A Future Without Waste

By Art Umble, wastewater practice leader, MWH

What the road to full resource recovery looks like and how to get on it.

"There is no waste in our future!” That was the declaration of Water Environment Federation President Ed McCormick at this year’s “Energy Positive Water Resource Recovery” symposium, co-sponsored by the National Science Foundation, the U.S. EPA, and the U.S. Department of Energy (DOE). Though a terrific challenge to us all, it’s not out of reach if we start today and take responsibility for leading the charge. The question is where do we start? Much of the answer lies in changing behavior away from “business as usual” and toward a radical embrace of full recovery of energy, water, and nutrients resources — primarily in that order.

Clearly, climate change is advancing due to our reliance on fossil fuel energy sources, and this has taken us down a dangerous path. In fact, the Japanese Meteorological Agency recently published that 2014 was the hottest year on record. In the U.S., the National Oceanic and Atmospheric Administration recently announced that the carbon dioxide (CO₂) concentration in our atmosphere has now exceeded 400 ppm, and it’s climbing at a rate historically unprecedented. A concentration of 450 ppm has been identified by the Intercontinental Panel on Climate Change as the threshold for our planet warming to a level of 2° C over baseline, at which the predicted consequences are not just dire but irreversible. Some are already underway. For example, the oceans are sinks to one-quarter of the atmospheric CO₂. The acidification resulting from absorbing more and more CO₂ is having detrimental impacts on shellfish — unable to form their shells — and a growing imbalance in global ecology is already emerging.

Energy-Water Nexus
To change our ways, socio-political and technical approaches abound. In the socio-political arena, some are making the bold call for global divestment from companies that promote fossil fuel development, claiming these companies essentially “own climate change” and should be accountable. On the technical side, accelerating development of renewable energy sources is the challenge. In the wastewater treatment industry, for example, this takes the form of recovering energy from raw organic matter in wastewater, in which about 10 times the energy required to operate today’s conventional treatment plants is embedded. Can this be captured and recovered?

Yes, numerous plants around the globe are recovering this energy. In fact, some are now producing more energy (in the form of electricity) than they need to operate, returning “surpluses” back to the power grid. As an example, today the East Bay Municipal Utility District (MUD) in Oakland, CA is at 130 percent energy-positive. The Strass, Austria, wastewater treatment plant is now at 170 percent energy-positive. Ithaca, New York’s plant is at 100 percent (neutral). How are they doing this? In East Bay’s case, they are taking in large quantities of high organic strength wastes (fats, oils, greases, and other food wastes) and “co-digesting” (anaerobically) these with sludges generated from within the plant from treatment of the wastewater. In the case of the Strass plant, they are applying aggressive, cutting-edge treatment approaches including carbon diversion/sequestration and mainstream deammonification technologies. Other plants are experimenting with algae production from wastewater and co-digesting the harvested algae to increase biogas production for energy. All of these activities are contributing to shifting our energy balance away from the primary climate change driver, fossil fuels.

Though our energy imbalance is causing climate change, the effect is significant changes to the global water-balanced budget. Climatic patterns alter rainfall distributions and intensities, which are already having a negative impact on water quantity and quality. This is placing higher demands on the limits of treatment technology. Many are promoting the acceleration of wastewater reuse, particularly in water-scarce regions, to offset depleting supplies. Others believe that desalination (including seawater, brackish groundwater, and wastewater) must be of highest priority since recent generations of membrane technology have dramatically reduced the energy inputs required. (Desalination of seawater requires about 3.5 kWh/m³ treated; desalination of wastewater about 1.7 kWh/m³.)

If we are to turn the tide against our “business as usual” inertia, most agree that reducing demand for both energy and water is paramount, followed by an intensification of innovative technology focused on all facets of resource recovery from all waste streams. This “intensification” refers to technology that is disruptive and transformative. In today’s world, technology is truly disruptive only if it reduces TOTEX (total expenditure from “cradle-to-grave” of the system) by a minimum of 30 percent over the course of its useful life, and physically fits into spaces smaller than conventional technologies. In wastewater treatment, examples include granulation technology, biocatalyst technology, highrate ballasted flocculation technology, deammonification technology, and sludge-reduction technology. Though disruptive indeed, few have gained a mature foothold in the marketplace. This means that both fundamental and applied research must increase in importance and be appropriately funded through both public and private sources.

Innovation At Work
But encouraging signs have recently been seen to address this, coming from the U.S. DOE. For example, Stanford University, in collaboration with the Colorado School of Mines, received a multi-million DOE grant to implement the “ReNUWIt” (Reinventing the Nation’s Urban Water Infrastructure) research center, focusing on engineering energy-efficient wastewater reuse. Interestingly, this “engineering” includes both technical and social aspects of systems integration for sustainable outcomes. The ReNUWIt center illustrates a methodology for moving innovative ideas forward: 1) research drives development; 2) development drives demonstration; 3) demonstration drives deployment. This is known as “R3D” in the vernacular.

In essence, the ReNUWIt research center represents a “live” example of what is known as a “test bed” for technology adoption. Right now a movement is afoot within federal agencies (EPA, DOE, Department of Defense, Department of Agriculture, U.S. Geological Survey, and others) to partner with academia and private business to construct a series of three to five regional water and wastewater “technology test bed” sites throughout the U.S. and Canada. These test beds would serve as “plug & play” facilities for anyone wishing to prove their technology within an open, transparent, standardized test protocol platform that immediately publishes critical performance results data to any who desire it. This is believed to be critical in streamlining the advancement of a new technology into the marketplace.

Because regulatory drivers have traditionally stifled innovation, the EPA is recognizing that it too must follow the innovation curve. The EPA’s participation in the “test bed” conversation has been applauded within our industry because it shows the EPA is rethinking its position on regulatory control: Early adopters may receive “relaxed” standards, such as “performance-based” standards and incentives; as the technology matures, more prescriptive limits can be imposed.

So what does this all mean for us right now? Historically, we humans tend to change our behaviors when our standards for living are threatened by some outside force, and furthermore, only when that force becomes a crisis. We tend to be comfortable with “business as usual” until the crisis hits and our backs are against the wall. Only then do we engage and respond, and to date, our innovative nature has always “saved the day” from catastrophe. Unfortunately, such luxury does not exist with climate change. We must act now. First, we must reduce our demand for energy and water and continue shifting our necessary consumptions to renewable resources. Then, we must intensify our efforts to recover all resources from all waste streams. To accomplish this, we must engage every opportunity to test every innovative idea efficiently and thoroughly. Public and private entities must partner to fund and drive the R3D process. We must adopt flexible regulatory frameworks that promote, not hinder, innovation. Not surprisingly, this is really more about leadership than it is about instituting mechanisms to advance innovative technology. Do we have the commitment within ourselves to lead to a sustainable future, one with no waste?

About The Author

Dr. Umble is the wastewater practice leader for MWH and provides technical analysis and support to design teams for new and rehabilitated municipal wastewater treatment facilities. Umble is a leader in initiatives promoting environmental stewardship, serving as a technical advisor/reviewer for Water Environment Research Foundation, International Water Association, and the WateReuse Foundation collaborative research projects.