GreenYes Archives

[GreenYes Home] - [Thread Index] - [Date Index]
[Date Prev] - [Date Next] - [Thread Prev] - [Thread Next]


[GreenYes] Informed solid waste management


All,

Few would argue that most of us want to do the "right thing."
Similarly, few would argue that fully informed decisions are anything
less than optimal. However, many decisions involving solid waste
management are made that are not fully informed. The suggestion has
been made by Barlaz et al., (2003a) that the public is not always able
to separate that which sounds appealing from true resource recovery. It
has become clear that while there are often positive externalities
(benefits) to our "do-good" actions there are also negative
externalities (costs) associated with our actions. These unaccounted
for external costs imply that our activities are inefficient. In this
circumstance society's net welfare is not maximized and is therefore
suboptimal.

On September 22, 2006 I sent an email to the GreenYes listserv (Is MSW
recycling the best policy?) soliciting commentary on the following
assertions by Lave et al. (1999). First, "the goal of MSW recycling
(presumably that of the US) should not be to increase MSW recycling but
rather to increase environmental quality and the sustainability of the
economy." Second, "from a review of the existing economic experience
with recycling and an analysis of the environmental benefits (including
estimation of external social costs)... for most communities, curbside
recycling is only justifiable for some postconsumer waste, such as
aluminum and other metals." Third, "curbside recycling of postconsumer
metals can save money and improve environmental quality if the
collection, sorting, and recovery processes are efficient." Finally,
"curbside collection of glass and paper is unlikely to help the
environment and sustainability save in special circumstances." What is
suggested by Lave et al. (1999) is that the diversion of materials in a
recycling program that increase the cost of waste management is not
appropriate when the added cost of the diversion, including
environmental discharges, resources, and energy, are more than those
associated with the extraction, transportation, and manufacture of
virgin materials. Consideration of cost, environmental discharges,
resources, energy, and other externalities (both positive and negative)
should occur when evaluating any waste management alternative.

There are tools available that quantify the relative benefits of the
various alternatives of solid waste management...tools that indicate the
appropriateness of integrated solid waste management. LCA is an
analytical tool that examines the often complex environmental impact of
a product, process, or service. Information returned from LCAs can be
used as an important input to informed solid waste
decision-making...decision-making that should incorporate periodic
reassessment. Such reassement includes, for example, measurement of the
efficacy of diversion programs at the material/commodity level.
Depending on ever-changing circumstances, halting the diversion of glass
bottles and jars in favor of spending the saved money on programs
targeting the diversion or perhaps elimination of high-risk products
might be an indicated course of action. Given the more than appreciable
expense of curbside collection of recyclables, a dollar spent on the
collection of glass, paper, or PET might be better spent elsewhere,
perhaps on drop-off or deposit programs or take-back schemes as has been
suggested (Lave et al., 1999; Barlaz et al., 2003a). As Barlaz et al.
(2003a) point out, saving gasoline has a lot more potential to reduce
greenhouse gas emissions than does PET recycling.

Any informed waste diversion program would not be complete without a
review of the literature focused on LCA in resource and solid waste
management including that which discusses the limitations of its use. A
couple of excellent places to get started are EIONET's Web site
(http://waste.eionet.europa.eu/lca) and the US EPA's Web page on
Life-Cycle Assessment Research
(http://www.epa.gov/ord/NRMRL/lcaccess/index.html). I've put together a
partial list of references focusing on life-cycle assessment (LCA) of
solid waste management. If anyone has other references to add I'd like
to know about them. It is important to note that failure to consider
that the rarely-static mix of circumstances/management
techniques/parameters/inputs differ between locations could result in
suboptimal or worse-than-before solutions when applying LCA results in a
cookie-cutter fashion. Additionally, not all LCAs are created equal.
Some are more accurate and(or) thorough in their consideration of input
parameters and externalities than others. Quantifying tangible and
intangible social benefits and costs can be very difficult. Concerning
the input data and the quality of the LCA, the old adage (and pardon the
pun) "Garbage In Garbage Out" certainly applies.


*Barlaz, M.A, Cekander, G.C., Vasuki, N.C., 2003a. Integrated solid
waste management in the United States. Journal of Environmental
Engineering 129(7): 583-584.


