1. Michael Talbert Mecklenburg County Solid Waste Dept.
Mecklenburg County’s Unpainted Gypsum Board (Drywall) Recycling Program
Michael Talbert
Mecklenburg County Solid Waste Dept.

2. What is unpainted gypsum board?
a family of panel products that consist of a noncombustible core, composed primarily of gypsum, and a paper surfacing on the face, back and long edges. It is used to make interior walls and ceilings.
Gypsum board is also known as drywall, plasterboard, and wallboard. Note: Sheetrock is a trademark brand name of drywall
Gypsum = calcium sulfate dihydrate, CaSO4·2H2O

3. Why Recycle Gypsum Board?
Save landfill space
Reduce hydrogen sulfide gases
Positive public information story that encourages building community to recycle

4. Mecklenburg County’s Program
Have been recycling gypsum since 2008
We offer a $10/ton reduced tipping fee for clean drywall from new construction (no painted drywall or material from demolition.
We were paying $20/ton for a company to pick it up and process it for sale to a fertilizer market
Beginning Summer 2014, that market couldn’t keep up with supply of material

5.
We averaged about 415 tons per month in FY16 unadvertised.

6. Gypsum Agricultural Applications
One of the earliest forms of fertilizer used in the US. It has been used in agriculture for more than 250 years.
Agricultural Crops
Nursery, Greenhouse, Landscape, and Sports Field Use
Tomato Seedlings

7. Gypsum Agricultural Benefit Findings
Adds calcium and sulfur
Increases crop yields
Remediates sodium-affected soils
More soluble than lime
Doesn’t need to be tilled to provide calcium and sulfur to grasses.
Ameliorates aluminum toxicity from high nitrogen fertilizer applications
Improves deep rooting, water and nutrient uptake
At 2 tons/acre – most effective and cost efficient way to reduce phosphorus in surface water runoff
improves surface infiltration
Reduces soil erosion

8. Sources of Gypsum for Agricultural Use
Synthetic Gypsum: Coal-fired power plants – Flue Gas Desulfurization (FGD)
Mined Gypsum
Gypsum Board (Drywall)
FGD – created in limestone-forced oxidation scrubbers that remove sulfur dioxide from the flue gas stream after coal combustion

9. Steps We Took To Develop a Market for Drywall
Contacted Agricultural Extension Agents in Mecklenburg and surrounding counties.
Found a farmer that was using a significant amount of gypsum.
Approached the farmer to see if they were interested in substituting some of their purchased gypsum with our gypsum board (drywall).
Worked with farmer to obtain relevant approvals

10. Submit crushed drywall sample to NCDA for a Waste Report (not a soil sample report)

11. In NC, Farmer applies to State Ag
In NC, Farmer applies to State Ag. for permission to land apply drywall material as a nutrient source
Description of material
Method of land application
Specific benefit to be derived from the land application
Best Management Practices to be used for land application
Best Management Practices to be used for storage

12. Application rate and diversion potential
Can be applied at a rate of between ½ - 4 tons per acre depending on the soil analysis and crops planted.
NCDA has established a load limit of 5 tons/acre for our farmer with our material.
Farmer we are working with currently buys about 30,000 tons per year.
About 4-5 times what we are currently collecting at our landfill annually
Not applied between mid-April and August
10,000 lbs/acre is limit set by USDA for Baucom Farms

13. The Operational Challenge
Our drywall
What the farmer was buying

15. First we tried crushing with landfill compactor

16. Getting Better
Our uncrushed drywall
Our crushed drywall

17. But more work was needed
Our crushed drywall
What the farmer is buying

18. Equipment demo in fair weather determined a processing path forward...

19. And then it rained…a lot

22. Ground Material – ready for shipment

24. 2016-17 Drywall Recycling Metrics
Pilot Processing Event (Jan. – Mar. 2016)
2nd Processing Event (Sept. – Oct. 2016)
3rd Processing Event (Dec Jan. 2017)
Total Cubic Yards Ground (.59 tons/cy)
12,072
7026
2812
Total Tons Ground
7,063
4,111
1,645
Total Yield Fines (tons)
4,736
2,704
1,095
Total Tons Overs
2,327
1,407
689
% Recovered as Fines 67 66
Tons shipped to market
3,531
1,784

25. 2016-17 Drywall Recycling Costs
Pilot Processing Event (Jan. – Mar. 2016)
2nd Processing Event (Sept. – Oct. 2016)
3rd Processing Event (Dec Jan. 2017)
Grinding/Trommel
$80,146
$43,913
$17,569
Loader Operator
$2,880
$975
Loader Rental
$11,660
$4,800
$1,800
Fuel
$4,386
$7,280
$1,358
Total Processing Cost
$96,192
$58,873
$21,702
Processing Cost per Ton
$13.62
$14.32
$13.20
We receive tipping fee for drywall (C&D rate - $10)
We receive $8/ton payment for material
So, you could add $2/ton to the cost/ton.
Of course, this doesn’t factor in potential costs of managing odors and leachate containing hydrogen sulfide
Or, opportunity costs of lost airspace.

26. Bonus Slide – according to the Gypsum Association, Gypsum can also be used:
As an additive in turbid water, particularly ponds, to settle dirt and clay particles without injuring aquatic life.
To create surgical and orthopedic casts.
As a food additive. Gypsum (calcium sulfate) is recognized as acceptable for human consumption by the U.S. Food and Drug Administration for use as a dietary source of calcium, to condition water used in brewing beer, to control the tartness and clarity of wine, and as an ingredient in canned vegetables, flour, white bread, ice cream, blue cheese, and other foods.
As a color additive for drugs and cosmetics.
A primary ingredient in toothpaste.
Gypsum also has played an important role in the entertainment industry. Historically, before the era of computers and high-tech special effects, film and television producers would drop “showers” of gypsum in front of the cameras to simulate snow storms.