Economic and Small Business Analysis Proposed Revisions to the Nonmetallic Mineral Processing Plants (Subpart OOO) NSPS


United Stales
^ |^/\ Environmental Protection
I	Agoncy
Economic and Small Business Analysis - Proposed Revisions
to the Nonmetallic Mineral Processing Plants (Subpart
OOO) NSPS

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EPA 452/R-08-001
April 2008
Economic and Small Business Analysis - Proposed Revisions to the Nonmetallic Mineral
Processing Plants (Subpart OOO) NSPS
By:
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Health and Environmental Impacts Division
Air Benefits and Costs Group
Research Triangle Park, NC
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SECTION 1
INTRODUCTION
To meet the requirements of section 111(b)(1)(B) of the CAA, the Environmental
Protection Agency (EPA) is currently conducting the second review of the new source
performance standards (NSPS) for non-metallic mineral processing plants (NMPP). The NMPP
NSPS was promulgated on August 1, 1985 (40 CFR Part 60 subpart OOO, 50 FR 31328) and
subsequently reviewed in 1997. Subpart OOO requires new, modified, or reconstructed affected
facilities at NMPP to achieve emission levels that reflect the best demonstrated system of
continuous emission reduction, considering cost, non-air quality health, environmental, and
energy impacts. These emission levels, referred to as "best demonstrated technology (BDT),"
are specified in subpart OOO.
The purpose of this report is to provide economic and small business impact analyses for
the requirements of this proposed NSPS. We include revenue and other economic data for
affected industries and businesses in the industry profile for this NSPS, and that is included in
this report. The analysis will focus on estimating such impacts by providing annualized cost as a
percent of sales or revenues for firms in industries likely to be affected by this NSPS. This
analysis is meant to meet the requirements of the Regulatory Flexibility Act (RFA) as amended
by the Small Business Regulatory Enforcement Fairness Act (SBREFA). The annualized costs
are those found in the memo "Cost, Environmental and Energy Impacts for the Proposed
Revisions to the NSPS for Non-Metallic Mineral Processing Plants (40 CFR Part 60, subpart
OOO)," prepared by RTI in March, 2008.
In summary, we find there to be minimal economic impacts associated with this proposed
NSPS, and no SISNOSE (significant impacts on a substantial number of small entities) resulting
from implementation of this proposal.
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SECTION 2
INDUSTRY PROFILE
2.1 NAICS 21231—Stone Mining and Quarrying
Stone is a naturally occurring aggregate of minerals that is typically used in one of two
forms—dimension stone and crushed stone. Dimension stone is natural rock that has been
quarried for the purpose of obtaining blocks or slabs that meet certain specifications, such as
size, shape, color and grain (USGS, 2007a). Dimension stone is primarily used in construction.
For example, it is often cut and shaped into ashlars, counter tops, flagstone, and rough block
(USGS, 2007a).
Crushed stone is rock that has first been mined from the ground then pulverized or
crushed into smaller pieces of a desired size. This material serves as a raw material in a variety
of products such as concrete (USGS, 2007b). It is important to note that while the two seem
similar, crushed stone is different from gravel, which is produced from a natural process of
weather and erosion.
The purpose of this industry profile is to characterize the stone mining industry and the
firms involved. First, the industry is defined using the North American Industry Classification
System (NAICS). Next, we examine historical data on production, international trade, prices, and
firm characteristics.
2.1.1 Industry Description
The stone mining and quarrying industry is classified under NAICS code 21231. It is
defined as all establishments that are either 1) primarily engaged in developing the mine site,
mining or quarrying dimension stone or crushed and broken stone or 2) primarily engaged in
beneficiating stone (e.g., crushing, grinding, washing, screening, pulverizing, and sizing) (U.S.
Census Bureau, 2002a).
Beneath this 5-digit NAICS code, the stone mining industry is further categorized into
different segments at the 6-digit NAICS code level. These segments include Dimension Stone
Mining (212311), Crushed and Broken Limestone Mining (212312), Crushed and Broken
Granite Mining (212313), and Other Crushed and Broken Stone Mining and Quarrying (212319).
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2.1.2 U.S. Stone Mining and Quarrying Production
This profile's primary source for Stone Mining production data was the U.S. Geological
Survey (USGS) Mineral Yearbooks published each year for Dimensional and Crushed Stone.
The data reported in these yearbooks is collected through voluntary surveys of stone mining
operations. The USGS independently determines which operations will be surveyed by using a
variety of sources to compile a list of all stone mining operations in the US. These surveys are
used to determine how much dimension and crushed stone is being produced in the US, where
it's being produced, and what it's being used for (USGS, 2007a).
Between 2000 and 2006, production of dimension stone remained relatively constant
around 1.3 million metric tons per year. In 2006, 1,330,000 metric tons of dimension stone was
produced inside the United States, nominally valued at $265 million (Table 2-1).1 Much of this
dimension stone was produced in states in the mid-west and the northern east coast (Table 2-2).
The largest dimension stone producing state in 2006 was Wisconsin, which accounted for 22%
of all dimension stone produced. The greatest single use for dimension stone in the US in 2006
was as rough blocks for building and construction (Table 2-4). This use accounted for
approximately 22% of all dimension stone produced in the United States.
During this same 5-year time period, production of crushed stone grew around 2% each
year. In 2006, 1.7 billion metric tons of crushed stone were sold or used by producers in the
United States (Table 2-1). This stone was nominally valued at $13.8 billion. The states producing
the largest amount of crushed stone are Texas, Florida, and Pennsylvania (Table 2-3). These
states account for approximately 22% of the crushed stone produced in the US. Nearly 40% of
crushed stone is used in the construction industry (Table 2-5).
2.1.3 International Trade
International trade is a growing part of the stone mining industry. A summary of the
nominal value of imports and exports of dimension and crushed stone for 2000 to 2006 can be
found in Table 2-6. As this table reports, imports of dimension stone grew very quickly between
2000 and 2006. Specifically, imports of dimension stone grew 154%) during this 5 year period
(an average growth rate of 30% per year). Imports of crushed stone also rose rapidly during this
period. Between 2000 and 2006, crushed stone imports grew 96% (an average growth rate of
19%) per year).
1 All monetary values are reported in nominal (not inflation-adjusted) dollars unless otherwise noted.
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The nominal value of exports of dimension and crushed stone has also grown
significantly in the past 5 years. Between 2000 and 2006, the nominal value of dimension stone
exports grew approximately 27% (around 5% each year), while exports of crushed stone grew
93% (around 19% each year).
Table 2-1. Dimension and Crushed Stone Sold or Used by US Producers: 2000 to 2006
2000 2001	2002 2003 2004 2005 2006
Dimension Stone
Quantity (1,000 metric 1,320 1,220 1,260 1,340 1,460 1,360 1,330
tons)
Value ($1,000)	235,000 263,000 254,000 268,000 281,000 269,000 265,000
Crushed Stone
Quantity (1,000 metric 1,550,000 1,590,000 1,510,000 1,530,000 1,630,000 1,700,000 1,720,000
tons)
Value ($1,000)	8,290,000 8,870,000 8,650,000 9,060,000 9,890,000 12,400,000 13,800,000
Source: U.S. Geological Survey. 2007a. 2006 Minerals Yearbook, Dimension Stone. Washington, DC: U.S.
Department of the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2007b. 2006 Minerals Yearbook, Crushed Stone. Washington, DC: U.S. Department of
the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2005b. 2004 Minerals Yearbook, Crushed Stone. Washington, DC: U.S. Department of
the Interior. Available at .
As obtained on March 25, 2008.
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Table 2-2. Dimension Stone Production by State: 2006
State	Quantity (1,000 Metric Tons)	Value ($1,000)
Wisconsin
297
35,400
Indiana
233
39,000
Vermont
100
27,600
Massachusetts
82
11,500
Georgia
81
19,100
North Carolina
41
17,800
California
40
10,000
New York
39
3,860
Pennsylvania
38
12,800
Texas
31
12,600
Total
1,330
265,000
Source: Geological Survey. 2007a. 2006 Minerals Yearbook, Dimension Stone. Washington, DC: U.S. Department
of the Interior. Available at . As obtained on March 25, 2008.
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Table 2-4. Dimension Stone by Major Use: 2006

