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Copyright @2oo2 by California Department of Conservation. All rights
reserved. No part of this publication may be reproduced without written
consent of the Califomia Department of Conservation. The California
Department of Conservation makes no warranties as to the suitablirfty
of this product for any particular purpose.
CONTENTS
INTRODUCTION........................................ ........................ ' .. ..... ............................
PART I: DESCRIPTION OF MAP. SHEET 52, AGGREGATE AVAILABILITY IN
CALIFORNIA.....:........:....:..................................................................:..................................1
Mineral Land Classification Reports and Aggregate Studies.........................................2
Fifty Year Aggregate Demand Forecast.......................................................................3
Methodology..........................................................:..................3
Effectiveness of the Per Capita Consumption Model .......................................... 5
Permitted Aggregate Resources................................................................................. .5
Permitted Resource Calculations
Fifty-year. Aggregate Demand Compared to Permitted Aggregate Resources................9
Non -Permitted Aggregate Resources .............................................................................9
Aggregate Production Areas and Districts ..................................... .................. 10
Aggregate Study Areas with Less than Ten Years of Permitted Resources..........:.......10
EndUses of Aggregate...............:...............................................................................11
PART II: OVERVIEW OF CONSTRUCTION AGGREGATE ..................... ....:.......11
.Annual Aggregate Production.....................................................................................11
'Aggregate Price ... ....................:.:........................... ......... .............. --------...12
• .... ....
� .. .Transportatian.....:...............................:........:.......::............:................... .
12
Aggregate Quality and Use............................................................................. .......
.... 12
:Factors. Affectin ate Deposit Quality
. g Aggreg ep............. ............................
.:.................... 14
Comparison of Alluvial Sand and Gravel to Crushed Stone Aggregate ......................15
Factors Affecting Aggregate Demand.........................................................................15
SLI04ARY..........................................................................................................................16
CONCLUSIONS AND 'RECONIN ENDATIONS..................................................................16
ACKNOWLEDGMENTS.................................................................::................................:..18
B�FERENCES CITED ..................................... ....................................................................................18
APPENDICES
Appendix A- Mineral land classification reports by Department of Conservation,
California Geological Survey (Special. Reports and Open File Reports with
information on aggregate resources) ...........:........... ..._...:.:...:..... 1
........................................... 9
Appendix B: Description of revisions made to permitted aggregate resource calculations
• and 50 -year aggregate demand projections in aggregate classification reports (methods
used in updating information used in the development of Map Sheet 52) ..................
_ iii . .
• INTRODUCTION
California Department of Conservation, California Geological Survey (CGS) Map Sheet 52, scale
1:1,100,000; and this accompanying report provide general information about the current
availability of California's permitted construction aggregate resources to state, regional, and local
.land -use planners and decision makers, as well as the general public. Neither Map'Sheet 52 nor
this report is intended to be used- as the sole soarce of information about aggregate
availability in planning and decision-making at the local level. Although the statewide and . .
regional information on the map and in this report may be useful to local decision -makers,
the more detailed information contained in each of the 32 aggregate studies used in the
compilation of Map Sheet 52 should be used for land -use and decision snaking purposes.
Permitted- aggregate resources are resources of aggregate that have been determined to be
acceptable for commercial use, which exist within properties owned.or leased by aggregate
producing companies, and for which permits have been granted to allow mining and processing of .
the material. -Aggregate resources that are currently permitted for mining are important because
they are the current source, and most likely future source, of construction aggregate used in a great
variety of public works and private -sector construction projects. Furthermore, because the cost of
aggregate is largely dependent on the distance the material must be hauled from where it is mined
and processed to where it is sold, local sources of aggregate are essential in maintaining reasonable
costs to the consumer.
Map Sheet '52 summarizes data from studies conducted by CGS for 32 aggregate resource areas
•throughout the state. These study areas cover about 25% of the state and provide aggregate for
about 90'0 of California's population. This report is divided into two parts: Part I provides data.
sources and methods used to derive the information presented on Map Sheet 52, and Part II is an
overview of construction aggregate. All the aggregate data presented on Map Sheet 52 pertain to
construction aggregate, which is alluvial sand and gravel or crushed stone that is used either
directly or indirectly in the production of "structures." Structures include residential dwellings,
commercial and public buildings, highways, roads,: bridges, dams, airports, canals, military
facilities, water and sewer facilities, railroads, and other public transit facilities. '
PART I: DESCRIPTION OF MAP SHEET 52, AGGREGATE AVAILABILITY IN
CALIFORNIA
Map Sheet 52 is a statewide map showing a compilation of data on aggregate availability that has
been collected over a period of about 23 years and has been updated to January 1, 2001. The main
focus of the map is a comparison of projected aggregate demand for the next 50 years with
currently permitted aggregate resources in various regions of state. The map also shows
aggregate production areas having less than 10 years of aggregate supply remaining, locations of
aggregate production. areas and the relative magnitude of annual production from each area, and a
diagram showing end uses of aggregate. The following sections describe data sources and
methodology that were used for the development of the map.
0
Mineral Land Classification Reports and Aggregate Studies
Much ofthe information regarding aggregate resources and projected aggregate demand in
California has been taken from a series of mineral land classification reports published as Special
Reports. and .Open File Reports by CGS between 1981 and 2001. These reports were prepared in
response to California's Surface Muting and Reclamation Act of 1975 (SMARA), which requires
the State. Geologist to classify land based on the known ,or inferred mineral resource potential of
that land. Classification is the process of identifying lands containing significant mineral deposits,
based solely on geologic factors, and without regard to present land use.or ownership. -The primary.
goal of mineral land classification is to ensure that the mineral resource potential of land is
recognized and considered in the land -use planning process. The classification process includes an
assessment of the quantity, quality, and extent of aggregate deposits in a study area based on.
1.. Examination and compilation of relevant geologic maps, aerial photos, geologic literature,
:. :aggregate industry data (some of which. are proprietary), and aggregate engineering test data:
2_ Interviews with aggregate operators, government agency personnel, and geologic consultants_ :
3.' Compilation and analysis of subsurface water well -log data and drilling records.
:4. Field investigation of active and depleted aggregate mines and quarries. and the geologic
formations that -could contain aggregate: resources.
The preparation of mineral land classification reports has been an evolving process: Some mineral
fic to aggregate resources, some contain information on both
land classification reports are speci:..
aggregate and other mineral resources, and some contain information only on non -aggregate
resources. Mineral. land classification reports focusing on aggregate include aggregate'resource
classification and mapping, estimates of permitted and non permitted aggregatexesources, 50 -year .
demand for permitted aggregate resources, and an estimate of when the permitted resources.will be
depleted. The reports also include as discussion on alternative aggregate resources..
Mineral land classification studies completed before 1989 used production -consumption (P -C) .
regions. as the study area boundary. AP -C region is one or more aggregate production*districts and
the -market area that those. districts serve. Because the counties are one of the primary users of
mineral laud classification reports, the State Mining and Geology Board (SMGB) passed a
resolution in 1989 to change the -scope of the reports from P -C regions to county -wide studies. As
a result of this change, classification reports became more user-friendly for local government
planners. However, because aggregate market areas do not generally follow county boundaries,
forecasting aggregate needs became more difficult.
Mineral land classification reports that,focus on aggregate resources include data either on one or
more P -C regions, or a county. For discussion purposes, each P-C.region or county aggregate study
will be referred to as an "aggregate study." There are 32 aggregate studies -that were used as the
framework for Map Sheet 52. These study areas are shown on the lower left-hand corner on the
map. Each aggregate study is assigned (referenced by) a Special Report'(SR) number or an
2
Open -File Report (OFR) number. It is important to note that an SR or OFR can include more than
•one aggregate study area. A list of these SRs and GFRs in numerical order is included in Appendix
A There are 28 completed aggregate studies and four studies in progress.
