Using C&D Fines and Residuals to Close Landfills – Lessons ... · PDF fileUsing C&D Fines and Residuals to Close Landfills – Lessons ... New or revised policies ........

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Using C&D Fines and Residuals Using C&D Fines and Residuals

to Close Landfills to Close Landfills –– Lessons Lessons LearnedLearned

James DoucettJames Doucett

Business Compliance DivisionBusiness Compliance Division

Bureau of Waste PreventionBureau of Waste Prevention

MassDEPMassDEP

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OverviewOverview

� Background – how did we arrive at

allowing use of C&D residuals in landfills

� Problems that developed

� Solutions

� Looking forward

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Key Issues for Massachusetts:Key Issues for Massachusetts:

� Lack of landfill capacity

� Goal to maximize diversion of C&D

waste from landfilling

� Number of old landfills never

properly capped and closed

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Since 2000 Master Plan:Since 2000 Master Plan:

�Banned disposal of specific C&D materials in 2006

�Conducted case studies to promote C&D source

reduction

�Provided over $700,000 in grants and loans to develop

C&D related recycling infrastructure

�Developing new end-use markets for processed C&D

and wood in particular

�Allowed C&D residuals to be used to close inactive

LFs

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Response by IndustryResponse by Industry

� In late 1990s, in response to the proposal to

ban disposal of C&D waste, the C&D

processing industry took off

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Response by IndustryResponse by Industry

� Before 2000 Master Plan:

– 6 C&D processing facilities

� Currently:

– 11 operating C&D processing facilities

– 2 in permitting

– 2 others located in NH on Mass border

� Over 3 million tpy of processing capacity, which

more than takes care of Mass C&D waste

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Snapshot of C&D ProcessingSnapshot of C&D Processing20042004

� 5,160,000 tons C&D generated

� 4,500,000 tons diverted/recycled– 3,470,000 tons - ABC materials

– 100,000 tons - Metal

– 30,000 tons - C&D wood recycled

– 50,000 tons - C&D wood for boiler fuel

– 50,000 tons - Woodwaste (clean wood)

– 20,000 tons - Other (ceiling tiles, carpet, gypsum wallboard, and

asphalt roofing shingles)

– 810,000 tons - C&D fines and residuals for closures

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Life is Good, Right?Life is Good, Right?

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Problems in Processor Problems in Processor

ParadiseParadise� C&D materials can be difficult to recover

and recycle

� Weak markets (C&D wood, for example)

– Wood biomass facilities located in Maine

– Controversy on burning C&D wood

� What do you do with residuals and fines?– Expensive to dispose of residuals and fines

($60-$100/ton)

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Industry ResponseIndustry Response

•Temporary closure of processors

- Nov. 1999

- no place to send residuals

•Proposed using residuals to close

old landfills!

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DEP ResponseDEP Response

� Unlined Landfill Closure Policy:– Allows use of materials for grading and shaping

old landfills prior to capping� C&D fines and residuals

� Coal ash

� Contaminated soils that meet MassDEP soils policy

� Dredge spoils, street sweepings, etc.

– Provides guidance on permitting process

– Establishes standards for materials and projects to promote consistency

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Why Use C&D Fines and Why Use C&D Fines and

Residuals to Close Residuals to Close LFsLFs??

� 700+ old MSW landfills in Massachusetts

– Lots of pre-1971 landfills never capped and

closed properly or only with minimal soil cover

– 1971 regulations had minimal closure standards

– 1990 regulations require up-to-date closures

� Have closed over 150 LFs since 1990

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Why Use Fines and Residuals?Why Use Fines and Residuals?

� Development pressures – land is valuable,

even old LFs

� Municipalities own most of those old

landfills

� Cost of closure is high

– no money set aside to close

– large burden on tax rate

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� Fines and residuals can be used to grade the

landfill substituting for higher cost soils

� Town can charge a tipping fee for the

materials

� Set aside $$ for assessment, closure,

capping and post-closure monitoring and

maintenance

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� The Big Issues:– What volume of grading and shaping material

is really needed?� To simply close the LF it is X

� To set aside enough money to also pay for the capping and closure it is X+Y

� To maximize profits it is X+Y+Z

– How much time is needed to grade then cap the landfill?

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Major Goals of PolicyMajor Goals of Policy

• Promote a permanent, permitted C&D

recycling/processing infrastructure

• Maximize recycling of C&D materials

• Ensure there is a home for C&D residuals

• Level Playing Field

• all landfill closures play by same rules

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The ProcessThe Process

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Stage 1 Stage 1 –– Consolidation and PreConsolidation and Pre--shreddingshredding

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Stage 2 Stage 2 –– Mechanical Separation/ScreeningMechanical Separation/Screening

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Stage 4 Stage 4 –– DuelDuel--line Picking Stationsline Picking Stations

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Stage 5 Stage 5 –– Float Tank/Density SeparationFloat Tank/Density Separation

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Stage 6 Stage 6 –– Residual & Fuel ProductionResidual & Fuel Production

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C&D Residuals in UseC&D Residuals in Use

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ProblemsProblems

� H2S gas generated that resulted in odor

problems

� Why? – theories

� Concentrations

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What Caused Odor Problem?What Caused Odor Problem?

� H2S issue much worse than expected

� Possible Causes:– Grinding wallboard increases surface area for

reaction

– Large amount of material going into LF over short period of time

– Conditions were ripe:� Anaerobic conditions

� Moisture

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How Bad Can it Be?How Bad Can it Be?

