Ridding Virginia of the Stump Dump

April 1, 2000

11 Min Read
Ridding Virginia of the Stump Dump

Rod Tyler

Working as a builder for more than 20 years, Bill Stinson of Richmond, Va., was all too familiar with the woody debris that could be created from land clearing during building operations. Eager to recycle this material and alleviate disposal problems, he considered working with local partners to find applications for the materials.

After some analysis, Stinson and his team found that the economies of shrinking the wood debris by grinding it prior to hauling offsite were advantageous. They purchased a CBI 4800 grinder and formed Grind-All LLC in 1998 to reduce all types of woody materials, including large logs typical in site clearing operations.

Moving from one building location to another, the Grind-All team began clearing numerous projects, leaving the wood chips onsite to be hauled off to one of the company's storage locations. However, the team soon found they had some excess grinder capacity. So in Spring 1999, Stinson negotiated a contract with the Central Virginia Waste Management Authority (CVWMA) to process yard trimmings at 13 area locations around Richmond, Va.

Chesterfield County, the largest county in the area, was the first to use Grind-All's services. Previously, most counties took yard trimmings from residents and had the material tub ground. However, the CVWMA contract allowed local municipalities to work with Grind-All voluntarily to reduce their materials. This business kept the company's machines at full capacity. Currently, Grind-All is processing materials at eight of the 13 locations.

Making a Market Grinding away and hauling chips off, Grind-All's inventory of wood chips began to pile up. The team needed to find markets for their finished mulch material, so they quickly assessed what products were suitable for the local marketplace.

"A lot of the first potential customers we talked with said they did not want mulch made from waste wood," Stinson says. "I knew we had to find another way to make the mulch look different or educate our market that this stuff was a suitable substitute for what they were using now, which was finely shredded hardwood bark mulch. We ended up giving them compost, which is in great demand in this area.

"There were a lot of grinders who would be glad to come in and grind for anybody, but nobody cared about moving the chips offsite," Stinson continues. "Even the ones who offered to move the material generally charged more for these services and, at that time, it was clear the wood chip markets were not paying much more than boiler fuel prices, which only covers the cost of transportation."

Realizing that not making products that matched customer needs would quickly put Grind-All out of business, the team reviewed the Yellow Pages and found several companies selling top soil, mulch and compost. Because the market was mature, the Grind-All team spoke with potential customers and found Richmond was a "gardening Mecca" for good-quality products.

Grind-All began marketing its ground materials, and in the process found many ways to help its local communities.

Years of Yard Trimmings For several years, the city of Richmond had accumulated leaf and yard trimmings, which were in various stages of decomposition. This caused localized fires from spontaneous combustion, as well as other complications. But the city could not remedy the problem itself - it did not have the storage space on site or the ability to move some of the material offsite to the marketplace.

The city hired Grind-All to screen its older piles of leaf humus - much of which was five years old - and grind material onsite.

Grind-All ran into an obstacle, however, because the city previously allowed "compostable" bags to be used. Unfortunately, these bags failed to live up to their claim and, as a result, contaminated the overs from the screened product, making it impossible to reprocess.

Eventually, the material was landfilled. In the meantime, Grind-All continued to grind the usable portion, and was able to sell thousands of cubic yards from the Richmond site.

With more space, the city broke down many of the existing piles into a more manageable system, speeding up decomposition and eliminating the fire potential.

Eventually, the city of Richmond wants to be able to grind leaves as they come in, rather than stockpiling them. This should speed up decomposition time.

So far, the city seems on track to reach its goal. The majority of the material that arrived in fall 1999 should be available for sale within the next year - something that never has happened at the site.

"Finally, we have room to operate more efficiently, and now we are analyzing other efficiencies that could [positively] impact our budget," says David Wahl, solid waste supervisor. "There are many satellite sites that may benefit by taking the grinder there first, [which would] thereby reduce the total hauling costs and offer savings to the city."

Richmond and Grind-All are working together to find a truly biodegradable bag for residential leaf collection. Bag manufacturer Biocorp USA, Redondo Beach, Calif., has coordinated preliminary trials with the city, and the results show the new bags performed favorably in managed windrows. If the Biocorp bags eventually are used by residents and end up at the Richmond site, the processing and disposal costs incurred by both Grind-All and the city should be reduced in the future.

Compost to Control Erosion Grind-All also has been working with the Virginia Department of Transportation (VDOT) to control erosion.

Controlling water and soil movement has become a focus of the department in recent years. However, this can be difficult on highway construction projects and on roadsides with uncontrollable factors. For example, from October through March, temperate climates due to cold weather, heavy rains and snow can make it difficult to establish vegetation to prevent erosion.

Compost is gaining popularity as a tool to help in slope stabilization and erosion control. As a result, Grind-All is formulating special products to help the VDOT improve performance in the landscape or on the roadside.

In November 1999, Grind-All worked with the VDOT on a pilot that tested the effectiveness of four composted products created across the state on eight plots with a 2:1 slope. Four different materials were used at two different depths, including, leaf compost, yard waste compost, overs from a screener and a 2-inch-minus mulch that also had been composted for 90 days.

The soil on the slope was a sandy clay and was highly erodable. All of Grind-All's products significantly prevented or reduced erosion on the slopes. On the other hand, the control areas on the other side of the road had high rates of erosion when the soil was left unprotected in late fall.

Slimming a Stump Dump Grind-All also assisted the VDOT in 1999 on a stump dump recycling job.