As mandated by SMARA, the State Geologist is required to review mineral land classification
after a period of 10 years to.determine if reclassification of the area is necessary and/or if the
projected 50 -year forecast'of constriction aggregate demand in the region should be revised. Since
completion. of the original mineral land classification studies; seven additional updated studies
have been completed that revise the information in the corresponding original reports. Update
studies were done by counties (Los Angeles, Orange, and Ventura) and by P -C regions (South San
Francisco Bay, Monterey Bay, Western San Diego County, and Fresno). The combined
Claremont -Upland and San Bernardino P -C Regions (SR 175), and the North San Francisco Bay
P -C Region (SR 179) updates are in progress. Because Los Angeles and Ventura counties had
more than one P -C region, separate updated 50 year forecasts were made for each region. The Los
Angeles County. update (OFR 94-14) includes the San Fernando Valley, San Gabriel Valley,
Saugus -Newhall, and the Palmdale P -C regions. The Ventura County update (OFR 93-10) includes
the Western Ventura and the Simi Valley P -C regions. The 'index map of aggregate studies shown
in the lower. left hand comer of Map Sheet 52 shows the latest updated reports that cover an
aggregate study area..Eariier reports covering the same areas or portions of areas are referenced in.
the updated report and in Appendix A with an asterisk (*).
Fifty Year Aggregate Demand Forecast
Fifty-year aggregate demand for each of the aggregate study areas is presented on Map Sheet '52 as
• a pie diagram (see Fifty -Pecs• Aggregate Demand Compared to Permitted Aggregate Resources
section of this report) and is also presented in. Table 1. The forecast information used in the
production of the map has been updated and modified from forecasts presented in previously
published mineral land classification reports or reports that are in progress. The updated or
modified forecast information depicted on Map Sheet 52 is for January.1, 2001 through December
2050. Most .50 -year projections of aggregate demand for Map Sheet 52 were made, first
extending the demand curves in the original reports to the end of 2050, followed by summing of
the annual aggregate demand over the 50 -year interval from January 1, 2001 through the end of
2050. Because the Western Ventura County and the Simi Valley P -C -regions showed a large
change in historical consumption since the original report was completed, new 50 -year forecasts
were made for these two regions. The methodology and effectiveness of forecasting are discussed
below.
Methodology
Before choosing a method for predicting a 50 -year aggregate demand, historical aggregate use was
compared to factors such as housing starts, gross national product, population, and several other
economic factors. It was determined that the only factor that showed a strong correlation to
historical aggregate use was population change.. Consequently, a per capita aggregate consumption
model was used'to forecast 50 -year aggregate demand. This method of forecasting aggregate
consumption benefits from its simplicity and the general availability of population forecast data.
California's Department of Finance regularly forecasts the state's population for all areas of
.
.California for use by city and county governments. Planning for allocations of resources by
population forecasting is a familiar exercise for local governments.
• : Table 1. Comparison of 50 -year aggregate demand to permitted aggregate resources for aggregate
study areas as of January 1, 2001_ Aggregate study areas with less than ten years of permitted
resources are bolded (see page 10; Aggregate Study Areas with Less than Ten Years of Permitted
Resources).
•
Aggregate Stude
(P -C Region/County)
50 -Year
Demand
(million tons)
Permitted
Aggregate
Resources
(Million tons)
Percentage of Permitted
Aggregate Resources as
Compared to the 50 -Year
Demand
Tehama County
52
40
77
Glenn County
79
56
71
Sacramento-FairiieldP-C R90on
225
130
58
North San Francisco Ba P -C Region
648
178
27
Stockton -Lodi P -C Region
337
260
77
South San Francisco Bay P -C Region
1,213
564
46
_Merced CounW
Eastern Merced County
Western Merced County
98
49
15
>56
15
>100
Monterey Bay P -C Re 'on
381
243
64
San Luis Obispo -Santa Barbara P -C Region
99
93
94
Sau Newhall P -C Region
86
151
>100
Western Ventura County P -C "on
.141
0
0
Simi Valley P -C Region*
116
129
>100
San Fernando Valley P -C Region
646
confidential
<1
San Gbriel Vali P -C Region
1,250
241
19
Claremont U land P -C Region
270
134. 50
Oran .Co
233
...27
12
Western San D' P -C Region
1,099
275
25
Temescal V P -C Re 'on
970
810
84
Palm Spbgs P -C Region
198
70
•35
SanBemardino P-CPe 'on
969
356
-37
Barstow V ctorMe P -C Region
165
115
70
Palmdale P -C Re 'on .
172
216
>100
Bakersfield P -C Region
246
167
68
Tulare
North Tulare County
South Ware County
107
77
12
196
11
>100
Fresno P -C Region
565
98
17 .
5tanislaus County
311
35
11
Sacramento County
686
65
9
El Dorado Comity
85
13.
15
Placer
126
43
34
Nevada County
169
135
21
Yuba City -Marysville P -C on
30
>2000
>100
Sbasta County
118
28
24
Total
12,016-
>6,845
Aggre�be study areas follow either a Pmdndion-Consumption (P -C) region boundary ora countybou uy. A
P -C region includes one or more aggregate production districts and the market area that those districts serve.
Aggregate resources are evaluated.within the bauadaries of the P -C regia L County studies evaluate all aggregate
resources within the county boundary.
z The county study has been divided into two areas, each Laving its own production and market area. A separate
permitted resource calculation and 50 -year forecast has been made for each area.
4
The steps used for forecasting California's 50 -year aggregate needs entail: 1) collecting yearly
historical production,and population data for a period of years ranging from the 1960s through.
2000; 2) dividing yearly aggregate production by the population for that same year to determine,
annual historical per capita consumption; 3) determining an average historical per capita
consumption; 4) projecting yearly population for a 50 year period; and 5) multiplying each year of
projected population by the average historical per capita consumption rate to get a total 50 -year
aggregate demand. It should be noted that the years chosen to determine an average historical .per
capita consumption differ. depending upon historical aggregate use forthat region. For example, in
Shasta County, major construction projects from the 1940s through the 1970s caused historical per
capita consumption rates to be extremely high and unrepresentative of future aggregate demand
(Dupras, 1997). Consequently, an average historical per capita consumption rate for Shasta Courcy
was based on the years 1980-1995.
Effectiveness of the Per Capita Consumption Model
The assumption that each person will use a certain amount of construction aggregate every year is .
a gross simplification of actual usage patterns, but it is intuitively correct to assume that an .
increase in the number of people will lead to the use of more aggregate. Over along enough
period, perhaps 20 years or longer, the random impacts of major public construction projects and
economic recessions tend to be smoothed out and consumption trends become similar to historic
per capita consumption rates: Per capita aggregate consumption has, therefore, become a
commonly used national, state, and regional measure for purposes of forecasting.
The per capita consumption model has proven to be effective.for prediction of aggregate demand
in the major metropolitan areas. The Western San Diego P -C Region and the San Gabriel Valley
P -C Region are examples of how well the model works havingonly a 2%o and a 5°
respectively, in actual versus Predicted Y /o difference .
P . aggregate demand (Miller, 1994, 1996). However,
-the
model may not work well in county -aggregate studies where boundaries have little correlation to . .
the aggregate market area and in P -C regions that import or export a large percentage of aggregate. .
In suchcases, projections were based on a modified per capita consumption model. For example, if
a P -C region imports 30% of its aggregates the total 50 year projected aggregate demand for. the
P -C region may be decreased by 30'/0.
Where no correlation could be made between population and historical use, 50 -year aggregate
demand was based on projections of historical production. This lack of correlation can exist when
a study area has a large percentage of aggregate imported into the region such as in Orange County
(Miller, 1995) or when a large percentage of aggregate is exported from a region such as in the .
Monterey Bay P -C Region (Kohler-Antablin, 1999).
