APPENDICES
ANALYSIS OF THE POTENTIAL BENEFITS
RELATED TO IMPLEMENTATION OF
THE CALIFORNIA TOXICS RULE
June, 1997
U.S. Environmental Protection Agency
Office of Policy, Planning and Evaluation
Office of Sustainable Ecosystems and Communities
401 M Street SW
Washington, DC. 20460
and
U.S. Environmental Protection Agency
Region DC
75 Hawthorne Street
San Francisco, California 94105
-------
These appendices were prepared in support of the report: Analysis of the Potential
Benefits Related to Implementation of the California Toxics Rule (U.S. EPA 1997) under the
direction of Christine Ruf, U.S. EPA, Office of Policy, Planning and Evaluation, Office of
Sustainable Ecosystems and Communities, and Diane Frankel, U.S. EPA, Region DC, San
Francisco, California. Industrial Economics Inc. prepared the Appendices and performed much
of the analysis and technical evaluation presented here.
-------
APPENDICES
Appendix A: 1994 Assessment of California Water Quality, by Region, for Toxics
Appendix B: California Fish Tissue Contaminant Data Bases
Appendix C: Fish Consumption Rates
Appendix D: Supplemental Information for the Angler Risk Assessment
Appendix E: Ecology and Ecological Effects
Appendix F: Loadings Data Used in Apportionment Analysis
Appendix G: Comparison of Possible Point Source Industrial PCB Discharges in California and
Great Lakes Region by SIC Code
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JUNE 1997
Appendix A
1994 ASSESSMENT OF CALIFORNIA WATER QUALITY BY REGION,
FOR TOXICS
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JUNE 1997
TABLE OF CONTENTS
Page
Region 1: North Coast Region A-2
Region 2: San Francisco Bay Basin A-9
Region 3: Central Coastal Region A-18
Region 4: Los Angeles Basin A-24
Region 5: Central Valley Region A-32
Region 6: Lahontan Region A-39
Region 7: Colorado River Basin A-51
Region 8: Santa Ana River Basin A-57
Region 9: San Diego Basin A-64
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JUNE 1997
Appendix A summarizes information on toxics water quality in California waters, and is
based on the State's Water Quality assessment (WQA) database, developed and maintained by the
State Water Resources Control Board (SWRCB). The WQA is a compilation of data from the State's
nine regional Water Quality Control Boards and is organized by region and by waterbody type. It
contains a range of information on surface water pollution, including the pollutants that adversely
affect water quality, bodies of water that have been evaluated, the sources of pollution, the beneficial
uses impaired, and an overall rating of water quality. The State relies on the WQA to develop the
biennial water quality report required by section 305(b) of the Clean Water Act. The WQA was last
updated in 1994. A description of the data and methodology used to develop these appendices is
presented in Chapter 2, Characterization of Baseline Water Quality, Analysis of the Potential
Benefits Related to Implementation of the California Toxics Rule (U.S. EPA, June 1997).
It is important to note that information on the extent to which California surface waters
currently meet the proposed toxic water quality criteria is incomplete. Water quality conditions in
many State waters have not been fully assessed, and assessments of waters that have been evaluated
often do not contain monitoring data that is extensive or detailed enough to determine whether the
waterbody meets all of the proposed criteria. According to water quality experts from U.S. EPA and
the State of California, extrapolating information presented in these Appendices to all waters in the
State may create a bias towards overestimating the extent of toxics contamination Statewide. These
include assuming that the percentage of toxics impairment found in assessed waters was the same
as the percentage of toxic impairment of waters throughout the State; that waters rated as medium
impaired waters (those which partially support their uses) were conducted together with those rated
as poor impaired waters (those which do not support their uses); and that waters listed as impaired
in one data base, and associated with toxics in a second data base, were considered waters impaired
by toxics.
Although the consensus of the U.S. EPA and State experts is that the above assumptions may
have created a bias toward overestimating toxics contamination Statewide, they also stated that
certain other assumptions used in the analysis may have created a bias in underestimating the extent
of toxics contamination. For example, the assumption that the type and scope of all toxics of
concern in all Stale waters appear in the WQA data base may underestimate the extent of toxics
impairment because of the infrequency of ambient monitoring throughout the State, or because of
the difficulty of detecting the ambient concentrations of certain toxic pollutants when their water
quality criteria fall below the minimum detection limit. Consequently, because of all of the
uncertainties associated with the WQA data base, State of California and U.S. EPA experts advise
against an attempt to quantitatively estimate the magnitude of the bias in either direction.
A-l,
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JUNE 1997
Region 1: North Coast Region
Hydrologic Setting
The North Coast Region covers approximately 18,000 square miles in the northwest comer
of California. It is bounded by the Pacific Ocean to the west, the California/Oregon border to the
north, the Modoc National Forest and the Trinity Mountains to the east, and the Marin-Sonoma Area
to the south. The topography consists mostly of rugged forested coastal mountains, divided by six
major river systems: the Eel, Russian, Mad, Navarro, Gualala, and Noyo Rivers. The area along
the eastern boundary is mostly National Forest land, with land use under the control of the National
Forest Service. Major population areas center around Humboldt Bay in the northern portion of the
basin and around Santa Rosa in the southern portion.1
The North Coast Region receives the highest levels of precipitation in the State. The North
Coast Region constitutes only about 12 percent of the area of California but produces nearly 40
percent of the annual water runoff. The runoff contributes to river flow and storage in lakes and
reservoirs; however, in combination with generally unstable soils, runoff has also created the hazard
of damaging floods.2
Figure A-l displays the major waterbodies of the North Coast Region.
