Landfill Cover Issues

Dennis A. Degner, P.E.Chief, Solid Waste Permits Section

Bureau of Waste Management, KDHE

SAL Owner & Operator WorkshopGarden City, Kansas

July 24-25, 2018

Overview Daily Cover – Soil and ADC Intermediate Cover Final Cover

Small Arid Landfill: Typical Daily Operation

SAL Operations – from Bolton

Daily Cover 28-29-108 (b) A minimum of 6 inches of daily cover or

approved alternate daily cover (ADC) Water hitting daily cover areas is

considered leachate and must be managed as leachate

Intermediate Cover 28-29-108 Minimum of 12 inches if area will not

receive additional waste or final cover in 60 days

Graded to facilitate drainage (no ponding of water)

Seeded if no waste received for entire growing season

Maintained to prevent erosion

Final Cover 28-29-121(e)(2)(ii) 18’’ low permeability layer – K = 1 x

10^5 cm./sec. = 0.00001 cm/sec. = 0.000004 in./sec. or 0.34 in./day

Final layer or top zone of cap Frost protection for low perm layer Vegetation on top to remove moisture &

control erosion

Key Issue: Daily Soil Cover Most serious operational issue for SALs Usage more than operators thought Usage more than design engineers

thought Usage more than necessary Design engineers projected 17-20% air

space consumed by soil

Daily Soil Cover (cont.) What is reality of air space consumed

by soil?

Daily Soil Cover (cont.) Reality = 50% to 70% total air space

ADC defined: KAR 28-29-108Alternative daily cover materials may be used if they achieve performance equivalent to 6” of soil material in the

Prevention of blowing debris Minimization of access to waste by vectors Minimization of the threat of fires at open

face Minimization of odors Shedding of precipitation

Objectives of Using ADC Reduce use of landfill air space Conserve soil usage Reduce heavy equipment use and fuel

consumption Extend landfill life

Usage of ADC by Kansas SALs ADC Usage

Before January 2006 audits – 4 Currently (July 2018) – 24 (16 in 2009) Currently 24 of 32 or 75% (49% in 2009)

SALs Using ADC NW

Cheyenne Co. City of Oakley (new) City of Sharon Springs (Wallace) Decatur (new) Gove Co. Ness Co.

SALs Using ADC (cont.) NW (cont.)

Norton Co. Osborne Co. Phillips Co. Rooks Co. Rush Co. (new) Sheridan Co.

SALs Using ADC (cont.) NW (cont.)

Smith Co. (new) Thomas Co. Trego Co. (new)

SALs Using ADC (cont.) SW

Barber Co. Kearny Co. Kiowa Co. Morton Co. (New) Ness Co. (New) Pratt Co.

SALs Using ADC (cont.) SW (cont.)

Stanton Co. Stevens Co. Unified Greeley Co. Wichita Co.

Types of ADC Approved for SALs

Spray on slurry (shredded paper, TopCoat, Posi-shell, etc.)

Contaminated soil (petroleum) Water treatment plant residuals Shredded tires with soil Tarp/Corrugated metal panels Plastic film

ADC Slurry Preparation Equipment

ADC Slurry Application

ADC Slurry Cover

Daily Soil Cover: Bolton’s Report Recommendations

Track soil use for 1-2 months Meet with your county engineer or design

engineer Reevaluate soil balance & site life Change operations & modify design, e.g.,

deeper excavations or change from trench to area fill method and use ADC

Daily Cover Ideas to Consider Daily soil cover solution is likely a

combination of ideas ADC Operational and soil usage analysis Develop and implement short-term (3-5 yr.)

excavation and fill sequence plans Change future and daily operations plans

Final Landfill Cover Goal Construct & Maintain Final Landfill Cap

Provides full containment and prevents waste being spread over landfill & nearby property

Prevents groundwater and surface water contamination

Protects human health and environment

Supplemental Reference Bolton, N., Operational Evaluation of 28

Small Arid Landfills Summary Report, Prepared for Kansas Department of Health and Environment, Atascadero, CA, 14 p., July 27, 2006

Contact InformationDennis A. Degner, P.E.Chief, Solid Waste Permits SectionBureau of Waste Management, KDHE1000 SW Jackson, Suite 320Topeka, Kansas 66612-1366785-296-1601dennis.degner@ks.govwww.kdheks.gov/waste