Quantifying the Disposal of PostConsumer Paint
Contract #68-W-01-039
Work Assignment 4-13
Revised Draft
September 17, 2004
Prepared for
Barry Elman
Sector Strategies Division
National Center for Environmental Innovation
U.S. Environmental Protection Agency
Mail code 1807T
Washington, DC
Prepared by
Abt Associates Inc.
55 Wheeler Street
Cambridge, MA 02138
Contents
1.
Introduction ................................................................................................................................ 1
2.
Quantity Estimation Case Studies ............................................................................................ 2
2.1.
California ........................................................................................................................... 2
MSW – 1999 California Statewide Waste Disposal Characterization Study .......... 2
California HHW Collection Programs .................................................................... 3
Comparison of the Quantity of Paint Discarded as MSW vs. the Quantity of Paint
Collected by HHW Programs .................................................................................. 3
2.2.
Iowa ................................................................................................................................... 4
MSW – 1998 Iowa Solid Waste Characterization Study ........................................ 4
Iowa Regional Household Hazardous Waste Collection Centers ........................... 4
Comparison of the Quantity of Paint Disposed in MSW Landfills vs. the Quantity
of Paint Collected by RCC Programs ...................................................................... 5
2.3.
Oregon ............................................................................................................................... 6
MSW – 2002 Oregon Solid Waste Characterization and Composition Study ........ 6
The State of Oregon ................................................................................................ 7
Portland Metro Tri-County Area ............................................................................. 9
Comparison of Portland Metro Tri-County Area with the State of Oregon .......... 10
Portland, Oregon Household Hazardous Waste Collection Program.................... 10
Comparison of the Quantity of Paint Disposed vs. Quantity of Paint Collected by
HHW Programs ..................................................................................................... 11
2.4.
Washington ...................................................................................................................... 11
MSW – 2003 Waste Composition Analysis for the State of Washington............. 11
Washington Moderate Risk Waste Collection ...................................................... 12
Comparison of the Quantity of Paint Disposed in MSW Landfills vs. the Quantity
of Paint Collected by MRW Programs .................................................................. 12
2.5.
Wisconsin ........................................................................................................................ 13
MSW - 2002 Wisconsin Statewide Waste Characterization Study ....................... 13
Wisconsin HHW Collection Programs ................................................................. 14
Comparison of the Quantity of Paint Disposed in MSW Landfills vs. the Quantity
of Paint Collected by HHW Programs .................................................................. 15
3.
National Estimates of Paint Waste ......................................................................................... 16
3.1.
Comparisons with PSI Estimates ..................................................................................... 16
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3.2.
4.
Ratio Estimation Method ................................................................................................ 17
Factors to Consider in Estimating the Quantity of Post-Consumer Paint ......................... 20
Under- and Over-Estimation of Paint Values ....................................................... 20
Confidence Intervals ............................................................................................. 23
5.
Conclusions .............................................................................................................................. 24
6.
References ................................................................................................................................ 25
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1.
Introduction
Abt Associates has conducted this analysis to estimate the amount of post-consumer architectural paint
disposed annually in the United States, as a way to approximate the amount that is generated. After a
consumer has used the paint from a particular purchase, the leftover paint may go into one of several
disposition pathways. These include:

Local Municipal Solid Waste (MSW) landfill (in liquid or dried form)