Degree and Sources of Toxics Impairment
Excluding bay areas, North Coast Region waters are relatively free of toxic contamination.
The types of toxic pollutants in the Region are limited to metals and pesticides, the primary sources
of which are agriculture, industry, municipalities, and urban runoff. Analysis of the WQA database
yields the following information:
• As summarized in Exhibit A-l, toxic pollutants impair a significant portion
of the bays assessed, but very little of other waterbody types. Toxics impair
16,500 acres of bays (55 percent of assessed) but only 625 acres of estuaries
(2 percent of assessed) and 16 miles of rivers and streams (less than 1 percent
of assessed).
1 Water Quality Control Plan, North Coast Basin; California Regional Water Quality Control
Board, North Coast Region, Region 1, December, 1993, pp. II1-112.
2 Ibid.
A-2
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NORTH COAST REGION(1)
Pnxtaori by
LKC
UJZPA Rcgioe 9 OS
Sq«. 27 1995
0 1020 30 KILOMETERS
SOURCES:
M3 USEPA 1992
S-184M
QJit
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JUNE 1997
Exhibit A-l
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREA
REGION 1: NORTH COAST REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
16,500
30,024
54.96%
Estuaries
(acres)
625
28,692
2.18%
Lakes & Reservoirs
(acres)
0
88,819
0.00%
Rivers & Streams
(miles)
16
3,085
0.52%
Saline Lakes
(acres)
0
0
NA
Wetlands
(acres)
0
18,060
0.00%
Source: EPA analyses of 1994 WQA database.
Exhibit A-2 demonstrates that agriculture, industrial point sources, municipal
treatment plants, and urban runoff all contribute to impairment of bay waters
by toxics. Industrial dischargers are the principal source of toxics for the
relatively small area of toxics-contaminated rivers, while mines also
contribute to toxics impairment through discharges of metals.
Key Waterbodies Affected
Based on California's 1994 303(d) report, a number of the waterbodies affected by toxics in
Region 1 are of significant priority. Twenty waterbodies in Region 1 appear on the priority list, six
of which are affected by toxics. Exhibit A-3 presents the pollutant types, 303(d) report ranking, and
area of impairment for those six waterbodies.3 Included are the Estero Americano and Estero de San
Antonio estuaries and the Klamath, Mad, Shasta, and Van Duzen rivers.4 While not included on the
303(d) list, Arcata Bay and Humboldt Bay are included in Exhibit A-3 to reflect the areal extent and
type of toxic pollution.
As shown, the Klamath River is listed as highest priority to the State (a ranking of " 1"), but
the area affected by toxics (according to the WQA database) is limited to only 1 mile of the river's
126 mile length. Based on 1996 data, the Klamath River was removed from the 303(d) list. The
3 The priority listings in the 303(d) report are determined by the Regional Water Boards and
are a function of the intrinsic value of the waterbody and the degree of impairment. The rankings
range form 1 to 5, with 1 representing highest priority waters. California Report on Impaired
Surface Waters, Prepared as Required in Clean Water Act Section 303(d), May 1994.
* California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May 1994.
Based on 1996 data, the Klamath River was removed from the 303(d) list.
A-4
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JUNE 1997
Exhibit A-2 ,
MAJOR SOURCES OF TOXIC POLLUTANTS
REGION 1: NORTH COAST REGION
Agriculture
Hydro. /Habitat Modification
Industrial
Land Development
Land Disposal
Mining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Urban Runoff
Bays
(acres)
16,500
0
16,500
0
0
0
16,500
0
0
0
16,500
Share of
Total Toxics-
Impaired Area
100%
0%
100°/«
0%
0%
0%
100%
0%
0%
0%
100%
Estuaries
(acres)
625
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
100%
0°/,
0%
0%
0%
0%
0%
0%
0%
0%
0%
Lakes &
Reservoirs
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Rivers &
Streams
(miles)
0
0
16
0
0
1
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
0°/«
0%
100%
0%
0%
6%
0%
0%
0%
0%
0%
Saline
Lakes
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wetlands
(acres)
0
0
0
. 0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Source: EPA analysis of 1994 WQA database.
A-5
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JUNE 1997
WQA data suggest that toxics impair only small segments of the rivers ranked in the second and
third tiers as well. In contrast, the WQA identifies the entire area of both the Estero Americano and
Estero de San Antonio as impaired by toxics.
