Waste Not, Want Not: How Innovations in Wastewater Treatment Are Turning Waste into Revenue

Sept. 22, 2014
When it comes to innovation in the water industry, a number of cutting-edge advancements are taking place in the area of wastewater. Many organizations are launching partnerships, working groups and other collaborative efforts to more quickly identify promising new wastewater technologies and shorten the time and costs of driving those innovations into operation.

By Sarah Fister Gale

When it comes to innovation in the water industry, a number of cutting-edge advancements are taking place in the area of wastewater. From harvesting energy from biosolids to using recently discovered bacteria in order to more efficiently remove nitrogen from waste, the latest generation of wastewater innovations has the potential to change the way we manage, pay for and profit from wastewater treatment.

The Cambi anaerobic digestion system utilizes high pressures and temperatures to convert organic materials to biogas more quickly and efficiently than traditional methods.

However, we will only benefit from these new technologies if the industry can discover how to more quickly transition great ideas into functional applications.

The highly regulated and conservative nature of the industry coupled with a tough financial market means it can sometimes take five to ten years or more to propel a new technology into operation, said Jeff Moeller, director of water technologies for the Water Environment Research Foundation (WERF). "That means utilities may miss out on significant opportunities for improved operations or cost savings, and it makes it very hard for new tech companies to make it to market."

Inside a digester at DC Water's Blue Plains facility. Photo courtesy of DC Water.

Increasingly stringent environmental regulations, funding challenges and an aging infrastructure and workforce are also slowing the rate of technology adoption, said Mark LeChevallier, director of innovations and environmental stewardship for American Water.

But that shouldn't discourage facility operators. "Every obstacle is also an opportunity," he said. Many wastewater systems were built in the 1970s, which means they are nearing the end of their lives. As municipalities consider building the next generation of wastewater treatment plants (WWTPs), they have a chance to build more efficient systems by utilizing the latest technologies. "It's an exciting time to imagine how we could manage our processes differently," said LeChevallier.

To overcome the barriers and make the best choices for the future, many organizations are launching partnerships, working groups and other collaborative efforts to more quickly identify promising new wastewater technologies and shorten the time and costs of driving those innovations into operation. Here are some exciting examples currently underway.

Cash Flow Positive in Year One

DC Water's massive new Blue Plains digester is an ideal example of how cross-industry collaboration can lead to successful outcomes. The Blue Plains WWTP produces 60 tanker trucks full of biosolids every day. DC Water's operating team wanted to generate methane from that waste, but because of the massive quantities and their limited acreage, they didn't have the space to build a conventional digester, which requires waste to cure for 20 days before methane can be extracted.

NPXpress is currently being tested at a full-scale WWTP in Jefferson, Peaks, N.J. Photo courtesy of American Water.

DC Water General Manager George Hawkins then learned of a system called Cambi Anaerobic Digestion being used in the UK. Cambi utilizes high pressures and temperatures to accelerate the process and optimize the total proportion of organic materials converted to biogas, which means it requires less time, space and energy to generate methane from waste. "It had never been used in the U.S. and was never built to the scale DC Water needed," he said. But that didn't discourage him.

To overcome the many questions and concerns the utility's board of directors posed about the technology, DC Water's research team partnered with experts from local universities and plants in the UK using Cambi to validate its science and technology and prove that a Cambi plant of this scale could work. In 2010, after five years of research, Hawkins' team convinced the board to invest $460 million of discretionary funds to build the new plant. It is expected to come online early next year, and the savings will start rolling in soon after, Hawkins said.

When fully operational, DC Water's Cambi plant will generate 13 megawatts of energy and halve the amount of biosolids being trucked off site. Photo courtesy of DC Water.

When it is fully operational, the plant will generate 13 megawatts of energy and cut in half the amount of biosolids being trucked off site, which together will save DC Water $10 million per year. It will also reduce the facility's carbon footprint by one-third.

"Beginning in 2015, we will save more money from this plant than we pay on the bond to pay for it," Hawkins said. In other words, it will be cash-flow positive almost from the outset. The bond will be paid off completely within 14 years.

Although it took 10 years to get this innovation into operation, that's pretty remarkable for a plant of this scale, Hawkins said. "It will still be operating a century from now, and from a savings perspective, it is going to have a huge impact."

