Expertise and equipment: key components in San Diego county compost site’s success

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Despite readily-available evidence to the contrary, many municipalities cling to the belief that implementing a compost program is costly, time consuming and offers no real benefit to the community. As a result, they either shy away from undertaking a composting effort entirely or — in a sort of self-fulfilling prophecy — grudgingly implement a bare-bones program. North San Diego County residents, on the other hand, are fortunate to have at their disposal, the El Corazon Compost Facility, an extremely well-planned, well-operated example of all that can go right with a composting site. Owned and operated by Mary Matava through her company, Agri-Service, the facility serves the north San Diego County communities of Oceanside, Vista, San Marcos and Carlsbad. According to Matava, the secret to her success is really no secret at all: combine equal parts expertise, planning and smart equipment purchases and the rest will fall into place.

Change in Direction
Agri-Services has been around for about two decades, but bears little resemblance to the company Matava started out.

“My background is in agronomy so I actually started out doing soil testing. However, in 1994, after California made the decision to divert 50 percent of its green waste from landfills, I wrote a proposal to the City of Oceanside that said we could recycle their green waste through the El Corazon site. Because green waste is 30 percent of their total waste stream, I helped them see that doing so could dramatically reduce their waste transportation costs. Today, they estimate they’ve reduced those costs by a couple hundred thousand dollars a year. In addition, at the time, they actually had a need for mulch and had plans in place to purchase it. The price tag on that purchase alone was estimated at about a million dollars. I told them we could give them all the mulch they needed. In short, I convinced them that letting us help them would be a win-win situation for both of us. And it’s certainly turned out that way.”

Can’t Beat the Classics
In most respects, El Corazon is a classic compost site, that is, they take in material, grind it, windrow it, water it, turn it, screen it and sell it. Where it differs from the norm, however, is in Matava’s attention to detail, both in the composting process itself and in the broader promotion of composting as a viable option for the area.
“I put a lot of thought and planning into our operation and that extends into my decision as to what equipment best meets our needs. We use a Morbark 1200 tub grinder to handle all of our grinding; currently that involves processing a steady 200 tons of green waste a day. I chose the 1200 for a number of reasons including power — it’s a 650 HP grinder. The big benefit to us at this time, however, is its portability and the manageability of the wear parts. Screen changeouts are simple and the unit can be moved onsite in as little as 10 minutes. And since we do move it rather regularly, that ease of movement is a big plus for us.”

Matava says the 1200 can be fitted with 4-inch or 5-inch screens and that the unit easily processes material as large as 3-feet in diameter. “We feed the 1200 a broad range of sizes, have had no problems with it and are getting excellent product. The material that has the most value for us is the fines on the backend, so we try to maximize those fines as much as possible. After grinding, material is screened through a trommel screen. The composting process is really a surface area reaction; a microbe isn’t going to breakdown a two by four. So the smaller the particle size the more surface area available. However, that that has to be balanced with larger pieces to ensure proper aeration. It’s a finely tuned model and the Morbark 1200 meets the process demands nicely.”

It’s in the Mix
According to Matava, the fines generated in grinding are used as a soil amendment to enhance the chemical and physical soil properties and the overs from the screening are used as a mulch-based top cover for erosion control and moisture conservation in orchards.

“Not many people realize it but San Diego County leads the nation in avocado production, so the mulch is ideal for use by avocado growers. Avocados are a sub tropical crop and demand a great deal of water so using mulch like this green waste compost mulch can cut water costs by about 20 percent. Since farmers in this area pay up to $700 an acre foot for water, those savings can be significant. In addition, the mulch keeps the moisture in the soil longer and, since it’s still microbially active, it actually mimics a sub tropical soil instead of an arid soil.”

She adds that the majority of the material composted is used within a ten-mile radius of the site — the bulk of which is slated for use in landscaping and agriculture.