Based on other available information, the toxics-impaired waters from the 303(d) list are
clearly not the only waterbodies in the North Coast Region affected by toxic pollutants. California's
Bay Protection and Toxic Cleanup Program (BPTCP) lists toxic "hot spots" - defined as areas of
significant toxicity, high levels of bioaccumulation, and impairment of ecologic beneficial uses -
in key coastal waterbodies. While there are no known toxic hot spots identified in Region 1, many
"potential" toxic hot spots (areas exhibiting elevated toxic concentrations in water or sediment) are
listed. The areas cited as potential hot spots are the Smith River Estuary, Lake Earl, Crescent City
Harbor, Klamath River Estuary, Redwood Creek Estuary, Stone Lagoon, Big Lagoon, Trinidad
Coast, Little River Estuary, Mad River Estuary, Arcata Bay, Somoa Peninsula, Humboldt Bay, Eel
River Estuary, and Mattole River Estuary.5
Exhibit A-3
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN THE NORTH COAST REGION (REGION 1)
Waierbody
Estero Americano
Estero de San Antonio
Klamath River'
Mad River
Shasta River
Van Duzrn River
Arcata Ba>
Humboldt Ba>
Pollutants
Metals
Metals
Metals, Pesticides
Pesticides
Pesticides
Pesticides
Metals, Pesticides
Metals, Pesticides
303(d)Priority
2
2
1
2
3
2
Not Listed
Not Listed
Area Affected
370 acres
255 acres
1 mile
3 miles
2 miles
2 miles
8,500 acres
8,000 acres
Sources .W
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JUNE 1997
Natural Resources and Beneficial Uses Affected
The surface waters of the Northern Coastal Region support diverse wildlife resources as well
as a variety of beneficial human uses. Exhibit A-4 presents a summary of beneficial uses associated
with the waterbodies on the 303(d) list (and the major toxics-impaired bays), as contained in the
Region 1 Basin Report. The services and activities listed for each waterbody are based on the
judgment of regional staff and are indicative of beneficial uses currently provided by the waterbody.
They are not directly related to use designations as defined under the Clean Water Act.
As shown in Exhibit A-4, many of the Region 1 waterbodies on the 303(d) priorities list
supply water for municipal and agricultural use, and all supply water for industry. All are also
utilized for both contact and non-contact water recreation, including swimming, boating, camping,
and nature-watching. All provide habitats for wildlife and most aid in the survival and maintenance
of rare, threatened, or endangered plant or animal species. Many of the waterways also support fish
spawning and migration, as well as groundwater recharge.
A-7
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JUNE 1997
Exhibit A-4
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY WATERBODIES
Walerbody
Estero
Americano*
Estero de San
Antonio*
Klamalh
River
Mad River
Shasta River
VanDuzen
River
Arcala Bay*
Humboldl
Bay
Beneficial Uses
Municipal
Supply
X
X
X
X
Agriculture
X
X
X
X
X
Industrial
X
X
X
X
X
X
X
X
Commercial
and Sport
Fishing
X
X
X
X
X
X
X
Water
Contact
Recreation
X
X
X
X
X
X
X
X
Non-Contact
Water
Recreation
X
X
X
X
X
X
X
X
Groundwater
Recharge
X
X
X
Freshwater
Recharge
X
X
Wildlife
Habitat
X
X
X
X
X
X
X
X
Freshwater
Habitat
-
X
X
X
X
X
Saline
Habitat
X
X
X
Fish
Migration
X
X
X
X
X
X
X
X
Fish
Spawning
X
X
X
X
X
X
X
X
Preservation
of Biological
Habliauor
Special
Significance
X
X
X
Suppom
Rare or
Endanger*))
Speetn
X
X
X
X
X
X
X
Source H'aler Quality Control Flan. North Coast Basin. Region 1. California Regional Water Quality Control Board. December, 1993, Table 4
* The Region 1 Basin Report did not contain individual listings for these waterbodies. the listing for the estuary or bay category was therefore applied to the corresponding waters
A-8
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JUNE 1997
Region 2; San Francisco Bay Basin
Hydrologic Setting
Region 2, the San Francisco Bay Region, extends over approximately 1,620 square miles
along the central coast of California.6 The region is dominated by the San Francisco Bay system,
a complex of several interconnected waterbodies. The key segments include Suisun Bay (including
Grizzly and Honker Bays) to the east, Carquinez Strait, San Pablo Bay, and San Francisco Bay.
Together, these bays cover approximately 470 square miles, or about 30 percent of the area of
Region 2, making it the largest coastal embayment on the Pacific coast of the United States. The
system functions as the only drainage outlet for the waters of the Central Valley, to the east. Figure
A-2 shows the location of major waterbodies in Region 2.
The San Francisco Bay Region includes several other key waterbodies that add to the
diversity of water resources in the area. To the north of Suisun Bay is Suisun Marsh, the largest
brackish marsh in the United States, covering approximately 57,000 acres. In addition, a number
of freshwater rivers and streams also drain to the Bay. Among the more significant are the Napa
River to the north and the Guadalupe River and Alameda Creek to the south. Also to the north is
Tomales Bay, a large (approximately 8,000 acres) and generally pristine estuary.
Because of their diversity, the water resources of the San Francisco Bay region support a
wide array of wildlife. Many fish species use the waters for feeding and nursery grounds. In
addition, anadromous fish and many species of waterfowl use the area as a migratory pathway.
These natural resources and the variety of beneficial uses supported are described more fully below.
Degree and Sources of Toxics Impairment
The water resources of Region 2 are among those most affected by toxic pollution. Exhibit
A-5 shows over two-thirds of the bays and about 60 percent of wetland areas are impaired by toxics.7
Significant portions of assessed lakes and rivers are also impaired.
6 Most of the discussion of the hydrologic setting of Region 2 is taken from two documents:
State of the Estuary: San Francisco Estuary Project, U.S. EPA and the Association of Bay Area
Governments, June, 1992; and Water Quality Control Plan, San Francisco Bay Basin Region 2,
California Regional Water Quality Control Board, December, 1986.