Household Hazardous Waste (HHW) collection program

Donation/Exchange for reuse by another party

Collection, management and disposal as hazardous waste

Poured down the drain/sewer

Stockpiled for future use or disposal (in a basement or garage, etc.)
Comprehensive national data on paint going into these pathways is not available. Therefore, we are
examining available data from select states. Specifically, this report presents case studies from the states
of California, Iowa, Oregon, Wisconsin and Washington, which have available data on the quantity of
paint both disposed at MSW landfills and brought to HHW collection centers. It is believed that the vast
majority of post-consumer paint disposed each year is disposed via these two major pathways. The case
studies provide state-specific estimates of the quantity of paint that is disposed, as well as data that can be
directly scaled up to a national level. Further, the analysis of this state data provides a comparison with
estimates provided by the Paint Product Stewardship Initiative (PSI) in the “Background Report for the
National Dialogue on Paint Product Stewardship.” PSI has estimated that approximately 2.5 -5% of the
architectural paint sold in the U.S. each year becomes leftover consumer house paint (PSI 2004a).
Section 2 of this report presents available data on the quantity of post-consumer paint disposed at MSW
landfills and brought to HHW collection centers in each of the 5 states. For the state of Oregon, HHW
data was obtained only for the Portland Metro area, but statewide data will be used for future versions of
this report. Data from the state studies is brought together in Section 3 to provide national estimates of
paint generation. That section also compares the annual quantity of paint disposed to annual U.S. paint
sales. There are many methodological and statistical considerations associated with the case studies and
national estimates presented throughout this report, and these are presented in Section 4. In Section 5 we
presents our conclusions.
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2.
Quantity Estimation Case Studies
2.1.
California
The California Integrated Waste Management Board (CIWMB) has conducted detailed MSW
characterization studies, and has also compiled statistics on the HHW collection programs around the
state. Data on both of these waste streams provide a basis for estimating the total amount of postconsumer paint disposed each year in the state of California.
MSW – 1999 California Statewide Waste Disposal Characterization Study
CIWMB conducted a statewide waste characterization study of MSW in 1999. They are currently
updating this study, the results of which will be available in the fall of 2004. This report uses the 1999
data.
The 1999 Waste Characterization Study divides the MSW stream into 3 sectors: commercial, residential,
and self-haul. The state was divided into five regions based on demographics and geographic features. In
each region, five disposal sites (landfills and transfer stations) were randomly selected as sampling sites
for single-family residential and self-haul waste streams.1 Collections at these sites totaled 148 single
family residential and 247 self-haul samples. In addition, a total of 1207 commercial generator and 80
multifamily residential samples were collected from randomly selected businesses and apartment
complexes within the geographical areas surrounding the selected disposal sites.
Waste sampling was conducted in both winter and summer to account for seasonal variations in waste
disposal patterns. Each sample was hand sorted and characterized using the 57 material types found in the
California Uniform Waste Disposal Characterization Method, as well as eight specific rigid plastic
packaging container (RPCC) categories identified for this study. Additionally, vehicle surveys were used
to estimate the portion of California’s MSW contributed by the residential, commercial, and self-haul
sectors. The generating sector represented by the waste was identified, and the net weight of each load
was recorded. A total of 3,648 surveys were completed. Table 1 shows the total MSW, HHW, and paint
waste for each of the waste sectors.
Table 1. California Statewide Landfill Waste Characterization Study Results
Total MSW
HHW
Paint
Paint as a % Paint as a %
Sector
estimated (tons) estimated (tons) estimated (tons)
of HHW of Total MSW
14,273,250
46,135
31,282
68%
0.22%
Residential
Commercial
Self-Haul
Total
18,318,002
4,908,750
37,500,002
59,969
6,280
112,385
9,037
4,179
44,498
15%
67%
40%
0.05%
0.09%
0.12%
Source: CIWMB, 1999
Note: “Paint” is defined as containers with paint in them. This includes latex paint, oil based paint, and tubes of
pigment or fine art paint. This does not include dried paint, empty paint cans, or empty aerosol containers.
The study notes a 90% confidence interval for these estimates. However, because paint is a very small percentage of
the total waste stream, and because numbers are rounded, the upper and lower confidence limits of the 90%
confidence interval for paint are the same as the estimate.
1
Not all MSW in California goes to a MSW landfill. There are three waste-to-energy incinerators in California that
accept MSW. Further, one or two counties export MSW out of state.
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California HHW Collection Programs
Local governments in California are required to keep household hazardous wastes out of the solid waste
stream pursuant to Public Resources Code 47100. They do this by providing both temporary and
permanent HHW collection events and facilities, and public education to their residents. In fiscal year
1998/99, 85 permanent HHW collection facilities, 245 temporary facilities/one day events and 107
Recycle-Only facilities2 were operated. About 50% of the state’s population has access to permanent
facilities, and temporary facilities serve about 40% of the population. Approximately 10% of the state’s
population has no access to collection opportunities. While the majority of the public has access to HHW
collection programs, they may not be convenient due to location or operating hours. Advertising and
outreach is limited due to budget constraints (CIWMB, 2001).
Local governments are required to report annually the quantity of waste collected by HHW programs and
the method of waste management. Paint is divided into three categories – latex, solvent-based, and PCBcontaining paint. Approximately one-half of the paint that was collected by HHW programs during the
1998/99 fiscal year was solvent-based, and there was also a notable quantity of PCB-containing paint that
was collected. This indicates that much of the paint that came to the collection sites was old, because
over 80% of the architectural paint produced in the U.S. is latex paint, and PCBs have been banned from
paint for some time. HHW program officials have observed that many of the people who bring in large
quantities of paint are elderly or are cleaning out the houses of deceased family members. This has
contributed to the assumption on the part of many program officials that much of the paint they receive
has been stockpiled for years. Based on annual statistics, CIWMB estimates that only approximately 4%
of residents participate in HHW collection programs each year. At this rate it may take years to collect all
of the stockpiled paint in California (CIWMB, 2000).
The quantity of HHW collected by California programs has grown, as has the percentage of the HHW that
is paint, since the programs were first introduced in California in 1993. In 1993, approximately 3,000
tons of paint was collected, and it accounted for 31% of all the waste collected at HHW collection centers.
By 2001, paint collection grew to 8,600 tons, or approximately 43% of all HHW collected. The quantity
of paint collected and the percentage of HHW that was paint during the 1998/99 fiscal year is shown in
Table 2.
Table 2. Paint collected in CA HHW programs during the 1998/99 fiscal year
Waste Category
Oil Based Paint
PCB-Containing Paint
Latex Paint
Total Paint Collected
Total HHW
% HHW Collected that is Paint
Paint Collected (tons)
4,044
21
4,005
8,069
19,883
41%
Source: Data received from Anna Ward, CIWMB, 2004.
Comparison of the Quantity of Paint Discarded as MSW vs. the Quantity of Paint Collected by HHW
Programs
Despite restrictions on landfill disposal of wet paint in California, a large quantity of paint is disposed of
in this manner every year. While it is legal to dispose of dried paint in MSW landfills in California, air
drying is not encouraged. Instead, disposal of wet paint at HHW collection is the suggested management
2
Recycle-only facilities are those that receive materials that could potentially be recycled, including latex paint.
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method. As shown in Table 3, approximately 85% of all of the paint that was disposed of in 1999 went to
MSW landfills.
Table 3. Paint Disposal in California in 1999 – MSW Landfill and HHW Collection
Disposal Pathway
Total Paint (tons)
% of Paint by Pathway
MSW Landfill
44,498
85%
8,069
HHW Collection
15%
Total
52,567
Sources: CIWMB, 1999 and data from Anna Ward, CIWMB, 2004.
* The landfill quantities here reflect quantities of HHW and paint from all sectors, residential and non-residential.
The large percentage of paint going to MSW landfills illustrates the importance of including MSW data
when estimating the quantity of leftover paint in the United States.
2.2.
Iowa
MSW – 1998 Iowa Solid Waste Characterization Study
The 1998 statewide solid waste characterization analysis for Iowa was conducted in the fall of 1997 and
the spring of 1998. More than 420 samples of MSW from residential, industrial/commercial/institutional
(ICI), and mixed generator loads were sorted into 45 discrete material categories at four landfills and a
transfer facility located throughout the state. Data from these sites (together with data from a previous
MSW characterization study conducted within the state) were used to develop waste composition
estimates for the 45 material categories, as well as for the residential and ICI waste streams and for
statewide totals.
Paint is not defined specifically or quantified individually in this study, but is included in the “paints and
solvents” subcategory, which is part of the broader household hazardous materials (HHM) category.
Based on the experience and judgment of two professionals who conduct waste composition studies, paint
is estimated to comprise approximately 90% of the “paints and solvents” subcategory3. This proportion is
applied to data from Iowa in Table 4 below.
Table 4. 1998 Iowa Statewide Landfill Composition Study Results
Waste Type
Tons per Year
% of Total Waste
Household Hazardous
16,472
0.7%
Materials
2,517
0.11%
Paint*
Total MSW
2,203,848
% of HHW
15.3%
Source: IA DNR, 1998.
* This value represents 90% of the “paints and solvents” category.
Note: The study notes a 90% confidence interval for these estimates. However, because paint is a very small
percentage of the total waste stream, and because numbers are rounded, the upper and lower confidence limits of the
90% confidence interval for paint are the same as the estimate.
Iowa Regional Household Hazardous Waste Collection Centers
In FY2003, Regional Collection Centers (RCCs) in Iowa collected over 1000 tons of HHW. There are 39
permanent facilities and 35 annual temporary collection events that accept HHW in Iowa. The RCCs
service area covers 60% of Iowa and serves 74% of the population. These facilities also accept paint and
hazardous materials from conditionally exempt small quantity generators. In FY2003, 28,171 households
3
Based on conversations and data from Tanya Tarnecki of Cascadia Consulting, and Brad Anderson of Sky Valley
Associates.
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and 562 CESQGs brought paint to RCC facilities. This represents approximately 3.3 percent of all
households and 25 percent of CESQGs in the state (PSI, 2004b; U.S. EPA, 2004).
Latex paint and oil-based paint are two of the dominant types of HHW and CESQG waste collected by
RCC programs in the state. In 2003, a total of 469 tons of paint were collected by the RCCs, accounting
for approximately 39% of all the waste collected. Approximately 23% of this paint was oil-based and
77% was latex. In contrast to California and Washington, which collect a high proportion of oil-based
paint, this breakdown is more consistent with the ratio of oil-based to latex paint that is currently sold in
the United States. Since the collection of a high proportion of oil-based paint may be an indication that
much of the paint being collected is old and has been stockpiled for many years, the data in Iowa may
indicate less stockpiling of paint among residents and businesses participating in collection programs.
However, with only approximately 3 percent of households in the state participating in such programs, it
is difficult to extrapolate these results to the general population.
The quantity of paint collected by RCC programs in Iowa and the percentage of HHW that is paint are
shown in Table 5.
Table 5. Paint collected in Iowa RRC programs in FY2003
Waste Category
Bulk oil-based paint
Oil-based paint in cans
Bulk latex paint
Latex paint in cans
Total Paint Collected
Total HHW collected
% HHW Collected that is Paint
Total (tons)
87
22
154
205
469
1,201
39%
Source: data from Theresa Stiner, IA DNR, 2004.
It should be noted that people in Iowa are encouraged to dry out their latex paint and put it in the trash.
This practice could lead to an underestimation of the quantity of latex paint, as the dried paint would not
be counted in either the MSW landfill characterization study nor in the RCC data. While paint is not
specifically defined in the Iowa solid waste characterization study, several other state studies specifically
include only wet paint in their weight counts of paint. Indeed, in Iowa wet paint is not accepted in MSW
landfills and the RCC program does not accept dry paint.
Comparison of the Quantity of Paint Disposed in MSW Landfills vs. the Quantity of Paint Collected by
RCC Programs
Despite the restriction on landfill disposal of oil-based paint and wet latex paint, a large quantity of paint
is disposed of in this manner every year. As shown in Table 6, approximately 84% of the paint that was
disposed of in Iowa went to MSW landfills.
Table 6. Paint Disposal in Iowa – Landfill and HHW Collection
Total HHW
Total Paint
Disposal Pathway
Disposed (tons)
Disposed (tons)
16,472
2,517**
MSW Landfill*
1,201
469
Regional Collection Centers**
17,673
2,986
Total
% of Paint Disposed
by Pathway
84%
16%
Sources: IA DNR, 1998 data from Theresa Stiner, IA DNR, 2004.
* The MSW landfill quantities here reflect quantities of HHW[/CESQG] and paint from all MSW sectors.
** This value represents 90% of the “paints and solvents” category.
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The large percentage of paint going to MSW landfills illustrates the importance of including MSW data
when estimating the quantity of leftover paint in the United States.
2.3.
Oregon
MSW – 2002 Oregon Solid Waste Characterization and Composition Study
The State of Oregon regularly conducts solid waste composition studies4 as required by state law. The
most recent study used in this analysis is from 2002. Statewide studies were conducted by the Department
of Environmental Quality (DEQ) in 2000, 1998, 1994/95, and 1992/93. In addition to statewide studies,
the Portland Metro area5 also conducted individual studies in 1993/94 and earlier. This case study
includes data on the quantity and composition of paint collected and disposed to landfills or burned in
Oregon and Portland Metro.
To conserve funds, the DEQ currently conducts “half-studies”; the 2002 Oregon Solid Waste
Characterization and Composition study is the second half of a combined 2000/2002 waste composition
study. The 2002 study collected a total of 844 composition samples in 4 geographic areas – Portland
Metro, Marion County, Eugene and the “rest of Oregon”. The Metro area alone considered 349
composition samples. Within each geographic area, unbiased, representative loads of waste, weighing
approximately 200 pounds from each load were selected as field samples. The 2002 study considered
waste samples from eight "waste substreams":