Permitted Aggregate Resources .
Permitted aggregate resources (also called reserves) are aggregate deposits that have been
determined to be acceptable for commercial use, exist within properties owned- or leased by
aggregate producing companies, and have permits allowing miming and processing of aggregate
material. A "permit" means any authorization from or approval by -a lead agency, the absence of
which would preclude mining operations. In. California,mining permits are issued by local lead
.agencies (county or city governments) not by the state. Map Sheet 52 shows permitted aggregate
resources as a percentage of the 50 -year demand on each pie diagram (see Fift Year Aggregate
5
• Demand Compared to Permitted Aggregate Resources section of this. report). The actual tonnage is
given in Table 1. Individual operator or company data are proprietary, and the estimates for
permitted resources are composites of three or more companies in each study area. Approximately
6,845 million tons of construction -grade permitted, aggregate resources lie within the 32 aggregate
study areas shown on Map Sheet 52.
•
Permitted resource estimates shown on Table 1 and used for Map Sheet 52 were revised from
estimates made in the mineral land classification reports. All permitted resource estimates are
current as of January I, 2001. Table !'and Appendix B summarize these revisions. Permitted
resource estimates from reports with recent completion dates were updated by subtracting
aggregate production for each year since the permitted resources were calculated and adding any
newly permitted resources. For example, if permitted resources were determined through 1996,
aggregate production was subtracted for 1997, 1998, 1999 and 2000, and newly.permitted .
resources since 1996 were added to the original tonnage. Reports with olden completion dates
usually required new calculations of permitted resources. CGS staff made tonnage estimates from. .
information in reclamation plans that were submitted to the Office of Mme Reclamation (OMR) y
mine operators. Estimates were also discussed with operators. In cases where reclamation plans
were inadequate to make independent calculations, estimates obtained from companies were used-
Aggregate
sedAggregate studies having new permitted resource estimates are noted with a superscript (3) and
corresponding footnote on the index map.
The amount of permitted resources available in any given study area is a dynamic number. The
estimates of permitted resources presented on Map Sheet 52 are based on the best information
available at the time of this study. However, permitted resources. are constantly changing due to
continuing aggregate production, closure of existing mining operations, changes in permit
conditions at existing mining operations, issuance of new or expanded mining permits, or other
factors: Also, permitted resources may include aggregate deposits that are permitted, but for a
variety of reasons have not yet begun to be mined or may not be mined in the firture. Those '
interested in .current information should consult with local lead agencies to determine the present
status of mining operations -in areas of interest.
Permitted Resource Calculations
In most cases, CGS staff independently calculated permitted resources for'each mining property
within the 32 aggregate study areas.. The methodology used for calculating permitted resources
varied depending on the -information that was available at the time of the study. Site visits were
made by CGS staff to each mining operation; time company representatives were asked questions
such as deposit thickness, waste factors, in-situ density, aggregate uses, quality, extent of the
permitted properly and permit conditions. Mining regulations vary greatly depending on the.lead
agencies involved. Information needed to. determine permitted resources includes mining limits,
minimum setbacks, finished slopes for pit and quarry walls, and mining. depth Mining plans,
reclamation plans, and cross sections were used if available. Site-specific mining regulations were
also obtained from lead agency files and from OMR files. Whenever possible, calculations of
permitted resources were.compared to company estimates, and, if major discrepancies were found,
every effort was made to resolve them..
6
Table 2. Summary of data used to revise the permitted aggregate resources and 50 -year aggregate
demand presented in the published reports. Reports that have new permitted resource calculations
are shown in italics, the Production Since Report and the Permitted Resources Added Since
Report columns are not applicable (NA) -for these reports. Confidential data are indicated by a "C."
Aggregate Study Area
+;
SR =Special Report
V�a.-�a
°
°n°
OFR Open -File Report
V,
a
04
�N
d
1. Tehama County SR 176
2000
41
1
0
.40
52
2. Glenn County OFR 97-02
1995
J 61
5
0
56
- 79
3. Sacramento -Fairfield. SR. 156. ..
1985
40
NA
NA
130
225
4. North San Francisco Bay SR 176
2000
178
NA
NA
178
-64s
5. Stockton. -Lodi SR 160
1986
80
NA
NA
260
337
6. South San Francisco Bay .
1994
676
112
0
564
1,213
--OFR 96-03.
7. Merced OFR 99-08
Eastern Merced County
1999
.4
3
14
' . 15
98
Western Merced County
1999
>50
C
0
>50
49
S. Monterey Bay OFR 99-01
1997
269
26
0
243
381
9. San Luis Obispo -Santa Barbara
1987
107
22
8
93
99
SR 162
10. Saugus -Newhall OFR 94-14
1992
-158.
7
0
151.-
. 86
11. Western Ventura County
1991
C
C
0.
0
141
OFR 93-10
.12. Simi Valley OFR 93-10
1991
156
27
.0
129
116
13. San Fernando Valley .OFR 94-14'-
1992.
51
C
0
C
646
14. San Gabriel Valley. OFR 94-14
1992
334
93
0
241
1,250
15. Claremont -Upland SR 176
2000
134
NA
NA
134
270
16. Orange County OFR 94 -IS
1993
84
NA
NA.
27
J 233
Table 2 is continued on following page.
7
Aggregate Study Areas .
SR = Special Report
OFR = Open -File Report
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17. Western San Diego County
'OFR 96-04
1994
352
77
0
275
1,099
18. Temescal Valley SR 165
1989
.924J..
114.
0
810
.970
19. Palm Springs SR 159 :
-.1985
67
NA
NA
70
198
20. San Bernardino SR 175
2000
:: 355
NA
NA
356
.969
21. Barstow-PUtorville OFR 92-06
1990
87
NA
-NA
115
165
22. Palmdale OFR 94-14.
1992
.'207
21
30,
216
172
23. Bakersfield SR 147
1984
212
NA
NA
167
•246
24. Tulare County 'OFR- 97-01..
North Tulare County:'
South Tulare County .
1994
1994
19
-200
7
4.
0
0
12
:.196
.107 .
77
25. Fresno: OFR. 99-02
1991
93
:- '... 15
.' 20
:: 98
.:565
26. S3tardslaus County SR 173
A991
. 28
NA
NA
35
311
27. Sacramento County OFR 99-09"
1998
- .: 53
'21
33
65
686
28. El Dorado County SR 178
-2000
13
0.
0
13
85
29. Placer County OFR 95-10
1994
50
NA
NA
43
126
30. Nevada County .SR 164
1989.
: .29
NA
NA
' . '35
-169
31. Yuba City Marysville 'SR 132
1984
1,260
NA
NA
>2,000
.30
32. Shasta County OFR 97-03
1995
30
6
. .4
28
118
Total
>6,845
12,016
' . Last Database Year is the most recent year that aggregate production data were available at the time the
report was completed
i Report Permitted Resources is the tonnage of aggregate resources permitted to be mined by the lead agency
at the time the report was co4leted:: _
3 Numbers' are in millions of toes (one ton = 2,000 pounds). '
° Undated to January 1, 2001.
8
Fifty-year Aggregate Demand Compared to Permitted Aggregate Resources
Fifty-year aggregate demand compared to current permitted aggregate resources is represented by .. ; .
one or.two pie diagrams for each aggregate study shown on Map Sheet 52. Each pie diagram is in
the approximate center of the study area it represents. There are. four different sizes of pies, each
size representing a 50 -year demand range. The smallest pie category.represents 50 -year demands
ranging from 25-200 million tons while the largest represents a 50 -year demand of over goo.
million tons. The actual 50 -year demand tonnage is shown on the map next to the pie diagram. The
whole pie represents the total 50 -year aggregate demand for a particular aggregate study area The
blue portion of the pie represents the permitted aggregate resource (shown as a percentage of the
50 -year demand) while the purple -colored portion of the pie represents that portion of the 50 year
demand that will not be met by these resources. For example, if the blue portion is 250/6, and the
purple portion is 75% of a pie diagram that represents a total of 400 million tons of aggregate .
demand, the permitted resources are 100 million tons, and the region will need an additional 300
million tons of aggregate to supply the area for the next 50 years. If a pie. is completely colored
purple, such as' in the case of Western Ventura County, the region no longer contains' any permitted..
resources. A'pie that is completely colored blue shows that permitted aggregate resources are equal
to or greater than the 50 -year aggregate demand.