Quantity
Value
State
(1,000 Metric Tons)
($1,000)
Rough blocks for building and construction
294
$45,500
Other3
213
50,300
Flagging
158
15,500
Ashlars and partially squared pieces
147
27,000
Curbing
129
20,500
Total
1,330
265,000
aOther includes panels and veneer, tile, blackboards, exports, uses not specified, and uses not listed.
Source: Geological Survey. 2007a. 2006 Minerals Yearbook, Dimension Stone. Washington, DC: U.S. Department
of the Interior. Available at . As obtained on March 25, 2008.
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Table 2-6. Dimension and Crushed Stone Import and Export Data: 2000 to 2006

2000
2001
2002
2003
2004
2005
2006
Dimension Stone







Exports ($1,000)
59,800
73,500
64,400
63,500
63,700
66,100
76,000
Imports ($1,000)
986,000
1,070,000
1,190,000
1,390,000
1,790,000
2,180,000
2,500,000
Crushed Stone







Exports ($1,000)
29,700
35,600
54,000
45,600
54,500
50,500
57,300
Imports ($1,000)
105,000
110,000
124,000
143,000
149,000
194,000
206,000
Source: U.S. Geological Survey. 2007a. 2006 Minerals Yearbook, Dimension Stone. Washington, DC: U.S.
Department of the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2007b. 2006 Minerals Yearbook, Crushed Stone. Washington, DC: U.S. Department of
the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2005b. 2004 Minerals Yearbook, Crushed Stone. Washington, DC: U.S. Department of
the Interior. Available at .
As obtained on March 25, 2008.
2.1.4 Market Prices
Dimension stone tends to receive higher prices than crushed stone. For example, in 2006,
the average nominal unit value for granite dimension stone was $254 per ton, while the average
nominal unit value of crushed granite was $9.60 per ton. However, prices also differ based on
type of stone. For example, the average nominal unit value for marble dimension stone is $390
per ton, approximately $140 more than the nominal unit value for granite dimension stone. A
summary of the nominal unit values of dimension stone and crushed stone in recent years is
provided in Table 2-7. Between 2000 and 2006, the nominal unit value of dimension stone only
grew approximately 4% each year. In contrast, the unit value of crushed stone grew
approximately 10% over the same time period.
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Table 2-7. Average Unit Values for Dimension and Crushed Stone Sold or Used by US
Producers: 2000 to 2006
2000 2001 2002 2003 2004 2005 2006
Dimension Stone
Unit Value ($ per metric ton) 178.0 215.6 201.6 200.0 192.5 197.8 199.2
Crushed Stone
Unit Value ($ per metric ton) 5.3 5.6 5.7 5.9 6.1 7.3 8.0
Source: U.S. Geological Survey. 2007a. 2006 Minerals Yearbook, Dimension Stone. Washington, DC: U.S.
Department of the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2007b. 2006 Minerals Yearbook, Crushed Stone. Washington, DC: U.S. Department of
the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2005b. 2004 Minerals Yearbook, Crushed Stone. Washington, DC: U.S. Department of
the Interior. Available at .
As obtained on March 25, 2008.
Producer price data for the stone mining industry was obtained from the Bureau of Labor
Statistics (BLS) to better understand how prices received by stone mining companies moved
relative to prices received by companies in other industries. According to the BLS, the Producer
Price Index (PPI) for the stone mining industry (which measures the nominal prices firms receive
for their products) rose an average of 6% each year. This growth rate is relatively slow when
compared with prices received by firms in other industries. For example, during the same 6-year
time period, prices received by other U.S. mining firms have risen an average of 17% each year
during the same period. This data is presented in Table 2-8.
2.1.5 Industry Concentration
Data on the concentration of the stone mining firms was obtained from industry reports
prepared by Dun and Bradstreet (D&B). These industry reports are based on data that companies
operating within various segments of the stone mining industry voluntarily provided D&B. As a
result, these reports necessarily exclude information on firms that did not provide financial
information to D&B.
D&B received financial information from 199 companies operating in the Dimension
Stone Mining industry segment. These companies earned an estimated $148 million in sales in
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2007. Approximately 40% of these sales were generated by the 10 largest companies reporting
financial information to D&B. Approximately 60% of sales was generated by the 25 largest
companies (D&B, 2008a).
In addition, D&B received financial information from 125 companies operating in the
Other Crushed and Broken Stone industry segment. These companies earned an estimated $376
million in sales in 2007. Approximately 70% of these sales were generated by the 10 largest
companies reporting financial information to D&B. Approximately 85% of sales was generated
by the 25 largest companies (D&B, 2008b).
This information would suggest that the stone mining industry is potentially highly
concentrated. However, since data was not available for all industry segments and only a portion
of companies in this industry provided financial information, this assessment cannot be
conclusive.
2.1.6 Firm Characteristics: Average Revenue and Employment
To better understand the characteristics of firms operating in the stone mining industry,
this profile relied heavily on data collected by the U.S. Census Bureau. In particular, the 2002
Economic Census and annual Statistics of U.S. Businesses were the primary sources of data
presented bellow.
Table 2-8. Producer Price Index Industry Data: 2000 to 2006
Stone Mining and Quarrying
(NAICS 21231)
Total Mining Industries
Year
PPI
Annual Percentage
Change in PPI
PPI
Annual Percentage
Change in PPI
2000
147.3
4%
113.5
46%
2001
152.2
3%
114.3
1%
2002
156.1
3%
96.6
-15%
2003
160.2
3%
131.3
36%
2004
166.1
4%
153.4
17%
2005
176.7
6%
201
31%
2006
192.7
9%
208.7
4%
Source: U.S. Bureau of Labor Statistics (BLS). 2008. "Producer Price Index Industry Data: Customizable Industry
Data Tables." Available at . As obtained on March 25, 2008.
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It is important to note that while the USGS surveys attempts to independently identify all
stone mining operations, the U.S. Census Bureau is only interested in collecting economic data
for private enterprises (it excludes most government entities). In addition, the U.S. Census
Bureau classifies each establishment it surveys into various NAICS industries based on the
establishments own self-description, not based on an independent assessment. As a result of
these and other variations, differences between USGS and U.S. Census data can be expected.
2.1.6.1 Average Revenue and Employment
According to the US Economic Census, there were 1,362 firms occupying this industry,
owning 2,514 establishments in 2002.2 These firms earned a cumulative total of over $9.3 billion
in revenue (measured in 2002 dollars) or an average of $6.8 million per firm. A complete
summary of 2002 sales and employment data for firms in these industries is reported in Table 2-9
by enterprise size (as measured by the number of employees).
Table 2-9. Employment and Receipts Data by Enterprise Size (NAICS 21231): 2002
Employment Size of the Enterprise