Residential route garbage trucks (over 90% of this waste is from single-family or multifamily
residences)

Commercial route garbage trucks (over 90% of this waste is from businesses)

Mixed route garbage trucks (contains a mixture of residential and commercial wastes)

Compacting drop boxes (used by individual grocery stores, malls, or other retail operations)

Loose drop boxes (used for construction and demolition and for "yard-cleaning" activities)

Self-haul (wastes hauled directly to the transfer station or landfill by the person or business that
generated the waste)

Mixed Solid Waste Processing Facility (MSWPF) residual wastes (wastes leftover for disposal
after recoverable materials have been removed at the facility)

Special Purpose Landfills (mostly collected either at general-purpose landfills or at transfer
stations that ship all their waste to general-purpose landfills. In the Metro area however,
significant waste amounts were from limited-purpose landfills that prohibit accepting food and
other putrescible wastes.)
4
Peter Spendelow with Portland Metro does not recommend using waste composition studies to quantify wastes
such as paint, as the appearance of such materials are very erratic in the waste streams and there is great variance in
samples.
5
According to the Metro Planning Department, “Metro” includes three counties (Clackamas, Multnomah, and
Washington Counties), which are comprised of 24 cities in the Portland Metropolitan region.
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The number of samples collected from each waste substream depended on the absolute quantity of waste
disposed from each substream, and the expected variability of waste in the substream, based on past
composition studies.
As part of this study, DEQ also conducted a “contamination analysis” to better characterize the actual
quantities of solid waste materials being disposed (see Section 3.2 for details). This effort was conducted
with a goal of developing a “correction factor” for each material that could then be multiplied by the field
data results in order to determine the amount of each material, excluding contaminants, that was being
disposed of. For the 4 paint samples taken, a correction factor of 20% was derived for latex paint and 5%
for oil-based paint/thinners. The preceding tables include collected field data collected as well as data
corrected for contamination (i.e., adding back paint found in nearly empty containers).
This study also presents historical data that provides estimates of paint disposal in 2000, 1998 and 1994.
These independent estimates could reduce the statistical uncertainty associated with a single estimate
based on limited sampling of landfill waste. These data have been presented in Table 7.
The State of Oregon
According to the DEQ study, more than 2.7 million tons of MSW were generated in Oregon and disposed
in landfills or solid waste burning facilities in 2002. Total MSW generated accounted for 73% of
statewide solid wastes. The remaining portion of solid wastes generated included industrial & other
wastes, alternative daily cover, contaminated soils, inerts, asbestos, and septage sludge. Most of the
MSW was disposed in Oregon, with only about 19,000 tons being exported to other states for disposal.
Data in this report reflects MSW data and construction and demolition waste excluding pure inerts (for
example, concrete).
Table 7. Paint Disposed in Oregon During Select Years
Waste Type
2002
(tons)
Latex Paint
2,998
Oil Paints /
Thinners
1,729
Total Paints
4,728
90% CI
(1,501 4,921)
(684 - 3,028)
2000
(tons)
90% CI
1998
(tons)
90% CI
1994
(tons)
90% CI
918
(302 - 1,775)
3,181
(0.07 – 0.17)
2,312
*
1,784
(515 - 3,630)
1,590
(0.03 – 0.09)
1,074
*
3,386
*
2,702
4,771
Source: OR DEQ, 2002; historical data from Peter Spendelow, OR DEQ, received August 2004.
CI = Confidence Interval
* Confidence Interval not calculated for statewide numbers
Note: Tonnage and confidence intervals presented have been corrected for contamination (correction factor for latex
paint = 20.45% and oil based paints/thinners = 4.52%)
Table 8 presents the amount of paint disposed in Oregon as a percent of total solid waste. Total solid
waste disposed was over 2.7 million tons in the state of Oregon.
Table 8. Percent of Paint in Total Solid Waste Disposed in Oregon in 2002
90% Confidence
90% Confidence Interval
2002 Percent
Interval
Percent (Detailed
(Detailed sample
Waste Type
(Field data)
(Field data only) sample correction)
correction)
Latex Paint
0.09%
(0.05 - 0.14%)
0.11%
(0.05 - 0.18%)
Oil Paints / Thinners
0.06%
(0.02 - 0.11%)
0.06%
(0.02 - 0.11%)
Total
0.15%
0.17%
Source: OR DEQ, 2002
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Note: Field data are data as sampled. Data corrected for contamination incorporate an “add-back” factor of 20.45%
for latex paint and 4.52% for oil paint/thinners.
Paint includes latex paint and oil-based paints and oil thinners. Total paint disposal was 4,728 tons
including 2,998 tons of latex paint and 1,729 tons of oil-based paints/thinners, as shown in Table 9.
Table 9. Paint Disposed in Oregon by Waste Substream in 2002 (with contamination correction)
Oil-Based/
Total Paint
Latex
(tons)
Thinners (tons)
Waste Substream
(tons)
Residential Garbage Route Trucks
630
364
994
Commercial Garbage Route Trucks
430
248
679
Mixed Garbage Route Trucks
474
273
747
Compacting Drop Boxes
212
122
334
Loose Drop Boxes
298
172
469
Self-Haul - Regular Landfill or T.S.
614
354
968
Special Purpose Landfill (hauler & self-haul)
166
96
262
Residuals: Mixed Solid Waste Processing
174
101
275
Facility
Total
2,998
1,729
4,728
Source: OR DEQ, 2002
Note: Data are derived based on the percent of paint in total solid waste. Data are corrected for contamination. (In
the case of paint the contamination analysis “added-back” the paint in containers that was weighed in other
categories.)
To account for seasonal variations in waste disposal patterns, waste sampling was conducted by waste
substream, in four 3-month periods. Seasonal (cold and warm) data for disposal of paints were
extrapolated and have been presented in Table 10. Seasonal variations were minimal; of the total solid
waste disposed, 53% was disposed during the warmer months and 47% during the cold season.
Table 10. Oregon Seasonal Breakdown of Waste Disposed in 2002
Cold*
Warm**
(tons)
(tons)
Waste Substream
490
504
Residential Garbage Route Trucks
Commercial Garbage Route Trucks
321
358
Mixed Garbage Route Trucks
363
384
Compacting Drop Boxes
163
171
Loose Drop Boxes
212
258
Self-Haul - Regular Landfill or T.S.
436
532
Special Purpose Landfill (hauler & self-haul)
113
150
Residuals: Mixed Solid Waste Processing Facility
127
148
Total
2,223
2,505
Total Paint
(tons)
994
679
747
334
469
968
262
275
4,728
Source: OR DEQ, 2002
*Includes the months October through March
**Includes the months April through September
Note: Data are derived based on the percent of paint in total solid waste. Data are corrected for contamination. (In
the case of paint the contamination analysis “added-back” the paint in containers that was weighed in other
categories.
The seasonal variations in waste disposed are within the confidence interval of the total estimate, so is not
a significant factor. One seasons’ data can be used to estimate for the whole year.
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Portland Metro Tri-County Area
The Portland Metro tri-county area disposed of 2,221 tons of paint in 2002 that comprised of 1,546 tons
of latex paint and 676 tons of oil paints/thinners, as shown in the following two tables.
Table 11. Percent of Paint in Total Solid Waste Disposed in Portland Metro in 2002
Waste Type
Latex Paint
Oil Paints / Thinners
Total
2002 Percent
(Field data)
0.11%
0.05%
0.16%
90% Confidence
Interval
(Field data only)
(0.03 - 0.21%)
(0.01 - 0.11%)
Percent (Detailed
sample
correction)
0.13%
0.06%
0.19%
90% Confidence
Interval
(Detailed sample
correction)
(0.04 - 0.26%)
(0.01 - 0.12%)
Source: OR DEQ, 2002
Note: Field data are data as sampled. Data corrected for contamination incorporate an “add-back” factor of 20.45%
for latex paint and 4.52% for oil paint/thinners.
Table 12. Waste Disposed in Portland Metro by Waste Substream in 2002
Oil-Based/
Latex
(tons)
Waste Substream
Thinners (tons)
Residential Garbage Route Trucks
312
136
Commercial Garbage Route Trucks
248
108
Mixed Garbage Route Trucks
255
111
Compacting Drop Boxes
147
64
Loose Drop Box - Regular Landfill or T.S.
134
58
Self-Haul - Regular Landfill or T.S.
164
72
Special Purpose LF- Hauler
68
30
Special Purpose LF - Self-Haul
95
42
Residuals: Mixed Solid Waste Processing Facility
123
54
Total
1,546
676
Total Paint
(tons)
448
357
366
211
192
236
97
137
177
2,221
Source: OR DEQ, 2002
Note: Data are derived based on the percent of paint in total solid waste. Data are corrected for contamination. (In
the case of paint the contamination analysis “added-back” the paint in containers that was weighed in other
categories.
Table 13 presents the seasonal variations for total solid wastes and paints disposed by waste substream in
the Portland Metro tri-county area in 2002.
Table 13. Portland Metro Tri-County Area Seasonal Breakdown of Waste Disposed in 2002
Cold*
Warm**
Total Paint
Waste Substream
(tons)
(tons)
(tons)
Residential Garbage Route Trucks
226
222
448
Commercial Garbage Route Trucks
175
182
357
Mixed Garbage Route Trucks
174
192
366
Compacting Drop Boxes
104
107