Except for Tulare and Merced counties, all the aggregate study areas have just one'50 year demand.
Pie diagram in the center of the aggregate study area that it represents. The Tulare County and
Merced County aggregate studies each has two 50 -year pie diagrams because there are two distinct
market areas in each of these counties.
As seen on.Table 1 and Map Sheet 52, some regions ofthe state have more than enough permitted .
' aggregate reserves to meet the projected 50 year demand in those areas, but most have fewer
permitted resources than will be required to meet the projected 50 -year demand. There are several
options by which the future 50 -year demand for construction aggregate may be met in these areas.
1. Permits for new aggregate mines or expansions toexisting aggregate mines may be granted to
accommodate the demand for aggregate.
2. Aggregate may be imported from'other regions of the state or even from outside of the state to
meet the demand for aggregate. Due to the costs associated with transporting aggregate, such
options may increase the cost of aggregate to the consumer. -
I. Increased -aggregate recycling may reduce the future demand for aggregate resources.
However, recycled material cannot now be used to make concrete aggregate or asphalt
aggregate. Its use in California is limited to class H asphalt base and some Recycled Asphalt
Pavement — old asphalt that is torn up and mixed in small percentages with new asphalt paving
at the batch plant.
Non -Permitted Aggregate Resources
Non permitted aggregate resources are deposits of sand and gravel or crushed stone that may meet
specifications for construction -grade aggregate, are recoverable with vdsting technology, have no
land overlying them that is incompatible with mining, and are - currently not permitted for mining.
While not shown on Map Sheet 52, non permitted aggregate resources are identified and discussed
9
in the individual mineral land classification reports used to compile the map (see.Appendix A).
• There are currently an estimated 74 billion tons of non -permitted construction -grade aggregate
resources in the 32 aggregate study areas shown on the map. While this number seems large, it is .
unlikely that as significant portion of these resources -will ever be mined due to social, environ-
mental, or economic factors. Land -use conflicts occurring when non -permitted aggregate resources
areloo close to urban or. environmentally sensitive areas can -limit or stop the development of these
resources. Non -permitted resources may also be too far from a potential market to be economically
mined and transported to the market area. In spite of these possible constraints, non -permitted
aggregate resources are the most likely future sources of construction aggregate potentially
available to meet California's continuing demand.
The factors used to determine the areal extent and tonnage of non -permitted resources are given in
each of the aggregate classification reports listed in AppendixA
Aggregate Production Areas and Districts
Aggregate production areas (both sand and gravel,'and crushed stone) are shown on.the map -as
five different.triangle sizes. A triangle may represent.one or more active aggregate mines. The
relative size of each symbol corresponds to the amount of yearly production for each mine or
group of mines. Yearly production was based on data from OMR records for the calendar year
2000.. The smallest triangle represerrts ap Auction area that produces less than 0.5 .million tons of
rroducatoii
gteper year.:These triangles usually represerri just one mine operation. About 85% of the
areas on the map -fall into this category and are mostly in rural parts of the state. The. =
Iaigest.triangle represents aggregate mining districts with.production over 10 million tons per year.
Only two production areas fall into. this category: the Temescal Valley Production District in
western Riverside County; and the San Gabriel Valley Production District in Los Angeles Cb.
aty.
The San Gabriel Valley Production District. produced over 15 million tons of aggregate.in 2000; . .
'and is the largest aggregate production district in the United .States.
Aggregate Study Areas with Less than Ten Years of Permitted Resources
Seven of the 32 aggregate study areas shown on Map Sheet 52 have less. than 10 years of permitted.
aggregate resources remaining. They are highlighted by red halos around the pie -diagrams on Map.
Sheet 52. and appear in bold type in. Table 1. Aggregate study areas with less than five years of
permitted resources remaining include Western Ventura County (depleted in 1997) and the
San Fernando Valley. Aggregate*study areas where permitted resources wr71 be depleted in 5 to 10
years include the. eastern portion of Merced County, the northern portion of TulareCounty,
Sacramento County, Orange County and Stanislaus County.
Estimates of depletion years are made by comparing the currently permitted resources to the
projected annual aggregate consumption in the study area on. a year -by -year basis. This is not the
same as dividing the total projected 50 -year demand for aggregate by 50 because, as population
increases, so does the projected annual .consumption of aggregate for a study area. It should be
noted that these numbers are estimates and they can quickly change. 'For example, if a neighboring
P -C region runs out of aggregate and begins to import aggregate from another region, a 10 -year
supply can quickly drop to just a few years supply. .
10 .
51
End Uses of Aggregate
The map of Aggregate Availability in California includes a pie diagram showing end uses of all .
construction aggregate. The diagram is based on a nationwide study done by Coopers and Lybrand.
(1998x, b) and has been modified for Map Sheet 52. The diagram shows that building construction
uses about 56% of total construction aggregate produced and includes residential housing (34%),
commercial buildings (17%), schools and hospitals (20/6), and other public buildings (3%). Road
construction and maintenance use about 290/6 of all construction aggregate produced, public
highways, streets and transit facilities comprise 26%, while private roads amount to about 3%. .
Other construction aggregate uses include water and sewer facilities 5%, railroads 1%, utilities 4%,
other public facilities 3%, and other private facilities 2%
Both the public and private sectors are consumers of construction aggregate. Nationwide, about
'43% of allconstruction aggregate is used for*public works projects and is paid forwith tax dollars.
In California, this would have amounted to roughly $573,000,000 spent by public agencies in 2001
to purchase construction aggregate. The amount of construction aggregate used in public works
projects varies in different areas of the country and state and also varies with fluctuations of the
economy. The California Traffic Congestion Relief Pian announced in April 2000, -will fund nearly
100 high-priority transportation projects throughout the state, at a cost of $5.3 billion.
PART II: OVERVIEW OF CONSTRUCTION AGGREGATE
Construction aggregate is the leading non -fuel mineral commodityproduced in California as well
as in the nation. Valued at $1.33 billion, aggregate made up about 41% of Californias $3.27
billion non -fuel mineral production in 2001. California is the nation's leading producer of
construction aggregate. Total production of construction aggregate in 2001 amounted to almost
230 million tons. .
Annual Aggregate Production
A histogram (Figure) shows California's annual production of construction aggregate for 1960-
2000.
960.2000. Historical production data were obtained from OMR records, and from U.S. Geological
Survey (USGS) and U.S. Bureau of Mmes mineral statistics..
Large public works construction projects can significantly influence aggregate consumption
trends. For example, massive interstate highway, dam, and aqueduct projects throughout California
in the 1960s through the early 1970s caused aggregate production to be generally high and fairly
constant for these years in spite of a recession in the early 1970s. With the completion of these
large projects by the mid 1970s, California's aggregate industry became more sensitive to the ups
and downs of the economy. The Figure reveals three main production lows that generally
correspond to recessionary periods in the mid 1970s the early 1980% and early 1990s. Aggregate
production lows do not correspond exactly to recessionary times because there is generally a lag
time between onset of recessions and decline in aggregate use. Conversely, there were large
increases in aggregate use in the late 1980s and the late 1990s corresponding with periods of
• strong economic growth
11
Aggregate Price .
