As part of the 浪花直播 Center and 鈥檚&苍产蝉辫;, Choke Point: Port Cities will examine how Oakland, California, and Shenzhen, Guangdong Province, are responding to interlinked water, energy, and pollution challenges. These multimedia reports are meant to inform exchanges and convenings in 2016 to share among leaders of both cities and others like them around the Pacific Rim.
Although treating wastewater generally ranks alongside police and fire safety, schools, and transit as the top priorities of any sensible city hall, new ideas about cleaning up sewage almost never attract headlines or TV airtime. In its 90-year history, for instance,The New Yorker, the most urbane and expansive magazine in the country, has never published a feature article on sewage treatment.
鈥淲astewater really isn鈥檛 waste鈥
It has taken to change that. A seven-year-old treatment plant in Orange County that recycles wastewater to recharge drinking water aquifers 鈥 and generates most of its own energy 鈥 is attracting international attention for its design and effectiveness. City authorities in Modesto and Turlock are working with the Del Puerto Water District in Patterson to recycle wastewater from two municipal treatment plants to supply almond, fruit, and vegetable growers with , equal to a third of the water district鈥檚 annual demand.
Here in Oakland, the 64-year-old regional wastewater treatment plant has elevated an essential urban service to a new level of innovation and civic importance. The East Bay Municipal Utility District (EBMUD) treatment plant, a formidable assembly of mixing tanks, pumps, and pipes on the city鈥檚 north side, has 11 megawatts of biogas-fueled electrical generating capacity, more than the plant鈥檚 power demand. The excess power is sold to the Port of Oakland, and in electric expenses a year.
The EBMUD plant produces more electricity 鈥 11 megawatts a year 鈥 than it consumes
According to , the industry鈥檚 premier trade magazine, the Oakland plant is the first in the nation to sell extra electricity produced entirely from waste back to the regular grid.
Equally significant is that the plant鈥檚 gas-producing operations, generated from digesting sewage, food waste, and other biodegradable byproducts, occupy a central role in the city鈥檚 ambitious recycling program. Overall, the city wants to
鈥淲hat you see here in a plant built in the early 1950s is an evolution in how we look at sewage,鈥 Dave Allen, who supervises the plant鈥檚 electrical power operations, said in an interview. 鈥淲astewater really isn鈥檛 waste. It has important value that Oakland recognizes. It鈥檚 not just about cleaning up people鈥檚 poop.鈥
Dave Allen supervises the ERBMUD plant鈥檚 electrical power operations
Three years ago Allen鈥檚 team installed a 4.5-megawatt gas turbine, adding to the three gas-fired generators that EBMUD has operated since 1985. The power plant generates up to 11 megawatts, depending on the capacity of the 12 digesters to convert waste to gas. Anything above the six megawatts needed to turn pumps and mixers and other water treatment equipment is excess power available for sale.
The conversion of waste to energy has been so effective, said Allen, that the utility is steadily making big capital investments to improve efficiency and enlarge capacity. The most recent change in operations is collecting and processing more of the Oakland region鈥檚 oils, fats, grease, and other food wastes to convert to biogas.
In 2006, Oakland adopted its Zero Waste Strategic Plan to reduce the city鈥檚 363,000 metric tons of annual waste, much of it sent to landfills, . , according to city figures, was food waste from institutions, stores, restaurants, and homes. The city鈥檚 strategic plan essentially called for reducing the volume of solid waste through changes in packaging and purchasing habits, and recycling what鈥檚 left for useful purposes.
Daniel Hamilton, Oakland鈥檚 sustainability program manager, said in an interview that the 2020 goal is likely to be met. One reason is that the treatment plant is upgrading its capacity to digest food waste and is aggressively marketing its waste-to-energy recycling program to food waste producers, including farms hundreds of miles away.
Drought and water use reduction programs have reduced flows to the plant
The EBMUD plant treats an average of from 650,000 people and businesses in Oakland and eight surrounding cities. The drought and water use reduction programs have reduced flows to the plant.
One feature that has not grown quieter is the facility鈥檚 food-waste receiving station, the busiest section of the treatment plant by far. A steady stream of trucks growl to a stop and park with a hiss. Thick hoses snake across the facility to drop their cargo into holding tanks. Three to four weeks later, after passing through digesters stocked with hungry waste-converting bacteria, high-energy gas is combusted to produce power.
鈥淥akland鈥檚 poop converted to energy,鈥 said Allen. 鈥淚t鈥檚 food waste converted to energy. Power goes to the city, the port, the area鈥檚 businesses. It鈥檚 cool.鈥
Keith Schneider is senior editor and chief correspondent at and helped develop the . A two-time winner of the George Polk Award and other honors for his work, he also reports on energy, agriculture, the environment, and policy for The New York Times, where he has served as a national correspondent and contributor since 1981.
Sources: Oakland Food Policy Council, Treatment Plant Operator.
Photo Credit: Keith Schneider/Circle of Blue.
This article was first posted on the on , the blog of the Environmental Change and Security Program.