� Raw LF gas from gas probes:

– MSW landfill not using residuals or fines – H2S

<100 ppm

– Landfill using residuals and fines – H2S>20,000

– 30,000 ppm

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Where Did We Get into Where Did We Get into

Trouble?Trouble?

� Happened quickly – anaerobic conditions,

moisture and short period of time (9 months

to 1 year)

� No financial assurance to cover H2S

pretreatment and flaring LF gas

– Pretreatment is expensive

– Pretreatment technology not fool-proof

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SolutionsSolutions

� Source separation of wallboard at job sites

� Front-end removal of wallboard by C&D

processors

� Mix soils with residuals

� Install gas collection, pre-treatment and

flaring systems as closure progresses

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What Has MassDEP Done?What Has MassDEP Done?

� Require operator to address site-specific

problems when they arose

– Cover what’s there

– Stop taking more residuals until under control

– Install gas collection and pre-treatment

� New or revised policies

� Demonstration project

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� Site specific solutions

– Gas pre-treatment to knock down H2S

– Gas treatment – flares

– Reduce or eliminate use of fines and residuals

– Require higher ratio of soil to fines and

residuals, at least 3:1 recommended

– Apply final cap as soon as possible in phases if

necessary

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� Pre-treatment Issues:– 2 basic systems:

� Sulfa-treat – low capital cost, high operating cost

� Scrubbing – high capital cost, low operating cost

– Systems not designed for high concentrations of H2S - must change out media often - $$$$

– If concentration of H2S at inlet to flare is too high, flare will exceed permitted SO2 conc.

– Supplemental fuel needed, not enough methane

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� Policies

– Modify Unlined Landfill Closure Policy to

include Addendum with BMPs

– Developed H2S Policy to address odors

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Best Management PracticesBest Management Practices

� Addendum to Closure Policy

– Setbacks to residences for future projects

– Wallboard separation program required

– Monitor sulfate content in residuals and fines

– Require minimum 3:1 ratio of soil to residuals

– Develop odor control plan (H2S Policy)

– Financial assurance for gas treatment

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HH22S PolicyS Policy

� Requires Odor Control Plan be developed by

landfills using C&D residuals and fines

� Establishes Action Levels:

– Odor Action Level

– H2S Action Level

� 15 ppb over 8 hr; or

� 30 ppb over 1 hr.

� Progressive series of steps if problems develop

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� Steps:

– Log complaints

– Determine nature, extent and severity of odor

problem

– Implement corrective actions (stop using

residuals, apply soil daily cover, etc.)

– Implement 24 hr. monitoring if not a specific

source using soil probes/wells and near-surface

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� Steps (continued):

– Implement off-site gas monitoring if necessary

– Install gas collection, pre-treatment and flare

– Implement community communication plan

– Conduct additional off-site monitoring at

receptor locations

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Demonstration ProjectDemonstration Project

� Marion LF Demonstration Project

– Project Requirements

� Gypsum removal

– Concentrations of sulfate measured before and after

gypsum removal program

� Mix ratio of soils with fines and residuals

� Limited to residuals from only one C&D processor

� Monitored H2S generation

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Gypsum Wallboard Removal PlanGypsum Wallboard Removal Plan

� To create a low gypsum/sulfate product at

New Bedford Waste Services, they…

� Educated customers that gypsum wallboard is a problem

� Surcharged clients who delivered co-mingled gypsum

wallboard

� Bypassed all visual wallboard from the C&D processing line

� Hand sorted clean gypsum wallboard for recycling

� Created fines and residuals with a lower sulfate content

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Clean Gypsum Wallboard Clean Gypsum Wallboard

Recycling (covered container)Recycling (covered container)

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NBWS InNBWS In--house Sulfate house Sulfate

Levels Data Levels Data (pre(pre--gypsum removal)gypsum removal)

41,000 mg/Kg11/10/2005Fines/Residuals




ConcentrationDateMaterial

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NBWS InNBWS In--house Sulfate house Sulfate

Levels Data Levels Data (post(post--gypsum removal)gypsum removal)





ConcentrationDateMaterial

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Marion LF Results to DateMarion LF Results to Date

� Odors have not developed

� No need for LF gas pre-treatment or flaring so far

� Monitoring Data:

– 15 soil gas probes inserted 12 feet into the LF

– H2S measured in the LF soil ranged from 0.0 ppm to

48.0 ppm (1 sample)

– H2S measured at the LF surface at 0.001 ppm or 1 ppb

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Looking ForwardLooking Forward

� Managing C&D has been interesting:– Processors stepped up to the plate and built

facilities

– Markets for reuse/recycling/diversion still an issue

– Still believe residuals and fines can be successfully used, but must apply BMPs

– Management of residuals key if processors are to remain a part of our C&D management infrastructure

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� Work To Do:

– Reduce the amount of residuals and fines generated� Firm up markets for C&D wood

� Expand wallboard recycling

� Recycle ceiling tiles and carpets

– Ensure use of residuals and fines will not cause problems in future

– Continually push for source separation to achieve better products

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� Ze-Gen Pilot Project – gasification of C&D wood

� Clean Wood BUD

� Biomass Projects

– Will facilities burning C&D wood get Renewable

Energy Credits (RECs)?

� Wallboard recycling

– Clean wallboard scraps currently recycled

– Old wallboard

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Need More Information?Need More Information?

� James Doucett – 617-292-5868

email – [email protected]

� MassDEP website

www.mass.gov/dep/recycle

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