In general, aggregate is more expensive in northern California than in southern California.. Some of
the most expensive aggregate in the.state is in the north San Francisco and Monterey Bay regions.
This higher cost is -due mainly to a general shortage of portland cement concrete -grade (PCC -
grade) permitted aggregate resources in these areas. PCC -grade aggregate from the north San
Francisco Bay region can cost up to $20.00 per ton compared to the Los Angeles -area where PCC-
grade
CGgrade aggregate generally does not exceed $8.00per ton. The average cost of PCC -grade aggregate
in California is about $8$10 per.ton.
Transportation
Transportation plays a major role in the cost of aggregate to the consumer. Because aggregate is a
low unit:value; high -bulk -weight commodity, it must be obtained from nearby sources to
mWmize both the dollar:cost.to the aggregate eonsumer'and ober environmental and econ6mic
costs associated with transportation. -If nearby sources.do not exist, then transportation costs can'
quickly exceed the value of the aggregate. Transporting aggregate 25 to 35 miles will generally
double the price of the' aggregate: Transporting aggregate from distant sources also fesults in'
increased fuel consumption, air pollution, traffic congestion, and road maintenance. Moreover,
transportation cost is the principal constraint defining the market area for an aggregate.wining .
operation ..
An adequate supply, of local aggregate is critical to the building acid infiastructure needs of
California: In order -to ensure local sources of aggregate,-i..is. neeessary,to identify California's .
permitted aggregate resources and to projecf future aggregate demand-
Aggregate materials are. essential both tomaintain-the existing infi astructure and to provide for
new construction. The demand far aggregate is expected' to increase throughout. California as our
economy grows. :
Aggregate Quality and Use
Construction -aggregate provides the bulk and strength to portland cement concrete.(PCC),
asphaltic concrete (AC), plaster and stucco. Aggregate is also used as road base, subbase, railroad
ballast and fill. Aggregate normally forms W/o to.100'/o of the material volume in these uses.
Rarely, even from the highest -grade deposits, is in-place aggregate raw material physically or
chemically suited for every .type of aggregate use. Every potential deposit must be tested to
determine how much of the material can meet specifications fora particular use, and what.
processing is required. Specifications.for various uses of aggregate have been established by
several agencies such as the U.S. Bureau of Reclamation, the U.S. Army. Corps of Engineers, and
the California Department of Transportation (Caltrans), to ensure that aggregate is satisfactory for
specific uses. These'agencies and other major. consumers test aggregate using standard test
procedures of the American Society for Testing Materials .(AS TIVI); the American Association
State Rghway Officials, and other organizations.
42
Most aggregate specifications have been established to ensure the manufacture of strong, durable
• structures capable of withstanding the physical and chemical effects of weathering and use. For
example, specifications for PCC and concrete products prohibit or limit the use ofrock�materials
containing mineral substances such.as gypsum, pyrite, zeolite, opal, chalcedony, chert, siliceous
shale, volcanic glass, and some high -silica volcanic rocks. Gypsum retards the setting time of
Portland cement; pyrite dissociates to yield sulfuric acid and an iron oxide stain; and other
substances contain.silica in a form that reacts with alkali substances in the cement, resulting in
cracks and "Pop -outs." Alkali reactions in PCC can be minimized by the addition of pozzolanic
admixtures such as fly ash or naturally occurring pozzolanic materials. Pozzolan materials are
defined as a siliceous or siliceous and aluminous material of natural or artificial origin that, in the
presence of moisture, reacts with calcium hydroxide to form cementitious compounds. Naturally
occurring pozzalonic materials include diatomaceous earth, diatomite, volcanic ash, opaline shale,
pumieite, tuff and certain clays such as kaolinite.
Specifications also call for precise particle -size distribution for the various uses of aggregate.
Aggregate is commonly classified into two general sizes: coarse and fine. Coarse aggregate is rock
retained on a 3%8 -inch or a 94 U.S. sieve. Fine aggregate passes a 3/8 -inch sieve and is retained on
a #200 U S..sieve (a sieve with 200 weaves per inch). For some uses, such as asphalt paving,
particle shape is specified. Caltrans Standard Specifications (1992) require that at least 25% by
weight of coarse aggregate (1/4- to 3/4 -inch diameter) used as Class II aggregate base material
shall be crushed particles. Furthermore, aggregate material used with bituminous binder (asphalt)
to form sealing coats on road surfaces shall consist of at least 90% by weight of crushed particles.
Crushed stone is preferable to mtural gravel in asphaltic concrete (AC) because asphalt adheres
.:
better to broken surfaces than to rounded surfaces, and the interlocking of angular particles.
'.'strengthens, the AC and road base. .
'The material specifications for PCC and AC aggregate, collectively referred to as "concrete
aggregate," are more restrictive than the specifications for aggregate for other applications such as
base, subbase and fill. The restrictiveness of these specifications makesdeposits acceptable for
use as PCC or. AC aggregate the scarcest and most valuable aggregate resources. This also means
that aggregate produced from such deposits can be, and commonly is, used in applications other
than concrete. Because of its*versatility, values importance in construction and relative scarcity,
deposits of concrete aggregate are of major concern when planning for future availability of
aggregate commodities. Some areas of California, such as the Los Angeles Basin have abundant
high-quality aggregate deposits that typically meet the specifications for concrete aggregate.
Aggregate .consumers in these areas of the state typically pay lower prices for construction
aggregate. In. other areas. of the state, such as the San Francisco Bay area, deposits of high quality
that meet the specifications for concrete aggregate are much less common, and the cost.
of -concrete -aggregate to the consumer is typically higher.
Factors Affecting Aggregate Deposit Quality
The major factors that affect the quality of an aggregate deposit are the rock type and the degree of
weathering of the deposit. Rock type determines the hardness, durability, and potential chemical
reactivity of the rock when mixed with cement to make concrete. In alluvial. sand and gravel
deposits, rock type is variable' and reflects the rocks present in the drainage basin of the stream or
river. in crushed stone deposits, rock type is typically less variable, although in some types of
14
• deposits such as sandstones or volcanic rocks there may be significant variability of rock type .
within a deposit. Rock type may also influence aggregate shape. For example, some metamorphic
rocks, such as slates, tend to break into thin platy fragments that are unsuitable for many aggregate
uses, while many volcanic and granitic rocks break into blocky fragments more suited to a wide
variety of aggregate uses. Deposit type also affects aggregate shape. For example, in alluvial sand
and gravel'deposits, the natural abrasive action of the stream rounds the edges of rock particles, in
contrast to the sharp edges of particles from crushed stone deposits.
Weathering -is the in-place physical or chemical decay of rock materials at or near the earth's .
surface. Weathering commonly decreases the physical strength of the rock and may make the
material -suitable only for uses in which high strength and durability are not specified. Weathering
may also alter the.chemical composition of the aggregate making it less suitable. for some
aggregate uses: If weathering is severe enough, the material may not be suitable for use as
construction aggregate. Typically, the older a deposit is, the more likely it has been subjected to
weathering, and the severity of weathering commonly increases with increasing age of the deposit.
Comparison of Alluvial Sand and Gravel to Crushed Stone Aggregate
The preferred use of one aggregate material over another in construction practices depends not
only on specification standards, but also on economic considerations. Alluvial gravel is typically
preferred to. cru stone for PCC aggregate because the rounded particles of alluvial sand and
gravel result in a wet mix that is easier to work than a mix made of angular fragments. Also,
crushed stone is less desirable. in applications where the concrete is placed by pumping, because .
• sharp .edges will increase wear and damage to the pumping equipmeni.. The workability of a mix
consisting of Portland cement with crushed stone aggregate can be improved by adding more sand.
-and water, but more cement must then be added to the mix to meet concrete durability standards.
