Completing the cycle

Completing the cycle

Features - Organics Management

Recology returns nutrient-rich compost made from the food and yard waste it collects back to the soil.

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June 6, 2017
Kristin Smith

California is known for many things, but the state has two attributes that make it a great market for organics recycling: plenty of people to produce food and green waste and plenty of farmers who need compost.

San Francisco-based Recology recognized the opportunity years ago and continues to grow its organics collection and composting operations in California and north to Oregon and Washington.

One of its biggest customers for waste and recycling collection is the city of San Francisco, where the company has worked alongside officials to achieve some of the most aggressive recycling and diversion goals in the country.

“Back in 1995, the city saw an opportunity to turn the organic/food fraction of the waste stream into a resource for the agricultural industry, specifically [as] compost,” says Paul Yamamoto, P.E., Recology’s director of technology and engineering. “We initiated a food scrap pilot program in conjunction with the city in 1996, which has continued to grow and change the way our customers view the materials they generate.”

CUSTOMERS WHO CARE

Even before San Francisco started organics diversion, Recology began a compost pilot project in Vacaville, California, using green waste in 1994. Today, customers throughout California, Oregon and Washington participate in the company’s organics collection programs.

“We are fortunate to be able to serve many communities who are like-minded in their desire to keep materials out of landfill,” Yamamoto says. “Many of these communities have voluntary or required composting programs that we facilitate on their behalf. We also seek out and work with private companies focused on sustainability. We work with several large grocery stores to manage organic waste streams that are past their useful lives.”

Yamamoto says Recology’s customers are extremely knowledgeable when it comes to doing the right thing with their residual materials.

“We do our best to make participation in the programs convenient and are constantly learning through feedback from our customers,” he says.

Recology provides its residential customers with small containers they can use to collect food trimmings and plate scrapings in their kitchens. On trash pickup days, residents transfer their food waste into their curbside green waste carts.

Commercial customers are provided with a combination of residential-type carts and commercial bins that are dedicated to collecting food scraps.

The company uses a combination of collection vehicles from semiautomated rear-loaders, front-end loaders and fully automated side-loaders. To transfer larger volumes of compost, the company uses transfer trailers that can handle about 40 cubic yards of material.

Recology educates its customers in a variety of ways. It creates timely articles in its customer newsletters and on its website. “We serve a very diverse customer base, so we also place stickers on our containers with photos depicting what should and should not go in each container that are instructive regardless of the language one speaks,” Yamamoto says. About 5,000 customers and guests visit the company’s San Francisco recycling facility for tours and recycling classes.

TURNING INTO COMPOST

Recology operates eight composting operations in California and Oregon to process the food and green waste it collects from its various customers throughout California, Oregon and Washington. It has the ability to produce 400,000 tons of compost, or 18,000 truckloads, annually to sell to farmers in the region.

“Fully half of the nation’s foodstuffs are grown in California, and Recology plays a big role by providing nutrient-rich compost and soil blends to ensure successful cultivation of crops,” says Yamamoto.

Major customers for Recology’s compost includes growers of nuts, grapes for wine and table and organic row crops, such as carrots and lettuce.

“Many of our customers are vineyards throughout northern and central California and Oregon, as well as organic farmers and conventional farmers who understand the benefits of enhancing overall soil health through the use of compost,” says Yamamoto.

A growing segment of the company’s compost business is custom soil blends. “There are limitless combinations of materials that our compost is blended with,” he says. “Oftentimes our growers work in conjunction with soil agronomists to develop a specific blend to get the best growing results for their crops. Recology also is working on some new crop-specific soil blends to further diversify our own product offerings.”

It takes several pieces of equipment to process the organic waste Recology receives and turn it into compost. The materials are screened, sorted, separated, ground and shredded through various machines and are sent through an air lift separator to remove contaminants. Windrow turners and aeration systems are used to enhance the composting process, while water treatment systems safely manage liquids produced by composting.

“The fundamentals of a healthy composting process require the right combination of air, water and carbon and nitrogen (in the form of green and food waste) so that the micro-organisms that convert organic material into compost are able to thrive,” says Yamamoto. “Through years of experience, our team has developed an optimal ratio of green and food waste to ensure a healthy mix of feedstock.”

To minimize odor, Recology has installed automated systems that draw a vacuum on the composting material. This is designed to ensure a healthy aerobic environment that minimizes odors. The air that is drawn through the compost is treated through a biofiltration system to further reduce residual odor and emissions to the atmosphere.

“We also capture and treat any liquids produced by the composting process that otherwise have the potential to create nuisance odors,” says Yamamoto. “Over time we have developed dozens of best management practices that reduce and eliminate odors—some as simple as housekeeping and washing down heavily used areas—to systematic on- and off-site monitoring.”

DEVELOPING AND GROWING

Demand for Recology’s compost is strong, according to Yamamoto. He says the fall and spring are the busiest times for the composting products. As the push toward more diversion takes hold in more communities, Yamamoto says Recology is well-positioned to handle that additional volume.

“As communities continue to push, whether by regulation or outreach and advocacy for greater diversion of organic materials away from disposal and toward reuse, we believe our network of composting facilities, our permitted capacity and environmental programs distinguish us in a way that favorably positions Recology to meet our communities’ expanding needs,” Yamamoto says.

He says Recology is pleased with the nationwide momentum to recover food waste and offers advice. “Over the years, we’ve learned through experimentation, partnerships and the good ’ol method of trial and error optimal ways to produce high-quality finished compost while protecting the environment.”

Known for its innovation, including its early adoption of organics recovery, Recology isn’t stopping where it’s at. “We are always looking to innovate all our lines of business,” says Yamamoto. “For composting in particular, we are in the process of applying leading edge improvements at our operations to be more efficient through the use of automated aeration process and controls and meeting other key environmental objectives to protect air, water and soil and the communities we serve.”

He adds, “Our customers are among the best recyclers in the world, yet there are still resources in the residential carts and bins that end up as disposal. Our overall plan is to process and find the highest and best use for all the resources in those carts and bins, including organics.”

The author is editor of Waste Today and can be reached at ksmith@gie.net.