0-4
5-9
10-19
20-99
100-499
500+
Total
Firm
480
223
252
257
79
71
1,362
Establishments
480
226
255
360
263
930
2,514
Employment
796
1,515
3,454
8,947
7,176
23,211
45,099
Receipts ($1,000)
$172,291
$199,660
$495,021
$1,468,369
$1,322,523
$5,637,963 !
£9,295,827
Average Receipts per
$359
$895
$1,964
$5,713
$16,741
$79,408
$6,825
Firm ($1,000)

Source: U.S. Bureau of the Census. 2002b. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All
Industries 2002. Available at . As obtained on March 17, 2008.
According to the Small Business Administration (SBA) standards, a small business in the
stone mining and quarrying industry is defined as any firm employing 500 employees or less
(SBA, 2008). Under this definition, over 95% of firms in the stone mining industry would be
2 An establishment is a single physical location at which business is conducted or where services or industrial
operations are performed. An enterprise is a business organization consisting of one or more domestic
establishments under common ownership or control. A firm is defined as that part of an enterprise tabulated
within a particular industry, state or metropolitan area. For example, an enterprise with establishments in more
than one industry would be counted as a firm in each industry in which it operates an establishment, but is also
counted as only one firm in national all-industry tabulations. Thus, summing the firms across industries would
overstate the number of unique firms. However, employment size is determined only for the entire enterprise. As
a result, counterintuitive results are possible, for example, only 100 employees in a category of firms with 500
employees or more in a particular state (U.S. Bureau of the Census, 2004b).
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considered "small businesses." In 2002, these small businesses earned an average of $3.7 million
in revenue and employed 17 workers.
Between 2002 and 2005, total industry employment rose by approximately 9%. During
this same period, firms classified as "small businesses" slightly increased their share of total
employment, from 49% in 2002 to 50% in 2005 (Table 2-10). A summary of 2005 employment
data for firms is reported in Table 2-11.
2.1.6.2 The Cost of Production
Firms mining stone require labor, capital, and supplies such as fuel and intermediate
goods. Data was collected from the 2002 Economic Census to determine how much firms spend
on each factor of production. In 2002, stone mining firms spent $5.7 billion on these inputs. As
Figure 2-1 illustrates, over 52% of this spending was used to acquire supplies (U.S. Census
Bureau, 2004b).
Table 2-10. Distribution of Employment Between Small and Large Firms: 2002 to 2005