7 The impaired wetland acreage is all accounted for by the Suisun Marsh wetlands.
A-9
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SAN FRANCISCO BAY REGION(2)
LKC
USEPA Begin 9 GC
Sept 27. 199S
10
15 MILES
0 5 10 15 KILOMETERS
SOURCES
Sbcmc RF3 USEPA 1992
*T IWwcr Co*** Bo*
S-l»44
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JUNE 1997
Exhibit A-5
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREA
REGION 2: SAN FRANCISCO BAY REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
197,500
285,341
69.22%
Estuaries
(acres)
25
26,833
0.09%
Lakes & Reservoirs
(acres)
3,272
16,281
20.10%
Rivers & Streams
(miles)
244
619
39.42%
Saline Lakes
(acres)
0
0
NA
Wetlands
(acres)
57,000
95,055
59.97%
Source: EPA analysis of WQA database.
The sources that contribute to toxics pollution in Region 2 are varied. In many cases, the
WQA data do not list sources contributing to pollution of Region 2 waters. Where data are available,
they suggest that urban runoff and other nonpoint sources affect the greatest areas. Point sources are
also cited, with municipal treatment plants affecting the Suisun Marsh wetlands and mining
contributing to impairment of some lakes and rivers. Exhibit A-6 summarizes how the major
categories of pollutant sources affect surface waters in Region 2.
Other information sources support the data found in the WQA data base. Exhibit A-7
summan/cs loadings of key toxic pollutants to San Francisco Bay and the other waters of the delta
estuan Sources examined include municipal/industrial effluent, urban and non-urban runoff,
deposition from the air, and loadings from the San Joaquin River (originating with point and
nonpoim discharges in the Central Valley). As shown, non-urban runoff (runoff from agricultural
land, forcsu. and other open areas) is a major contributor for a number of toxics, including arsenic,
cadmium, chromium, copper, lead, mercury, and zinc. Urban runoff contributes significant shares
of lead and PCBs. A large share of trace-element loadings can be traced to irrigation return flows
and other nonpoint sources in the Central Valley, transported to San Francisco Bay via the San
Joaquin River.1
Kr> \\ atrrbodies Affected
Based on California's 303(d) list, a number of the waterbodies affected by toxics in Region
2 arc of significant priority.9 Exhibit A-8 presents information on the 15 waterbodies listed in the
30?id i report. Included are all major sections of San Francisco Bay, Tomales Bay, the Suisun Marsh
wetlands, and a number of lakes and rivers. Metals are the most common source of the impairment,
although trace elements and pesticides are also problematic.
* An aquatic life criterion for selenium is already in effect for the Bay-Delta.
* California Report on Impaired Surface Waters. Clean Water Act Section 303(d), May 1994.
A-ll
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JUNE 1997
Fi MM! A-*
MAJOR sorw FS OF TOXIC POLLUTANTS
REGION 2: SAN FRANCISCO BAY REGION
Agriculture
Hydro /Habitat Modificalion
industrial
Land Development
[.and Disposal
fining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Urban Runoff
Bays
(«cres)
400
0
0
0
0
400
0
67,700
0
0
24.500
Shirt of
Total Toxics-
Impaired
Art!
0%
0%
0%
0%
0%
0%
0%
34%
0%
0%
12%
Estuaries
(acres)
0
0
25
0
25
0
0
0
0
0
25
Shire of
Tola! Toxlcs-
Impalred
Aret
0%
0%
100%
0%
100%
0%
0%
0%
0%
0%
100%
Likes &
Reservoirs
(acres)
no
0
0
0
0
602
0
2,240
0
0
430
Shire of
Total Toxlcs-
Impilred
Area
3%
0%
0%
0%
0%
18%
0%
68%
0%
0%
13%
Rivers &
Streams
(miles)
25
0
0
0
0
75
0
116
0
0
112
Shire of
Total Toxles-
Impilred
Area
10%
0%
0%
0%
0%
31%
0%
48%
0%
0%
46%
Saline
Likes
(•cres)
0
0
0
0
0
0
0
0
0
0
0
Shire of
Total Toxics-
Impaired
Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wetlands
(acres)
0
0
0
0
0
0
57,000
57,000
0
0
57,000
Shire of
Total Toxics-
Impalred
Are*
0%
0%
0%
0%
0%
0%
100%
100%
0%
0%
100%
Source: EPA analysis of WQA database.
A-12
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JUNE 1997
Exhibit A-7
SUMMARY OF POLLUTANT LOADINGS TO
THE BAY/DELTA ESTUARY FROM MAJOR SOURCES
(Metric Tons/Year)
Pollutant
' Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium1
Silver
Zinc
PCBs
Municipal and
Industrial
Effluent
1.5-5.5
1.8-4.0
12-13
19-30
11-16
0.2 - 0.7
19-27
2.1
2.7 - 7.2
77-80
N/A
San Joaquin River
12
N/A
66
80
51-55
N/A
51
4.2
N/A
164-175
N/A
Urban Runoff
1.0-9.0
0.3 - 3.0
3.0-15
7.0-59
30 - 250
0.026-0.15
N/A
N/A
N/A
34 - 268
0.006 - 0.40
Total Nonurban
Runoff
10 - 120
0.52 - 6.0
130 - 1500
51 - 580
31-360
0.15-1.7
N/A
N/A
N/A
130 - 1450
N/A
Atmospheric
Deposition
N/A
0.14-0.35
N/A
1.9-3.1
6.0-21
N/A
N/A
N/A
N/A
N/A
N/A
Dredged Material
N/A
0.02-0.2
N/A
1.0- 10
1.0-10
0.01-0.1
2.0 - 20
N/A
N/A
3.0 - 30
0.00067 - 0.0067
Note: Values in bold face indicate the largest quantified source of each pollutant; multiple major sources are shown where ranks are relatively ambiguous.