This results in a more expensive concrete mix and a higher cost to the consumer. In addition,
aggregate from a crushed stone deposit is typically more expensive than that from an alluvial
deposit due to the additional costs associated with the ripping, drilling and blasting necessaryto
remove material from most quarries and the additional crushing required to produce the various
sizes of aggregate. Manufacturing sand by crushing is more costly than mining and processing
naturally occurring sand. Although more care is required in pouring and placing a wet mix
containing crushed stone, PCC made with this aggregate is as satisfactory as that made with
alluvial sand and gravel of comparable rock quality.: Due to environmental concerns and regulatory
constraints in many areas. of the state, it is likely that extraction of sand and gravel resources.$om
instteam and floodplain areas will become more difficult in the fi ftwe. If this trend continues,
crushed stone may become increasingly more important to the California market.
Factors Affecting Aggregate Remand
Strong economic growth may contribute to a faster rate of aggregate depletion than what has been
forecasted in the CGS classification. reports. The nation's strong economy since about 1995 has
brought about a resurgence of new home and business construction as well as large construction
projects such as airports, new roads, rail systems and re -paving of existing roads. Large .
construction projects expected to make a major drain on California's aggregate supply locally
• include the expansion of the San Francisco Airport and the proposed 700 -mile high-speed rail
15
system connecting northern and southern California. The San Francisco Aiiport expansion is
• estimated to need as much as 66 million tons of crushed stone over a two-year Period to construct
the platform runways. Unforeseen events such as"a major earthquake in populated areas may also
contribute to an increased aggregate demand. - ' . :
C7
Several factors may. contribute to extending the life of California's permitted aggregate -resources.
A recession in the state's or the nation's economy will result in a decrease in construction
activities. Also, an increase in the use of recycled aggregate for base rock will decrease the need
for new aggregate. The importation of aggregate from other states and countries such as Canada.
and Mexico is also expected to extend the life of California's permitted
state -of -the -at ships are capable -of haulin p aggregate resources.. New
r
. hauling'up to 70,000 tons of aggregate,
SUAEKARY
Construction aggregate is the largest non -fuel mineral commodity
produced in California as well
as in the nation. Aggregate production plays a major role in the economy of California. Demand
for aggregate is expected to increase as the state's population continues to grow and infrastructure .
is maintained and improved upon. For the last 23 years, CGS has identified and assessed aggregate
resources throughout the state and continues to do so. Map Sheet 52 summarizes updated data
from these CGS aggregate studies. The map Presents state, re 'o
� decision make the � � � local land -use planners
makers, aggregate�industry, and the general public with a statewide overview. of
aggregate needs and permitted resources.
CONQ,IISiUNS AND RECOMIVB✓NDATYONS
Construction aggregate is essential to the needs of our modern society',
construction and maintenance of roadways, dams, canals, buildings anoother parts ofhe for the
infisstructure of our state. Construction aggregate can also be found in our homes, schools,
hospitals and shopping centers. In 2000 and 2001, California consumed from 230 to.240 million
tons of construction aggregate annually, or about 7 to. per person.for every
child in the state. About 43% of construction w°�' �d
aggregate is used in public works projects .
nationwide, and is paid for with tax dollars. The remaining 57% is purchased by private parties. and
used for residential and commercial buildings, private roads and other private facilities..Because*
the cost of transporting construction aggregate is a significant part of the total cost to the
consumer, aggregate mines generally are close to communities that consume the aggregate.
The following conclusions can be drawn from Map Sheet 52 and this accompanying report,:
Reference is made to the 34 aggregate consumption areas that are represented by the 34 pie
diagrams shown on Map Sheet -52:
1. Seven of the aggregate consumption areas are estimated to have less than ten years of
Permitted aggregate resources remaining as of January 2001 (pie diagrams highlighted with red
borders).
16
.2. An additional five of the aggregate consumption areas have less than 25% of the permitted
aggregate resources they will need to meet the projected 50 -year aggregate demand in those
areas..
3. Seven of the aggregate consumption areas have 25% to*50% of the permitted aggregate
resources they will need to meet the projected 50 -year aggregate demand in those areas..
4_ Five of the aggregate consumption areas have between 50% and 75% of the permitted
aggregate resources they will need to meet the. projected 50 -year aggregate demand in those
areas. .
5. Four of the aggregate consumption areas have between 75% and 100'/0 of the permitted
aggregate resources they will need to meet the projected 50 -year aggregate demand in those
areas.
6. - Six of the aggregate consumption areas have adequate permitted aggregate resources to meet
orexceed the projected 50 -year demand in those areas. However, most of these study areas, are
in more rural parts of the state where demand for construction aggregate is lower.
Map Sheet 52 provides local land -use planners and decision -makers with general information
about California's construction aggregate availability --More detailed information on aggregate
resources is. given in the supporaggregate studies that are referenced at the end of this report.
ting
• The information presented on Map Sheet 52 and in the referenced reports is provided to assist .
,land use planners and decision -makers in identifying those areas containing construction aggregate
resources and to identify potential future demand for these resources in different regions of the
state. This information should help planners and decision makers to balance the need for'
.construction aggregate with the many other competing land use -issues in their jurisdictions and to
provide for adequate supplies of construction aggregate to meet future needs.
•
Land -use planners should become familiar with the.information presented in the mineral land.
classification reports that pertain to their jurisdictions, and, as mandated by SMARA, incorporate
the information into their land -use planning process: Staff of the Department of Conservation's
California Geological Survey are available to assist local planners, decision makers, and others in
urterpreting the information. contained in these reports. Interested. parties are encouraged to contact
CGS for further assistance.
17
L`
ACKNOWLEDGMENTS
A preliminary version of the map was reviewed by aggregate industry representatives, local
government planners and private consultants with expertise in aggregate mining issues. The .
reviewers were chosen to represent northern, central and southern California and were asked to
review the content, clarity, usability and aesthetics of the map. The CGS staffwould like to thank
the following participants for their comments: Bruce Jensen, .Senior Planner for Alameda County
Community Development Agency, Dave Morrison, Assistant Director for Yolo County Planning
and Public Works Department; Rich Touslee, Senior Associate Planner for San Bernardino County
Advance PIanning Mining Division; Steve Bledsoe, President of the Southern California Rock
Products Association; Gene Block, Retired _(former Vice President of Legislative A$a4 Vulcan
Materials Company, Western Division); William Butler, Vice President and General Manager of
Hansen Aggregates Mid Pacific Inc.; Pete Cotter, Regional Manager for Aggregate Resources,
RMC Pacific Materials; Linda Falasco, Executive Director of the Construction Material
Association o£California; and.John Hecht, President of West Coast Environmental and
Engineering.
REFERENCES CITED
California Department of Transportation, 1992, Standard Specifications.
Ajoopers and Lybrand, 1998a, -The economic and budgetary impact of repealing the percentage
lNepletion _deduction for aggregate: in house report, 19 p.
Coopers and Lybrand;- 1998b, C and L study evaluates impact of repealing the percentage
depletion deduction for aggregates: A,ggregatesmmiager, v. - 3 no. 3, p. 6-8.'
Division of Mines and Geology, 2000, California surface mining and reclamation policies and
procedures: Special Publication 51, third revision.
Dupras, D.L.,.1997; Mineral land classification of alluvial sand and gravel, crushed stone, volcanic
cinders, limestone, -and diatomite within Shasta County, California. ' .
Kohler-Antablin, S.L.; 1999, Update of mineral Iand classification: aggregate materials in the
Monterey Production -Consumption Region, California.
Miller, R.V., 1994, Update of mineral land classification of portland cement concrete aggregate in
Ventura, Los Angeles, and Orange counties, California: Part H — Los Angeles County.
Miller, RV., 1995, Update of mineral land classification of portland cement concrete aggregate in
Ventura,.Los Angeles, and Orange counties, California: Part III — Orange County.
Miller, RV., 1996, Update of minerals land classification: aggregate materials in the western San
sego County Production -Consumption Region.