211
Loose Drop Box - Regular Landfill or T.S.
88
105
192
Self-Haul - Regular Landfill or T.S.
108
128
236
Special Purpose LF**- Hauler
44
53
97
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Special Purpose LF - Self-Haul
59
78
137
Residuals: Mixed Solid Waste Processing Facility
82
95
177
1,060
1,161
2,221
Total
Source: OR DEQ, 2002
*Includes the months October through March
**Includes the months April through September
Note: Data are derived based on the percent of paint in total solid waste. Data are corrected for contamination. (In
the case of paint the contamination analysis “added-back” the paint in containers that was weighed in other
categories.
Again, the seasonal variations in waste disposed in the Portland Metro area are within the confidence
interval of the total estimate, so is not a significant factor. One seasons’ data can be used to estimate for
the whole year.
Comparison of Portland Metro Tri-County Area with the State of Oregon
The comparison of Portland Metro and statewide wastes disposal data may be useful in providing insight
in the rural/urban split within the State of Oregon. Table 14 shows that Portland Metro accounted for 47%
of the paint disposed in the state.
Table 14. Comparison of Paint Disposed in Oregon & Portland Metro by Waste Substream in 2002
OR Metro
OR
Metro
OR Metro
Latex Paint
Oil Paints
Total Paint
Metro %
(tons)
/Thinners (tons)
(tons)
Waste Substream
of Oregon
Residential Garbage Route Trucks
630
312
364
136
994
448
45%
Commercial Garbage Route Trucks
430
248
248
108
679
357
53%
Mixed Garbage Route Trucks
474
255
273
111
747
366
49%
Compacting Drop Boxes
212
147
122
64
334
211
63%
Loose Drop Box - Regular Landfill or T.S.
298
134
172
58
469
192
41%
Self-Haul - Regular Landfill or T.S.
614
164
354
72
968
236
24%
Special Purpose Landfill (hauler & self-haul) 166
163
96
71
262
234
89%
Residuals: Mixed Solid Waste Processing
174
123
101
54
275
177
64%
Facility
Total
2,998
1,546
1,729
676
4,728
2,221
47%
Source: OR DEQ, 2002
Note 1: Data for the State of Oregon (OR) include Portland Metro (Metro) data
Note 2: Data are derived based on the percent of paint in total solid waste. Data are corrected for contamination. (In
the case of paint the contamination analysis “added-back” the paint in containers that was weighed in other
categories.
Portland, Oregon Household Hazardous Waste Collection Program
The HHW collection sites in Portland Metro, Oregon annually collect 2.4 million pounds of paint.
Portland relies on 4 permanent collection sites – 2 permanent HHW collection facilities and 2 retail paint
stores. These drop-off locations are supplemented by 35 one- or two-day annual collection events at
various locations in their service area. The Program’s service area covers 360 square miles consisting of
urban and suburban households. Of the 500,000 households in the service area, an estimated 10% of all
households annually bring paint to the collection locations. A limited number of households deliver HHW
without bringing paint. Some households deliver only paint products. All paint is processed by Portland
Metro, Regional Environmental Management. (PSI, 2004).
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In the State of Oregon, HHW collected data for paint includes latex paint and oil-based paint/thinners. In
Portland, 64% of the paint collected is latex and 36% is oil-based paint. In contrast to California and
Washington, which collect a high proportion of oil-based paint, this is more consistent with the ratio of oil
to latex paint that is currently sold in the United States. (PSI, 2004).
It is noteworthy that Portland has achieved a 10% service level and has been able to encourage higher
levels of participation from its community due to its unique length of service (since the 1980s). Portland
also pays attention t collection of leftover paint as well as developing the local infrastructure for the
recycling of 100% post-consumer latex paint. (PSI, 2004).
Comparison of the Quantity of Paint Disposed vs. Quantity of Paint Collected by HHW Programs
A large quantity of paint is disposed to landfills every year. As shown in Table 15, 65% of all the paint
disposed in Portland Metro was disposed at landfills or solid waste burning facilities. The majority of
paint going to landfills/solid waste facilities illustrates the importance of including these data when
estimating the quantity of leftover paint in the United States.
Table 15. Paint Disposal in Portland Metro
Stream
Landfill/Burned
HHW Collection
Total
Paint
2,221
1,215
3,436
% of Paint by Pathway
65%
35%
100%
Sources: PSI, 2004b and OR DEQ, 2002.
2.4.
Washington
MSW – 2003 Waste Composition Analysis for the State of Washington
The 2003 statewide waste composition analysis for Washington uses data from studies of 10 counties and
one city to estimate the quantity and percentage breakdown of 76 material categories making up the solid
waste stream of Washington State. In order to extrapolate beyond these 11 jurisdictions to the whole
state, the percentage breakdown of the material categories in each of these jurisdictions were applied to
the disposal tonnages for other counties with similar demographics. Those figures were then summed to
derive a statewide total for each waste category, as well as for residential and commercial sources and the
waste stream as a whole.
The statewide analysis focuses on municipal solid waste (MSW) brought to landfills for disposal.
Hazardous wastes are not addressed in the analysis, except in cases when these are disposed of with
municipal solid waste.
Latex paint and oil-based paint are included in the analysis as subcategories within the broader category
of hazardous and special waste. Table 16 shows the total quantities of MSW, Hazardous and Special
Waste, and paint waste going to MSW landfills in Washington (WA ECY, 2003b).
Table 16. 2003 Washington Statewide Waste Composition Study Results
Waste Type
Tons per Year
% of Total Waste
50,090
0.9%
Hazardous and Special Waste
8,250
0.15%
Latex Paint
2,810
0.05%
Oil Paint
11,060
0.2%
Total Paint
5,538,700
Total Waste
% of HHW
16.5%
5.6%
22.1%
Source: WA ECY, 2003(b).
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It should be kept in mind that there is a significant degree of statistical uncertainty associated with the
tonnage figures presented in Table 16. First, there are uncertainties associated with the estimates that were
generated for each of the 11 jurisdictions that served as the basis for the statewide waste composition
analysis. But beyond this, an additional and even larger source of uncertainty results from extrapolating
the data from these jurisdictions to other counties, with all of the associated assumptions about similar
demographics and other factors. The resulting level of uncertainty cannot be precisely quantified (WA
ECY, 2003(b)).
Washington Moderate Risk Waste Collection
In 2003, the state of Washington published the “Solid Waste in Washington – 12th Annual Status Report,”
which includes information on moderate risk waste (MRW). MRW is a combination of household
hazardous waste (HHW), conditionally exempt small quantity generator (CESQG) waste, and used oil
(UO). HHW is considered waste that was generated in the home, while CESQG is small quantities of
business or non-household waste. Both HHW and CESQG waste are exempt from hazardous waste
regulations.
In Washington State there are 42 programs that manage MRW. All 39 counties have some sort of MRW
program (or access to a MRW program in a neighboring county). Three types of MRW collections
operate in the state – permanent facilities, mobile units, and periodic collection events. It is estimated that
6% of all households in Washington use collection events and fixed facilities (WA, 2003a).
In 2002, MRW programs in Washington collected over 6,750 tons of HHW, almost 4,600 tons of UO,
and over 700 tons of CESQG waste, for a total of nearly 12,150 tons.
Latex paint and oil-based paint are two of the dominant types of HHW and CESQG waste collected in the
state. Approximately 44% of the paint that is collected as HHW, and approximately 69% of the paint that
is collected as CESQG waste is oil-based. As in California, this quantity of oil-based paint may indicate
that a large percentage of the paint that comes to the collection sites is old, because over 80% of paint
now produced is latex paint. The amount of paint collected from households and from CESQGs, and the
percentage of MRW that is paint are shown in Table 17.
Table 17. Paint collected in Washington MRW programs in 2002
Waste Category
HHW (tons)
CESQG (tons)
1,342
57
Latex Paint
428
1
Latex Paint, Contaminated
1,297
129
Oil-Based Paint
3,067
187
Total Paint
6,757
698
Total Waste
45.4%
26.7%
% Waste that is Paint
Total (tons)
1,399
430
1,425
3,254
7,455
43.6%
Source: WA ECY, 2003(a).
Comparison of the Quantity of Paint Disposed in MSW Landfills vs. the Quantity of Paint Collected by
MRW Programs
Despite restrictions on the landfill disposal of paint, a large quantity of paint is disposed of in this manner
every year. As shown in Table 18, approximately 77% of the paint that was disposed of in Washington in
2002 went to MSW landfills.
Table 18. Paint Disposal in Washington in 2002 – MSW Landfill and MRW Collection
Total HHW/CESQG
Total Paint
% of Paint Disposed by
Disposal Pathway
Disposed (tons)
Disposed (tons)
Pathway
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MSW Landfill*