Firms with <500
Employees
Firms with 500+
Employees
Total
2002
21,888
23,211
45,099
2003
22,062
22,520
44,582
2004
23,776
22,848
46,624
2005
24,654
24,669
49,323
Sources: U.S. Bureau of the Census. 2005. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All
Industries 2005. Available at . As obtained on March 17, 2008.
U.S. Bureau of the Census. 2004a. Statistics of U.S. Businesses: Number of Firms, Number of Establishments,
Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All Industries
2004. Available at . As obtained on March 17, 2008.
U.S. Bureau of the Census. 2003. Statistics of U.S. Businesses: Number of Firms, Number of Establishments,
Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All Industries
2003. Available at . As obtained on March 17, 2008.
U.S. Bureau of the Census. 2002b. Statistics of U.S. Businesses: Number of Firms, Number of Establishments,
Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All Industries
2002. Available at . As obtained on March 17, 2008.
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Table 2-11. Employment and Receipts Data by Enterprise Size (NAICS 21231): 2005
Employment Size of the Enterprise
0-4	5-9 10-19 20-99 100-499 500+ Total
Firms
491
251
278
303
88
64
1,475
Establishments
491
251
280
397
274
992
2,685
Employment
796
1,679
3,748
10,619
7,812
24,669
49,323
Source: U.S. Bureau of the Census. 2005. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All
Industries 2005. Available at . As obtained on March 17, 2008.
Capital
$879,924,000
15%
Payroll
$1,885,150,000
33%
Supplies
$2,913,170,000
52%
Figure 2-1. Distribution of the Cost of Production Between Capital, Labor, and Supplies
2.1.6.3 Profitability of Stone Mining and Quarrying Firms
The profitability of firms in the stone mining and quarrying industry differs depending on
which part of the stone mining industry they occupy. For example, according to profit ratios
computed by Risk Management Associates for the 2006-2007 fiscal year, firms involved in
Crushed Limestone Mining (NAICS 212312) earned all. 1% average return on their sales.
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However, firms involved mining non-classified crushed stone (NAICS 212319) only earned an
average return of 8.6%.3
The profitability of firms within also depends on the size of the firm as measured in net
sales. Table 2-12 and Table 2-13 provide estimates of the mean profit (before taxes) to net sales
ratios for firms involved in Crushed Limestone Mining (NAICS 212312) and Other Crushed
Stone Mining (NAICS 212319) for the 2006-2007 fiscal year.4 As these ratios demonstrate,
firms in the Crushed Limestone Mining industry with sales over $25 million received a 10.6%
average return on net sales, while firms with assets valued between $5 and $10 million only
received a 12.2% average return. Similarly, firms in Other Crushed Stone Mining with sales over
$25 million received a 11.6% average return on net sales, while firms with assets valued between
$1 and $3 million only received a 12.2% average return.
Table 2-12. Mean Ratios of Profit before Taxes as a Percentage of Net Sales for Crushed
Limestone Mining (NAICS 212312), Sorted by Value of Assets






$10



Total

$1 Million
$3 Million
$5 Million
Million to



Number of
Oto $1
to $3
to $5
to $10
$25
$25 Million
All
Fiscal Year
Statements
Million
Million
Million
Million
Million
and Over
Firms
4/1/2006-
3/31/2007
71
N/A
N/A
N/A
12.2
11.2
10.6
11.1
Source: Risk Management Association (RMA). 2008. Annual Statement Studies 2007-8. Pennsylvania: RMA, Inc.
Note: N/A means that ratios of profit before taxes as a percentage of net sales are unavailable available for the asset
value category.
3	Profit ratios were calculated by Risk Management Associates by dividing net income into net sales. These data
were obtained from income statements for firms occupying each industry segment.
4	Profit ratios for other segments of the stone mining industry were unavailable.
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Table 2-13. Mean Ratios of Profit before Taxes as a Percentage of Net Sales for Other
Crushed Stone Mining (NAICS 212319), Sorted by Value of Assets

$10

Total

$1 Million
$3 Million
$5 Million
Million to

Number of
Oto $1
to $3
to $5
to $10
$25
$25 Million
All
Fiscal Year
Statements
Million
Million
Million
Million
Million
and Over
Firms
4/1/2006-
3/31/2007
54
N/A
17.1
N/A
N/A
3.6
11.6
8.6
Source: Risk Management Association (RMA). 2008. Annual Statement Studies 2007-2008. Pennsylvania: RMA,
Inc.
Note: N/A means that ratios of profit before taxes as a percentage of net sales are unavailable available for the asset
value category.
2.2 NAICS 212321—Construction Sand and Gravel Mining
Sand and gravel are among the most accessible and widely used natural resources in the
United States (USGS, 2006c). These materials have been particularly utilized in building and
construction. For example, sand and gravel are used to make cement, used as construction fill,
and used in the production of construction materials like concrete blocks, bricks, and pipes (Mil,
2008).
The purpose of this section of the industry profile is to characterize the construction sand
and gravel industry and the firms involved. First, the industry is defined using the North
American Industry Classification System (NAICS). Next, we examine historical data on
production, international trade, prices, and firm characteristics.
2.2.1 Industry Description
The construction sand and gravel mining industry is classified under NAICS code
212321. This industry is comprised of establishments primarily engaged in one or more of the
following activities: 1) operating commercial grade (i.e., construction) sand and gravel pits;
2) dredging for commercial grade sand and gravel; and 3) washing, screening, or otherwise
preparing commercial grade sand and gravel (U.S. Census Bureau, 2002a).
2.2.2 U.S. Construction Sand and Gravel Mining Production
This profile's primary source of production data for the construction sand and gravel
industry was the U.S. Geological Survey (USGS) Mineral Yearbook published each year for
Construction Sand and Gravel. The data reported in this yearbook is collected through voluntary
surveys of construction sand and gravel mining operations. The USGS independently determines
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which operations will be surveyed by using a variety of sources to compile a list of all
construction sand and gravel mining operations in the US. These surveys are used to determine
how much construction sand and gravel is being produced in the US, where it's being produced,
and what it's being used for (USGS, 2007c).
Between 2000 and 2006, construction sand and gravel production grew approximately
4% each year (Table 2-13). In 2006, the USGS reported that over 1 billion metric tons of
construction sand and gravel has been produced that year. This sand and gravel was valued to be
worth over $8.5 billion. Approximately 51% of the sand and gravel produced in 2006 was mined
in only 10 states (Table 2-14). The largest construction sand and gravel producing state was
California, which accounted for 12% of all sand and gravel produced. 20% of all sand and gravel
produced was used as concrete aggregate (Table 2-15).
Table 2-13. U.S. Production of Construction Sand and Gravel: 2000 to 2006

2000
2001
2002
2003
2004
2005
2006
Quantity (1,000
1,120,000
1,130,000
1,130,000
1,160,000
1,240,000
1,280,000
1,320,000
metric tons)