18
APPENDIX A: MINERAL LAND CLASSIFICATION REPORTS BY DEPARTMENT OF
• CONSERVATION, CALIFORNIA GEOLOGICAL SURVEY: Special Reports- and Open -
File Reports, with information on aggregate resources..
*These Mineral Land'Classification reports have been updated and are not shown on the
index map (lower left -band corner of Map Sheet 52).
SPECIAL REPORTS (SR)
SR 132:
*SR 143:
*SR 143:
*SR 143:
*SR 143:
*SR 143:
*SR 143:
*SR 143:
Mineral Land Classification: Portland Cement Concrete -Grade Aggregate in the
Yuba City -Marysville Production -Consumption Region.
By Habel, RS.. and Campion,' L.R, 1986.
Part I: Mineral Land Classification of the Greater Los Angeles Area: Description of
the Mineral Land Classification Project of the Greater Los Angeles Area.
By Anderson T.P., Loyd, RC., Clark, W.B., Miller, RM, Corbaley, R, Kohler,
S.L. and Bushnell, MM, 1979.
Part II: Mineral Land Classification of the Greater Los Angeles Area: Classification
of Sand and Gravel Resource Areas, San Fernando Valley Production -Co ksumption
Region
By Anderson T.P:, Loyd, RC_; Clark, WB., Miller, R.M., Corbaley, R, Kohler, .
S.L. and Bushnell, M.M., 1979:
-Part III: Mineral Land Classification of the Greater Los Angeles Area:
Classification of Sand and Gravel Resource Areas, Orange County-Temescal
Valley Production -Consumption Region.
By Miller; RV. and Corbaley, R; 1981.
Part IV: Mineral Land Classification of the Greater Los Angeles Area.
Classification of Sand and Gravel Resource Areas, San Gabriel Valley Production -
Consumption Region.
By Kohler, S.L., 1982.
Part V: Mineral Land Classification of the Greater Los Angeles Area: Classification
of Sand and Gravel Resource Areas, Saugus -Newhall Production -Consumption
Region and Palmdale Production -Consumption Region
By Joseph, S.E, Miller, RV.; Tan, S.S. and Goodman, RRW., 1987. .
Part VL• Mineral Land Classification of the Greater Los Angeles Area:
Classification of Sand and Gravel Resource Areas, Claremont -Upland Production -
Consumption Region.
By Cole,'J.W., 1987.
Part VII: Mineral Land Classification of the Greater Los Angeles Area:
Classification of Sand and Gravel Resource Areas, San Bernardino Production -
Consumption Region.
By Miller, RV.,1987: .
19
*SR 145: Part T:
Mineral Land Classification of Ventura County: Description ofthe Min
-Land Classification Project of Ventura County. eral
• By Anderson, T.P., Loyd, R
Miller, C., Kiessling, E.W., Kohler; S.L. and
R V., 1981.
*SR 145:Part . Mineral Land Classification of Ventura Co
Gravel, and Crushed Rock Resource Areas, Simi Pro ucaan- ovation of the Sand, .
By Anderson, T.P., Loyd, RC., Kiessling, E.W, Kohler, S.L. andmPEonRegion.
Miller, R V., 1981.
*SR 145: Part III:
Mineral Land Classification of Ventura. County: Classification of the Sand
Production -Consumption Region
and Gravel, and Crushed Rock Resource Areas, Western Ventura`County .
By Anderson, T.P., Loyd, R_C., Kiessling; E:W; Kohler,.S L. and
Miller, RV., 1981.
*SR 146: Part I: Mineral Land Classification:
Classification for Construction A Project Description: Mineral Land
By Stinso M1 C g� gate in the San
n, M
anson, MW. and Plappert, JFrancisco-Monterey Bay Area.
,J,1987:.. .
*SR 146: Part IL Alineral Land Classification Aggregate Materials in the
San Francisco Bay Production -Consumption South
B -Y Stinson, Region
.. n, MC.,
Manson.XW: and PIaPP , JJ, 1987. ;
*SR 146: P49M Mineral Land Classificatio
• San Francisco Bay Production -Co agate Materials. in.the North
By.Stinso .. ption Region.
n, MC., Manson, MW- -and Pla
PPert,.1987:
*SR 146: Part Imo . Mineral Land Classification..
ication: Aggregate Materials in the Monterey Bay
resumption Regiegion.
By Stinson, MC-, Manson, M.W. and P1aPPM JJ, 1987.
SR 147:. Mineral Land Classification:
Consumption Region. Aggregate Materials in.the Bakersfield Production=
By Cole, J.W., 1988.
*SR 153: Mineral Land Classification:Aggregate Materials in the Western San - � Diego Co
.
Production -Consumption Region. unty
By Kohler, S.L. and Miller, R V., 1982.
SR 156: Mineral Land Classification: Portland Cement Con _
Aggregate in the Sacramento -Fairfield Production-Consu.
BY Dupras, D.L_, 1988. mption Region.
*SR 158: Mineral Land Classification: A
Consumption Region. Aggregate Materials in the Fresno Production -
By Cole, J W. and Fuller, DR, 1986.
20
SR 159:
Mineral Land Classification: Aggregate Materials in the Palm Springs Production-
Consumption Region..
By Miller, RV.,1987.
" SR 160:
Mineral Land Classification: Portland Cement Concrete -Grade Aggregate in the .
Stocldon-Lodi Production -Consumption Region.
By Jensen, L.S. and Silva, MA., 1989.
SR 162:
Mineral Land Classification: Portland Cement Concrete Aggregate and Active
Mines of All Other Mineral Commodities in the San Luis Obispo -Santa Barbara
Production -Consumption Region
By Miller, RV., Cole, J.W. and Clinkenbeard, J.P.,1991.
SR 164:.
1Viineral Lajid Classification of Nevada County, California
By Loyd, R.C. and Clinkenbeard, IJ?-.' 1990:
SR 173:
Mineral Land Classification of Stanislaus County, California.
By Higgins, C.T. and Dupras, DJ,' 1993:
SR 175:.
Update of Mineral Land Classification of Portland Cement Concrete Aggregate in
the Claremont Upland and San Bernardino Production -Consumption Regions,
California.
By Koehler, BMand Miller, RV., 2002 (in progress).
•
SR 176:
Mineral Land Classification of Concrete -Grade Aggregate Resources in Tehama .: ..:..
..County, California.
By Foster, B.D., 2002 (m Progress). :
SR 178:
Mineral Land Classification of El Dorado County, California.
By Busch L.L., 2002 (1n progress)..
SR 179:
Update of the Mineral Land Classification: Aggregate.Materials in the North San
Francisco Bay Production -Consumption Region
By Dupras, D.L., 2002 (m progress).
OPEN FILE REPORTS (OFR)
OFR 92-06:
Mineral Land Classification of Concrete Aggregate.Resources in the Barstow-
Victorville Area.
By Miller, R.V., 1993.
OFR 93-10:
Update of Mineral Land Classification of Portland Cement Concrete Aggregate in
Ventura, Los Angeles, and orange Counties, California: Part I - Ventura County.
By NOer, PLV., 1993.
0
21
�FR 9414: Update of Mineral Land Classification of Portland Cement Concrete Aggregate in
Ventura, Los Angeles; and Orange Counties, California: Part H - Los Angeles
County.
By Miller, RV., 1994.
OFR 9415: Update of Mineral Land Classification of Portland Cement Concrete Aggregate in
Ventura, Los Angeles, and Orange Counties, California: Part III -Orange County.
By Miller, R.V., 1995.
OFR 95-10: Mneral Land Classification ofPIacer County,- California_
By Loyd, RC.,1995.
OFR 96-03:. Update of Mineral Land Classification: Aggregate Materials in the South
San Francisco Bay Production -Consumption Region.
