The home front: WasteCap Wisconsin residential recycling program finds market for recycled gypsum.

How did one of Wisconsin's largest home builders get named Environmentalist of the Year, keep 1,250 cubic yards (approx 624,000 pounds) of gypsum drywall out of landfills after less than a year, build soils and have the partnership of state regulatory authorities in this new recycling program?

Starting in February 2004, Bielinski Homes, one of Wisconsin's largest home builders, partnered with Prairie Tree Landscape and WasteCap Wisconsin to start an aggressive residential recycling program. Building approximately 640 homes per year, Bielinski generates a substantial amount of construction waste--much of which is now being recycled.

WHO IS INVOLVED?

The Bielinski recycling program was set up to reduce, reuse and recycle as much from the waste stream as possible. According to the National Association of Home Builders, drywall, wood and cardboard make up approximately 70 percent of a home's construction waste. The Bielinski recycling program reuses wood, masonry and drywall and recycles cardboard and metal. Starting in 2005, the program will begin recycling vinyl siding, which will continue to raise the amount of material that will be recycled on a Bielinski site. To date, this program has resulted in a 61 percent recycling rate by weight, and the elimination of more than 8,000 cubic yards of construction waste from Wisconsin landfills in just 10 months.

Prairie Tree Landscape handles the logistics of the recycling program. This includes the grinding, collecting and processing of recyclable material and waste at each home site. Prairie Tree Landscape also provides reports to WasteCap that details the quantities of each recyclable material collected. WasteCap compiles and synthesizes these reports to create monthly reports that track the progress of the program.

WasteCap, Prairie Tree Landscape and Bielinski all work together to educate trade partners (subcontractors) about the recycling program and make sure the program runs smoothly. WasteCap also helps to enforce, evaluate, monitor and improve the program by conducting monthly site visits to the development sites and to speak with trade partners. This process has led to the inclusion of vinyl siding in the recycling program and to modifying the ways trash is collected. Currently tests are being done for using a small dumpster at each home site instead of the trash pens. WasteCap also provides technical and research assistance, market information and helps share the story of the recycling program and its results.

THE PROCESS

The Bielinski recycling program was set up on an individual home basis. Each home site has a trash pen, which is essentially a box defined by green snow fencing and stakes. In each pen are cans with heavy-duty bags that are to contain trash. Trade partners fill these cans with their construction debris that is not recyclable. Items that are too large for the cans are to be placed inside the pen next to the cans.

Materials to be reused or recycled are put into separate piles next to the trash pen. This includes wood, drywall, metal and masonry. This system works well, as typically only one of these items is generated at any time and thus only one pile at a time is outside the trash pen. Cardboard is flattened and kept inside the garage.

Prairie Tree Landscape crews go to each home site weekly. They collect trash from the pens, metal from beside the pens and cardboard from the garages and take these items to central dumpsters. A Packer 750 grinds the drywall, wood and masonry. The brick and block typically represents a very small amount, about 0.25 cubic yards per home and is incorporated into the sub-base for the driveways. On average, 11 cubic yards of wood per home is ground and taken to a central location where it is then used as landscape mulch around shrubs, trees, other plantings and for paths in natural areas in the developments.

THE REUSE OF DRYWALL

Drywall is second only to wood as the largest material in the residential construction scrap stream, and Bielinski has been able to reuse this material on its construction sites as part of its recycling program.

Gypsum drywall is a source of calcium and sulfur similar to agricultural gypsum. Most turf grasses and ornamental plants need these nutrients, and gypsum drywall helps break up the heavy clay soils common throughout Southeast Wisconsin where Bielinski Homes are installed. The drywall does not change the pH in the soil like lime because it's pH neutral.

Prairie Tree Landscape stops at a house to grind the drywall once after the drywall process has been completed. It takes approximately 1.5 hours to grind 8 cubic yards of gypsum, the quantity of gypsum drywall scrap generated by an average house in a Bielinski home. A large sleeve covers the conveyor belt and chute to minimize dust. Grinding drywall can be a very dusty operation, and the sleeve does a nice job of minimizing dust.

The gypsum is ground into the size of roughly a dime or less in diameter. The paper, when it is ground, is ripped from the gypsum, resulting in segments of roughly 2 inches in spread. Grinding the wallboard is much quicker and creates less wear and tear on the grinder than grinding the wood for wood chips. The ground drywall drops into the back of a truck, and the truck takes the ground drywall to a centralized area in the development.