Barlaz, M.A., Kaplan, P.O., Ranjithan, S.R., 2003. Using life-cycle
analysis to compare solid waste management alternatives involving
recycling, composting and landfills. MSW Management 13(3): 42-43.


Barlaz, M.A., Kaplan, P.O., Ranjithan, S.R., Rynk, R., 2003. Evaluating
environmental impacts of solid waste management alternatives. BioCycle
44(10): 52-56.
*

*Camobreco, V., Ham, R., Barlaz, M., Repa, E., Felker, M., Rousseau, C.,
Rathle, J., 1999. Life-Cycle inventory of a modern municipal solid waste
landfill. Waste Management and Research 17(6): 394-408.*

*Abstract*
The Environmental Research and Education Foundation (EREF), in
conjunction with Ecobalance and researchers from the University of
Wisconsin and North Carolina State, is nearing completion of a
comprehensive 2-year project on the life-cycle inventory (LCI) of a
modern municipal solid waste (MSW) landfill. Data for the model
came from both primary (over 100 landfills world-wide) and secondary
data sources. Partners in the project included waste management
companies from North America and Europe (including Waste Management
Inc., SITA and CREED). In addition to the landfill LCI model, the
project also includes the development of a software tool. The final
report will provide a sound basis for assessing, on a life-cycle
basis, the emissions and resource consumption associated with a
modern MSW landfill. The model and report can be used to assess the
importance of: (1) the various stages in the life cycle system; (2)
the time horizon selected; and (3) the air and water management
techniques selected.



*Denison, R.A., 1996. Environmental life-cycle comparisons recycling,
landfilling, and incineration: A review of recent research. Annual
Review of Energy and the Environment 21(1): 191-237.
*

*Abstract*
This paper reviews and analyzes the major recent North American
studies that have compared on an environmental basis the major
options used to manage the materials that comprise municipal solid
waste (MSW). The reviewed studies provide quantitative comparative
information on one or more of the following environmental
parameters: solidwaste output, energy use, and releases of
pollutants to the air and water. The review finds that all of the
studies support the following conclusions: Systems based on recycled
production plus recycling offer substantial system-wide or
"life-cycle" environmental advantages over systems based on virgin
production plus either incineration or landfilling, across all four
parameters examined. Only when the material recovery or waste
management activities are analyzed in isolation? (which does not
account for the system-wide consequences of choosing one system
option over another?) do the virgin material?-based systems appear
to offer advantages over recycled production plus recycling.

*

Eriksson, O., Carlsson-Reich, M., Frostell, B., Bjorklund, A., Assefa,
G., Sundqvist, J.-. Granath, J., Baky, A., Thyselius, L., 2005.
Municipal solid waste management from a systems perspective. Journal of
Cleaner Production 13(3): 241-252.
*

*Abstract*
Different waste treatment options for municipal solid waste have
been studied in a systems analysis. Different combinations of
incineration, materials recycling of separated plastic and cardboard
containers, and biological treatment (anaerobic digestion and
composting) of biodegradable waste, were studied and compared to
landfilling. The evaluation covered use of energy resources,
environmental impact and financial and environmental costs. In the
study, a calculation model (Orware) based on methodology from life
cycle assessment (LCA) was used. Case studies were performed in
three Swedish municipalities: Uppsala, Stockholm, and Älvdalen. The
study shows that reduced landfilling in favour of increased
recycling of energy and materials lead to lower environmental
impact, lower consumption of energy resources, and lower economic
costs. Landfilling of energy-rich waste should be avoided as far as
possible, partly because of the negative environmental impacts from
landfilling, but mainly because of the low recovery of resources
when landfilling. Differences between materials recycling, nutrient
recycling and incineration are small but in general recycling of
plastic is somewhat better than incineration and biological
treatment somewhat worse. When planning waste management, it is
important to know that the choice of waste treatment method affects
processes outside the waste management system, such as generation of
district heating, electricity, vehicle fuel, plastic, cardboard, and
fertiliser.