Thirty years ago, developers in the area pushed stumps, woody debris and other project waste into a large pit and covered it with dirt from highway excavation. As the local development and projects grew, so did the stump dumps. Almost 30 years after the stump dump began, Greater Richmond needed to develop new roads and interchanges, and the entombed material became a roadblock to progress.

All of the city's options appeared to be costly and to present additional problems: Burning the stump dump would create unnecessary smoke. Burying would require land to be set aside for non-use for a long time. Hauling the material to a local landfill would put the site over their required volume limit for closure.

Fortunately, Grind-All was awarded the optional bid for a cleanup project, which, after processing the materials onsite and recycling them on a nearby farm staging area, would create usable products.

Using a variety of equipment [see "Stump Dump Recycling Equipment" on left] Grind-All is processing the material to yield high-quality topsoil, coarse ground mulch and organic fines, which will be blended back with topsoil once aged, to create a high-end topsoil blend. Overall, the entire process will require several steps and about three years.

The first phase of the project - prescreening to remove concrete, tires and other large rubble - nearly is complete.

Once the materials are prescreened, a bigger challenge includes the processing and marketing of woody debris in the stump dump. Old stumps, limbs and other wood wastes must be processed through a disk screener and then a finger screener to remove as much dirt, rock and other debris as possible. Once source separated, the wood debris will be sheared and sent through a CBI 4800 grinder to create a coarse mulch.

The coarse materials then will be aged for at least 30 days and reground using a CBI 4000, which allows the size of most of the mulch to pass a 2-inch-minus grade.

Topsoil will be produced by disking, drying and screening the material yielding a 1-inch-minus topsoil with a natural organic content of 5 percent or more. This process will take place over the next two years.

In the end, Grind-All expects to help VDOT and the state recapture more than 90 percent of the materials originally destined for the landfill and turn these materials into valuable topsoil sales of approximately 150,000 cubic yards.

As a result of the stump dump project, Grind-All has focused on finding other special projects to supplement its growing organic recycling business.

Operations in South Carolina, Massachusetts and other areas currently are targeted for growth in 2000. The company also has created a special projects division that will concentrate on all future stump dump-type jobs as a separate focus for a limited time.

This has allowed concentration of predictable vs. non-predictable revenues to be managed without conflicting with each other, Stinson says. "It is awfully difficult to predict just when the next stump dump project will be around, but when it is, we think staffing it separately from our existing business will give us more controls."

Filter berms can be an attractive option because they:

1. Cost less than using sediment fences and straw bales.

* Have reduced labor installation and cleanup costs.

2. Are environmentally friendly.

* Control runoff and protect areas sensitive to high sediment/runoff;

* Keep soils in specific areas without allowing them to migrate offsite;

* Are easier and more aesthetic to use; and

* Allow turtles, salamanders and other animals to navigate over them, unlike conventional straw bales.

3. Improve water quality clarity percolating to nearby waterways and tributaries.

* Filter chemical compounds leaching off of roadways;

* Reduce water runoff by allowing for more water infiltration and water for plant and seed establishment;

* Reduce phosphorous leaching and other chemical leaching effects, which reduces the potential for algae and other harmful environmental effects; and

* Reduce settleable and suspended solids, which means more soil will remain on slopes instead of running into waterways.

4. Can be left in place after a job is completed.

* Allow vegetation to grow over them, which keeps the filter working and eliminates cleanup;

* Reduce material, labor and disposal costs;

* Are 100 percent organic, annually renewable, 100 percent recyclable natural materials; and

5. Easy to install.

* Can be applied at rates of over 85 linear feet per hour to 150 linear feet per hour;

* Can be installed when weather is inclement;

* Easy to apply in hard-to-reach places with blower trucks and an applicator hose;

* Can be applied where water already has accumulated; and

* Can be applied in any direction or configuration, or adjusted to outlines of areas.

6. Can be seeded at the time of compost or mulch application.

* May actually create a "living filter berm" that combines extra filtration of growing plant roots within the filter berm.

Bill Stewart, an expert on compost quality currently with Bio-Reaction Industries Inc., Tualatin, Ore., conducted much of the initial research about using mulch and filter berms as erosion control. According to his data, using erosion control mulches, compost, and filter berms allows less sediment and chemicals to reach our waterways [see chart below]. Additionally, compost improves plant growth and seed establishment, which further reduces erosion.

Taking costs into consideration, filter berms often are less expensive than silt fences and straw bales, and they provide a safer and more environmentally friendly environment for animals in and around our landscapes.

Since the research was conducted, several other field studies have verified the success produced from this initial research. For example, the Virginia Department of Transportation, recently worked with Grind-All, Richmond, Va., in testing a leaf compost, yard waste compost, recycled overs from a screener and a 2-inch-minus composted mulch that had been composted for 90 days to control erosion on eight different plots with a 2:1 slope.

The specifications used in the Grind-All/VDOT project were adapted from the U.S. Composting Council (USCC), Amherst, Ohio, and can be varied to fit other projects based on local weather, slope severity, available products and soil type.

Currently, several other states are either using compost for filter berms and erosion control, or are considering it. However, many of the states do not include compost or filter berms in the specifications when projects are bid.

And while much of today's research has not been repeated in other areas of the country because of project setup, data collection and analyzing costs, the existing pilots prove that compost, mulch and filter berms are effective erosion control options.

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