EPA

Outer Loop LandfillEPA/WMI Bioreactor Research

2nd Intercontinental Landfill Research SymposiumAsheville, NC

14 October 2002

David CarsonOffice of Research and Development

National Risk Management Research Laboratory

Cincinnati, OH, USA

EPA

Presentation Content

uEPA Bioreactor CRADA with Waste Management, Inc.» Initial Data from Research Project

uSupporting Research

uDiscussion Questions

EPA

Bioreactor Fundamentals

u In simplest form, leachate reintroduced to the waste mass

u In more complex forms, sequenced addition of liquids, air or other combinations performed with aim of controlled, accelerated degradation

EPA

Bioreactors – Potential Benefits

u Bioreactors reduce long-term environmental risk

u Bioreactors act as on-site leachate pre-treatment systems, produce less potent leachate

u New bioreactors require relatively few physical modifications compared to traditional landfills

u Bioreactor techniques may be applicable to landfill remediation

u Bioreactors produce the same amount of methane, but at a faster rate corrective actions.

EPA

Key Performance Objectives

uAs a research effort: identify key operating parameters and develop guidance on operation and monitoring

uDemonstrate environmental protection benefits of bioreactor operational technique via enhanced control of leachate and gas

EPA

Bioreactors – Research Challenges

§ How can bioreactors enhance environmental protection?

§ Which bioreactor operational techniques most efficiently degradewaste?

§ How can operators distribute leachate and collect gas efficiently?

§ Is an interim cover necessary to cover a waste mass that is settling?

§ How do operators ensure physical stability over time?

§ How much moisture addition is optimal for degradation?

§ What limitations exist for natural degradation?

§ When can the landfill be “switched off” and closed?

§ Can post-closure care be reduced?

EPA

ORD Bioreactor Research

u Bioreactor CRADA» Cooperative Research and Development Agreement

with Waste Management Inc.— Share tasks and information— Signed in 2000 designed to end in 2005

u Supporting and Related Research Projects» State-of-the-Practice of Bioreactor Landfills» Microbial Temporal Analysis of Waste Degradation» Liner/GCL Interaction with MSW Leachate

u Upcoming EPA Bioreactor Workshop in February 2003

EPA

CRADA Bioreactor Research Team

NRMRL Bioreactor Team

<-- CRADA -->

Contractor Support

WMI Site Personnel

Waste ManagementBiosites Group

Gary HaterRoger Green

David CarsonContainment

Larry WetzelSolids Sampling

Jennifer GoetzSolids Sampling

Contractor SupportIn House

Wendy Davis-HooverSolids Decomposition

Bruce HarrisGas Emissions

Contractor SupportField

Susan ThorneloeLandfill Gas

Fran KremerProject Coordination

Contractor SupportStatistics & Data Mgt.

EPA

CRADA Project Objectives

§ To determine the parameters and trends that should be monitored to control and assess the performance of a bioreactor landfill.§ Leachate§ Gas Management/Fugitive Emissions§ Solids Decomposition

§ Two primary sites§ Area 7 – New fill§ Area 5 – Existing fill to be retrofitted, and will use

nitirified leachate to control ammonia levels§ Shared experimental control area

EPA Outer Loop Landfill, Louisville, KY

Unit 5RetrofitAnaerobic

Unit 7.3Control

Unit 7.4NewAerobic/Anaerobic Sequence

EPA

Experimental Design

u Facultative Landfill Bioreactor (FLB) and Aerobic-Anaerobic Landfill Bioreactor (AALB) treatments

u Conventional (no leachate addition) landfill control

u Treatment and control units composed of independent, paired cells

AALBA

AALBB

FLBA

FLBB

CTLA

CTLB

Received Waste2001

Received Waste1996-1998

Received Waste1999-2000

Source: Jim Markwiese, Neptune and Co.

EPA

Critical Measures

Example: Volatile Organic Acids

Critical measures were selected to capture waste stabilization

[ V

OA

] (

mg

/L)

Acclimation

Maturation

TransitionAcidogenesis

Methanogenesis

TimeSource: Jim Markwiese, Neptune and Co.

EPA

Critical Measures

uLeachate»BOD, COD, Temperature, pH, VOA’s

uMunicipal Solid Waste/Solids»Biochemical Methane Potential, Organic

Solids, Temperature, Settlement (GPS), Density, pH, Moisture Content

uGas»Methane, Carbon Dioxide, Oxygen, Volume

Source: CRADA Quality Assurance Project Plan Final 21 SEP 2001

EPA Figure Courtesy of Waste Management, Inc.

EPA

Outer Loop Unit 5

EPA

Unit 5 Trench Schematic

TYPICAL LATERAL CROSS SECTION

GROUND

GROUNDSURVEY POINTS

VALVE VAULT (12 “ CCP)

SURVEY POINTS

SURVEYPOINT

SURVEY POINTS

RISER TOGAS HEADER

GASRISER

THERMOCOUPLEMONITORING

WELL

SURVEY POINT3 “ HDPE PERFORATED DISTRIBUTION PIPE

3 “ HDPE SOLIDLEACHATE

DISTRIBUTION PIPEGAS

COLLECTIONPIPE

THERMOCOUPLEMONITORING WELL

PIEZOMETER

GAS HEADERPIPE (SOLID)

3 “ LEACHATERISER PIPE (SOLID)

VALVE

PIEZOMETER

Figure Courtesy of Waste Management, Inc.