When fully operational, DC Water's Cambi plant will generate 13 megawatts of energy and halve the amount of biosolids being trucked off site. Photo courtesy of DC Water.

In the NPXpress Lane

American Water is another major utility actively seeking out innovations to improve efficiencies in its operations. To spur progress, the organization has adopted an open collaboration process, called the Innovative Development Model (IDP), intended to make it easier to partner with technology companies. The IDP enables American Water to be more proactive about identifying and accelerating adoption of technologies that have the most promise, LeChevallier said.

One the most exciting innovations to come out of IDP is NPXpress, an American-Water patented process that reduces aeration energy consumption by up to 50 percent and supplemental carbon source by 100 percent. It is currently being tested at two full-scale WWTPs in Mapleton and Jefferson Peaks, N.J.

"Aeration accounts for about half of the energy costs in the typical wastewater plant," LeChevallier said. By changing the operating conditions in the plant to favor organisms that grow in low levels of oxygen, the NPXpress technology is able to create a more stable operating system to reduce the amount of oxygen necessary in that aeration step. "When you need less oxygen, you use less energy," he said.

The technology is currently being installed at six other American Water WWTPs as part of the company's overall initiative to achieve sustainable, energy-neutral wastewater treatment. And in April, American Water signed a worldwide licensing agreement for NPXpress with Abengoa, an international company that applies innovative technology solutions in the energy and environment sectors. It is the first time American Water has licensed an internally-generated technology achieved through its IDP.

"This agreement is a perfect example of innovation and collaboration that helps address challenges in the water industry," said Jeff Sterba, president and CEO of American Water. "The NPXpress technology has demonstrated promising capabilities, and we are excited that others in the industry will benefit from this innovative approach."

SAWS Turns Waste into Revenue

The leaders at the San Antonio Water System (SAWS) utility are constantly looking for innovations that could improve their processes, said COO Steve Clouse. "We are all about finding efficiencies, especially if they are combined with environmental benefits," he said.

That combination of goals drove SAWS to partner with Ameresco, a national renewable energy company, to build a biogas and digester gas purification plant adjacent to their WWTP to harness biogas instead of burning it off using flares.

"We had so much biogas, but it doesn't put out a lot of BTUs," Clouse said. That meant it was cheaper to buy power off the grid than to convert the biogas to energy using conventional turbines or internal combustion systems. But he didn't give up. "It just pushed us to be more open-minded," he said.

Eventually, SAWS found a digester model that could more efficiently convert the biogas to electricity, making it cost-effective. Through a request for proposal (RFP), SAWS found one company willing to build the $7-million facility at their own cost, in exchange for a share in the savings and profits. By September 2013, the power plant was fully operational.

The new facility substantially reduces the amount of sludge that SAWS has to deal with, which cuts disposal costs. The utility also receives roughly $200,000 in annual royalties through the sale of biogas, which reduces its operating costs and helps keep rates affordable, Clouse said.

Clouse is now searching for the next success story. In July, he met with a solar company that uses curved solar panels to incinerate sludge, burning it down to an ash while extracting every bit of gas out of it. "It's purely at the academic level now," he said. "But it could be an exciting step for our future."

Clouse noted that he regularly meets with academic groups and tech startups that all have great ideas, but getting them into operation at a major WWTP is complicated. "Time is always going to be our biggest obstacle," he said. "As a large utility, we can't just build things that haven't been proven. I'd love to move faster, but we can't put that kind of risk on the utility."

Playing TAG

Isle Inc. is trying to help reduce the time and risk that stand in the way of utilities like SAWS that are embracing new innovations. The company acts as a kind of innovation liaison for the wastewater industry, bringing utilities together with wastewater treatment tech companies to more efficiently present new ideas to market. Through Isle's Technology Approval Group (TAG) model, utility leaders come together as a group to hear pitches from tech companies then discuss the technology together and offer feedback to the firms.

Having representatives from multiple utilities review the technology together makes it easier for the tech companies to present their ideas, and it leads to a more robust vetting process, said Bill Kelly, president of Isle. "Getting people to look at the technology and debate the merits is an important part of the innovation process," he said. "If we can accelerate the time it takes to get these ideas into trials and eventually to commercial distribution, both the utilities and the tech companies will benefit."