When loading up a truck to transport the gypsum from the stockpile to the lot, the landscape crew selects the older, wetter portion if possible. This is because the crews discovered that when the gypsum was wet, it was easier to work with and less likely to be carried in the wind. On windy days, the dry gypsum and paper can be carried in the wind, usually ending up over the mulch beds that have already been completed, which is not an aesthetically pleasing result for the client.

When the gypsum is wet, it has similar characteristics to compost, which is rich in organic matter. Gypsum and compost form into small dumps or balls when wet. However, once it rains, the dumps break down into the soil. The paper breaks down quickly as well.

Two methods were implemented when landscaping and applying gypsum. One method would mix the gypsum and compost (which was added 1-inch thick over the topsoil) together in the street with the skid loader. This method is more time intensive, but the material is easier to spread than gypsum alone. The gypsum and compost mixture is then spread across the entire lot.

The other method spreads the gypsum before the compost, which allows for less of the gypsum to be seen by the homeowner. This method was implemented in neighborhoods where more comments were made regarding the gypsum. Because this method shows less of the gypsum, it worked best in those subdivisions.

After applying the gypsum and compost, the crews add erosion mat where needed, seed and hydromulch and then a triple-10 fertilizer. With some homes, sod is placed on the front and side of the lots. It takes about three quarters of a working day (in summer conditions) to landscape a lot. Applying sod to the lots takes longer.

The gypsum was applied at a rate of roughly 4 cubic yards per 22 cubic yards compost. The range was from 2 to 6 cubic yards of gypsum on the smaller lots. These lots are the smallest within the Bielinski subdivisions that Prairie Tree Landscape has worked on in 2004. The application rate nearly matches the gypsum generated for each home, so this allows for an ongoing market for the scrap gypsum from the lots as well as a valuable soil amendment.

Dry ground scrap wallboard weighs about 400 pounds per cubic yard. The application rates would then be as follows:

* 4 Cubic Yards Gypsum: 8,888 pounds/acre (4.44 tons/acre) for an average 8,000 square foot lot

* 3 Cubic Yards Gypsum: 6,666 pounds/acre (3.33 tons/acre) for an average 8,000 square foot lot

The application rate for the ground gypsum wallboard is based on the amount of silt and clay present in the soil surface and on information from a Wisconsin soil scientist. Research has shown that nutrient imbalances because of gypsum application generally do not develop in soils high in silt and clay. High rates of gypsum application can sometimes cause a problem with magnesium in sandy soils. All of the development sites where ground gypsum was used had soils high in silt and clay. According to soil scientist Dick Wolkowski, who has studied ground gypsum application on Wisconsin soils for many years, an application rate of approximately four tons per acre is appropriate for these soils.

WORKING WITH REGULATORY AUTHORITIES

Bielinski Homes, Prairie Tree Landscape and WasteCap Wisconsin have worked closely with the regulatory authorities throughout the duration of the program. Before drywall and wood recycling could begin, we applied for and obtained from the Wisconsin Department of Natural Resources a Low Hazard Exemption for using ground, dimensional lumber and ground, engineered lumber for erosion control and a Pilot Project for utilizing ground scrap drywall as an agricultural gypsum substitute at home construction sites in Southeast Wisconsin.

The pilot project has been completed and a final report was given to the Wisconsin Department of Natural Resources in December 2004. This final report, along with other resources and studies for recycling drywall, can be found on WasteCap Wisconsin's Web site at www.wastecapwi. org/drywall.htm. The final step of this pilot project is to create a best management practices document for recycling of drywall from residential sites, which the Wisconsin Department of Natural Resources can adapt and provide to builders throughout the state. This document will be available on WasteCap's Web site, as well.

Bielinski Homes, Prairie Tree Landscape and WasteCap Wisconsin continue to work together to reduce, reuse and recycle all possible recyclables from Bielinski Home construction sites and transform waste into resources. Jenna Kunde is the executive director of WasteCap Wisconsin, based in Milwaukee, Wis., and can be reached at [e-mail].

Katie Udell is a landscape designer at Prairie Tree Landscape and can be reached at [e-mail].