EPA

Unit 5 Trench Infiltration/Gas Collection Gallery

MUNICIPALSOLID WASTE

TIRE CHIPS

FLUFFEDSOLID WASTE

LIQUID PIPE DISTRIBUTION

LANDFILL GASCOLLECTION PIPE

COVER

THERMOCOUPLE MONITORING WELL2.5 ‘

30 “

7 ‘ to 12 ‘

APPROX. 5 ‘

2 ‘ to 3 ‘

6 “

Figure Courtesy of Waste Management, Inc.

EPA

Unit 5 Sub Cell ArrangementGas Monitoring

1 5

4

Northmeteringstation

Southmeteringstation

32

to flare

N5.2 a and 5.2b

North5.1a and 5.2b

South

EPA Figure Courtesy of Waste Management, Inc.

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Outer Loop Unit 7

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Initial ResultsUnit 5Gas

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Unit 5.1 Gas Composition vs. Time

Figure Courtesy of Neptune, Inc.

LeachateInjectionBegins

EPA

Unit 5.2 Gas Composition vs. Time

Figure Courtesy of Neptune, Inc.

LeachateInjectionBegins

EPA

Modeled v. Actual Methane ProductionUnit 5

1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

methane production

(ft3/min)

0

100

200

300

400

500

k=0.03

k=0.07

k=0.05

MODEL ASSUMPTIONS:2,085,748 tons (1995-2001)

L0=1.6 ft3/lbcollection efficiency= 100%

Figure Courtesy of Waste Management, Inc.

EPA

Modeled v. Actual Methane ProductionUnit 5

9/1/2001 12/1/2001 3/1/2002 6/1/2002

methane production

(ft3/min)

0

100

200

300

400

500

k=0.03

k=0.05

k=0.07

sdf

Figure Courtesy of Waste Management, Inc.

EPA

Initial ResultsUnit 5

Leachate

EPA

Outer Loop Unit 5 Leachate Sampling

EPA

Outer Loop Unit 7 Leachate Sampling

EPA

Unit 5Cumulative Liquid Addition and AUF vs. Time

5/1/2001 9/1/2001 1/1/2002 5/1/2002

gallons

0

500000

1000000

1500000

2000000

2500000

3000000

AUF

0.810

0.812

0.814

0.816

0.818

0.820

0.822

0.824

0.826

0.828

Figure Courtesy of Waste Management, Inc.

EPA

Unit 5Liquid Addition and Leachate Removal vs. Time

CUMULATIVE LIQUID ADDITIONCUMULATIVE LEACHATE REMOVAL

Figure Courtesy of Waste Management, Inc.

51A(gallons)

500000

1000000

1500000

200000051B

52B

1/02 3/02 5/02 7/02 9/02 11/02

52A

1/02 3/02 5/02 7/02 9/02 11/02

500000

1000000

1500000

2000000

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Unit 5 LeachateBOD/COD vs. Time

Figure Courtesy of Neptune, Inc.

LeachateInjectionBegins

EPA

51A

05/01 09/01 01/02 05/02

(gal

lons

)

0

200000

400000

600000

800000

(mg/

L)

0

500

1000

1500

2000

2500

pH (

s.u.

)

6.0

6.5

7.0

7.5

8.0

tem

pera

ture

(o C

)

20

25

30

35

40

cumulative liquid added

BOD COD pH

leachate temperature

Unit 5.1A Leachate Composition vs. Time

Figure Courtesy of Waste Management, Inc.

EPA

Initial ResultsUnit 5Solids

EPA

Baseline Waste Sampling

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Baseline Waste Sampling

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Solids Analysis

EPA

Unit 5.1AWaste and Ambient Temperature and Leachate Addition vs. Time

04/12/02 04/19/02

Liquid Volume (gallons)

0

200

400

600

800

1000

Temperature

(oC)

0

10

20

30

40

51A T04 Ambient

Figure Courtesy of Waste Management, Inc.

EPA

Unit 5 Waste Density vs. Time

Figure Courtesy of Waste Management, Inc.

06/01 10/01 02/02 06/02 10/02

(tons/yd3)

0.810

0.812

0.814

0.816

0.818

0.820

0.822

0.824

0.826

0.828

fgd

EPA

Unit 5 Waste Volume vs. Time

Figure Courtesy of Waste Management, Inc.

06/01 10/01 02/02 06/02 10/02

waste volume

(yd3)

2520000

2530000

2540000

2550000

2560000

2570000

2580000

jkil

EPA

Unit 5 Airspace Recovery vs. Time

Figure Courtesy of Waste Management, Inc.

2001 2002 2003 2004 2005 2006

airs

pace

vol

ume

chan

ge (p

erce

nt)

0

5

10

15

EPA

Fugitive Air Emissions Monitoring

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Static FTIR - Background

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Scanning FTIR

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Summary

uProject is in the initial stages of a multiyear study»This project, coupled with supporting research

will enhance understanding of bioreactors—Project XL—Assessment of Bioreactor Performance

StudyuEarly bioreactor results are as expected

EPA

CRADA Next Steps

uContinue Monitoring»Revise Monitoring Plan as Needed

u Issue Interim Report in 2003

u Issue Detailed Technical Report in 2005

EPA

Discussion Questions

uQ. How effective is bioreactor technology in achieving desired aims?

u A. Too early to tell at this project, but beneficial trends as expected.

uQ. What research gaps exist?u A. Which monitoring parameters needed at working fills

to maintain control.uQ. What challenges were faced?u A. Continuity of operations, retrofitting of system to

existing fill, changing waste stream, daily operations, permit proceedings

EPA

Discussion Questions (cont’d)

uQ. What recommendations can be made for future design and operation?

uA. Waste placement planning, gas collection timing

uQ. How were instruments used in process control?

uA. Parameter control is direct for some parameters, delayed for others, data management is a concern

EPA