Materials Characterization Paper

	In Support of the	

Advanced Notice of Proposed Rulemaking –

Identification of Nonhazardous Materials That Are Solid Waste

Construction and Demolition Materials – Disaster Debris

December 16, 2008

===================================================================

1.	Definition of Disaster Debris 

Each year, natural disasters, such as wildfires, floods, earthquakes,
hurricanes, tornadoes, and winter storms, generate large amounts of
debris. This poses a challenge for public officials who must manage this
debris in a manner that is as efficient and cost-effective as possible.
The debris resulting from natural disasters often includes building
materials, sediments, vegetative debris, personal property, and other
materials (EPA 2008, p. 11).  Generally, this material has not been
discarded.  Rather, it is the product of a natural disaster.

2.	Annual Quantities of Disaster Debris Generated and Used

Sectors that generate Disaster Debris: 

Disaster debris may be generated by any sector affected by a natural
disaster (e.g., households, businesses, government, etc.). 

Quantities and prices of Disaster Debris generated:   

While each natural disaster is unique, the top two natural disasters
that created the greatest recorded amounts of disaster-related debris in
the United States were Hurricane Andrew in 1992 (43 million cubic yards
(CY) of debris) and Hurricane Katrina in 2005 (over 100 million CY of
debris) (Luther 2006, p. 2).

The annual generation of disaster debris depends on the frequency and
severity of the natural disasters that occur during any given year and
the location where these disasters occur.

The market price of disaster debris varies by constituent.  Based on the
U.S. price of woody biomass, however, vegetation debris could generate
revenues of approximately $5 to $15 per ton (Yepsen 2008, p. 51).

Trends in generation of Disaster Debris:  

The generation of disaster debris is episodic.  Information on disaster
debris trends is not readily available. 

Uses of Disaster Debris

Fuel uses of Disaster Debris:  

A large percentage of disaster debris is vegetative debris, which is
commonly used as boiler fuel. Oven-dry wood produces about 9,000 Btu/lb
when burned, and it can be converted to liquid or gaseous fuel.  Mixed
wood debris with some green wood has a Btu value typically near 7,300
Btu/lb, and debris with higher percentages of green wood would have
lower Btu values. In addition, it is possible to produce different forms
of solid fuel, such as charcoal, from wood debris (SWANA 2002a, pp 4,
18). 

Wood debris associated with disasters is heterogeneous, and can include
treated wood, such as wooden utility poles, railroad ties, and some
lumber from decks, fences, landscaping materials, and wood bridges. 
Treated wood contains chemical preservatives that can contaminate
recycled wood products. These woods can be combusted in certain energy
recovery facilities, provided the facilities comply with existing
federal, state and local requirements, but they should not be “open
burned” in piles or combusted in air curtain incinerators (ACIs).  In
general, treated wood should be handled separately from vegetative
debris being recycled (EPA 2008, pp 24, 30).

Similarly, other materials in disaster debris such as plastics and paper
may also have fuel value and be able to be combusted in some energy
recovery facilities, but the heterogeneity of these materials in the
debris stream may present a technical limitation to this application
(EPA 2008).

A notable trend in the use of disaster debris as a fuel is the increased
export of U.S. disaster debris to Europe. Due to European greenhouse gas
regulations, woody biomass sent from North America to Europe is
commanding a price of $100 to $125 per ton. However, despite the
financial incentive provided by foreign markets, the exportation of
disaster debris is often limited by several practical considerations. 
For example, communities affected by disasters are usually focused on
clearing disaster debris as quickly and conveniently as possible, and
often lack the local infrastructure to store, process, and ship high
quantities of debris produced in such situations (Yepsen 2008, p. 51). 
In addition, it is sometimes necessary to quarantine debris from a
region to address potential issues with pests.  For example, parts of
Louisiana have Formosan termites and this debris was therefore difficult
to ship to potential users after Hurricane Katrina (EPA, 2008, p. A-2).

Asphalt shingles can be used as fuel in cement kilns, and the mineral
components remaining after combustion can serve as raw material for the
cement (EPA 2008, p. 23).  However, while the use of asphalt shingles as
fuel is a well-established market in Europe, this use is limited in the
United States because of air pollution concerns and concerns about the
previous use of asbestos in older shingles (Shingle Recycling.org 2007).

