Energy and Water/Wastewater Infrastructure

An estimated 3% of national energy consumption, equivalent to approximately 56 billion kilowatt hours (kWh), is used for drinking water and wastewater services. This equates to adding approximately 45 million tons of greenhouse gas to the atmosphere. Energy is usually one of the top three expenses at municipally-owned water and wastewater treatment facilities, frequently as much as 1/3 of the budget, and these facilities are often the largest energy users in their municipalities. Proper energy management at these facilities is the best way for water system operators to save money and energy AND have a positive impact on air quality and energy system reliability.

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.

Water Efficiency is Linked to Energy Efficiency

If one out of every 100 American homes was 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. As of October, 2008, more than 50 facilities around New England have taken advantage of the tool to see where they stand.

ENERGY STAR Portfolio Manager for wastewater and drinking water treatment facilities.

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, 1.9MB, about PDF)

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.

CHP for Municipal Wastewater Treatment Facilities

Auxiliary and Supplemental Power

Utilities may want to consider using various alternative energy sources to reduce the need of energy from traditional sources. Some of the options include solar cells, fuel cells and wind turbines.

Municipal Technology Program Alternative Energy Fact Sheets (See "Energy Conservation and Management" at bottom of the linked page)

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.

Clean Water State Revolving Fund

Drinking Water State Revolving Fund

State Efforts to Promote Energy Efficiency

Some states have 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

Regional Example: Lowell, Massachusetts

As energy costs began to steadily increase in the 1990’s the Lowell Regional Wastewater Utility (LRWWU) began focusing on energy efficiency, tracking energy costs and cost effective process improvements. As shown in the Energy Use Reduction Chart, since 1996 the facility has decreased energy use by over 35% through investments in high efficiency equipment and adopting an approach that makes energy efficiency a priority.

Some of the key areas that have made the LRWWU energy program so successful include:

Making a commitment to incorporating energy efficiency in system designs and operations.
Creation of an energy management team within the organization to review energy savings opportunities.
Tracking energy use and costs on a regular basis.
Performing periodic energy audits.
Setting energy saving goals and monitoring results
Taking full advantage of utility energy incentive programs to provide evaluations and support for project implementation.
Making use of on-site emergency generators to participate in demand response programs.

As the LRWWU continues to refine their program, they have embraced the "Plan-Do-Check-Act" approach in the EPA’s new Energy Management Guidebook for Water and Wastewater Utilities. The utility is currently pursuing new energy-related projects including more efficient blowers, green roofs on all buildings, solar panels for electricity, and solar heat for some buildings.

This chart shows annual energy use at the Lowell Regional Wastewater Utility from 1994-2007. Chart courtesy of LRWWU.