As industrial operations go, wastewater treatment is essentially hidden in plain sight. Some 16,000 wastewater treatment plants dot the U.S., serving millions of residential, commercial and industrial “customers” daily. But most of those who benefit from these operations know little about where the closest treatment facility is or what it does. Plant sizes vary, of course, and even though they’re tax-funded, these facilities typically operate as unobtrusively as possible. After all, who but an engineer wants to think about sewage? A treatment plant is expected to run 24/7/365, clean up the nasty stuff (somehow) and move it along. What else is there?
“Plenty!” says WEF, the Water Environment Federation (or “the Federation”), an Alexandria, VA-based not-for-profit, non-lobbying group formed in 1928 to educate and train water-quality professionals. The primary goal of its new strategic plan, for example, is to enlighten everyone—from treatment-plant operators and politicians to citizens—that wastewater is not really “waste.” A cornerstone of this effort is WEF’s “Energy Roadmap,” an initiative that includes training, guidance documents, a recognition program and more. Its basic tenets are summarized in a six-page matrix of best practices. It was created to help stakeholders understand how the treatment of wastewater (a.k.a. sewage) can become energy-neutral or, better yet, energy-generating. Through that understanding, the group hopes to lead the treatment business away from obscurity toward a new role as a sustainability leader.
A map for every driver
“We’ve always used public outreach,” explains Matt Ries, WEF’s Chief Technical Officer, “but never with this kind of focus.” The need for such focus became obvious, after WEF conducted an extensive survey of its 36,000+ membership and non-member water-sector professionals. The findings revealed a feeling among respondents “that there was a lack of leadership and thought leadership” in the water sector, says Ries. “We heard that loud and clear.” In retrospect, he adds, it’s not surprising respondents felt this way. Not only is WEF itself a federation comprised of 75 member associations, countless other factions must be considered with regard to how water is treated, dispensed and used, from geographical and technical to regulatory and political. According to Ries, the need to satisfy all of them has long been a significant challenge to large-scale initiatives.
The first page of WEF’s Energy Roadmap matrix section outlines in simple terms
the steps that wastewater treatment plants can take to achieve sustainability.
As a result, WEF revamped its strategic initiatives last year to include one that commits the Federation to driving what, it believes, is the water sector’s critical need for innovation. Conceptually, this began with its WATER’S WORTH IT® campaign (www.waters-worth-it.org) that “stresses the inner-connectivity between all water bodies and sources,” according to Ries. Complementing this work are “sector-wide initiatives to improve water access, to facilitate breakthrough concepts about resource-recovery and, for wastewater, the nutrients and energy that can be recovered from it. The one area we have specifically called out is about inspiring and supporting a movement toward an energy-positive water sector.”
Understanding the need to satisfy the sector’s many stakeholders, WEF chose to create “a high-level, easy-to-use, non-prescriptive framework to push people in the right direction,” says Barry Liner, Director of WEF’s Water Science and Engineering Center. “We want to become energy-positive, but one of the issues facing utilities is what to do first.” For guidance, Roadmap creators looked at the Smart-Grid Maturity Model (www.sei.cmu.edu/smartgrid) from the electric industry and saw a shift from centralized generation and transmission to a decentralized approach “similar to our sector’s move from waste disposal to resource recovery.”
In wastewater, this journey involves changing the perception of a treatment plant’s main input—raw sewage—from useless waste to an energy-producing commodity that has value. One of the main ways wastewater treatment plants can use sewage to generate energy is through anaerobic digestion. In this process, microorganisms break down biodegradable material, which includes most components in sewage, without oxygen. The digestion process makes biogas, which can then be burned to generate electricity or used for other purposes.
The anaerobic-to-biogas process is not new, but is not in wide use. Most wastewater treatment plants are built around the traditional aerobic/activated sludge process, which involves biological treatment of sewage and a settling period that leaves behind solids that must be disposed. According to WEF’s Biogas Data project (www.biogasdata.org), about 1230 waste-water plants in the U.S. have anaerobic digesters, 837 of which use the biogas for energy and 292 of which generate electricity from the biogas. Another 74 deliver electricity to the grid, and 25 deliver biogas directly to pipelines. A few more have digesters, says Liner, but use them only for storage. He points out that anaerobic digestion is not the only way treatment plants can generate energy. Other technologies include gasification of biosolids and the production of ethanol and other biofuels from algae-based processes. “There’s also small-scale hydro power,” he notes, “but right now, only a very small number of plants are energy-positive at all, so there’s a lot of opportunity here.”
The addition of a new low-emission biogas turbine (at left) made it possible last year for the Oakland, CA, East Bay Municipal Utility District to become the first net-zero wastewater treatment plant in North America.
New directions needed
WEF’s Roadmap acknowledges the great leap needed for most plants to reach “energy-positive.” The document itself uses a straightforward, easy-to-grasp approach to outline the many steps most operations would have to take to become more sustainable. Many of the steps are universal enough to be instantly recognized by any industrial professional who has ever participated in an operational improvement effort.
“We looked at the first, middle and advanced steps,” recalls Liner. “Then we put this framework together, a lot of which has nothing to do with putting in any energy-conservation or any generation equipment. It talks about how you need to have a visionary and a champion to run it. You need to communicate to staff and empower staff to shift the culture. Then we get into more technical things, such as conserving energy, which is demand-side management, and on the supply side, which is energy-generation. The last topic area is ‘Innovating for the Future,’ where we offer ways to keep moving forward.”