*

Harrison, K.W., Dumas, R.D., Nishtala, S.R., Barlaz, M.A., 2000. A
life-cycle inventory of municipal solid waste combustion. Journal of the
Air and Waste Management Association 50(6): 993-1003.
*

*Abstract*
Evaluation of alternative strategies for municipal solid waste (MSW)
management requires models to calculate environmental emissions as a
function of both waste quantity and composition. A methodology to
calculate waste component-specific emissions associated with MSW
combustion is presented here. The methodology considers emissions
at a combustion facility as well as those avoided at an electrical
energy facility because of energy recovered from waste combustion.
Emission factors, in units of kg pollutant per metric ton MSW
entering the combustion facility are calculated for CO2-biomass,
CO2-fossil, SOx, HCI, NOx, dioxins/furans, PM, CO, and 11 metals.
Water emissions associated with electrical energy offsets are also
considered. Reductions in environmental emissions for a
500-metric-ton-per-day combustion facility that recovers energy are
calculated.

*

Harrison, K.W., Dumas, R.D., Solano, E., Barlaz, M.A., Brill, D.E.,
Ranjithan, S.R., 2001. Decision support tool for life-cycle-based solid
waste management. Journal of Computing in Civil Engineering 15(1): 44-58.
*

*Abstract*
Existing solid waste management (SWM) planning software provides
only limited assistance to decision makers struggling to find
strategies that address their multifarious concerns. The
combinatorial nature (many waste items and many management options)
and multiple objectives of the SWM problem severely constrain the
effectiveness of a manual search process using these tools.
Recognizing this, researchers have proposed several
optimization-based search procedures. These methods, however, enjoy
limited use due to the substantial expertise required for their
application. This paper presents a new computer-based decision
support framework that addresses these limitations. The new
framework integrates process models that quantify the lifecycle
inventory of a range of pollutants and costs for an extensive
municipal solid waste system, an optimization search procedure that
identifies strategies that meet cost and environmental objectives
and site-specific restrictions, and a user-friendly interface that
facilitates utilization of these components by practitioners. After
describing the software design, the use and value of the tool in
typical waste management scenarios is demonstrated through a
hypothetical, but realistic, case study in which several alternative
SWM strategies are generated and examined.

*

Kaplan, P.O., Solano, E., Dumas, R.D., Harrison, K.W., Ranjithan, S.R.,
Barlaz, M.A., Brill, E.D., 2003. Life-cycle-based solid waste
management. Second International Conference of the International Society
for Industrial Ecology, June 29-July 2, 2003, Ann Arbor, MI.
*

*Abstract*
The development of integrated solid waste management (ISWM)
strategies that are efficient with respect to both cost and
environmental performance is a complex task. There are numerous
interrelations among the different unit operations in the solid
waste system; e.g., collection, recycling, combustion, disposal, and
large numbers of design parameters that affect estimates of cost and
environmental emissions. The objective of this study was to develop
and demonstrate an ISWM model to assist in the identification of
alternative SWM strategies that meet cost, energy, and environmental
emissions objectives. The modeled system includes over 40 unit
processes for collection, transfer, separation, treatment (e.g.,
combustion, composting), and disposal of waste as well as
remanufacturing facilities for processing recycled material. Waste
composition and generation rates are defined for three types of
sectors: single family, multifamily and commercial. The mass flow of
each item through all possible combinations of unit processes is
represented in a linear programming model using a unique modeling
approach. Cost, energy consumption and environmental emissions
associated with waste processing at each unit process are computed
in a set of specially implemented unit process models. A life-cycle
approach is used to compute energy consumption and emissions of
numerous pollutants, including CO, fossil- and biomass-derived CO2,
NOx, SOx, particulate matter, and CH4. The model is flexible to
allow representation of site-specific issues, including recycling
and composting targets, mass flow restrictions, and targets for the
values of cost, energy and each emission. The model was applied in
a hypothetical case study. Several SWM scenarios were studied,
including the variation in energy and environmental emissions among
alternate SWM strategies; the effect of mandated waste diversion
(through recycling and other beneficial uses of waste such as
combustion to recover energy) on environmental releases and cost;
the tradeoff between cost and the level of waste diversion; and the
tradeoff between cost and greenhouse gas emissions. In addition,
the flexibility of the model is illustrated by the identification of
alternate SWM strategies that meet approximately the same objectives
using distinctly different combinations of unit processes. Use of
the model illustrates the potential impact of solid waste management
policies and regulations on global environmental emissions.
Recently, the model was extended to enable consideration of
uncertainty in input parameters. Monte Carlo simulation with Latin
Hypercube Sampling was integrated within the ISWM model to estimate
the uncertainty in cost and emissions for a specific SWM strategy.
For each realization, the cost and LCI coefficients are computed.
These are then combined with the mass flows of waste items
corresponding to an SWM strategy to estimate its cost and
emissions. After repeating this procedure for all realizations, the
resultant cost and emissions values are used to form output
cumulative distribution functions. The extended capability of the
ISWM decision support tool

