Mecklenburg Countys Unpainted Gypsum Board Drywall Recycling Program

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

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, Ca. SO 4· 2 H 2 O

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

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

2014 2016

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

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

Sources of Gypsum for Agricultural Use • Synthetic Gypsum: Coal-fired power plants – Flue Gas Desulfurization (FGD) • Mined Gypsum • Gypsum Board (Drywall)

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

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

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 storage

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

The Operational Challenge Our drywall What the farmer was buying

First we tried crushing with landfill compactor

Getting Better Our uncrushed drywall Our crushed drywall

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

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

And then it rained…a lot

Ground Material – ready for shipment

2016 -17 Drywall Recycling Metrics Pilot Processing Event 2 nd Processing Event (Jan. – Mar. 2016) (Sept. – Oct. 2016) 3 rd Processing Event (Dec. 2016 - 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 67 Tons shipped to market 3, 531 4, 111 1, 784

2016 -17 Drywall Recycling Costs Pilot Processing Event 2 nd Processing Event 3 rd Processing Event (Jan. – Mar. 2016) (Sept. – Oct. 2016) (Dec. 2016 - Jan. 2017) Grinding/Trommel $80, 146 Loader Operator $43, 913 $17, 569 $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

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.