September 16, 2008
Millbrae Grease-Recycling System Notches One Million Gallons
By Kyveli Diener
MILLBRAE -- Since the implementation of a new grease-receiving method in January 2007, the city's Water Pollution Control Plant has recycled 1 million gallons of used kitchen grease, a milestone that will be celebrated this morning during a ceremony at the plant.
The approximately $6.1 million project is entirely self-funding, earning money from reduced electricity purchase costs and revenue from the waste grease hauling company Liquid Environmental Solutions.
"We're extremely proud," Mayor Gina Papan said last week. "It's a fabulous program that really makes you realize what impact a single city can have in affecting the environment."
Papan also commended city staff "for reaching outside the box and coming up with this innovative idea."
Dana King, senior vice president of business development for Liquid Environmental Solutions, said that Millbrae's grease- receiving system is unique. Though the city of Riverside in Southern California has a similar system and other states are talking about implementing related plans, Millbrae's setup puts the city at the forefront of an emerging technology, he said.
"Millbrae is understanding the urgent needs to develop some sound environmental strategies to deal with grease trap waste and, in general, the handling of waste so it can be positive on the environment instead of a negative," King said.
King said the efficiency of the grease-recycling process is one of its main assets. He said the system easily removes the grease from his company's truck -- a service for which the company pays the city -- and disposes of the large materials like trash and straws.
The method then "very efficiently prepares a grease and food cocktail for the microbes," King said.
The microbes of which he speaks are those living in the digesting tank at the plant. When the Liquid Environmental Solutions trucks empty the grease they collected from restaurants into the plant's 12,000-gallon storage tank, the water is separated for standard cleansing and the grease and bits of food are fed into the digester.
Here, the microbes eat the waste and release "biogas," which is 70 percent methane and 30 percent carbon dioxide.
The biogas is then fed into a 250-kilowatt microturbine generator, which makes electricity and keeps the methane and carbon dioxide out of the air. Any waste heat from the microturbine is used to heat the water for the digester.
The system, which was awarded the Sustainable San Mateo County award in 2007, also reduced the amount of biosolids that can end up in landfills by 36 percent in its first year of operation.
Magner said the work accomplished by his "baby" is all he had hoped for and more. He said his favorite part about the project, in addition to the positive effects on the environment, is overcoming the doubts of many pollution treatment professionals who said the method would never work.
He added that he has no doubt that the system he helped create will help others invent similar systems, but that it will take time for this recently proven method to catch on with other processing plants. He commended the "forward-thinking people" of the City Council for accepting the new equipment he and York proposed to them.
"This was not a proven technology," Magner said. "They took a chance and it's paying off in spades."By the numbers
166 acres of newly planted trees would be needed match the pollution-reducing effect of Millbrae's grease-recycling system.
1.7 million kilowatt-hours produced by the system each year.
7,000 completely filled bath tubs would be needed to hold one million gallons of grease.
-- City of Millbrae
Originally published by Kyveli Diener, San Mateo County Times.
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