*

Komilis, D.P., Ham, R.K., 2004. Life-Cycle inventory of municipal solid
waste and yard waste windrow composting in the United States. Journal of
Environmental Engineering 130(11): 1390-1400.
*

*Abstract*
This paper presents a life-cycle inventory (LCI) for solid waste
composting. Three LCIs were developed for two typical municipal
solid waste (MSW) composting facilities (MSWCFs) and one typical
yard waste (YW) composting facility (YWCF). Municipal solid waste
was assumed to comprise three organic components, food wastes, yard
wastes, and mixed paper, as well as various inorganic components.
Total costs, combined precombustion, and combustion energy
requirements and 29 selected material flows (also referred to as LCI
coefficients) were calculated by accounting for both the processes
involved in originally producing, refining and transporting a
material used in the facility as well as consumption during normal
facility operation. Total costs ranged from $15/ t to $50/ t and
energy requirements from 29 kw h/ t to 167 kw h/ t for a YWCF and a
high quality MSW composting facility, respectively. More than 90%
of the overall CO2 emissions in all facilities were due to the
biological decomposition of the organic substrate, while the rest
was due to fossil fuel combustion.

*

Lave, L.B., Hendrickson, C.T., Conway-Schempf, N.M., McMichael, F.C.,
1999. Municipal solid waste recycling issues. Journal of Environmental
Engineering 125(10): 944-949.*

*Abstract*
Municipal solid waste (MSW) recycling targets have been set
nationally and in many states. Unfortunately, the definitions of
recycling, rates of recycling, and the appropriate components of MSW
vary. MSW recycling has been found to be costly for most
municipalities compared to landfill disposal. MSW recycling policy
should be determined by the cost to the community and to society
more generally. In particular, recycling is a good policy only if
environmental impacts and the resources used to collect, sort, and
recycle a material are less than the environmental impacts and
resources needed to provide equivalent virgin material plus the
resources needed to dispose of the postconsumer material safely.
From a review of the existing economic experience with recycling
and an analysis of the environmental benefits (including estimation
of external social costs), we find that, for most communities,
curbside recycling is only justifiable for some postconsumer waste,
such as aluminum and other metals. We argue that alternatives to
curbside recycling collection should be explored, including product
takeback for products with a toxic content (such as batteries) or
product redesign to permit more effective product remanufacture.



*Morris, J., 2005. Comparative LCAs for Curbside Recycling Versus Either
Landfilling or Incineration with Energy Recovery. International Journal
of Life Cycle Assessment 10(4): 273-284.*

*Abstract*
Background.

This article describes two projects conducted recently by Sound
Resource Management (SRMG) - one for the San Luis Obispo County
Integrated Waste Management Authority (SLO IWMA) and the other for
the Washington State Department of Ecology (WA Ecology). For both
projects we used life cycle assessment (LCA) techniques to evaluate
the environmental burdens associated with collection and management
of municipal solid waste. Both projects compared environmental
burdens from curbside collection for recycling, processing, and
market shipment of recyclable materials picked up from households
and/or businesses against environmental burdens from curbside
collection and disposal of mixed solid waste.