N/A = Data not available.
Source: State of the Estuaiy: San Francisco Estuary Project, U.S. EPA and the Association of Bay Area Governments, June, 1992, p. 172.
1 An aquatic life criterion 5 /ug/1 for selenium is already in place for the Bay-Delta.
A-13
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JUNE 1997
Exhibit A-8
PRINCIPAL WATERBODEES IMPAIRED BY TOXIC
POLLUTION IN SAN FRANCISCO BAY BASIN (REGION 2)
Waterbody
San Francisco Bay, Central
San Francisco Bay, Lower
San Francisco Bay, South
Suisun Bay
Tomales Bay
Calero Reservoir
Guadalupe Reservoir
Herman Lake
Alameda Creek
Alamitos Creek
Guadalupe River
Napa River
Petaluma River
Walker Creek
Suisun Marsh
Pollutants
Metals, selenium (1)
Metals
Metals, trace elements (1>
Metals, arsenic
Mercury
Mercury, arsenic, trace
elements
Nickel, trace elements
Mercury
Trace elements
Mercury, trace elements
Pesticides, other toxics
Metals
Metals
Mercury
Metals
303(d) Priority
1
1
1
n.a.
3
4
4
5
4
4
4
3
3
4
1
Area Affected
67,700 acres
79,900 acres
24,500 acres
25,000 acres
400 acres
350 acres
80 acres
1 10 acres
27 miles
14 miles
30 miles
55 miles
25 miles
25 miles
57,000 acres
Sources: 303(d) list; WQA Data Base
1 An aquatic life criterion 5 Mg/1 for selenium is already in place for the Bay-Delta.
As shown, several waterbodies are listed as being of highest priority to the state (a rank of
"1"). These include San Francisco Bay (Central, Lower, and South) and Suisun Marsh. All are
affected by metals contamination, and portions of San Francisco Bay are impaired by trace elements.
Other toxics-impaired waterbodies of medium priority include Tomales Bay, the Napa River, and
the Petaluma River.
A-14
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JUNE 1997
California's Bay Protection and Toxic Cleanup Program (BPTCP) provides yet another
indicator jof key waterbodies affected by toxic pollutants. The known toxic hot spots identified by
this effort include Suisun Bay proper as well as several wetlands and smaller bays (Peyton Slough,
Boynton Slough, Chadboume Slough, and Honker Bay); Miller Creek (feeding the Central Bay);
Castro Cove and Richmond Harbor (off of the Lower Bay); and Oakland Inner Harbor, Hunters
Point, Redwood Creek, Dumbarton Bridge, and the area south of Dumbarton Bridge (South Bay).
Region 2 also includes a number of other "potential" toxic hot spots identified by the monitoring
program.10
Natural Resources and Beneficial Uses Affected
The surface waters of the San Francisco Bay Basin support diverse wildlife resources as well
as a variety of beneficial human uses. Exhibit A-9 presents a summary of beneficial uses as reported
in the Basin Report for Region 2.
As shown in Exhibit A-9, the majority of the waterbodies impaired by toxics are either
freshwater habitat areas and/or wildlife areas. Many of the waters are also fish migration and
spawning areas. The region is home to a variety of wildlife species that are in decline or listed as
threatened or endangered. This is reflected in the beneficial use data as well as in other information
sources."
Increasing urbanization has limited natural habitat and is thought to threaten the wildlife of
the region. While it is difficult to gauge the specific influence that toxic surface water pollution has
had on the reduction in quantity and quality of wildlife habitat, it is clear that key species are
exposed to toxics. Exhibit A-10 shows typical concentrations of selected toxic pollutants in various
biota. As shown, toxic pollutants in several cases are present in biota tissue in concentrations
exceeding alert levels. Most significantly, a number of metals are present in shellfish in
concentrations that exceed general international guidelines on levels of concern (median
international standards or MIS). Likewise, copper, mercury, selenium, DDT, and PCBs have been
measured in fish at levels exceeding federal, state, and/or international standards. Elevated selenium
is also present in some waterfowl tissue samples. Finally, there are a number of potentially
problematic pollutants for which levels of concern have not been established.
|f Ba\ Protection and Toxic Cleanup Program, Staff Report; State Water Resources Control
Board, State of California, November, 1993, p. 109, Figure 7.
1' State of the Estuan: San Francisco Estuary Project, U.S. EPA and the Association of Bay
Area Governments. June, 1992, p. 85.
A-15
-------
JUNE 1997
Walerbody
San Francisco Ray.
Central
San Francisco Day.
Lower
San Francisco Bay.