Non-combustion uses of Disaster Debris:

Non-combustion beneficial use applications of vegetative disaster debris
include composting, land spreading (i.e., spreading debris across empty
land to facilitate biodegradation), and agricultural applications
(Alexander 2008, p. 13).

Asphalt roofing shingles can be reused in hot-mix asphalt (NAPA 1997, p.
1).

Metal in disaster debris can be recycled into other metal products (EPA
2008, p.23).  In addition, other types of debris, such as household
white goods, electronics, concrete, and asphalt pavement, can in some
cases be recovered for recycling. (EPA 2008, p. 22).

Quantities of Disaster Debris landfilled: 

While the precise quantity of disaster debris disposed in landfills
depends on the natural disaster and the community affected, the majority
of disaster debris is landfilled or open burned (Yepsen 2008, p. 51).
This occurs partly out of necessity and convenience, as the focus of
most communities is to clear material as quickly as possible after a
disaster.

Quantities of Disaster Debris stockpiled/stored:

In many cases, the lack of storage capacity prevents disaster debris
from being stockpiled (Yepsen 2008, p. 51).

4.	Management and Combustion processes for Disaster Debris

Types of units using Disaster Debris:

Vegetative disaster debris can be ground into chips and used by
wood-fired industrial boilers and burners.  In addition, municipal
energy recovery facilities can in some cases manage mixed debris as well
as vegetative debris (EPA 2008).

Sourcing of Disaster Debris:

Communities affected by natural disasters, or state or Federal
governments, typically hire private contractors to remove and dispose of
disaster debris. 

Processing of Disaster Debris:  

To process vegetative disaster debris, contractors typically use
grinders to reduce debris into chips.  With respect to the beneficial
use of vegetative debris as a fuel source, the challenge with grinding
is that it is better suited to volume reduction than the production of
the uniform chips needed by biomass fuel plants. However, if communities
hire a processor accustomed to producing biomass fuel, the debris can be
ground into chips that meet combustor specifications (Yepsen 2008, p.
51).

The economics of utilizing biomass are challenging: the expense of
shipping woody biomass, which has a high volume to weight ratio, has
traditionally limited use to a 50 or 100-mile radius around disaster
sites (Yepsen 2008, p. 51).

Processing disaster debris is complicated by several factors: the
effects of the disaster on transportation infrastructure, the large
quantities of debris produced, the unpredictability of the quantity and
location of generation, the need for quick removal, and the tendency of
disaster debris to be composed of a mixture of materials (potentially
including contaminants) (Yepsen 2008, p. 51).  In addition, debris from
certain regions may require quarantine due to pests (EPA 2008, p. 6). 

State status of Disaster Debris use as fuel:  

According to state responses to a 2006 survey by the Association of
State and Territorial Solid Waste Management Officials (ASTSWMO), the
state of Florida has approved the use of vegetative hurricane debris as
fuel on at least one occasion.  Both New York and North Carolina have
approved the use of recovered wood materials as a fuel source on at
least one occasion, but it is unclear whether these approvals apply to
vegetative debris or the beneficial use of finished wood product.  In
all three states, these uses do not appear to have pre-approved status,
suggesting that a case-by-case approval process for designation of
beneficial use is in place in these states (ASTSWMO 2007, p.B-41-42).  

5.	Disaster Debris Composition and Impacts	

Composition of Disaster Debris:

Hurricane-related disaster debris is generally 76 percent vegetative, 17
percent mixed, 7 percent construction and demolition, and 1 percent
white goods (Alexander 2008, p. 8).  Other types of disaster debris will
have varying composition, and may include components such as ash (e.g.,
from wildfires) or sediment (e.g., from floods). 

Impacts of Disaster Debris use:

Cost Impacts: Natural disasters impose significant costs on affected
communities. The disposal of disaster debris represents just one of the
costs of a natural disaster, but the beneficial use of this debris can,
in some cases, lessen these costs.  Overall, however, the net cost
impacts associated with the beneficial use of disaster debris depend on
the circumstances of the disaster and are uncertain.  For example, while
disaster debris may be valuable as a fuel source, transportation costs
and time-sensitivity can make landfill disposal the most cost-effective
management option (EPA 2008, p. 22). 

