D.C. Turns Poop to Power

The District of Columbia Water and Sewer Authority (D.C. Water), "which also treats sewage from much of the Maryland and Northern Virginia suburbs, recently became the first utility in North America to use a Norwegian thermal hydrolysis system to convert the sludge left over from treated sewage into electricity," writes Katherine Shaver for The Washington Post.

In a Washington Post article last year on the process, Ashley Halsey III wrote that "D.C. Water is the (local) electricity company’s No. 1 customer. By converting poop to power, the water company will cut its Pepco bill by about one third and reduce by half the cost of trucking treated waste elsewhere." The electricity generation from the biomethane produced through anaerobic digesters amounts to 13 megawatts of power.

Anaerobic digestion is not what's new here—it's the "'pressure cooker' technology that can fit such a system in the relatively tight confines of an urban treatment plant," writes Shaver. D.C. Water officials say it’s the largest of its kind in the world. Click here to view the graphic.

“It’s a huge deal on so many fronts,” D.C. Water General Manager George S. Hawkins said after Wednesday’s [Oct. 7] official unveiling of the system. “It’s a public utility leading the world in innovation and technology. We have private and public water companies coming from all over the world to see this.”

From the 2014 article:

“It could be a game changer for energy,” said George Hawkins, an environmentalist who became general manager of D.C. Water. “If we could turn every enriched-water facility in the United States into a power plant, it would become one of the largest sectors of clean energy that, at the moment, is relatively untapped.”

In addition to producing biomethane for electricity generation, the plant produces a "Class A compost-like substance (that) could show up in the next year or so on the shelves of Home Depot as a soil nutrient for home gardens, officials said," adds Shaver.

When you consider the "toilet-to-tap" wastewater recycling process out west, one is left with the recognition that sewage treatment centers may be one of America's last unexploited resources, although this exploitation is environmentally sustainable. Not tapping it would be a shame.

Correspondent's note: See the Department of Energy's Alternative Fuels Data Center to distinguish renewable natural gas from biogas.

Hat tip: Kenyon Karl, Sierra Club