August 2007, Vol. 19, No.8
Energy Management: The Fifth Pillar of Sustainable Infrastructure?
G. Tracy Mehan
A little more than 4 years ago, the U.S. Environmental Protection Agency (EPA) unveiled its “Four Pillars of Sustainable Infrastructure.” These pillars consist of better management, full-cost pricing, efficient water use, and watershed approaches to protection. In developing these pillars, EPA aimed to create a sustainable regime of infrastructure investment and management that looked at water and wastewater facilities in a broader context: the demand side as well as the supply side, the watershed as well as the treatment works, and the responsibilities of ratepayers themselves as opposed to nonuser taxpayers.
At the time EPA released the Four Pillars, it did not emphasize energy management. (Since I was in charge then, I should probably say we did not emphasize it.) I could say that energy management and efficiency were implicit in the pillars for better management and water efficiency, but I would be fibbing to you. These concepts were not on the radar screen at that point.
But now, it is well past time to incorporate energy management and efficiency into the vision of sustainable infrastructure. Global pressures on energy prices due to surging demand in China and India — not to mention environmental concerns — have moved these issues to the top of the water and wastewater industry’s agenda. Energy management might well be on its way to becoming the fifth pillar of sustainable infrastructure.
According to Patrick Clifford, a senior associate at CTE Engineers (Chicago), the water and wastewater industry consumes approximately 3% of the total electricity generated by the U.S. electric power industry. Clifford estimates that energy consumption at water and wastewater facilities will grow by more than 20% in the next 15 years. Given the significant cost of energy for the water sector, as well as the self-evident nexus between water and energy efficiency, it is important to consider energy management as an element of sustainability.
EPA recognized the need to emphasize energy efficiency in the water sector and established a new focus group as part of Energy Star, its flagship voluntary program. According to EPA, drinking water and wastewater systems spend about $4 billion a year on energy to pump, treat, deliver, collect, and clean water. The energy costs to run drinking water and wastewater systems can represent as much as one-third of a municipality’s energy bill. The potential for cost savings is significant.
There are numerous opportunities for saving money while saving the planet. Replacing old pumps, saving water, and switching to renewable energy all are fair game in the quest for a sustainable operation.
Utility managers might look for chances to partner with other utilities to buy energy in bulk, signing contracts for low-cost energy in off-peak hours. Managers may be able to implement changes in treatment design if capital investments are on the horizon.
Water and wastewater systems allocate about 40% of their revenue to debt services and 60% to operating costs. Operating costs typically are divided into three roughly equal parts: personnel, materials, and energy. So energy savings can substantially reduce operating costs.
Given the continued rise in energy prices, alternative or renewable energy sources will become more popular. For instance, we have seen in WE&T and other publications that the use of biogas is becoming more common simply because it is a resource readily available onsite. Biogas is produced by decomposition of matter in anaerobic digestion and can be substituted for natural gas in space heating and process heating applications.
The City of Akron, Ohio, and KB Compost Services Inc. (Akron) have started construction of a $7 million plant that will rely on bacteria to feed on solids, thereby producing gas to power an electric generator.
This first-in-the-nation project will generate multiple benefits. With expansions, it could eventually allow Akron to replace its foul-smelling composting plant presently handling 4542 m3/wk (1.2 million gal/wk) of biosolids at a cost of $6.2 million per year. The remainder will power other operations at the wastewater treatment plant unless the city decides to sell the gas outright. Akron plans to reduce at least some of its $1.35 million in annual electricity costs for wastewater treatment.
Sound energy management yields savings that go straight to the bottom line. These savings represent “found money” for those operations that approach the issue in a systematic way. So, why not add another pillar to the house of sustainable infrastructure?
G. Tracy Mehan is a principal in the Arlington, Va., office of The Cadmus Group Inc. (Boston) and a member of the International Program Committee of the Water Environment Federation (Alexandria, Va.). He was assistant administrator for Water at the U.S. Environmental Protection Agency from 2001 to 2003. Contact him at email@example.com.
Tracy Mehan is a principal in the Arlington, Va., office of The Cadmus Group Inc. (Boston) and a member of the International Program Committee of the Water Environment Federation (Alexandria, Va.). He was assistant administrator for Water at the U.S. Environmental Protection Agency from 2001 to 2003. Contact him at firstname.lastname@example.org.
Editor’s Note: For more information about EPA’s Four Pillars of Sustainable Infrastructure and Energy Star program, see www.epa.gov/waterinfrastructure and energystar.gov/index.cfm?c=government.wastewater_focus.