While the net cost impacts associated with the beneficial use of
disaster debris are uncertain, the fuel cost savings of fuel-related
beneficial use applications can be measured based on the value of the
fuel that the debris would replace.  The recent prices of conventional
fossil fuels that may be replaced by this material are as follows:

Natural Gas (Industrial): $7.35 / MMBtu (EIA 2008a, Table 20)

No. 2 Distillate (Industrial): $16.80 / MMBtu (EIA 2008b, Table 36)

Residual Fuel Oil Average:  $9.19 / MMBtu (EIA 2008b, Table 38)

Coal – Average Delivered Price in 2006: $2.23 / MMBtu (EIA 2007, Table
ES1)

Emissions Impacts of Combustion: Emissions associated with the use of
disaster debris are likely to depend on the specific material used as a
fuel.  As indicated above, however, vegetative debris (e.g., wood) can
represent approximately 76 percent of disaster debris.  Thus, as an
illustrative example, Exhibit 1 compares the emission factors for wood
with the corresponding values for conventional fuels that disaster
debris may displace.  The estimates in the exhibit suggest that the
combustion of wood results in higher PM emissions than natural gas or
distillate oil, but lower PM emissions than coal or residual oil
systems. The data in Exhibit 1 also suggest that wood results in lower
SO2 emissions than most conventional fuels.  The estimated NOx emissions
associated with wood combustion are similar to those associated with
distillate and lower than the NOx emissions for other conventional
fuels.  

The emissions profile of treated woods or wood with lead paint may
differ from the values presented in Exhibit 1.  For example, concerning
the combustion of railroad ties, creosote in the ties increases the
combustion temperature, resulting in a more complete combustion of some
organics such as benzene, formaldehyde, and dioxins.  However, the
creosote itself contains 200 to 300 chemicals (Reid 2002).  In addition,
wood treated with chromium copper arsenate (CCA-treated wood) contains
arsenic, copper, and chromium that may be emitted when this wood is
combusted (Iida et al. 2004).  Similarly, lead may be emitted during the
combustion of lead-painted wood. Information on the magnitudes of these
emissions is not readily available.

Lifecycle Emissions Impacts: Use of disaster debris as a replacement for
traditional primary fuels may eliminate the environmental impacts
associated with extraction and processing of traditional fuels.  In
addition to the emissions impacts of combustion described above, Exhibit
1 lists the quantities of the total cradle-to-gate emissions for these
fuels based on typical processes in the United States in the late 1990s,
with wood scrap combustion presented as a proxy for disaster debris. 
Note that there may be impacts associated with the processing of
disaster debris into useable fuel that are not accounted for in the
values presented in Exhibit 1.  In addition, there may be alternative
uses (e.g., composting) that are environmentally preferable to
combustion.  



Exhibit 1:  Comparative Impacts of Wood Combustion versus Alternative
Primary Fuels

Pollutant	Wood	Coal	Distillate Fuel Oil	Residual Fuel Oil	Natural Gas

	Combustion	Combustion	Combustion plus Upstream	Combustion	Combustion
plus Upstream	Combustion	Combustion plus Upstream	Combustion	Combustion
plus Upstream

	------------------------------------------- lb./MMBtu
---------------------------------------

Criteria Pollutants

PM2.5	-	-	-	-	-	-	-	-	-

PM10	0.019	0.054	0.054	0.011	0.011	0.093	0.093	0.009	0.009

PM, unspecified	-	-	0.246	-	0.012	-	0.012	-	0.004

NOx	0.167	0.482	0.504	0.173	0.234	0.367	0.428	0.301	0.417

VOCs	-	0.006	0.014	0.001	0.363	0.002	0.367	0.009	0.524

SOx	0.008	1.446	1.469	0.209	0.394	1.593	1.781	0.073	1.985

CO	1.511	0.068	0.085	0.036	0.082	0.033	0.079	0.058	0.282

Pb	1.33x10-4	8.93x10-6	9.19x10-6	4.60x10-6	5.61x10-6	5.80x10-5	5.90x10-5
-	2.72x10-7

Hg	-	2.05x10-6	2.14x10-6	1.58x10-6	1.77x10-6	8.67x10-6	8.85x10-6	-
7.18x10-8





Source:

Franklin Associates 1998.

