May 20, 2008 | General

Making "Mountains" Of Mulch And Compost

BioCycle May 2008, Vol. 49, No. 5, p. 37
Working with an area hauler and landfill company, wood processor diverts green waste for booming mulch and compost business.
Rhodes Yepsen

HANSEN’S Tree Service, in Missouri’s St. Louis metropolitan area, has an unusual setup, one that has proven to be quite successful for owner and President Jeff Hansen. In the 1980s, Hansen drove a garbage truck during the week, and cut trees with his uncle on the weekends. The experiences of those two jobs form the backbone of his current business, where arrangements with a trash hauler and the landfill allow him to be the area’s main green waste processor.
To build markets for the large volumes of processed green waste, Hansen learned how to make a high quality product superior to straight sawmill mulch. He visited John and Tim Martin of Martin Mulch in Lancaster, Pennsylvania, who taught him about the importance of carbon to nitrogen ratios in compost and mulch for enhancing plant growth. “I learned that mulch made from sawmill and pallet material is so high in carbon that it actually robs plants of nutrients, essentially leaching nitrogen out of the soil that plants need to grow,” recalls Hansen. “On the other hand, mulch with a healthy carbon to nitrogen ratio doesn’t just look pretty on landscapes, it offers the plants nutrients.”
With more than 75 acres divided between three sites, Hansen’s has ample room for composting. Wood destined for mulch is allowed to dry out on an asphalt pad for about a year before being ground. Other green waste is mixed with horse manure and composted in trapezoidal aerated static piles (ASP). Approximately 400 to 500 yards/week of manure are delivered in roll-off containers from the waste haulers. “Our product is STA certified to ensure it’s well-balanced and meets top quality standards,” explains Hansen.

In 1988, Hansen quit his garbage collection job and started his tree trimming business, with two trucks and a chipper. By 2000, he was bringing in over 50 tons/day, and was having trouble handling the volume. He bought a grinder in 2001, and soon decided that with his knowledge of trash hauling, he could start green waste collection. After Hansen purchased 30 to 40 roll-off containers, local hauler Crown-Excel Disposal identified the competition and bought him out. “We hadn’t been competitors before, so Crown-Excel suggested that we each focus on what we did well,” says Hansen. “For Crown-Excel it’s trash hauling, and for Hansen’s it’s tree service and recycling wood waste debris.”
Crown-Excel is a subsidiary of the area’s predominant road builder, Fred Weber Inc., which also owns a landfill. “Fred Weber agreed to continue bringing us the green waste, and it also offered to let us process green waste at its 650 acre landfill,” he continues. “The landfill is at an active quarry, and we compost right on the quarry floor.” Besides the advantage of an impervious rock surface for composting, the site is already fully permitted.
Having positive relationships with the hauler and the landfill make life easier, remarks Hansen. “Remaining friendly with the other players in your industry will only help your business. We’ve also been loyal to our equipment vendors and banks, instead of jumping around, and they in turn go the extra mile for us.” Hansen’s owns four Vermeer grinders (one horizontal and three tubs), and one CBI.
In 2007 Hansen’s sold 25,000 tons of material, 17,000 tons of which was mulch. Approximately 80 percent of the wood coming into the sites goes to mulch, and 20 percent to compost, along with the horse stall waste. Hansen predicts that this year the volume sold will increase rapidly, to between 60,000 and 75,000 tons. “This higher number is a combination of more production and more popularity of our product,” he says. “People are learning about the difference between sawmill mulch and our composted mulch, and once they do, there’s no competition.”
About 60 percent of the mulch sold last year was colorized, but all signs say that it will be more like 80 percent this year. Although coloring mulch adds steps, it’s significantly more profitable, and customers ask for it. Hansen’s uses a Colorbiotics Sahara III with Starburst colorant. (For more on mulch colorizing, see Nuts & Bolts on page 32.)

A goal of Hansen’s is to market increasing amounts of material. One avenue it’s pursuing is bagging mulch, having worked out an exchange agreement with a local bagging company that needed to use a colorizer. “In the near future, however, we’ll own a bagging facility,” he says. “It will be about a million dollar investment, with everything automated, where we dump material into a hopper on one end and pick up the shrink-wrapped pallets with a forklift on the other.”
The boiler fuel market is just beginning to take off in the St. Louis area, which will be another destination for Hansen’s ground wood. “A power plant recently began sourcing 150 tons/week of wood chips from us in order to meet a 35 percent renewable materials mandate,” says Hansen. Unlike some mulch and compost producers, who are losing money due to the increased competition with boiler fuel purchasers, Hansen’s arrangement with the hauler, as well as contracts with several nearby municipalities, will secure a steady flow of incoming material.
Other potential areas Hansen’s has considered moving into include erosion control and food waste composting. “The state of Missouri is picky about erosion control and construction sites,” explains Hansen. “Recently they’ve allowed rough grindings for silt fencing berms, and some filtration socks.”
“We’ve looked at the Peterson blower truck, if the time comes to move into erosion control.” As far as food waste composting, it’s a matter of needing better infrastructure for collection from restaurants and grocery stores. “Our permits wouldn’t have to change, since we’re operating at the landfill, but we’d monitor the piles more frequently,” he says. Because landfills are already zoned and controlled for leachate, they are prime locations for composting operations.

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