Methodlogy.
The SLO IWMA project compared curbside recycling for households and
businesses against curbside collection of mixed refuse for
deposition in a landfill where landfill gas is collected and used
for energy generation. The WA Ecology project compared residential
curbside recycling in three regions of Washington State against the
collection and deposition of those same materials in landfills where
landfill gas is collected and flared. In the fourth Washington
region (the urban east encompassing Spokane) the WA Ecology project
compared curbside recycling against collection and deposition in a
wasteto- energy (WTE) combustion facility used to generate
electricity for sale on the regional energy grid. During the time
period covered by the SLO study, households and businesses used
either one or two containers, depending on the collection company,
to separate and set out materials for recycling in San Luis Obispo
County. During the time of the WA study households used either two
or three containers for the residential curbside recycling programs
surveyed for that study. Typically participants in collection
programs requiring separation of materials into more than one
container used one of the containers to separate at least glass
bottles and jars from other recyclable materials. For the WA Ecology
project SRMG used life cycle inventory (LCI) techniques to estimate
atmospheric emissions of ten pollutants, waterborne emissions of
seventeen pollutants, and emissions of industrial solid waste, as
well as total energy consumption, associated with curbside recycling
and disposal methods for managing municipal solid waste. Emissions
estimates came from the Decision Support Tool (DST) developed for
assessing the cost and environmental burdens of integrated solid
waste management strategies by North Carolina State University
(NCSU) in conjunction with Research Triangle Institute (RTI) and the
US Environmental Protection Agency (US EPA)1. RTI used the DST to
estimate environmental emissions during the life cycle of products.
RTI provided those estimates to SRMG for analysis in the WA Ecology
project2. For the SLO IWMA project SRMG also used LCI techniques and
data from the Municipal Solid Waste Life- Cycle Database (Database),
prepared by RTI with the support of US EPA during DST model
development, to estimate environmental emissions from solid waste
management practices3. Once we developed the LCI data for each
project, SRMG then prepared a life cycle environmental impacts
assessment of the environmental burdens associated with these
emissions using the Environmental Problems approach discussed in the
methodology section of this article. Finally, for the WA study we
also developed estimates of the economic costs of certain
environmental impacts in order to assess whether recycling was cost
effective from a societal point of view.

Conclusions.
Recycling of newspaper, cardboard, mixed paper, glass bottles and
jars, aluminum cans, tin-plated steel cans, plastic bottles, and
other conventionally recoverable materials found in household and
business municipal solid wastes consumes less energy and imposes
lower environmental burdens than disposal of solid waste materials
via landfilling or incineration, even after accounting for energy
that may be recovered from waste materials at either type disposal
facility. This result holds for a variety of environmental impacts,
including global warming, acidification, eutrophication, disability
adjusted life year (DALY) losses from emission of criteria air
pollutants, human toxicity and ecological toxicity. The basic
reason for this conclusion is that energy conservation and pollution
prevention engendered by using recycled rather than virgin materials
as feedstocks for manufacturing new products tends to be an order of
magnitude greater than the additional energy and environmental
burdens imposed by curbside collection trucks, recycled material
processing facilities, and transportation of processed recyclables
to end-use markets. Furthermore, the energy grid offsets and
associated reductions in environmental burdens yielded by generation
of energy from landfill gas or from waste combustion are
substantially smaller then the upstream energy and pollution offsets
attained by manufacturing products with processed recyclables, even
after accounting for energy usage and pollutant emissions during
collection, processing and transportation to end-use markets for
recycled materials. The analysis that leads to this conclusion
included a direct comparison of the collection for recycling versus
collection for disposal of the same quantity and composition of
materials handled through existing curbside recycling programs in
Washington State. This comparison provides a better approximation
to marginal energy usage and environmental burdens of recycling
versus disposal for recyclable materials in solid waste than does a
comparison of the energy and environmental impacts of recycling
versus management methods for handling typical mixed refuse, where
that refuse includes organics and non-recyclables in addition to
whatever recyclable materials may remain in the garbage. Finally,
the analysis also suggests that, under reasonable assumptions
regarding the economic cost of impacts from pollutant emissions, the
societal benefits of recycling outweigh its costs.