“However, we also put a lot of effort into working with the community gardens. Here in southern California — throughout the state actually — most homes are so close together that people don’t have room for a garden of any size to grow their own vegetables. The same holds true for people living in apartment complexes or high-rises. So, in many cases, a group will get a plot of land donated to them by their respective city or municipality and individuals will have their own 20 x 20 or 20 x 40 area in which to grow the crop of their choice. I first saw this concept in eastern Europe. There, gardens have been springing up in areas in which buildings have been demolished. Gardens are very relaxing and can of course be beneficial to someone on a fixed or limited income. In some of the Asian communities in Los Angeles —Signal Hill or Long Beach, for example — people are raising incredible amounts of produce. In those cases, the motivation is to grow many of the fruits and vegetables to which they are accustomed — things they can’t find in any traditional grocery store. So I go before these groups and teach the benefits of rotating the crop, using soil additives and so on. It has really been a fun yet rewarding thing to do.”

Equipment Challenges
While Matava says they have been very pleased with their choice of processing equipment, the Morbark is actually the second grinder used by Agri-Service at the El Corazon site.

Though I hate to even think about it, we first started out using a horizontal grinder. There’s no nice way to describe that unit except to say it had some obvious design flaws in it. It was extremely slow, did nowhere near the tonnage the company predicted, and would send large pieces of material — some as large as a baseball bat— through it. Just unacceptable performance. In addition, in the first few months alone, we replaced almost every hydraulic hose on it. To add insult to injury, the company was basically unresponsive to my complaints. It was obvious we needed to find a better way to handle the onsite grinding.”

Matava says an equipment salesman for a screening plant was visiting and convinced her to sit down and see just what that unit was costing her in terms of lost production, rental costs, contract grinding charges, and so on.

“It took me an evening to do that and I immediately saw the reality of it. I realized first, that we needed to make an alternative purchase. However, I also determined that a demo unit was not the way I would ever go again. I wanted a machine with some proven hours already hours on it — that’s when you know what kind of machine it really is. So we brought in the Morbark, saw how it actually operated, were able to look at operational costs, fuel consumption, and so on. Based on all that — and the portability factor — we chose the 1200 and it’s fit the bill nicely. We get a consistent product and steady solid production off of it, and that’s what we needed.”

Additional Pluses
To balance productivity and costs, Agri-Service offers a number of additional onsite programs including one in which area residents can come to the El Corazon facility and take compost for free. Matava says she includes recycling and composting-based literature with each load that is taken — a move made as much on her commitment to green waste recycling as on an ulterior motive.

“Initially the City wanted us to pay some fees for operation. To avoid those, I wrote a proposal several years ago that said that, in exchange for their waiving those fees, we would run a giveaway program for the City to help meet the educational component of its legislation,. Today, we have between 500 and 900 residents a month coming to the site and filling up their pick up trucks, containers or bags with free compost and with each load comes the literature. It’s really been a successful program.”

Because soils in the Oceanside area are extremely low in calcium yet high in magnesium, additives to balance those levels are needed. Clean, unpainted, untreated Gypsum board, collected and processed through the Morbark 1200 does that and more. “We have a formula wherein we mix a specific amount of the gypsum with the compost and it enhances its properties. While that alone is a nice benefit, it also counts towards the City’s diversion credit. State law says if the City doesn’t divert 50 percent of its waste from landfill they can be fined up to $10,000 a day. So there is a definite incentive to do this.”

For Matava, it is all just so much common sense. “My decision to get into this business was based upon a realization I had that there was a lot of valuable material simply being thrown away — things for which there is a need right here in the community. Consider this: if you added up all the organic waste in the state of California you could still only supply about 10 percent of agriculture’s nutrient needs. Obviously, in light of that, it’s a sin to be throwing any of this away. And if you need it in dollars and cents, it’s far more economical to compost. The landfill tipping fees are $38 a ton — ours are $22. It just makes good sense to do this and I’m glad we’ve been able to make the impact we have.”

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