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The City of San Antonio is ramping up its program to collect organic waste from every home in San Antonio by next spring. The City’s partner company, New Earth Compost, is ready to turn that extra 4,000 tons of organic material per month into nutrient-rich garden soil and mulches.
The deal means less waste and a greener landscape, and makes San Antonio the first city in Texas to offer full residential composting,
The City’s Organics Recycling Program will be released in conjunction with the Pay As You Throw program, which allows residents to choose their trash bin size for disposing of garbage and pay a price according to how large it is. Depending on which trash bin a household uses, the monthly bill will be between $20.43 and $22.18.
The City’s Solid Waste Management Department began the implementation of the Pay As You Throw pilot program last October with a test group of residents that live in each City Council district. The pilot successfully converted the approximately 28,000 homes to the program. By this October, 190,000 residents will have the program, and it will be rolled out to all residents by April 2017.
Fallen leaves, grass, tree trimmings, food scraps, and food soiled paper are primarily what the organics program is intended to collect. Residents are encouraged to carefully screen what they use in their bins. Plastic and metals can be a serious obstacle to property composting waste.
After residents put organic waste into the the green bin, the material takes a journey across town to become soil. First, the Solid Waste Department picks up material in the green bins and brings it to New Earth’s facility along IH-10, east of Loop-410. Their trucks are weighed going in and out to quantify the exchange.
After the material is in the facility, it is piled into stacks where non-organic debris like plastic or metal are sorted out. For now, workers manually remove debris, but a new, large sorting conveyor belt will soon automate most of the process.
The piles are then left to sit, like a fine wine, for 9-12 months. Bacteria converts the waste into chemical form useful for plant growth. To help the bacteria, New Earth employees use big equipment to sort and stir the piles to make sure enough moisture and air gets in.
The bacteria produce enough heat within the piles to produce steam, and the piles are kept under a maximum size to stay manageable and avoid fires.
New Earth has been operating since 1997 and has gradually grown. In addition to composting residential organic waste, it converts large volumes of commercial manure and human biosolids from San Antonio Water System (SAWS). However, the facility smells surprisingly like soil – not garbage. The property is teeming with seagulls, grackles, sparrows, and sandpipers who have a healthy food source, a catchment pond to cool down in, and trees nearby to shelter in.
The City and New Earth both had to make large investments in order to handle the compostable waste stream from a city of 1.4 million people. The City purchased more curbside bins and pay for staff and equipment to transport and store the organic matter. New Earth bought and installed huge sorting machines to process the increased amount of material. It hired more employees, too.
These expansions are part of the gradual increase of the City’s organics program that’s been planned since city council approved it in 2010 and updated its goals in 2013.
“In 2010 the city adopted a Recycling and Resource Recovery Plan. As part of the plan the City established a goal of increasing the residential recycling rate to 60% by 2025,” said Solid Waste Department Assistant Director Nick Galus. “A critical component of reaching this goal is organics recycling, which allows residents more opportunities to recycle than ever before.”
From 2013 to 2015, residents could get composting at their home, but they had to pay a $3 fee for the containers and pickup and the City didn’t market the opportunity very far. The current full scale rollout program should make a greater difference.
“We expect the Organics Recycling Program to increase residential recycling by 10-15%,” Galus said.
That can have a huge positive effect on the sustainability of the entire city.
Composting helps increase the lifespan of landfills, reducing the need to find and fill new ones. San Francisco, which established its municipal composting operation in 2009, has converted more than 1 million tons of plant waste into soil that would have been gone directly into a landfill.
At a global scale, composting can make a big difference in contributions to climate change. The airless environment of conventional landfills ensures that the plant matter produces methane as it degrades. Methane is an extremely powerful greenhouse gas, many times more powerful than each individual particle of CO2.
In a compost pile with enough oxygen, however, the chemistry works in such a way that methane is never released, and the carbon and hydrogen that would have been off gassed is instead sequestered into soil.
The availability of relatively cheap, local, and high quality compost also helps the overall landscaping and soil quality throughout the city. That allows for a greener city without requiring the use of expensive fertilizers which become destructive as they runoff into streams or penetrate the aquifer into the city’s groundwater.
The composting program establishes environmental leadership for San Antonio and signals a heightened seriousness for its existing sustainability initiatives. The decision turn waste into something productive is the exact opposite of the status quo – to bury the problem underground, cover it, and hope for the best.
“Our goal is to pioneer waste solutions for future generations,” said New Earth’s Director of Business Development Mark Manny. “The organics program will help move the city toward better waste diversion and allow us to return organic matter to soils, which will aid in water conservation and plant health.”
Top image: Organic debris are piled and left to sit for 9-12 months during which bacteria converts the waste into nutrient-rich soil. Photo by Kathryn Boyd-Batstone.