilities. The Portfolio Manager  is an interactive energy management tool that tracks and assesses energy and water consumption. The tool can help a utility set targets for investment priorities, verify efficiency improvements, and calculate its carbon footprint. ENERGY STAR offers free online training to help get you started. 

Paying for Energy Efficiency Improvements

  • EPA's Clean Water and Drinking Water State Revolving Funds are important sources of financing for wastewater and drinking water infrastructure. Equipment upgrades to improve energy efficiency and reduce energy use are eligible for funding from these programs.
  • Database of State Incentives for Renewables and Efficiency (DSIRE) Exit - A comprehensive source of information on state, local, utility, and federal incentives and policies that promote renewable energy and energy efficiency. Established in 1995, DSIRE is an ongoing project of the North Carolina Solar Center and the Interstate Renewable Energy Council, funded by the U.S. Department of Energy.
  • U.S. Department of Energy Federal Energy Management Program (FEMP)  - Information on incentives, by state, regarding energy efficiency and renewable energy technologies.

State Efforts to Promote Energy Efficiency

States are developing programs to help public water systems and wastewater treatment facilities better manage their energy use. Examples include:

Related Links

The following links exit the site Exit

Top of Page

Renewable Energy Options

Green power is electricity produced from renewable resources, such as solar, wind, geothermal, biomass, and low-impact hydroelectricity. Buying green power is one of the easiest and most effective ways to improve your organization's environmental performance.

On-site Energy Generation

In addition to consuming energy, wastewater utilities can generate energy. Combined heat and power (CHP), also known as cogeneration, is a reliable, cost-effective option for wastewater treatment facilities that have, or are planning to install, anaerobic digesters. Biogas from anaerobic digesters can be used in a CHP system as "free" fuel to generate reliable electricity and power.

In addition to CHP, utilities can use various alternative energy sources to reduce their dependence on traditional energy sources. Options include solar panels (the most common), wind turbines, fuel cells, and micro turbines. Utilities can purchase and operate their own renewable energy generation equipment or contract with a third-party provider that owns and manages the green power on-site for them.

Purchasing Green Energy

Instead of generating renewable energy on-site, some utilities opt to purchase renewable energy directly from the power grid or by purchasing renewable energy certificates (RECs). RECs are credits sold separately from electricity. They represent the environmental, social, and other positive attributes of power generated by renewable resources and enable organizations to choose renewable power even if their local utility or power marketer does not offer a green power product. Whether these options are available varies based on your facility's location and your electricity provider's offerings.

  • Guide to Purchasing Green Power (PDF)(50 pp, 961 K, About PDF) - The Green Power Partnership is a voluntary program through the EPA that supports organizations by offering expert advice, technical support, tools, and resources to buy green power and reduce the environmental impacts associated with purchased electricity use. Partnering with EPA can help your organization lower the transaction costs of buying green power, reduce its carbon footprint, and communicate its leadership to key stakeholders.

Funding Green Power

  • U.S. Department of Agriculture, Rural Development, Rural Energy for America Program (REAP) Guaranteed Loan Program - This program encourages the commercial financing of renewable energy (e.g., bioenergy, geothermal, hydrogen, solar, wind, and hydroelectric power) and energy efficiency projects. Under the program, project developers work with local lenders, who in turn can apply to U.S. Department of Agriculture Rural Development for a loan guarantee of up to 85 percent of the loan amount.
  • Database of State Incentives for Renewables and Efficiency (DSIRE) Exit - This database contains information on state, local, utility, and federal incentives and policies that promote the adoption of solar technologies. Funded by the U.S. Department of Energy's Solar Energy Technology Program, DSIRE SOLAR is a new component of the DSIRE project that provides solar-specific policy information to consumers, policy makers, program administrators, the solar industry, and other concerned parties.

State and Local Efforts to Promote Green Energy

State and local governments are developing programs to help public water systems and wastewater treatment facilities use renewable energy.

The following links exit the site Exit

  • The Massachusetts Department of Environmental Protection is working on several efforts to integrate renewable energy and green building into their state clean water and drinking revolving loan fund programs.
  • The City of Palo Alto's PaloAltoGreen Program invites customers to voluntarily pay 1.5 cents more per kilowatt. This enables the city to purchase renewable energy certificates. The city uses funds allocated to the purchase of renewable energy to support the growth of "clean energy" technology jobs and renewable energy facilities. Over 20 percent of the city's electric service customers are enrolled.
  • The Washington Suburban Sanitary Commission is embracing wind power as an energy source to run one-third of its drinking water and wastewater operations. Their action places them as one of the Top 30 Local Government partners in EPA's GreenPower Partnership.
  • The West Lafayette, Indiana, Waste Water Treatment Plant (WWTP) replaced two 50 year old anaerobic digesters with a new, efficient, externally pumped mixing system housed inside a new digester building. The building also incorporates a new sludge heating system, with heat exchangers and a boiler, and a co-generation system that uses the digester gas (methane) to generate electricity. The WTTP also allows the city to convert fats, oils, and grease to produce energy at the plant. This innovative waste-to-energy treatment system reduces the plant's overall operating and maintenance costs, decreases the overall carbon footprint of the community, and reduces waste going to landfills.
  • Tualatin Valley Water District in Beaverton, Oregon, purchases green power for 100 percent of its operations, including its headquarters building and outlying pump stations.
  • The Los Angeles County Sanitation Districts in California provide environmentally sound, cost-effective wastewater and solid waste management for over one-half of the population of Los Angeles County by converting biomass into energy on-site.
  • The City of Santa Barbara's El Estero WWTP is an 11-million-gallons-per-day secondary treatment facility equipped with a 4.3-million-gallons-per-day tertiary treatment for recycled water. The plant uses waste gas fuel cell technology to produce nearly one-half of the facility's electricity needs.

Related Resources

  • U.S. Department of Energy, Energy Efficiency and Renewable Energy's The Green Power Network provides information about green power products available through utility green pricing programs throughout the nation.
  • Climate Communities Exit is a national coalition of cities and counties that educates federal policymakers about the essential role of local governments in addressing climate change and promoting a strong local-federal partnership to reduce greenhouse gas emissions.
  • EPA's State and Local Climate and Energy Program provides technical assistance, analytical tools, and outreach support to states and local and tribal communities.
  • The Water Research Foundation's Climate Change Clearinghouse Exit provides resources to water supply utility managers including information about climate change impacts and how these impacts will affect utility operations.

Top of Page