MRW Collection
Total
50,090
7,455
56,847
11,060
3,254
14,127
77%
23%
Sources: WA ECY, 2003(a), and WA ECY, 2003(b).
* The MSW landfill quantities here reflect quantities of HHW and paint from all sectors, residential and nonresidential.
The large percentage of paint going to MSW landfills illustrates the importance of including MSW data
when estimating the quantity of leftover paint in the United States.
2.5.
Wisconsin
Wisconsin conducted a statewide waste characterization study in 2002 to estimate the quantity and
composition of waste disposed in the state’s municipal solid waste (MSW) landfills. In addition, the
Environmental Resources Center (ERC), located at UW-Madison, has compiled data for Wisconsin oneday household hazardous waste collection programs from 1984 to the present and permanent household
collection programs since 1996.
MSW - 2002 Wisconsin Statewide Waste Characterization Study
As part of the statewide waste characterization study, 14 of 36 active MSW landfills were sampled in
Wisconsin, which account for approximately 78% of all MSW disposed in the state and lie in each of five
distinct geographic regions. Seasonal variations were accounted for by sampling half of the landfills in
summer and half in winter; however, the results were presented as an aggregate for the entire year.
Samples were first divided into three distinct substreams—residential, ICI, and C&D activities—and then
further divided between commercially collected (including private and municipal haulers) and self-hauled
waste loads. A total of 400 waste samples (116 residential, 166 ICI, and 118 C&D) were taken from the
selected loads and sorted into 64 distinct material categories. Waste tonnages were estimated for the
individual landfills, and then composition estimates were calculated at a 90% confidence level for the
state as a whole and the 5 distinct geographic regions; for residential, ICI, and C&D generators; and for
self-hauled and commercially collected wastes. Results from the 14 landfills were aggregated using a
weighted averaging technique to develop a statewide estimate for the composition of disposed waste.
Table 19 shows statewide estimates for total MSW, HHW, and latex and oil paint waste for each waste
sector (WI DNR, 2003).
Table 19. 2002 Wisconsin Statewide Waste Characterization Study Results
Total MSW
HHW
Latex Paint Oil Paint Total Paint
Sector
(tons)
(tons)
(tons)
(tons)
(tons)
Residential
1,535,679
3,286
293
49
342
Industrial/Commercial/
2,100,198
15,524
1,028
411
1,439
Institutional
Construction &
1,116,341
7,345
5,667
635
6,302
Demolition
Total Waste
4,752,218
26,155
6,988
1,095
8,083
% of
HHW
10.4%
93%
85.5%
30.9%
Source: WI DNR, 2003
Latex paint is estimated to be 0.1% of total MSW, with 90% confidence that it is not more than 0.3%. For oil paint,
the study notes a 90% confidence interval, however because oil paint is a very small percentage of the total waste
stream, and because numbers are rounded, the upper and lower confidence limits of the 90% confidence interval for
oil paint are the same as the estimate.
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Wisconsin HHW Collection Programs
Wisconsin collects HHW through both permanent and one-day collection programs. Although the
number of permanent programs has been growing since 1996, the number of one-day programs fluctuates
annually based on funding. In 2001, there were 12 permanent programs and 9 one-day programs. ERC
distributes annual surveys to collect data from these programs. For the permanent programs, the survey
breaks down the waste by type (e.g., pesticides, latex paint, lead/oil paint, etc.); the one-day programs are
only asked to report the total volume of HHW collected. The most recent year for which complete waste
data are available for the permanent and one-day programs is 2001, with the exception of Milwaukee
County, which is only complete to 2000. Tables 20 and 21 show the HHW collection data by county for
the permanent and one-day programs, respectively.
Table 20. Wisconsin HHW Collected by Permanent Programs in 2001
Total HHW
County
(tons)
Brown
213
Dane
230
Kenosha
10
20
Marathon
Milwaukee (2000 data)
418
NWRPC*
98
Oneida
32
11
Ozaukee
Sheboygan
19
Waukesha**
121
Waupaca
0.6
Winnebago
10
Total
1183
Total Paint
Lead/Oil Paint (tons) Latex Paint (tons) (tons)
78
66
143
59
105
165
Quantity not specified No data available
Quantity not specified No data available
139
182
321
Survey not returned No data available
Quantity not specified
19
19
Survey not returned No data available
8
No data available
8
Quantity not specified No data available
Quantity not specified No data available
7
No data available
7
291
372
662
% of
HHW
67
72
77
0
60
40
65
56
Source: ERC, 2004
*Northwest Regional Planning Commission (NWRPC) is a group of 10 counties that collect and report on HHW as
a cooperative group.
**Includes data for the Superior Emerald Park Landfill (SEPL), which is in Waukesha County but reported
separately in 2001; these two facilities began reporting a combined value in 2003.
Table 21. Wisconsin HHW Collected by One-Day Programs in 2001
County
Chippewa
Eau Claire
Green
Iowa
Langlade*
Menominee
Racine
Trempeleau
Washington*
Total
Total HHW (tons)
17
25
12
3
12
4
4
2
5
84
Source: ERC, 2004
*These counties reported waste in pounds (6,618; 7,304) and gallons (4,290; 775). The totals represent the (pounds
+ (gallons*4))/2000, assuming the gallon containers are half full.
September 20, 2004—DRAFT
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Of the 12 permanent programs, 10 reported that they collected lead/oil paint, but only 5 reported the
quantities of lead/oil paint collected. Reporting on lead/oil paint quantities was more complete than for
latex paint due to the environmental concerns associated with this waste stream. Four of the permanent
programs reported the quantity of latex paint collected.
The method of ratio estimation was used to estimate the total amount of paint that goes to HHW
collection programs annually in Wisconsin. This uses the available data on paint quantities to scale up
and provide a statewide estimate of paint waste. The total estimated amount of lead/oil paint was
calculated by dividing the total weight of lead/oil paint collected by permanent programs by the total
weight of HHW collected by permanent programs that reported a lead/oil paint quantity. This value was
multiplied by the total HHW (permanent and one-day) collected in the state to provide an estimated
volume of lead/oil paint that would be collected statewide:
291 tons Pb/oil paint
889 tons HHW
* (84 tons HHW  1183 tons HHW)  415 tons Pb/oil paint
The same methodology was applied to estimate the volume of latex paint that would be collected
statewide:
372 tons latex paint
892 tons HHW
* (84 tons HHW  1183 tons HHW)  528 tons latex paint
The total estimated weight of paint that would be collected by HHW programs annually is 943 tons.
Comparison of the Quantity of Paint Disposed In MSW Landfills vs. the Quantity of Paint Collected by
HHW Programs
The majority of the paint disposed of in Wisconsin (92%) goes to MSW landfills. Again, the large
percentage of paint going to MSW landfills illustrates the importance of including MSW data when
estimating the quantity of leftover paint in the United States.
Table 22. Paint Disposal in Wisconsin in 2001 – MSW Landfill and HHW Collection
Total HHW Disposed or
Disposal Pathway
Collected (tons)
Total Paint (tons) % of Paint by Pathway
26,155
8,083
92%
MSW
1,265
662*
8%
HHW Collection
27,420
8,745
Total
Sources: WI DNR, 2003; ERC, 2004
*This value represents actual paint collected by permanent programs.
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September 20, 2004—DRAFT
3.
National Estimates of Paint Waste
This section presents an initial approach to estimating the quantity of post-consumer paint disposed of in
landfills or collected by HHW programs in the U.S.
3.1.
Comparisons with PSI Estimates
The PSI background document provides an estimate of the quantity of leftover paint generated annually in
the United States, based on data from California HHW and Washington state MRW collection programs.
The PSI estimate was developed using HHW and MRW collection data, U.S. Census data on households
in each state and in the country, and an estimate of the percent of the population served by permanent or
temporary HHW or MRW collection programs in each state. The quantity of leftover paint generated in
the U.S. was estimated to be in the range of 16 million to 35 million gallons per year. That estimate does
not include volumes of leftover paint generated by contractors, where the paint is removed from the job
site by the contractor, or take into account the quantity of paint sent to MSW landfills every year. We
estimate that approximately 85% of the total paint disposed of in California in 1999, and approximately
77% of the paint disposed of in Washington in 2002, was sent to MSW landfills (see Tables 3 and 18).
This indicates that the HHW and MRW collection programs in these states may only be capturing a
limited portion of the leftover paint that is generated.
With this critical factor in mind, we refined the PSI estimates for California and Washington, adding in
the quantity of paint disposed in MSW landfills. As reflected in Table 23, we also developed estimates
for Iowa, Wisconsin and the Portland Metro region of Oregon (we are still reviewing statewide HHW