Several pilot projects are currently moving forward thanks to TAG meetings, Kelly said. Most recently, after attending a 2013 TAG event, five utilities expressed interest in piloting controlled-flow cavitation technology for sludge treatment from a company called Arisdyne. The technology pushes liquid at higher pressures through a smaller orifice to increase the velocity and reduce the static pressure. When the pressure is as low as the boiling point, vapor bubbles are created. When they collapse, it generates shear forces that disrupt agglomerates and lyse cells. This decreases the amount of sludge produced by an anticipated 30 percent and increases the amount of biogas by up to 25 percent.

"It's exciting technology," Kelly said. "And because it has a small footprint, it can be very cost-effective to implement."

Need a LIFT?

The Water Environment Research Foundation (WERF) has also been a leading advocate of wastewater innovation. The non-profit organization's mission is to advance science and technology by funding research projects, conducting technology evaluations, and providing peer-reviewed reports, tools and other resources, said Moeller. "We want to help move innovative technologies to market quicker and make the industry more attractive for venture capitalists and financial institutions," he said.

To do that, WERF, in partnership with the Water Environment Federation (WEF), created the Leaders Innovation Forum for Technology (LIFT), a collaboration initiative that brings together scientists and industry specialists to accelerate adoption of innovative technologies. "By collaborating, we can share the costs and risks associated with new technology so they don't all fall to one organization," Moeller said.

The LIFT program focuses on technological, social, regulatory, and policy innovation that could benefit the wastewater treatment industry. The program includes a Technology Scan component that searches the marketplace for innovation and provides a process to vet new and emerging technologies. The current Scan call for innovative technology submissions is open until Sept. 12, 2014. All of the areas LIFT explores support WERF's vision for the ‘utility of the future,' in which utilities transition from being treatment facilities to 'resource recovery operations.'

The LIFT program brings scientists and industry specialists together to accelerate adoption of innovative technology. Photo courtesy of WERF.

LIFT participants, including over 275 wastewater facility owner representatives, are particularly focused on becoming energy neutral and on recovering nutrients from wastewater for reuse, Moeller said. In one example, WERF is currently working with the San Francisco Bay Area Biosolids to Energy Coalition to provide peer review of three demo projects using different technologies to generate energy from biosolids. "These kinds of technologies have potential to be a game changer for the wastewater industry," Moeller said.

Bacteria In, Energy Out

Another technology that is gaining much attention in both the media and at water industry events is Pilus Energy's ‘bactobots.' Bactobots are genetically-enhanced, highly-metabolic bacteria that digest pollutants in wastewater and turn them into electricity that is captured by an electrogenic bioreactor platform.

One of the unique value propositions of bactobots is that they cut costs by cleaning water while generating energy for use in other parts of the treatment process, said Seth Shaw, chairman and CEO of Tauriga Sciences, which recently acquired Pilus. "The potential economic and environmental benefits are enormous," he said.

Pilus recently launched a multi-phased pilot project with the Metropolitan Sewer District of Greater Cincinnati (MSDGC), which serves 800,000 homes and businesses. "The pilot will be a living laboratory and proving ground," said Biju George, interim director of Greater Cincinnati Water Works, in a letter to stakeholders about the project.

Through the pilot, Pilus plans to tweak the application and ensure that the bactobots are meeting required pollutant removal goals while generating the anticipated level of electricity. "We are very optimistic about this technology," Shaw said. "It is a mission-critical solution that uses a small platform to solve real-world problems."

Still Work to be Done

All of these collaboration models -- and the technologies that emerge from them -- have the potential to dramatically change the way our society deals with wastewater treatment. But even working together, there are no easy ways to overcome the obstacles that lie in the way.

The best thing the industry can do is to keep sharing ideas and look for new strategies to manage risk and improve the speed to market. "Innovation is as much a social process as it is a technical one," Moeller said. "We have to create a culture in this industry that embraces innovation and develop tools and resources that help us all learn from each other."

About the Author: Sarah Fister Gale is a freelance journalist based in Chicago, Ill. Over the last 15 years, she has researched and written dozens of articles on water management trends, wastewater treatment systems and the impact of water scarcity on businesses and municipalities around the world.

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