South
Suisun Bay
Tomates Bay
Calero Reservoir
Guadalupe Reservoir
Herman Lake
Alameda Creek
Guadalupe River
Napa River
Petaluma River
Walker Creek
riMMt A-9
NATt RAI RFSOI Rf TS AND BENEFK IAI. USES
ASSfK IATED WITH KEY WATERBODIES
Beneficial Uses
Agriculture
X
X
Municipal
Supply
X
X
X
Grounriwafer
Recharge
X
X
X
Indnitrial
X
X
X
X
X
Navigation
X
X
X
X
X
X
Water
Contact
Recreation
X
•
X
X
X
X
X
X
X --
X
Non-
Contact
Water
Recreation
X
X
X
X
X
X
X
X
X
X
Commercial
Fishing
X
X
X
X
X
X
X
Freshwater
Habitat
X
X
X
X
X
X
X
X
Wildlife
Habitat
X
X
X
X
X
It
X
X
X
X
X
Sapports
Rare,
Endangered
Speciet
X
X
X
X
X
X
X
X
Marine
Habitat
X
X
Flih
Migration
x
X
X
X
X
X
X
X
X
Fbh
Spawning
X
X
X
X
X
X
X
X
X
Shellfish
H«rvc*tm|
x
X
X
X
X
Note Beneficial use data for Suisun Marsh and Alamtlos Creek are not available
Source Water Quality Control Plan, San Francisco Bay Satin Region 2, California Regional Water Quality Control Board, December, 1 986, Table II-
A-16
-------
Exhibit A-10 I!
< ONC F.NTRATIONS OF SELECTED POLLUTANTS IN BAY/DELTA ESTUARY BIOTA ' I
(ppm wet wf Ijhl) H
Pollutant
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tributylotin
Zinc
DDT and
metabolites
PCB
Mimrl
1.16-2 16
0.11 -4.91
0.014-2.114
0.314-4.395
0.03 - 74
0.01 -0.46
0.5 - 2.4
0.19-0.66
0.02 - 22.5
0.120-2.960
11.0-45.8
<.002-3.21
0.009 - 0.657
Clam
..
..
0.15-3.92
10- 100
•»•
-
—
0.3-1.30
0.14-28.57
-
-
-
—
FUh
013- 1.20
0.03 - 0.48
0.02-0.1
1.8 (striped bass)
1.3-30
0.02 - 0.2
0.13-0.94
0.8
0.28 - 22.0
0.13-0.94
--
16.0-43.0
"0.020-5.18
0.05 - 6.99
Bird
«• V
4.17
-
7.14- 13.86
64- 102
0.16-0.6
0.1
24-58
0.33 - 3.70
-
21.6
-
-
Seal
..
<.06 - .33
--
3.0 - 8.7
0.13-1.22
0.40 - 3.65
0.11-4.10
2.07 - 6.49
-
—
—
5-34
0.05 - 330
Concentrations II
Exceeding II
Alert Levels* H
Yes. Levels in some Bay shellfish exceed MIS. ||
Yes. Levels in some Bay shellfish exceed MIS. j]
Yes. Levels in some Bay shellfish exceed MIS.
Yes. Levels in some Bay shellfish exceed MIS. Levels 1]
in some Suisun Bay and Delta fish exceed MIS. ||
Yes. Levels in some Bay shellfish exceed MIS. ||
Yes. Levels in some Bay shellfish and Delta fish II
exceed MIS. II
No alert levels established for tissue. ||
II
Yes. Levels in some Bay shellfish exceed MIS. Levels
in some Bay fish exceed MARL. Levels in some Bay II
ducks exceed MARL. ||
No alert levels established for tissue. ||
No alert levels established for tissue. 11
II
No alert levels established for tissue. ||
Yes. Levels in some Delta fish exceed FDA action II
level.
Yes. Levels in some Bay and Delta fish exceed FDA f
action level. ||
Note: Concentrations are shown for wet weight; data originally given for dry weight have been converted by dividing by seven. For seals, trace element data represent
concentrations in dry whole blood; data for DDT and PCB represent concentrations in blood plasma lipids.
* The alert levels referred to in this table are the maximum tissue residue levels that are protective of human health. They include: 1) the median international standard
(MIS), which is a general guideline of what other nations consider to be elevated contaminant levels in fish and shellfish tissue; 2) the U.S. Food and Drug Administration
(FDA) action levels, which represent maximum allowable concentrations for some toxic substances in human foods; and 3) the State Department of Health Service's
maximum allowable residue levels (MARL), established to ensure that a consumer of specified fish or wildlife species does not exceed the permissible intake level for
particular contaminants.
-------
JUNE 1997
Apart from supporting wildlife, the 303(d) waterbodies identified above as being impaired
by toxics also support recreation and other human activities. Data in the Basin Report for Region
2 indicate that virtually all the waters support some form of recreation. The major segments of the
Bay system support both water contact recreation such as swimming and fishing as well as non-
contact recreation such as boating and hiking.
The waters of Region 2 also support human uses beyond recreational activity. The major
segments of the Bay are used for commercial fishing, shellfishing, and shipping, as well as for
industrial applications such as cooling. The two reservoirs affected by toxics are used for municipal
water supply, while Alameda Creek supplies irrigation water for agriculture.
Region 3: Central Coastal Region
Hydrologic Setting
Region 3, the Central Coastal Region, encompasses over 11,000 square miles, extending
nearly 300 miles along the coast and ranging 40 miles inland. Included in the area are prime
agricultural lands such as the Salinas, Santa Maria and Lompoc Valleys, areas of high rainfall like
the Santa Cruz mountains in the west, and arid areas like the Carizo Plain to the east.12 As shown
in Figure A-3, significant waterbodies in this region are the Nacimiento Reservoir, the Salinas River,
the Cuyama River, and the Santa Ynez River.
On balance, most of the Central Coast region is considered to be relatively arid. The
combination of low precipitation levels and a growing human population has led to the harnessing
of many nvers and streams as storage reservoirs for municipal and agricultural purposes. The
Nacimiento. San Antonio, and Huasana rivers have all been diverted or dammed to create the
Nacimiento, San Antonio, and Twitchell reservoirs, respectively. The divergence of major
waterways has led to reductions in aquatic habitats, ground water recharge, and other beneficial uses.