*

Solano, E., Ranjithan, S.R., Barlaz, M.A., Brill, E.D., 2002. Life-cycle
based solid waste management I: Model development. Journal of
Environmental Engineering 128(10): 981-992.*

*Abstract*
This paper describes an integrated solid waste management ~ISWM!
model to assist in identifying alternative SWM strategies that meet
cost, energy, and environmental emissions objectives. An SWM system
consisting of over 40 unit processes for collection, transfer,
separation, treatment ~e.g., combustion, composting!, and disposal
of waste as well as remanufacturing facilities for processing
recycled material is defined. Waste is categorized into 48 items
and their generation rates are defined for three types of sectors:
single-family dwelling, multifamily dwelling, and commercial. The
mass flow of each item through all possible combinations of unit
processes is represented in a linear programming model using a
unique modeling approach. Cost, energy consumption, and
environmental emissions associated with waste processing at each
unit process are computed in a set of specially implemented unit
process models. A life-cycle approach is used to compute energy
consumption and emissions of CO, fossil- and biomass-derived CO2
,NOx ,SOx , particulate matter, PM10 and greenhouse gases. The
model is flexible to allow representation of site-specific issues,
including waste diversion targets, mass flow restrictions and
requirements, and targets for the values of cost, energy, and each
emission. A companion paper describes the application of this model
to examine several SWM scenarios for a hypothetical, but realistic,
case study.



*Solano, E., Dumas, R.D., Harrison, K.W., Ranjithan, S.R., Barlaz, M.A.,
Brill, E.D., 2002. Life-cycle based solid waste management II:
Illustrative applications. Journal of Environmental Engineering 128(10):
993-1005.*

*Abstract
*A companion paper described the development of the integrated solid
waste management ~ISWM! model that considers cost, energy, and
environmental releases associated with management of municipal solid
waste. This paper demonstrates the application of the ISWM model to
a hypothetical, but realistic, case study. Several solid waste
management ~SWM! scenarios are studied, including the variation in
energy and environmental emissions among alternate SWM strategies;
the effect of mandated waste diversion ~through recycling and other
beneficial uses of waste such as combustion to recover energy! on
environmental releases and cost; the tradeoff between cost and the
level of waste diversion; and the tradeoff between cost and
greenhouse gas emissions. In addition, the flexibility of the model
is illustrated by the identification of alternate SWM strategies
that meet approximately the same objectives using distinctly
different combinations of unit processes. This flexibility may be
of importance to local solid waste management planners who must
implement new SWM programs. Use of the model illustrates the
potential impact of solid waste management policies and regulations
on global environmental emissions.



*US EPA, 2002. Solid Waste Management and Greenhouse Gases: A Life-Cycle
Assessment of Emissions and Sinks. EPA530-R-02-006. Washington, DC,
Author. http://www.epa.gov/epaoswer/non-hw/muncpl/ghg/greengas.pdf
<http://www.epa.gov/epaoswer/non-hw/muncpl/ghg/greengas.pdf>**


Weitz, K., Barlaz, M.A., Ranjithan, S.R., Brill, D.E., Thorneloe, S.,
Ham, R., 1999. Life cycle management of municipal solid waste.
International Journal of Life Cycle Assessment 4(4): 195-201.*

*Abstract*
Life-cycle assessment concepts and methods are currently being
applied to evaluate integrated municipal solid waste management
strategies throughout the world. The Research Triangle Institute
and the U.S. Environmental Protection Agency are working to develop
a computer-based decision support tool to evaluate integrated
municipal solid waste management strategies in the United States.
The waste management unit processes included in this tool are waste
collection, transfer stations, recovery, compost, combustion, and
landfill. Additional unit processes included are electrical energy
production, transportation, and remanufacturing. The process models
include methodologies for environmental and cost analysis. the
environmental methodology calculates life cycle inventory type data
for the different unit processes. The cost methodology calculates
annualized construction and equipment capital costs, and operating
costs per ton processed at the facility. The resulting
environmental and cost parameters are allocated to individual
components of the waste stream by process specific allocation
methodologies. All of this information is implemented into the
decision support support tool to provide a life-cycle management
evaluation of integrated municipal solid waste management strategies.

* <http://www.epa.gov/epaoswer/non-hw/muncpl/ghg/greengas.pdf>*
Regards,
Stephan



--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "GreenYes" group.
To post to this group, send email to GreenYes@no.address
To unsubscribe from this group, send email to GreenYes-unsubscribe@no.address
For more options, visit this group at http://groups.google.com/group/GreenYes
-~----------~----~----~----~------~----~------~--~---


[GreenYes Home] - [Date Index] - [Thread Index]
[Date Prev] - [Date Next] - [Thread Prev] - [Thread Next]