collection data for Oregon). In order to account for paint disposed in MSW landfills, we slightly
modified the calculation methods that were employed in the PSI study, using HHW collection data, MSW
composition data, U.S. Census data on population and households in the state and in the country, and an
estimate of percent of national paint sales for each state (pending). Our estimates are shown in Table 23.
Table 23. Refined Estimate of Leftover Consumer Paint in the U.S.
State
% of U.S.
[A]
Households
California
10.9%
Iowa
1.1%
Washington
2.2%
Wisconsin
2.0%
[B]
Pop.
12.1%
1.0%
2.1%
1.9%
Paint Collected (gallons)
Estimate Total Leftover Paint
(gallons) based on:
[C]
[D]
[E]
[G]
Paint
HHW
MSW
[F]
%
[H]
[I]
Sales Collection Landfill
Total Households % Pop. % Sales
TBD 1,613,828 8,899,600 10,513,428 96,180,045 87,173,043 TBD
TBD
93,835
503,460
597,295 54,690,436 57,324,551 TBD
TBD 650,776 2,212,000 2,862,776 132,629,762 136,408,844 TBD
TBD 132,400 1,616,000 1,749,000 87,450,000 92,052,631 TBD
Metropolitan Area
Portland
Metro
0.54%
0.51% TBD
243,000
326,600
569,600 105,257,449 110,767,185
TBD
Sources: CIWMB, 1999; data from Anna Ward, CIWMB, 2004, IA DNR, 1998; data from Theresa Stiner, IA DNR,
2004; OR DEQ, 2002; WA ECY, 2003(a), and WA ECY, 2003(b).
Note: all paint quantities are in gallons
Calculations:
September 20, 2004—DRAFT
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A. Based on 105 million households in U.S. according to U.S. 2000 Census.
B. Based on a population of 280,849,847 in U.S. according to U.S. 2000 Census.
C. Based on data from the 1997 U.S. Economic Census or other sources.
D. Quantities of paint collected in HHW programs in this state.
E. Quantities of paint disposed of to landfills in this state.
F. Combines paint collected from HHW programs and landfills. Paint quantity was converted from tons, assuming
an average weight of 10 pounds per gallon of paint.
G. National estimate of the quantity of leftover paint extrapolating by % households in the state: [ F ] / [ A ]
H. National estimate of the quantity of leftover paint extrapolating by % population in the state: [ F ] / [ B ]
I. National estimate of the quantity of leftover paint extrapolating by % households in the state: [ F ] / [ C ]
As shown above, the inclusion of paint disposed in MSW landfills increases the estimate of the quantity
of post-consumer paint disposed annually in the U.S. quite dramatically. The estimate is now in the range
of 54 million to 136 million gallons, as opposed to the previous range of 16 million to 35 million gallons.
The U.S. Census of Manufacturers estimates that in 2001, 618,436,000 gallons of architectural paint were
sold in the U.S. Using this quantity and each of the national estimates of waste paint reflected in Table
23, we compute the annual quantity of post-consumer paint disposed in the U.S. as a percentage of annual
architectural paint sales. These estimates are shown below in Table 24.
Table 24. Estimates of Post-Consumer Paint Disposal as a Percent of New Architectural Paint Sales
State
Based on Households
Based on Population
Based on Sales
15.6%
14.1%
TBD
California
8.8%
9.3%
TBD
Iowa
17.0%
17.9%
TBD
Portland Metro
21.4%
22.1%
TBD
Washington
14.1%
14.9%
TBD
Wisconsin
Sources: CIWMB, 1999; data from Anna Ward, CIWMB, 2004, IA DNR, 1998; data from Theresa Stiner, IA DNR,
2004; OR DEQ, 2002; WA ECY, 2003(a), and WA ECY, 2003(b).
3.2.
Ratio Estimation Method
This section presents two methods for estimating the total quantity of post-consumer paint disposed
annually in the U.S. The first method uses households as a basis for estimating the paint disposed
annually in the U.S. based on the estimates developed for California, Iowa, Washington, Wisconsin and
the Portland Metro area. The second method uses population for this purpose.
In Table 25A we compute the ratio of the total amount of paint disposed in the 4 states and the Portland
Metro area to the total number of households in these jurisdictions. This ratio is then applied to the total
number of households in the U.S. From Table 25A we see that this results in a ratio of 0.931 gallons per
household. Applying this ratio to the total number of households in the U.S. (105,000,000, U.S. 2000
Census), we get a national estimate of 97,755,000 gallons of post-consumer paint disposed annually.
Table 25A. Gallons of Paint Disposed Annually Per Household for Five Jurisdictions (Based on the
total number of households)
A
F
R = F/A
Number of
Total Paint
Gallons Per
State
Households
(Gallons)
Household
California
11,445,000
10,513,428
0.919
Iowa
1,155,000
597,295
0.517
Washington
2,310,000
2,862,776
1.239
Wisconsin
2,085,000
1,804,780
0.866
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Portland Metro
Total
567,000
569,600
1.004
17,561,544
16,347,879
0.931
In Table 25B we compute the ratio of the total amount of paint disposed in the 4 states and the Portland
Metro area, to the total population in these jurisdictions. This ratio is then applied to the total population
of the U.S. From Table 25B we see that the ratio is 0.330 gallons per person. Applying this ratio to the
total number of people in the U.S. (280,849,847, U.S. 2000 Census), we get a national estimate of
92,680,450 gallons of post-consumer paint disposed annually.
Table 25B. Gallons of Paint Disposed Annually Per Person for Five Jurisdictions (Based on the
total population)
F
A
Total Paint
Ratio= F/A
State
Population
(Gallons)
Gallons Per Person
California
33,982,831
10,513,428
0.309
Iowa
2,808,499
597,295
0.213
Washington
5,897,847
2,862,776
0.485
Wisconsin
5,363,675
1,804,780
0.336
Portland Metro
1,516,589
569,600
0.375
Total
49,569,441
16,347,879
0.330
Given these two estimates of post-consumer paint disposed, we can compare to the amount of paint sold
annually in the U.S. According to the U.S. Census, the estimated U.S. total quantity of Architectural
Coatings in 2001 was 618.4 million gallons6 (U.S. Census, 2002). Table 26 shows that between 15 and
16% of this can be estimated to be disposed annually.
Table 26. Percent of Paint Sold in the U.S. that is Disposed
U.S. Total Quantity Estimated Paint Disposed Annually
of Shipments
Based on:
(million gals)
(million gals)
Household
97.8
618.4
Population
92.7
Percent of Paint Sold Annually in
the U.S. that is Disposed
15.8%
15.0%
Source: U.S. Census 2002
The accuracy of the national estimates presented above is affected by two factors. The first is that these
estimates are based on a very small sample of 4 states and a metropolitan area. A sample of 5 different
states in the U.S. could have given entirely different estimates. This is known as sampling error. We are
unable to determine the sampling error, as this sample of 4 states and the metropolitan area is not a
random sample from the population of 50 states and the District of Columbia. The second factor is
possible bias within the estimates. The first source of potential bias is due to the 4 states and the
metropolitan area in the sample being nonrandom. If these jurisdictions are not representative of the
population of all states, the estimates presented could be too high or too low. Also, the estimates of the
quantity of post-consumer paint disposed for the individual states and for the Portland Metro area could
be biased due to measurement errors, as determining the amount of paint going to MSW landfills and
HHW collection programs is subject to different measurement methodologies.
6
The Census Bureau issued a revised estimate of 667.0 million gallons in their Current Industrial Reports for Paint
and Allied Products: 2002, issued in July 2003. The earlier estimate is used here to be consistent with the PSI
report.
September 20, 2004—DRAFT
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In spite of the potential inaccuracies in the estimates presented here, we feel that these estimates may
provide useful ballpark projections of the total quantity of post-consumer paint disposed annually in the
U.S., and of the percentage of paint sold nationally that becomes waste. However, we do emphasize that
these estimates are gross estimates and should be used with caution.
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September 20, 2004—DRAFT
4.
Factors to Consider in Estimating the Quantity of PostConsumer Paint
Under- and Over-Estimation of Paint Values
When estimating the quantity of post-consumer paint that is generated or disposed based on MSW
composition studies and HHW collection data, there are a number of factors that could lead to over- or
under-estimation of paint quantities. Several of these factors are discussed below:
Inclusion of Containers in Paint Quantity Estimates. Our research indicates that the waste sorting
protocols used in most waste characterization studies call for distinguishing between empty paint
containers (which are typically classified as “containers” or some other category of waste), containers
containing dried latex paint (which are typically classified as “mixed” material), and containers
containing liquid latex paint or oil-based paint in any form (which are classified as “paint”). When a
container is found to contain liquid latex paint or oil-based paint, the paint is typically weighed in its
container, and the combined weight of the paint and the container is included in the estimate for paint.
We have obtained empirical information from two sources that can be used to estimate the fraction of this
combined weight that is attributable to the container:

Portland Metro estimates that an average gallon paint container weighs 0.9 pounds, with gallon
containers being the most common size. They further estimate that latex paint weighs between 10
– 11 lbs./gallon and oil-based paint weighs between 7 – 8 lbs./gallon, and that paint cans come
into their HHW collection program, on average, 45% full. Based on these considerations,
Portland Metro estimates that containers constitute 15 – 22% of the total combined weight of the
paint and containers they collect.

Product Care in British Columbia, Canada, estimates that approximately 20-25% of the combined
weight of the paint and containers it collects can be attributed to the containers.
It should be recognized, however, that paint containers collected by HHW programs might contain more
paint, on average, than containers disposed in MSW landfills, although this has not been formally
examined. As the amount of paint in a container decreases, the weight of the container, relative to that of
its contents, increases. Therefore, the estimates reported by Portland Metro and Product Care may
represent a lower bound for the fraction of the reported quantity of disposed paint that can be attributed to
paint containers in waste composition studies.
Since paint containers must typically contain some non-trivial quantity of paint in order to be classified as
“paint” in a waste composition study, each study must establish this threshold quantity of paint. The
protocol for the Oregon Waste characterization study specifies that to be classified as paint, a paint
container must contain a quantity of paint that is at least equivalent to the weight of the container (i.e., the
container itself may account for no more than 50% of the combined weight). Therefore, a likely upper
bound for the fractional weight of the containers in studies, such as the one conducted in Oregon, would
be 50%.
Based on these considerations, we preliminarily estimate that approximately one third of the weight
recorded as “paint” in state and local waste characterization studies is likely to be attributable to paint
containers, and approximately two-thirds of the weight may be attributed to the paint itself.
The weight of paint containers is generally not an issue for HHW collection programs, since the estimates
provided for the quantity of paint collected by these programs are typically based on the weight of the
paint itself.
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Metro Portland is planning to undertake an empirical analysis, in collaboration with Oregon DEQ, to
determine what portion of the weight recorded as “paint” in an upcoming waste composition analysis,
covering the Portland Metro area, is attributable to containers. This analysis is likely to be completed
during the next 18 months and the results can be used to further refine the quantitative estimates of
disposed paint provided in this report.
Liquid vs. Dried Paint. As discussed above, waste composition studies typically do not classify paint
containers that contain dried latex paint as “paint” and include them in their quantity estimates for paint.
Similarly, dried paint that is found outside of a paint container is normally not included in the quantity
estimates for paint.
To address the weight of dried paint, we look to three different sources of information.

