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Tons of 'Recycled' Yard Waste Being Dumped in San Diego Landfills

Green yard waste from recycling bins is being buried in county landfills by the ton. It’s happening in several communities in San Diego County. It’s legal. In fact, the state of California calls it

Tons of 'Recycled' Yard Waste Being Dumped in San Diego Landfills

Green yard waste from recycling bins is being buried in county landfills by the ton. It's happening in several communities in San Diego County. It's legal. In fact, the state of California calls it recycling. KPBS reporter Joanne Faryon has more.

At the Sycamore Landfill in Santee, the grinder works throughout the day to shred all the green waste that is dumped here. In 2006, this machine devoured 128,000 tons of leaves, branches and other yard waste collected from recycling bins in several neighborhoods.


Once the green material passes through the grinder it's called Alternative Daily Cover, or ADC. That transformation, in size and name, makes it a recycled material in California.

Landfills are free to use it to cover garbage to keep rats away and smells at bay. And communities are free to count every ton dumped in the landfill, as recycling.

Wayne Williams, county recycling expert: The green waste is not recycled in the way people would expect.

Wayne Williams is the recycling expert for San Diego County. He says green yard waste is an organic material and organics in landfills create greenhouse gasses.

Williams: Green material in the landfill is bad because it rots. During the rotting process, methane is produced, all kinds of noxious gasses, cancer causing volatile organic compounds are produced, a lot of carbon dioxide is produced and water is produced. And these gasses either are some of them are poisonous and very dangerous.


According to the state agency that regulates recycling in California, more than 260,000 tons of ground up green yard waste, or ADC, was buried in two of the county's three largest landfills. And every ton is counted as recycling.

In fact, four jurisdictions in San Diego County would not meet their required 50 percent recycling rate if it wasn't for all that green going into the landfill. Escondido, Chula Vista, La Mesa and unincorporated San Diego County would fall below 50 percent.

Faryon: Is using green waste as ADC recycling?

Mary Matava: Of course not. ADC is a method of utilizing green waste that does not go to a compost facility.

Mary Matava owns and operates a compost facility in Oceanside. One of the few cities where all green waste is recycled by composting, rather than putting it in a landfill.

Matava: That is an income stream and it's a very lucrative income stream for landfill owners to take in this green waste, grind it up and put it in the landfill and say it's a beneficial reuse.

Faryon: The more you put in the landfill, the more money you make.

Matava: Of course.

Neil Mohr manages Sycamore and Otay landfills, both privately owned by Allied Waste Industries.

Neil Mohr: So by us processing the material here, we're enabling these communities to get these recycling credits. And the question always is its still going into the landfill, but it's being used at the landfill. It's not really going into the landfill and that' s the issue we really need to look at.

Mohr says the law requires landfills to cover the garbage every day. Many landfills use dirt, others use tarps. At Sycamore and Otay they spread a layer, a foot deep, of the green landfill cover every day, and then cover it with tarps.

Mohr says the practice saves precious landfill space because rotting green waste takes up less space than dirt.

Miramar Landfill, operated by the city of San Diego uses only dirt to cover its garbage at night. And very small amounts of green cover in wet weather.

Many landfills in northern California discourage putting any type of organics into landfills. The more organics, the more methane gas -- one of the most potent greenhouse gasses.

Williams: Looking at the amount of organic material that goes into the landfills since 1998, all the jurisdictions in the county have deposited 1.5 million tons of organic material into our landfills, if you look at the total conversion of that, which is not possible, but you might have 50 percent conversion, the total conversion of that material into gas is almost 1.4 billion cubic yards of gas. That's a lot of gas.

All large landfills have a method to capture methane gas and many convert it to electricity. But the California Air Board says 25 percent escapes into the atmosphere.