Energy and Water
Reducing climate impacts, saving money, and saving water – these are the goals of projects and programs that exploit the nexus between energy use and water use. Identifying approaches to integrate energy efficient practices into the daily management and long-term planning of the water sector also contribute to the long-term sustainability of water infrastructure by reducing operation costs and adding to a utility’s bottom line. This page provides information on a number of activities EPA is supporting to improve energy efficiency at water utilities across the country.
- On this page
Basic Information
How much energy do drinking water and wastewater utilities use?
An estimated 3% of national energy consumption, equivalent to approximately 56 billion kilowatt hours (kWh), is used for drinking water and wastewater services. Assuming the average mix of energy sources in the country, this equates to adding approximately 45 million tons of greenhouse gas to the atmosphere.
Does energy efficiency save money?
Yes. The ENERGY STAR program estimates that about $4 billion is spent annually for energy costs to run drinking water and wastewater utilities. If the sector could reduce energy use by just 10% through cost-effective investments in energy efficiency, collectively it would save about $400 million annually.
Does water efficiency save energy?
Yes. If one out of every 100 American homes retrofitted with water-efficient fixtures, we could save about 100 million kWh of electricity per year and avoid adding 80,000 tons of greenhouse gas to the atmosphere. EPA’s WaterSense program is helping to identify water efficient products that will help reduce energy needs to treat and deliver drinking water and wastewater.
Benchmarking Energy Use at Utilities
The ENERGY STAR program recently added wastewater and drinking water treatment facilities to the suite of facilities addressed under its Portfolio Manager - an interactive energy management tool that can be used to track and assess energy and water consumption. The tool can help a utility to set targets for investment priorities, verify efficiency improvements, and calculate its carbon footprint. EPA will also be releasing a best practices guide that will provide examples of how energy-efficient technologies and practices can reduce energy use and save money.
Managing to Maximize Energy Efficiency
Environmental management systems (EMS) involve a set of management processes and procedures that allow an organization to analyze and reduce the environmental impact of its activities. EPA has developed a step-by-step workbook to help utilities use an EMS approach to reduce energy use at water and wastewater facilities and is holding a number of workshops to promote the approach.
- Ensuring a Sustainable Future: An Energy Management Guidebook for Wastewater and Water Utilities PDF (113 pp, 1.2MB, About PDF)
- Innovative Energy Management for Water and Wastewater Systems – New England workshops focus on using EMSs to save energy. Additional workshops will be planned across the country in 2008.
On-Site Energy Generation
Increasingly wastewater utilities are realizing that, as well as being a consumer of energy, they can be a generator. 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 these digesters can be used in a CHP system as "free" fuel to generate reliable electricity and power.
Auxiliary and Supplemental Power
Utilities may want to consider use of various alternative energy sources to reduce need from traditional sources. Some of the options include solar cells, fuel cells and wind turbines.
- Municipal Technology Program Alternative Energy Fact Sheets (at bottom of the linked page)
- The Washington Suburban Sanitary Commission is embracing wind power as an energy source to run 1/3 of its drinking water and wastewater operations. Their action places them as one of the Top Ten Local Government partners in EPA's Green Power Partnership. Learn more at their Power Up! site.
Paying for Energy Efficiency
EPA’s Clean Water and Drinking Water State Revolving Funds (SRF) serve as an important source of financing for drinking water and wastewater infrastructure. Upgrades to decrease energy use are eligible for funding from these programs.
State Efforts to Promote Energy Efficiency
States are beginning to develop programs to assist public water systems and wastewater treatment facilities to better manage their energy use.
- Massachusetts - Energy Management Pilot for Wastewater and Drinking Water Plants
- Massachusetts – the Department of Environmental Protection is working on a number of efforts to integrate renewable energy and green building into their SRF program. Information about this and other related efforts is available on the MA DEP page.
- Wisconsin - The Energy Center of Wisconsin developed a report that looked at energy use at drinking water facilities which included information on steps facilities can take to reduce their energy use. The state Public Service Commission has a link to the final report.