_ By Kohler Antablin, S.L. 1996.
OFR 96-04: Update ofMineral Land Classification: Aggregate Materials in the Western
San Diego County Production -Consumption Region.
ByM11er,RX.,1996.
OFR 97-01: Mineral Land Classification of Concrete Aggregate Resources in the Tulare County
Production -Consumption Region, California:
By Taylor, -G C., 1997.
IFR 97-02:.: Mineral Land Classifi- .
cation of Concrete -Grade Aggregate Resources in Glenn
County, California.,
By Shumway; D -O., 1997.
OFR 97-03: Mineral Land Classification of Alluvial Sand and Gravel, Crushed Stone, Volcanic
Cinders, Limestone, and Diatomite within Shasta County, California.
By Dupras, DL, 1997.
OFR 99-01: Update of Mineral Land Classification: Aggregate Materials in the Monterey Bay
Production -Consumption Region, California.
By Kobler-Antablin, S.L.,1990.
OFR 99-02: Update of Mineral Land Classification: Aggregate Materials in the Fresno
Production -Consumption Region, California.
By Youngs, L.G.- and Miller, RV., 1999.
OFR 99-0$: Mineral Land Classification of Merced County, California.
By Clinkenbeard, J.P., 1999.
OFR 99-09: -Mineral Land Classification: Portland Cement Concrete -Grade Aggregate and Clay
Resources in Sacramento County, California;
By Dupras, DZ., 1999.
22
APPENDIX B: DESCRIPTION OF REVISIONS MADE TO PERMITTED AGGREGATE
• RESOURCE CALCULATIONS AND 50 -YEAR AGGREGATE DEMAND PROACTIONS
IN AGGREGATE CLASSICICATION REPORTS: Methods used in updating information
used in the development of Map Sheet 52.
1. Tehama County (SR1762 report in progress)
• Determined permitted resources from preliminary :estimates.that may differ from.final
report.
• Determined 50 -year forecast frompreliminary data that may differ from final report_
2. Glenn County (OFR 97-02)
Subtracted 1996-2000 production from report permitted resources.
• Updated 50 -year forecast (2001 through 2050).
3. Sacramento -Fairfield (SR 156)
• Determined new permitted resources for the Cache Creek area (Yolo County) only. The
remaining aggregate production areas covered in the Sacramento -Fairfield P -C Region
have been updated in the Sacramento County aggregate study area, OFR 99-09.
• Updated 50 -year forecast. (2001 through 2050).
4. North San Francisco Bay (SR 179, report in progress)
• Determined permitted resources from preliminary estimates that may differ from final .
report. .. .. .. .. : .. .... .
• .. Determined 50 -year forecast from preliminary data that may differ from final report.
5. Stockton -Lodi (SR 160)
• Determined new permitted resources.
Updated 50 -year forecast (2001 through 2050).
6. South San Francisco Bay (OFR 96-03)
• Subtracted 1995-2000 production from report permitted resources. .
• Updated 50 -year forecast (2001 through 2050).
7. Merced County (OFR 99-01)
•` Subtracted 2000 production from report permitted resources for Western Merced County.
• Added 14,000,000 tons of permitted resources since original report estimates, were made
for Western Merced County.
• Updated 50 -year forecast (2001 through 2050) for Western Merced County.
• 2000 production from report permitted resources for Eastern Merced County -
Subtracted Updated 50 year forecast (2001 through 2050) for Eastern Merced County.
8. Monterey Bay (OFR 99-01)
• Subtracted 199&2000 production from report permitted resources.'
• Updated 50 -yeah forecast (2001 through 2050).
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• 9. San, Luis Obispo -Santa Barbara (SR 162)
• Subtracted 1988 2000.pioduction from report permitted resources.
• Added 8,000,000 tons of permitted resources since original report estimates.
• Updated 50 -year forecast (2001 through 2050).
10. Saugus -Newhall (OFR 94-14)
• Subtracted 1993-2000 production from report permitted resources:
• . Updated 50 -year forecast for Los Angeles County (2001 through 2050).
• Multiplied the total 50 -year aggregate demand by 0.04 to determine a separate demand for
the Saugus -Newhall P -C Region. The region has historically produced about 4%.ofLos
Angeles County's aggregate.
11. Westem Ventura County (OFR -93-10)
• Subtracted 1992-2000 production from report permitted resources.
Made new 50 year forecast for Ventura*County and multiplied_the total projected county
demand by0.55 to determine a separate demand for the Western Ventura County P C'
Region. The region has historically produced about 55% of Ventura County's aggregate:
-12- Simi Valley (OFR 93-1.0) .
•
Subtracted 1992-2000 production data from report permitted resources.
• Made new 50 -year forecast for Ventura County and multiplied the total projected county
demand by 0.45 to calculate a separate demand for the Simi Valley P -C, Region. The region
has historically produced about 45% of Ventura County's aggregate.
13. San:Fernando Valley (OFR 94-14)
• : Subtracted 1993-2000 production from reportpenmitted reserves:
Updated 50 -year forecast for Los Angeles County.(2001 through 2050).
Multiplied the total 50 -year aggregate demand by 0.30 to calculate a separate demand for
the San Fernando Valley P -C Region The region has -historically produced approximately
30% of Los Angeles County's aggregate.
14. San Gabriel Valley (OFR 94-14)
Subtracted 1993-2000 production from report permitted resources. -
• Updated 50 -year forecast for Los Angeles County. (2001 through 2050).
• Multiplied the total 50 -year aggregate demand by 0.58 to calculate a separate demand for
the San Gabriel Valley P -C Region. The region has historically consumed. about 58% of
Los Angeles County'. s aggregate.
15. Claremont -Upland (SR- 175, report in progress)
• Determined permitted resources from preliminary estimates that may .differ from final
report.
• Determined 50 -year forecast from preliminarydata that may differ from final report.
16- Orange County (OFR 94-14)
Determined new permitted resources using company data.
• Updated 50 -year forecast (2001 through 2050).
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• 17. Western San Diego County (OFR 96-04)
• Subtracted 1995-2000 production from report permitted resources:
• Updated 50 -year forecast (2001 through 2050).
18. Temescal Valley (SR 165)
• Subtracted 1989-2000 production from report permitted resources.
• Made new 50 year forecast.
19. Palm Springs (SR 159)
• Calculated new permitted resources.
• Updated 50 -year forecast (2001 through 2050).
20. San Bernardino (SR -175, report in progress)
• Determined permitted resources from preliminary estimates that may differ from final
report.
•Determined 50 year forecast from preliminary data that may differ from final report.
21: Barstow-Vietorville (OFR 92-06)
• Calculated new permitted resources.
• Updated 50 -year forecast (2001 through 2050).
22. Palmdale (OFR 94-14)
` • Subtracted 1993-2000 production from report permitted resources.
• •
Updated 50 -year forecast for Los Angeles County (2001 through 2050).
• Multiplied the total 50 year aggregate demand for Los Angeles County by 0.08 to get a;
separate demand for the Palmdale P -C Region that has historically produced approximately
8% of Los Angeles County's aggregate-
23. Bakersfield (SR 147)
• Determined new permitted resources using company estimates.
• Updated 50 -year forecast (2001 through 2050)-
24. Tulare County (OFR 97-01)
• Subtracted 1995-2000 production from report permitted resources for North Tulare County:
• Subtracted 1995-2000 production -from report permitted resources for South Tulare County.
• Updated 50 -year forecast for Tulare County (2001 through 2050).
• Multiplied the total 50 -year aggregate demand for Tulare County by 0.58 to get a separate
demand for North Tulare County that has historically produced. about 58% of Tulare
County's aggregate.
Multiplied the total 50 year aggregate demand for Tulare County by 0.42 to get a separate
demand for South Tulare County that has historically produced about 420/a of Tulare `
County's
lel•
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