Value ($1,000)
5,390,000
5,670,000
5,750,000
5,990,000
6,600,000
7,500,000
8,540,000
Source: U.S. Geological Survey. 2007c. 2006 Minerals Yearbook, Construction Sand and Gravel. Washington, DC:
U.S. Department of the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2005c. 2004 Minerals Yearbook, Construction Sand and Gravel. Washington, DC: U.S.
Department of the Interior. Available at As obtained on March 25, 2008.
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Table 2-14. U.S. Construction Sand and Gravel Production by State: 2006
State
Quantity (1,000 Metric Tons)
Value ($1,000)
California
153,000
1,520,000
Texas
99,500
603,000
Arizona
94,000
662,000
Michigan
50,500
215,000
Minnesota
50,300
240,000
Washington
48,400
315,000
Colorado
48,000
327,000
Ohio
46,300
289,000
Nevada
45,500
224,000
Florida
40,000
266,000
Total
1,320,000
8,540,000
Source: U.S. Geological Survey. 2007c. 2006 Minerals Yearbook, Construction Sand and Gravel. Washington, DC:
U.S. Department of the Interior. Available at . As obtained on March 25, 2008.
Table 2-15. U.S. Construction Sand and Gravel by Major Use: 2006

Quantity


(1,000 Metric
Value
State
Tons)
($1,000)
Concrete aggregates (including concrete sand)
264,000
1,920,000
Road base and coverings
128,000
716,000
Fill
78,800
335,000
Asphaltic concrete aggregates and other bituminous mixtures
66,300
551,000
Plaster and gunite sands
9,700
86,200
Total
1,320,000
8,540,000
Source: U.S. Geological Survey. 2007c. 2006 Minerals Yearbook, Construction Sand and Gravel. Washington, DC:
U.S. Department of the Interior. Available at . As obtained on March 25, 2008.
2.2.3 International Trade
A growing portion of US consumption of construction sand and gravel is supplied by
foreign sources. Between 2000 and 2006, exports of sand and gravel remained relatively
constant, while imports grew by more than 183% (approximately 37% each year). This trend is
illustrated in Table 2-16, which reports the value of sand and gravel imports and exports during
this 5 year period.
18

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Table 2-16. Construction Sand and Gravel Import and Export Data: 2000 to 2006

2000
2001
2002
2003
2004
2005
2006
Exports ($1,000)
24,200
19,100
23,400
24,900
32,100
28,200
24,100
Imports ($1,000)
33,300
40,800
53,900
57,700
56,900
86,800
94,100
Source: U.S. Geological Survey. 2007c. 2006 Minerals Yearbook, Construction Sand and Gravel. Washington, DC:
U.S. Department of the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2005c. 2004 Minerals Yearbook, Construction Sand and Gravel. Washington, DC: U.S.
Department of the Interior. Available at . As obtained on March 25, 2008.
2.2.4 Market Prices
The market price of construction sand and gravel differs by use. According to the USGS,
unit prices in 2006 varied from a high of $11.30 per ton for roofing granules to a low of $4.26
per ton for fill. Table 2-17 reports the average unit value of construction sand and gravel sold or
used by producers during this 5 year period. As one can see, nominal prices rose an average of
approximately 5% each year.
Table 2-17. Unit Value of Construction Sand and Gravel Sold or Used By U.S. Producers:
2000 to 2006

2000
2001
2002
2003
2004
2005
2006
Unit Value ($ per metric ton)
4.8
5.0
5.1
5.2
5.3
5.9
6.5
Source: U.S. Geological Survey. 2007c. 2006 Minerals Yearbook, Construction Sand and Gravel. Washington, DC:
U.S. Department of the Interior. Available at . As obtained on March 25, 2008.
U.S. Geological Survey. 2005c. 2004 Minerals Yearbook, Construction Sand and Gravel. Washington, DC: U.S.
Department of the Interior. Available at . As obtained on March 25, 2008.
This trend is also reflected in producer price data collected by the Bureau of Labor
Statistics (BLS). According to the BLS, the Producer Price Index (PPI) for the construction sand
and gravel industry rose (which measures the nominal prices firms receive for their products)
rose an average of 4% each year. This growth rate is relatively slow when compared with prices
received by firms in other industries. For example, during the same 6-year time period, prices
received by other U.S. mining firms have risen an average of 17% each year during the same
period. This data is presented in Table 2-18.
19

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Table 2-18. Producer Price Index Industry Data: 2000 to 2006

Construction Sand and Gravel

(NAICS 212321)
Total
mining industries
Year
PPI
Annual Percentage
Change in PPI
PPI
Annual Percentage
Change in PPI
2000
175.5
4%
113.5
46%
2001
181.6
3%
114.3
1%
2002
185.8
2%
96.6
-15%
2003
188.9
2%
131.3
36%
2004
195
3%
153.4
17%
2005
209.9
8%
201
31%
2006
229.1
9%
208.7
4%
Source: U.S. Bureau of Labor Statistics (BLS). 2008. "Producer Price Index Industry Data: Customizable Industry
Data Tables." Available at . As obtained on March 25, 2008.
2.2.5 Industry Concentration
Data on the concentration of the construction sand and gravel mining firms was obtained
from industry reports prepared by Dun and Bradstreet (D&B). These industry reports are based
on data that companies operating within the construction sand and gravel mining industry
voluntarily provided D&B. As a result, these reports necessarily exclude information on firms
that did not provide financial information to D&B.
D&B received financial information from 1,030 companies operating in the construction
sand and gravel mining industry. These companies earned an estimated $1.2 billion in sales in
2007. Approximately 42% of these sales were generated by the 10 largest companies reporting
financial information to D&B. Approximately 54% of sales was generated by the 25 largest
companies (D&B, 2008c).
This information would suggest that the construction sand and gravel mining industry is
potentially highly concentrated. However, since data only a portion of companies in this industry
provided financial information, this assessment cannot be conclusive.
20