Liner advises that the first major leap for many plants should be to address their energy use. This means “you must get your electric bills and look at them,” he says. “A lot of times, the bills go to finance and no one in operations ever sees them. As a result, operators have no idea how their bills are set up and how they could conserve, such as shaving peak usage.” The Roadmap’s energy-management theme includes section headers like “Initiate an Energy Audit” and “Set Goals for Reducing Energy Use and Cost,” which are followed by bullet points, but not cumbersome detail. “We say to initiate an audit, not to what extent,” says Liner. “It doesn’t prescribe that you have to get out there and actually set up current meters and see what the voltage drop is across something. It can just be a checklist or whatever is appropriate for your situation.”
Liner and Ries believe that the Roadmap will best further the universality of WEF’s goal to drive innovation by avoiding technicalities, formulas and anything that resembles a requirement. “People are happy this is not a thousand-page engineering document with a ton of equations,” says Ries. “And it’s not a certification program, so you don’t have to get a third-party audit to show that you’ve gone through the steps. It’s a non-threatening approach that allows you to make big changes.”
Granted, “big” is a relative term. Most of the nation’s treatment plants are, in fact, considered “small” operations, treating 1 million gallons per day or less. “And a lot of small plants may only have a couple of people running them,” says Ries. “These might be the same people who plow the streets and mow the lawns. So you might not have the technical expertise required to run a more complex system that recovers energy from wastewater. There are also a lot of cash-strapped utilities that, for various reasons, can’t raise the capital or raise their rates. And they may be dealing with aging infrastructure. But there are solutions to all these barriers,” he says, including “public/private partnerships, where another industry or ESCO [energy service company] might come in and partner with the utility through a long-term lease on equipment or a share of the energy savings.”
Liner points to the fact no investment is required for Roadmap users to implement basic efficiencies that the document outlines as first steps. “Changing your repair and rehab program or addressing when you fill up a tank or when you run a pump, for example, can save you money on the demand side. Some of the generation opportunities require money, but on the conservation side, you can simply save.” And WEF is betting that if the Roadmap reaches its target audience, good things will happen. This means getting it to utility managers, contractors and operators, a group, Liner adds, that can get things rolling just by asking to see their plant’s utility bills. “The Roadmap is written at so high a level,” he says, “it’s useful for water professionals, their customers and their local politicians.”
The document also includes new terminology that WEF hopes will get all stakeholders thinking along the same lines. “We want to reach the point where treatment plants are thought of not as energy consumers, but energy generators,” says Ries. “So the first page of the Roadmap makes the distinction that wastewater treatment plants are not waste-disposal facilities, but water-resource recovery facilities that produce water, nutrients and energy. We know that part of our success will come through the naming, so this is one thing WEF is doing now. As of January, we are ‘water- resource recovery facilities,’ and this is the term we’ll use in all of our publications.”
WEF will also work more closely with its partner organizations in 2013 to keep its revamped strategy highly visible to all in the water-treatment community. The hoped-for effect, of course, is that the Roadmap and the Federation’s other outreach efforts will be accepted not just as another collection of good ideas, but as real-life, workable strategies. As Ries describes it, a minimal goal is that “the concept of energy conservation and energy generation becomes a part of the everyday conversation and culture of treatment plants at all levels.” But he hopes for more. “We’ve been working on a sustainability initiative at WEF for over five years,” he says, “and we talk about the day when ‘sustainable approaches’ or ‘sustainable water management’ become phrases we don’t use anymore, because when you use a term like ‘sustainable,’ you set it aside from the conventional. It’s when sustainable becomes conventional and when energy-generation becomes the standard that we’ll know we’ve succeeded.” MT
To learn more about the Water Environment Federation or to download your copy of the “WEF Energy Roadmap, V1.0,” visit www.wef.org.
Water professionals speak in reverential terms about the wastewater treatment facility run by the East Bay Municipal Utility District (M.U.D.) in Oakland, CA. With regard to sustainability, “These people have already succeeded,” says Barry Liner, Director of the Water Environment Federation’s (WEF) Water Science and Engineering Center. “They had visionaries 20 years ago who started this plant. Now it’s the first recognized wastewater utility in the U.S. to become energy-positive,” a feat it achieved in February 2012.
East Bay M.U.D. became energy-positive by adding organic waste to its normal sewage intake and sending the mix to its anaerobic digesters to generate biogas, which it then burns for electricity. The added organic waste includes food-processing and agricultural waste, fats, oils, grease and food scraps, much of which previously went to landfill. The plant’s digesters turn the mixed wastes into nutrient-rich biosolids and biogas, an energy-rich mix of methane and carbon dioxide. A new 4.6 MW turbine helps the plant take advantage of all the gas it produces and create enough extra electricity to sell a portion back to the grid. The process is so successful that the plant is bringing on an additional digester that has nothing to do with wastewater. “It will simply process organic waste and generate more power,” says Liner.
Liner is pleased to note that WEF’s new Energy Roadmap(written to help water treatment plants become more sustainable and using East Bay as an example of the potential) can also help this highly successful operation. “The interesting thing about East Bay is that, because they had all this organic waste, [energy-] generation was the low-hanging fruit for them,” he says. “But they never really looked at energy conservation on the demand side.” He adds that the cutting-edge facility sees the Roadmap as an effective way to help ensure that its daily operation is as energy-efficient as it is energy-positive.