LOS ANGELES COUNTY, Calif. -- As America's largest landfill prepares to shut down next year, Los Angeles County begins to write a new chapter in U.S. waste disposal history - ushering in the age of waste-to-energy conversion.
And they have lots of garbage to work with – about 8.7 million tons a year.
Conversion technologies, which transform solid waste into useful products, are utilized abroad in Europe and Japan, but are relatively new in the U.S. There are many types of facilities, but four are preferred by L.A. County as an alternative to landfills – anaerobic digestion, pyrolysis, gasification and a combination of pyrolysis and gasification.
"We feel these technologies are working throughout the world, and that they could be readily applied in the United States," said Pat Proano, assistant deputy director of the L.A. County Department of Public Works Environmental Programs Division. He presented his findings to an audience at the American Public Works Association's recent International Public Works Congress and Exposition in Anaheim.
Through public-private partnerships, the county is willing to help companies get through the permitting process, secure grant funding from the state's energy commission, and provide additional technical and financial assistance through consultants.
Many waste management companies have been researching and developing conversion technology for years, and were looking for the right time to use it.
One of the companies L.A. County is focused on is CR&R Incorporated in Southern California, currently near the end of its permitting process to build and operate an anaerobic digestion facility in nearby Riverside County. The California Energy Commission has awarded the project with a $4.5 million grant for the digestion facility, and $400,000 more to build a fueling station.
CR&R plans to break ground next year. The anaerobic digester would convert separated organic and green waste into biofuel. It would be located on a 52-acre site shared with an existing Materials Recovery Facility.
"It's kind of a home run from an environmental perspective," said Paul Relis, CR&R senior vice president.
The biogas produced will be used to power the company's fleet of trucks, said Relis. It is a cleaner alternative to diesel and there are no greenhouse gas emissions, he said.
Relis said 150 tons of material a day can fuel 70 front-end loaders and street sweepers. And the project is scalable. At commercial scale, it has capacity for 5,000 tons a day, he said.
That's about how much Puente Hills landfill received per day in 2011, according to the latest annual Countywide Integrated Waste Management Plan. But that’s still just a portion of the 28,000 tons L.A. County residents and businesses sent to landfills each day last year, according to the report.
At the same time, a lot of organic waste is disposed. Heavily urbanized areas such as Los Angeles have difficulty permitting commercial composting facilities. There isn't a lot of land for these large facilities, the permitting and requirements are more stringent, and there is a limited market for the compost product that is generated, according to Coby Skye, L.A. County Department of Public Works Environmental Services civil engineer.
Relis said, "That's still a frontier in California." The state has mandated a 75 percent reduction in waste, by source reduction, recycling or composting by 2020. Finding a solution to organic waste is key to reaching that benchmark.
But a critical hurdle was getting the support of the environmental organizations.
“We feel that it has the support of the environmental community, which is important for permitting,” he said.
Anaerobic digestion is more acceptable compared to thermal technologies, which the pubic commonly associates with incinerators. L.A. County also has two other public-private partnerships with companies pursing thermal conversion technologies.
Without approved Renewable Portfolio Standards credits, thermal conversion technologies aren’t financially feasible. The difference can be significant: More than $100 per ton without credits and $60 to $65 per ton with credits, according to Proano.
One California municipal waste authority partnering with a Canadian firm saw their project stop in its tracks after the RPS credits, pre-certified by the state energy commission were rescinded. Environmental groups pressured the new governor to reverse the decision.
“There is a perception that it is incineration,” said Susan Warner, Salinas Valley Solid Waste Authority diversion manager. But the reality is these are heavily regulated facilities permitted by the local air board, she said.
Plasma gasification uses a thermal process to vaporize solid waste at high heat in an oxygen-deprived chamber. Incineration uses oxygen. Gasification produces synthetic fuel gas that can be used to generate electricity or steam. And the remaining solid residue, or slag, can be used for construction aggregate.
The Salinas Valley Solid Waste Authority in northern California is down to its last local landfill, and the other three are closed, said Susan Warner, diversion manager. The authority is responsible for five cities and unincorporated Monterey County, which produces a waste stream of 167,000 tons per year.
The proposal from Plasco Energy Group was one of nine that met the qualifications and criteria and offered the maximum amount of potential diversion from the landfill, said Warner.
The waste authority plans to focus on environmental review of another vendor to move a steam autoclave project forward from a pilot project and develop it for regular use. The autoclave pilot project, located on a closed landfill, uses pressure to break down organic material into cellulose. The pulp can be then used for making paper products, such as packaging paper or cardboard waffles. The anticipated cost is relatively low at $39 per ton.
The technology has been used to produce cellulose material from municipal solid waste in test runs in conjunction with the U.S. Department of Agriculture.
But what agencies such as Salinas Valley and L.A. County need today is direction from the state government on conversion technologies.
For Warner, that includes definition on what types of conversion technology qualify for RPS credits.
“California is usually a leader and has been in the past receptive to innovative technologies,” said Warner. But it’s disappointing because this technology is already prevalent in other parts of the world, she said.
For Proano, he’s counting on the state to enact legislation. When Governor Jerry Brown came into office in 2011, L.A. County worked with public relations consultants to educate the new administration in Sacramento, Proano said.
“The next couple of years for us is huge,” he said. “Because we have direction from the governor that he will support legislation for conversion technologies.”
Proano hopes the state agencies that regulate the permits, Cal Recycle, Cal EPA, the energy commission, the air resources board, will follow suit. The expectation is that these agencies can agree on a clear permitting pathway for conversion technologies.
For now, landfilling is still the cheaper alternative compared to conversion technologies. But as local landfills become scarce, costs are anticipated to go up.
The county sanitation districts' Waste-to-Rail system could transport trash in shipping containers to other parts of Southern California - specifically, the Mesquite Regional Landfill in Imperial County, which is also permitted to accept trash by truck. Construction is scheduled to be completed next year.
But as those landfills have finite capacity, it’s conversion technology that has everyone excited. L.A. County has identified at least 20 possible local demonstration sites. Jails or hospitals can be considered for such projects, too.
It’s to show that it works, said Proano.
“A lot of people have reservations about the viability of the CTs,” he said.
But even cities within the county, such as Santa Monica, have their own collection system and want to send their trash to a conversion technology facility instead of a landfill, even if they have to pay a little more, he said.