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2.2.6 Firm Characteristics
To better understand the characteristics of firms operating in the construction sand and
gravel industry, this profile relied heavily on data collected by the U.S. Census Bureau. In
particular, the 2002 Economic Census and annual Statistics of U.S. Businesses were the primary
sources of data presented below.
It is important to note that while the USGS surveys attempts to independently identify all
construction sand and gravel mining operations, the U.S. Census Bureau is only interested in
collecting economic data for private enterprises (it excludes most government entities). Further,
the Census Bureau classifies each establishment it surveys into various NAICS industries based
the establishments own self-description. As a result of these and other differences, divergences
between USGS and U.S. Census data can be expected.
2.2.6.1 Average Employment and Revenue
In 2002 there were 1,884 firms occupying this industry, owning 2,509 sand and gravel
mining establishments. These firms earned a cumulative total of over $4.8 billion in revenue
(measured in 2002 dollars) or an average of $2.6 million per firm. A complete summary of 2002
sales and employment data for firms in these industries is reported in Table 2-19 by enterprise
size (as measured by the number of employees).
Table 2-19. 2002 Employment and Receipts Data by Enterprise Size (NAICS 212321)
Employment Size of the Enterprise

0-4
5-9
10-19
20-99
100-499
500+
Total
Firms
867
324
283
268
83
59
1,884
Establishments
867
324
287
324
189
518
2,509
Employment
1,471
2,174
3,810
7,952
4,432
6,912
26,751
Receipts ($1,000)
$255,735
$274,124
$533,948
$1,193,402
$856,302
$1,702,068
$4,815,579
Average Receipts per
$295
$846
$1,887
$4,453
$10,317
$28,849
$2,556
Firm ($1,000)

-------
be considered "small businesses." In 2002, small businesses earned an average of $1.8 million in
revenue and employed 11 workers.
Between 2002 and 2005, total industry employment fell by approximately 2%. However,
during this same period, large businesses (firms employing 500 or more workers) increased their
share of total employment, from 26% in 2002 to 30% in 2005 (Table 2-20). A summary of 2005
employment data for firms is reported in Table 2-21.
Table 2-20. Distribution of Employment Between Small and Large Firms

Firms with <500
Employees
Firms with 500+
Employees
TOTAL
2002
19,839
6,912
26,751
2003
17,911
7,145
25,056
2004
18,351
6,954
25,305
2005
18,344
7,994
18,344
Sources: U.S. Bureau of the Census. 2005. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All
Industries 2005. Available at . As obtained on March 17, 2008.
U.S. Bureau of the Census. 2004a. Statistics of U.S. Businesses: Number of Firms, Number of Establishments,
Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All Industries
2004. Available at . As obtained on March 17, 2008.
U.S. Bureau of the Census. 2003. Statistics of U.S. Businesses: Number of Firms, Number of Establishments,
Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All Industries
2003. Available at . As obtained on March 17, 2008.
U.S. Bureau of the Census. 2002b. Statistics of U.S. Businesses: Number of Firms, Number of Establishments,
Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All Industries
2002. Available at . As obtained on March 17, 2008.
Table 2-21. 2005 Employment and Receipts Data by Enterprise Size (NAICS 212321)
Employment Size of the Enterprise

0-4
5-9
10-19
20-99
100-499
500+
Total
Firms
835
304
289
246
87
49
1,810
Establishments
835
304
296
297
185
493
2,410
Employment
1,390
2,042
3,836
7,229
3,847
7,994
26,338
Source: U.S. Bureau of the Census. 2005. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise for the United States, All
Industries 2005. Available at . As obtained on March 17, 2008.
22

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2.2.6.2 The Cost of Production
Firms mining construction sand and gravel require labor, capital, and supplies such as
fuel and intermediate goods. Data was collected from the 2002 Economic Census to determine
how much firms spend on each factor of production. In 2002, construction sand and gravel
mining firms spent $2.8 billion on these inputs. As Figure 2-2 illustrates, approximately 47% of
this spending was used to acquire supplies (U.S. Census Bureau, 2004b).
Figure 2-2. Distribution of the Cost of Production Between Capital, Labor, and Supplies
2.2.6.3 Profitability of Construction Sand and Gravel Mining Firms
Table 2-22 provides estimates of the mean profit (before taxes) to net sales ratios for the
construction sand and gravel industry (NAICS 212321) for the 2006-2007 fiscal year. These
ratios were calculated by Risk Management Associates using income statements for 180 firms in
the sand and gravel mining industry and are broken down based on the sales earned by the
reporting firms.
As these ratios demonstrate, firms that reported greater sales also tended to be more
profitable. For example, firms with sales over $25 million received an 11.9 % average return on
Capital
$428,372,000
Supplii
$1,332,956,000
47%
Payroll
$1,073,833,000
38%
23

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net sales, while firms with assets valued between $0 and $1 million only received a 6.7% average
return. The average return on sales for the entire industry was 9.5%.
Table 2-22. Mean Ratios of Profit before Taxes as a Percentage of Net Sales for NAICS
212321, Sorted by Value of Assets






$10



Total

$1 Million
$3 Million
$5 Million
Million to



Number of
Oto $1
to $3
to $5
to $10
$25
$25 Million
All
Fiscal Year
Statements
Million
Million
Million
Million
Million
and Over
Firms
4/1/2006-
180
6.7
5.4
8.4
12.1
9.9
11.9
9.5
3/31/2007








Source: Risk Management Association (RMA). 2007. Annual Statement Studies 2007. Pennsylvania: RMA, Inc.
24

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SECTION 3
COSTS, ECONOMIC IMPACTS, AND SMALL BUSINESS RESULTS
Model Plants and Cost Analysis
The number of firms affected by this NSPS is related to the number of facilities expected
to be affected by the proposed standard. In turn, the number of facilities likely to be affected is
estimated using model plants. Model plants are analytical constructs that are used to simulate
actual new plants potentially affected by this standard in a situation where we lack information
on emissions and controls for every potentially affected plant in each affected industry. The
model plants are used to estimate the baseline emissions for each mineral type and industry, and
are then used to estimate the costs of compliance associated with regulatory options under
consideration in this NSPS. New source impacts are considered for the 5 years following
promulgation of the standards (or 2009 to 2013). The most common control technologies used to
comply with subpart OOO include baghouses and wet suppression. The proposed changes to
subpart OOO would not change the control technology used. In the case of this analysis, the
incremental impacts of compliance involve increased monitoring instead of increased control
measures. Both capital and annualized costs of compliance are estimated.
Table 1 provides a nationwide summary of the new model plants, baseline emissions,
incremental emission reductions and incremental costs of compliance. These impacts are based
on the following regulatory options:
25