Note:

“-” signifies data not available; may equal zero.

The emission information presented in this table is derived from Life
Cycle Inventory (LCI) data, as compiled by Franklin Associates.   LCI
data identifies and quantifies resource inputs, energy requirements, and
releases to the air, water, and land for each step in the manufacture of
a product or process, from the extraction of the raw materials to
ultimate disposal. The LCI can be used to identify those system
components or life cycle steps that are the main contributors to
environmental burdens such as energy use, solid waste, and atmospheric
and waterborne emissions.  Uncertainty in an LCI is due to the
cumulative effects of input uncertainties and data variability.  

There are several life cycle inventory databases available in the U.S.
and Europe.  For this paper, we applied the most readily available LCI
database that was most consistent with the materials and uses examined.
These LCI data rely on system boundaries as defined by Franklin
Associates, as described in the documentation for this database,
available at:   HYPERLINK
"http://www.pre.nl/download/manuals/DatabaseManualFranklinUS98.pdf" 
http://www.pre.nl/download/manuals/DatabaseManualFranklinUS98.pdf .  



References

Alexander, Michael. 17 July 2008, "Shelter from the Storm: Increasing
Beneficial Use of Disaster Debris." NEWMOA Web Session.

Association of State and Territorial Solid Waste Management Officials
(ASTSWMO).  November 2007, 2006 Beneficial Use Study Report.

Biomass Energy Resource Center. "Emissions and Air Quality," Available
at:   HYPERLINK
"http://www.biomasscenter.org/information/emissions.html" 
http://www.biomasscenter.org/information/emissions.html 

Franklin Associates.  1998, “Franklin US LCI 98 Library”.

Iida, Kenjiro, John Pierman, Thabet Tolaymat, Timothy Townsend, Chang-Yu
Wu.  2004, “Control of Chromated Copper Arsenate Wood Incineration Air
Emissions and Ash Leaching Using Sorbent Technology,” Journal of
Environmental Engineering, February 2004.

Luther, Linda. June 2006, “Disaster Debris Removal after Hurricane
Katrina: Status and Issues.” Congressional Research Service.

National Asphalt Paving Association (NAPA). 1997, “Use of Waste
Asphalt Shingles in HMA: State-of-the-Practice.”

Reid, Magny.  17 February 2002, “Toxic Ties?” La Crosse Tribune,
Available at:   HYPERLINK
"http://findarticles.com/p/articles/mi_qa3652/is_200202/ai_n9039015/pg_1
?tag=artBody;col1" 
http://findarticles.com/p/articles/mi_qa3652/is_200202/ai_n9039015/pg_1?
tag=artBody;col1 

Shingle Recycling.org. 2007, “Markets for Recycling Asphalt
Shingles.” Accessed 26 September 2008. Last updated 15 January 2007.
Available at:   HYPERLINK
"http://www.shinglerecycling.org/index.php?option=com_content&task=view&
id=51&Itemid=147" 
http://www.shinglerecycling.org/index.php?option=com_content&task=view&i
d=51&Itemid=147 

Solid Waste Association of North America (SWANA). 2002a,  "Successful
approaches to recycling urban wood waste,” Madison, WI: U.S.
Department of Agriculture, Forest Service, Forest Products Laboratory.

United States Energy Information Administration (EIA). 2007, “Annual
Coal Report 2006”.

United States Energy Information Administration (EIA). 2005, Annual
Energy Review 2004.

United States Energy Information Administration (EIA). 2008a, “Natural
Gas Monthly”, July 2008.

United States Energy Information Administration (EIA). 2008b,
Preliminary Petroleum Marketing Annual 2007.

United States Environmental Protection Agency (EPA). March 2008,
“Planning for Natural Disaster Debris”.

Yepsen, Rhodes. 2008, "Generating Biomass Fuel from Disaster Debris,"
Biocycle, Vol. 49: page 51.  

  HYPERLINK "http://www.jgpress.com/archives/_free/001685.html" 
http://www.jgpress.com/archives/_free/001685.html 

 We note that the emission factors for wood presented in Exhibit 1
represent averages for wood-burning boilers.

Construction and Demolition Materials – Disaster Debris

		

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