Demand for water is increasing and competition for waters of adequate quality is expected to become
more intense in the future.13
'• Hater Quality Control Plan. Central Coast Basin; California Regional Water Quality
Control Board, Central Coast Region, Region 3, November, 1989, pp. 12-13.,
Ibid.
A-18
-------
-• »••* ->!••., ,'';\.->,;:^*
CENTRAL COAST REGION(3)
LKC
USEPA *£f*m 9 OS
Scft- 27. I99<
10 20 30 MILES
0
h • -i ' i H '
0 10 20 30 KILOMETERS
SOURCES
SbtOK KF3 US?A 1992
nuce Ca*** Bond
303(d) M S-IM4
Hntakgic SdH»OK Calit
Sue WMB Raona* CottoJ Boo
-------
JUNE 1997
Degree and Sources of Toxics Impairment
The Central Coastal Region waterbodies are impaired by a limited set of toxic pollutants
from a variety of sources, dominated by pesticide and trace element contaminants from agricultural
runoff. Analysis of the WQA database yields the following information:
• As summarized in Exhibit A-11, toxics impair a large area of most waterbody
types, including 11,685 acres of lakes and reservoirs (47 percent of assessed),
1,747 acres of estuaries (36 percent of assessed), and 585 acres of wetlands
(20 percent of assessed). However, the WQA database identifies only 233
river miles (7 percent of assessed) and 366 acres of bays (10 percent of
assessed) as impaired by toxics.
Exhibit A-ll
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREA
REGIONS: CENTRAL COASTAL REGION
Toxics-Impaired
Total Assesicd
Share
Bays
(•cm)
366
3.570
ID:**!
Estuaries
(acres)
1.747
4.823
36.22%
Lakes & Reservoirs
(acres)
11,685
24,868
46.99%
Rivers & Streams
(miles)
233
3,272
7.12%
Saline Lakes
(acres)
0
3,334
0.00%
Wetlands
(acres)
585
2,936
19.93%
Source: EPA aniKtit of WQA database.
As shown in Exhibit A-12, agriculture is a primary source of toxic pollution
and is associated with 100 percent of impaired wetland area, 58 percent of
impaired estuary area, 33 percent of impaired river miles, and 11 percent of
impaired bay area. Other significant sources of toxic pollutants are mining
and unspecified nonpoint sources.
Key Waierbodtr* Affected
•
BascJ on California's 1994 303(d) report, a number of the waterbodies affected by toxics in
Region 3 arr of upiificant priority.14 Eighteen waterbodies in Region 3 appear on the priority list,
14 of which arc aflccted by toxics Exhibit A-l 3 presents the pollutant types, 303(d) report ranking,
and area of impairment for those 14 waterbodies. Included are the entire areas of the Nacimiento
14 California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May 1994.
A-20
-------
JUNE 1997
Exhibit A-12
MAJOR SOURCES OF TOXIC POLLUTANTS
REGION 3: CENTRAL COASTAL REGION
Agriculture
Hydro./Habitat
Modification
ndustrial
Land Development
.and Disposal
Mining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Jrban Runoff
Bays
(acres)
40
0
0
0
0
74
0
326
0
0
0
Share of
Total
Toxics-
Impaired
Area
11%
0%
0%
0%
0%
20%
0%
89%
0%
0%
0%
Estuaries
(acres)
1,005
0
200
430
300
0
0
1,247
0
705
705
Share of
Total
Toxics-
Impaired
Area
58%
0%
11%
25%
17%
0%
0%
71%
0%
40%
40%
Lakes &
Reservoirs
(acres)
0
0
0
0
0
5,960
0
11,095
0
0
0
Share of
Total
Toxics-
Impaired
Area
0%
0%
0%
0%
0%
51%
0%
95%
0%
0%
0%
Rivers
&
Streams
(miles)
76
20
9
20
0
69
20
93
0
0
19
Share of
Total
Toxics-
Impaired
Area
• 33%
9%
4%
9%
0%
30%
9%
40%
0%
0%
8%
Saline
Lakes
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total
Toxics-
Impaired
Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wetlands
(acres)
585
0
0
100
0
0
0
335
0
235
335
Share of
Total
Toxics-
Impairet
Area
100%
0%
0%
17%
0%
0%
0%
57%
0%
40%
57%
Source: U.S. EPA analysis of WQA database.
A-21
-------
JUNE 1997
Reservoir, Elkhom Slough, and Watsonville Slough, as well as large segments of the Goleta Slough
and Salinas River. Pesticides are the most common cause of impairment of the waters listed, with
metals, trace elements, and priority organics also identified as problem pollutants.
As Exhibit A-13 indicates, none of the Region 3 waterbodies listed have been designated as
among the state's highest priorities (a rank of "1"), but the entire area of Elkhom Slough and
segments of Morro Bay and Carpinteria Marsh are contained in the second tier. Other toxics-
impaired waterbodies of medium priority include the San Lorenzo River, Nacimiento Reservoir,
Goleta Slough, and the Salinas River.
The pollutant types impairing priority waterbodies, and their respective sources, vary. The
Nacimiento Reservoir is contaminated entirely by mercury associated with past and present mining
activities. The Salinas River suffers from a variety of pesticides from agricultural sources. The
Elkhom Slough receives pesticides, herbicides, and metal pollutants from agricultural and other
nonpoint sources, and the Goleta Slough receives toxic metals and priority organics from urban and
industrial runoff.