-------
Stack PM concentration limit of 0.014 gr/dscf
Omission of the 7% stack opacity limit
Revised fugitive emission limits of 12% for crushers and 7% for other fugitive
affected facilities
Reduced Method 9 test duration or fugitive affected facilities (reduced to 30
minutes)
Added monthly inspection that water is flowing for future affected facilities with
water sprays
Added repeat Method 9 testing every 5 years for future affected facilities without
water sprays (e.g., fugitive affected facilities with water carryover, partial
enclosure, etc.)
Added quarterly 30-minute Method 22 VE observations for baghouses
Omission of §60.7(a)(1) notification of commencement of
constructi on/reconstruct on
More information on these options can be found in the cost and other impacts
prepared by RTI mentioned above and the preamble to this proposed NSPS.
26

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Table 1. Summary of Nationwide Cost and Air Impacts for the Proposed Subpart OOO
NSPS Revisions
Mineral type"
NAICS
for Each
Mineral
Type
No. new
model
plants
Total
potential
PM
emission
reductionb,
tpy
Percent
pm25c
Potential
pm25
emission
reduction,
tpy
Incremental
capital costd,
$
Incremental
annualized
cost, $/yr
(2007$)
Incremental
annualized
cost per
plant, $/yr
(2007$)
Crushed &
P.i'ukeii simic
212^1
or,
111
5
(.
(45~.<>00)
ls-.sr.o
1.05"
Sand A:
(iia\cl








Construction
Industrial
212321
212322
208
1
241
1
5
5
12
0.03
(991,467)
(4,767)
407,029
1,957
1,957
1,957
Class
IBentonite
Fuller's earth
Ball Clay
212325
212325
212324
1
4
1
5
21
5
20
20
20
1
4
1
(I 1."()())
(46,800)
(11,700)
i,:_u
5,080
1,270
1,2 "U
1,270
1,270
Rock
Salt/Sodium
Chloride
212393
1
5
5
0.3
(11,700)
1,270
1,270
Gypsum
212399
7
37
-
-
(81,900)
8,889
1,270
Sodium
Carbonate
212391
1
23
5
1
(15,600)
1,697
1,697
Pumice
212399
2
10
5
1
(23,400)
2,540
1,270
Barite
212393
8
37
5
2
(93,600)
10,159
1,270
Fluorspar
212393
1
3
5
0.2
(11,700)
1,270
1,270
Mica
212399
1
5
5
0.2
(11,700)
1,270
1,270
Total

332
503 tpy
456 Mg/yr

28 tpy
25 Mg/yr
(6% of total
PM)
(1,773,633)
631,560
1,902
aNo new model plants are projected in the 5 years following promulgation of the NSPS review for the following
mineral types: kaolin, fire clay, common clay, sodium sulfate, gilsonite, talc/pyrophyllite, boron (including
borax, kernite, and colemanite), feldspar, diatomite, perlite, vermiculite, or kyanite (including andalusite,
sillimanite, topaz, and dumortierite).
includes potential emission reduction associated with lowering the stack emission limit from 0.022 gr/dscf to 0.014
gr/dscf and the potential emission reduction associated with increased testing and monitoring (based on potential
emissions from malfunctioning controls). Potential reductions may be overstated because most baseline control
devices already perform at 0.014 gr/dscf (such that no additional emission reduction would be gained from
lowering the limits to 0.014 gr/dscf).
°The split between PM and PM2 5 varies depending on mineral, process, and control system used. The percent PM2 5
is a ballpark figure based on the limited available information in AP-42 and the 1982 BID.
dNo additional cost is required for control equipment. The incremental cost differences are associated with changes
in the MRR requirements. There is a negative capital cost because the revised NSPS would reduce costs of
initial testing requirements by (a) allowing a 30-minute Method 9 test instead of a 1-hour test for fugitive
affected facilities; and (b) by omitting the 7% stack opacity limit and associated initial testing from subpart
OOO.
Tpy = tons per year; Mg/yr = megagrams per year (1 Mg =1.1 tons).
27

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Affected Industries
This proposed NSPS will affect new and modified/reconstructed sources in the industries
listed in Table 1 above. These industries are:
NAICS 21231 - Stone Mining and Quarrying
NAICS 212321 - Construction Sand and Gravel Mining
NAICS 212322 - Industrial Sand Mining
NAICS 212324 - Kaolin and Ball Clay Mining
NAICS 212325 - Clay and Ceramic and Refractory Minerals Mining
NAICS 212391 - Potash, Soda, and Borate Mineral Mining
NAICS 212393 - Other Chemical and Fertilizer Mineral Mining
NAICS 212399 - All Other Nonmetallic Mineral Mining
The Small Business Administration (SBA) small business size standards for these industries is
500 employees per ultimate parent entity. These small business size standards can be found at
http://www.sba.gov/idc/groups/public/documents/sba_homepage/serv_sstd_tablepdf.pdf.
Thus, any business is classified as "small" by the SBA in these industries if the ultimate
parent entity has 500 employees or less. This is the definition of small business that will be
used for this rule and this analysis. The distribution of small businesses as we have estimated
by affected NAICS can be found in Table 2.
Table 2. Projected Number of New Model Plants that Could be Owned by Small
Businesses.
Mineral type
No. new model
plants3
Estimated number of small
businesses
Percent of firms
with less than SBA
500 employees
NAICS
Crushed & Broken stone
S;iiid K (ii;i\cl
Construction
Industrial
( la\ s
Bentonite
Fuller's earth
Ball Clay
Rock Salt/Sodium Chloride
Gypsum
Sodium Carbonate
Pumice
Barite
Fluorspar
Mica
Total
I)
208
1
0
1
4
1
1
7
1
2
8
1
1
332
02
202
1
1
3
1
1
6
1
2
6
1
1
318 (96% of model plants)
95.7%
97.3%
87.5%
82.9%
82.9%
73.9%
78.4%
92.3%
50.0%
92.3%
78.4%
78.4%
92.3%
212^1
212321
212322
212325
212325
212324
212393
212399
212391
212399
212393
212393
212399
aNo new model plants are projected in the 5 years following promulgation of the NSPS review for the following
mineral types: kaolin, fire clay, common clay, sodium sulfate, gilsonite, talc/pyrophyllite, boron (including
borax, kernite, and colemanite), feldspar, diatomite, perlite, vermiculite, or kyanite (including andalusite,
sillimanite, topaz, and dumortierite).
28