Many states and/or local communities advise their residents to dry out their leftover latex paint
and dispose of it in the garbage. Organizations such as the National Paint and Coatings
Association (NPCA) promote this approach as well. NPCA’s Six Point Program for Leftover
Paints advices consumers to dry their leftover latex paint away from children and pets (e.g., by
pouring it into a paper box or bag and adding absorbent material such as shredded newspaper or
cat box filler), and then to throw it away with their normal trash (NPCA 2004b). Even states such
as California that do not encourage this type of practice, nevertheless permit residents to dispose
of dried latex paint in the MSW waste stream.

A survey conducted for NPCA in the mid 1990s sought to learn about the disposition of leftover
paint, stain, thinners and similar materials in households. The survey found that when asked
“What do you typically do with … products that you no longer need?” 30% of respondents listed
“let liquid in can evaporate before disposal.” (NFO, 1995).

The 2002 Oregon Solid Waste Characterization and Composition Study included an analysis of
contaminants in disposed waste. For this analysis, paint containers that were nearly empty or
contained dried paint were included in the appropriate container category – either non-food steel
cans, rigid plastic containers, or mixed material – and then subject to contamination analysis.
Paint found in these containers was scraped out, weighed and then "added back" to the paint
category. The amount of dried latex paint found in containers was fairly large, so a fairly large
correction factor was produced. (Note that because the inverse analysis was not done, i.e.,
subtracting out the weight of the cans from the paint waste stream, the paint weight estimates
presented in the Oregon study can be expected to be over-estimations. However, the absence of
any correction factor in the other state studies could be a significant factor leading to underestimation.) The Oregon contamination analysis provided the following results for the 4 detailed
samples containing paint.
Table 27. Oregon contamination analysis in 2002
#
% Primary % Wet % Water
Detailed Material Contami
&
samples* clean/dry -nants Residue
Latex paint
3
100.00% 0.00% 0.00%
Oil-based
1
100.00% 0.00% 0.00%
paint/thinner
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2002 data
% Dry 2002 Field Corrected for Contamination
AddData (%
contamination
correction
backs composition) (%composition)
factor
20.45%
0.09%
0.11%
20.45%
4.52%
21
0.06%
0.06%
4.52%
September 20, 2004—DRAFT
In 2000, Oregon also conducted a waste composition study that included a contamination analysis
for paint. That analysis estimated a contamination correction factor of 30.40% for latex paint and
4.37%for oil paint/thinners. These estimates were based on 2 detailed samples containing paint.
The Oregon analyses come with caveats, however. A sample size of fewer than 10 is deemed too
few to provide meaningful results. In addition to a small sample size, applying the contamination
correction factors to studies in other states is not recommended since the results were strongly
influenced by factors specific to the Oregon studies. Comparing Oregon’s contamination
analyses to those conducted by other states would help in understanding the magnitude of the
variation across studies. However, as noted in Oregon’s 2002 study, no other state is thought to
have conducted a similar analysis.
A further point to make note of for the Oregon contamination analyses is that the weight of the
dried paint scraped off cans does not represent the original weight of the paint as a liquid. To
most accurately estimate the amount of paint that is leftover (versus the amount of material
reaching landfills), it would be necessary to back-calculate the weight of the paint when it became
"leftover." This could dramatically increase the magnitude of the "add back" resulting from the
contamination analyses, since new paint contains a large proportion of liquid. In addition, the
Oregon contamination analysis only looked at dried paint in containers. Significant quantities of
leftover paint may be dried by consumers and disposed outside of containers. This could further
increase the “add back” resulting from a more comprehensive contamination analysis.
This leads also to the general observation that the amount of paint reaching MSW landfills or
HHW collection programs does not directly equate to the amount of paint that can be reused,
recycled or otherwise reclaimed. There will always be some quantity of paint on the sides and
bottoms of cans that will dry out before disposal, as well as some quantity of paint that will be
contaminated or spoiled.
Paint Spillage. The issue of paint spillage pertains to the concern that paint is spilled from containers en
route to the disposal location, where it is subsequently weighed. The loss of paint (presumably adhered to
paper, food and other adjacent waste materials) would be reflected in an undercount of total paint at the
disposal site. It is safe to assume that some cans may get crushed on the way to the landfill, and that lids
may pop off. Brad Anderson of Sky Valley Associates said he would guess that they find spilled paint in
about 1% of their waste characterization samples (versus approximately 8% of these samples that contain
unspilled paint). This suggests that spilled paint may be a small, but not insignificant factor leading to
underestimates in the quantity of disposed paint. Sky Valley Associates does not quantify the percentage
of paint containers that arrive with their lids popped. They are engaged in a potentially comparable study
for the state of California to quantify spillage from oil containers, but there are no known studies for
paint.
Other Factors to Consider:

The misclassification of unknown paint or solvents is another factor that can lead to the misestimation of paint waste. If the person conducting the waste sort encounters an unlabeled
container that may contain paints or solvents, it may be classified as “unknown,” thereby
underestimating the amount of paint in the landfill. It could also be classified as paint, although it
may contain some other solvent or liquid that is not actually paint, thereby overestimating the
amount of paint being disposed.
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
If paint is counted as part of a combined category, such as “paints and solvents,” it could be
misestimated due to potential error in estimating the percentage of the category that is actually
comprised of paint.
Confidence Intervals
Several individuals involved with MSW waste sorts cautioned against using paint quantities as absolute
numbers, but rather for order-of-magnitude estimates. The reason for this is the proportionally low
quantities of paint in MSW waste streams (resulting in high sampling confidence intervals), and variation
in sampling methodology between studies. There are differences in how waste segments are defined,
sorted, and subsequently measured as well.
Confidence intervals and standard deviations are provided in this report where available in the source
data. They provide a measure of the precision of the point estimates, given that the specific point estimate
based on sampling is different from the population value. The width of the confidence interval gives us
some idea of how uncertain we are about the unknown population value. A very wide interval indicates
that more data would need to be collected before making definite statements about the population
parameter. Confidence intervals are more informative than point estimates. A confidence interval
provides a range of plausible values for the parameter.
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5.
Conclusions
Using the refined PSI calculation methods shown above in Tables 23 and 24, and the ratio estimation
method reflected in Table 26, we estimate preliminarily that anywhere from 8.8 to 22% of paint sold in
the U.S. goes to MSW landfills or HHW collection programs, with a best estimate of about 15%. These
quantities may not represent all of the leftover paint generated annually in the U.S. Some leftover paint is
undoubtedly dried out by consumers, spilled down drains, or disposed of by contractors and large
industrial, commercial and institutional users as hazardous waste. There may also be significant
quantities of retail surplus paint (e.g., miss-tint and discontinued products), which are not captured here.
On the other hand, there are other factors that may lead to over-estimation of the amount of paint disposed
in landfills or collected in HHW programs. In addition, our estimate does not account for the large
quantity of leftover paint that is stockpiled, nor does it provide a basis for determining if that stockpile is
increasing or diminishing over time. Nevertheless, these estimates may provide a useful ballpark
projection of the total quantity of architectural paint sold in the U.S. each year that becomes leftover postconsumer paint.
September 20, 2004—DRAFT
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6.
References
Anderson, Brad, Sky Valley Associates. Personal communication with Anna Leos-Urbel on June 23,
2004.
California Integrated Waste Management Board (CIWMB), 2001. California Integrated Waste
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CIWMB, 2000. California Integrated Waste Management Board, Board Meeting August 22-23, 2000.
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Culbertson, John, R.W. Beck Consulting, 2004. Personal communication with Anna Leos-Urbel on May
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http://www.moea.state.mn.us/publications/wastesort2000.pdf
National Family Opinion Research, Inc. (NFO), 1995. Consumer Architectural Coatings Disposal Study.
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Product Stewardship Institute (PSI), 2004b. National Paint Infrastructure Collection System Modeling
Executive Summary - DRAFT. Accessed:
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Quinn, Jim, Hazardous Waste Program Manager, Portland Metro, 2004. Personal communication with
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Spendelow, Peter, Oregon Department of Environmental Quality, 2004. Personal communication with
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Stiner, Theresa, Iowa Department of Natural Resources, 2004. Personal communication with Anna LeosUrbel on June 24, 2004.
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June 2, 2004.
United States Census, 2000. Population of the States and the Country. Accessed: http://www.census.gov/
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manufacturing Population of the States and the Country. Accessed:
http://www.census.gov/epcd/ec97/industry/E32551.HTM
United States Environmental Protection Agency (U.S. EPA), 2004. RCRAInfo (database) as of June 9,
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system on June 24, 2004.
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States – 2001 Facts and Figures. Accessed: http://www.epa.gov/epaoswer/nonhw/muncpl/msw99.htm#links
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