-------
For this analysis, since over 90 percent of the model plants that could be owned by small
businesses are found in two industries, NAICS 21231 and 212321, we focus our economic and
small business analysis on impacts to these industries. The industry profile, which contains
essential background information to this analysis and is found earlier in this report, has revenue,
profit margin, and other data for each of these industries. More details on the number of firms
in these industries, the organization of these industries, and their profit margins can be found in
the industry profile.
Economic Impacts
As shown in this report, small businesses are quite common in the industries that are the focus
of this analysis. In each industry, more than 95 percent of the businesses are classified as small
by the Small Business Administration (SBA) according to their size standards. For this analysis,
we use average annualized compliance costs as a percentage of firm-level sales or revenues,
otherwise called the "sales test," to estimate impacts to affected small businesses. Use of this
metric is consistent with Table 1 on pp. 24-25 of the latest EPA guidance for complying with the
Regulatory Flexibility Act (RFA) as amended by the Small Business Regulatory Enforcement
Fairness Act (SBREFA) found at http://www.epa.gov/sbrefa/documents/rfafinalguidance06.pdf.
Using average annual revenue for the small firms for each industry available in our industry
profile, and applying the average annualized compliance cost incurred by each firm (using model
plant costs), we arrive at the following impacts:
NAICS 21231 - Average Annual Revenue Per Small Firm = $3.7 million
Average Annualized Compliance Cost Per Small Firm = $1,957 (2007$)
Average Annualized Cost Per Annual Revenue for Small Firms =
1957/3700000 = 0.05 percent
NAICS 212321 - Average Annual Revenue Per Small Firm = $1.7 million
Average Annualized Compliance Cost Per Small Firm = $1,957 (2007$)
Average Annualized Cost Per Revenue for Small Firms = 1957/2000000 = 0.09
percent
We find that the average annualized compliance cost is no more than 0.09 percent of the sales
or revenues for an affected small firm in our analysis. Thus, we conclude there is no significant
impact on a substantial number of small businesses (or no SISNOSE) as a result of complying
with this proposed NSPS. We find that more than 90 percent of the small businesses affected by
this NSPS are found in these two industries, but we find no significant impact for any of these
small businesses.
29

-------
It should be noted that the cost to sales estimate per firm is an estimate of the maximum price
increase that a firm will need to experience with its output in order to see no net change in its
revenue assuming none of the costs can be passed along to its customers. Given that these firms
can pass along some share of the costs of production to their customers, the output price increase
can be no more than the cost to sales estimate. Hence, the maximum price increase for output
from these industries can be no greater than 0.09 percent (the cost to sales estimate for the
industry most impacted, NAICS 212321).
30

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REFERENCES
Dun & Bradstreet (D&B). 2008a. Dimension Stone Industry Report.
Dun & Bradstreet (D&B). 2008b. Other Crushed and Broken Stone Industry Report.
Dun & Bradstreet (D&B). 2008c. Construction Sand and Gravel Industry Report.
Mineral Information Institute (Mil). 2008. Sand & Gravel. Available at
. As obtained on March 18, 2008.
Risk Management Association (RMA). 2008. Annual Statement Studies 2007-8. Pennsylvania:
RMA, Inc
Small Business Administration. 2008. Table of Small Business Size Standards. Available at
 As obtained on March 31, 2008.
U.S. Bureau of the Census. 2005. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise
for the United States, All Industries 2005. Available at
. As obtained on March 17, 2008.
U.S. Bureau of the Census. 2004a. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise
for the United States, All Industries 2004. Available at
. As obtained on March 17, 2008.
U.S. Bureau of the Census. 2004b. 2002 Economic Census, Industry Series—NAICS 212321.
Washington, DC: Government Printing Office. Available at
. As obtained on March 18,
2008.
U.S. Bureau of the Census. 2003. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise
for the United States, All Industries 2003. Available at
. As obtained on March 17, 2008.
U.S. Bureau of the Census. 2002a. 2002 NAICS Definitions: 21231 Stone Mining and
Quarrying. Available at . As
obtained on March 17, 2008.
U.S. Bureau of the Census. 2002b. Statistics of U.S. Businesses: Number of Firms, Number of
Establishments, Employment, and Annual Payroll by Employment Size of the Enterprise
for the United States, All Industries 2002. Available at
. As obtained on March 17, 2008.
31

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U.S. Bureau of Labor Statistics (BLS). 2008. "Producer Price Index Industry Data: Customizable
Industry Data Tables." Available at . As obtained on March
25, 2008.
U.S. Geological Survey. 2007a. 2006 Minerals Yearbook, Dimension Stone. Washington, DC:
U.S. Department of the Interior. Available at
. As obtained on March 25, 2008.
U.S. Geological Survey. 2007b. 2006 Minerals Yearbook, Crushed Stone. Washington, DC: U.S.
Department of the Interior. Available at
. As obtained on March 25, 2008.
U.S. Geological Survey. 2007c. 2006 Minerals Yearbook, Construction Sand and Gravel.
Washington, DC: U.S. Department of the Interior. Available at
. As obtained on March 25, 2008.
U.S. Geological Survey. 2005a. 2004 Minerals Yearbook, Dimension Stone. Washington, DC:
U.S. Department of the Interior. Available at
.
As obtained on March 25, 2008.
U.S. Geological Survey. 2005b. 2004 Minerals Yearbook, Crushed Stone. Washington, DC: U.S.
Department of the Interior. Available at
. As
obtained on March 25, 2008.
U.S. Geological Survey. 2005c. 2004 Minerals Yearbook, Construction Sand and Gravel.
Washington, DC: U.S. Department of the Interior. Available at
. As obtained on March 25, 2008.
32

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United States	Office of Air Quality Planning and	Publication No. EPA
Environmental Protection	Standards	452/R-08-001
Agency	Health and Environmental Impacts	April 2008
Division
	Research Triangle Park, NC	
33

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