Other information sources reveal that the number of toxics-unpaired waterbodies in the
Central Coastal Region are not limited to those on the 303(d) list. California's Bay Protection and
Toxic Cleanup Program (BPTCP) provides an additional indicator for key coastal waterbodies
affected by toxic pollutants. BPTCP lists areas of significant toxicity, high levels of
bioaccumulation, and impairment of ecologic beneficial uses as toxic "hot spots". While there are
no known toxic hot spots identified in Region 3, many "potential" toxic hot spots (areas exhibiting
elevated toxic concentrations in water or sediment) are listed. All the enclosed bays and estuaries
on the 303(d) list, except Carpinteria Marsh, were sited as potential toxic hot spots. Also listed are
Santa Cruz Harbor, Harkins Slough, Pajaro River Estuary, Old Salinas River Estuary, Salinas
Reclamation Canal, Carmel Bay, San Luis Obispo Creek, San Luis Harbor, and Santa Barbara
Harbor.15
Additional information on toxic pollution in Region 3 is available from a workshop
conducted in early 1994 under the Water Quality Protection Program (WQPP) for Monterey Bay
National Marine Sanctuary which compiled a list of high priority waterbodies in the sanctuary and
its watersheds that are affected by toxic pollutants. The WQPP provides a regional perspective on
key waterbodies and generally concurs with lists compiled at a statewide level. High priority
waterbodies include many on the 303(d) list, but also include the Pajaro River, Alisal Canal, and
Carmel River.16
15 Bay Protection and Toxic Cleanup Program, Staff Report; State Water Resources Control
Board, State of California, November, 1993, p. 109, Figure 7.
16 Comparison of the California Water Quality Assessment and the January 1994 Workshop
Results; Monterey Bay National Marine Sanctuary Water Quality Protection Program, April, 1995,
p. 7, Table 4.
A-22
-------
JUNE 1997
Exhibit A-13
PRINCIPAL WATERBODEES IMPAIRED BY TOXIC
POLLUTION IN CENTRAL COASTAL REGION (REGION 3)
Waterbody
Monterey Harbor
Mono Bay
Moss Landing Harbor
Carpinteria Marsh
Elkhorn Slough
Goleta Slough/ Estuary
Watsonville Slough
Nacimiento Reservoir
Salinas River
San Lorenzo River
Espinosa Slough
Moro Cojo Slough
Salinas River Refuge
Lagoon (South)
Tembladero Slough
Pollutants
General Toxics
Mercury, other toxics
Pesticides, Herbicides
Priority Organics
DDT
Metals, Priority Organics
Pesticides, Herbicides,
Trace Elements
Mercury, other Metals
Pesticides
Trace Elements
Pesticides, Priority
Organics
Pesticides, Trace Elements
Pesticides
Pesticides
303(d)
Priority
4
2
4
2
2
3
4
3
3
3
4
5
4
3
Area
Affected
74 acres
100 acres
40 acres
80 acres
1,000 acres
200 acres
300 acres
5,370 acres
50 miles
20 miles
160 acres
145 acres
50 acres
75 acres
Sources: 303(d) list;WQA Data Base
Natural Resources and Beneficial Uses Affected
The surface waters of the Central Coastal Region support diverse wildlife resources as well
as a variety of beneficial human uses. Exhibit A-l 4 presents a summary of beneficial uses in waters
impaired by toxic pollutants, as contained in the Region 3 Basin Report. As shown in the exhibit,
all of the Region 3 waterbodies listed on the 303(d) priorities list support both contact and non-
contact water recreation. All support habitats for wildlife and most aid in the survival and
maintenance of rare, threatened, or endangered plant or animal species. In addition, many of the
waterways support fish spawning and migration, as well as shellfish harvesting.
A-23
-------
JUNE 1997
The impact of toxic pollution on the beneficial uses listed in Exhibit A-14 is not always clear.
In at least one case, however, the Nacimiento Reservoir, elevated levels of mercury in large-mouth
bass have led the State of California to issue a fish consumption advisory.
Regiop 4: Los Angeles Basin
Hydrologic Setting
Region 4 encompasses nearly 4,000 miles of southwest California, extending from Rincon
Point in westernmost Ventura County to the eastern tip of Los Angeles County. The region is
extremely mountainous, and is interlaced with a complex network of rivers and streams that transport
surface runoff from the mountains to the Pacific Ocean. Geographically, the region is bordered by
the Santa Ynez mountains to the north, the Liebre-Sawmill mountains to the west, and the San
Gabriel mountains to the south.
Large river systems comprise the majority of inland surface waters in the region. In the
north, the Ventura River channels runoff from the Santa Ynez mountains. In the middle portion of
the region, the Santa Clara River drains the San Gabriel, Santa Susana, and Liebre-Sawmill
mountains. In the south, the Los Angeles and San Gabriel Rivers, as well as Ballona Creek, drain
the Transverse Ranges. Figure A-4 shows the major rivers, lakes, and reservoirs of the region.17
The Pacific Ocean forms the western border of the region. Important features of the coastline
include Santa Monica Bay in the north and Los Angeles and Long Beach Harbors in the south. The
coast is also punctuated with smaller harbors, inlets, and beaches.
The region's waterbodies, particularly the bays and estuaries, provide habitat for a wide
variety of wildlife and plant life. Several of the region's waters have been recognized as significant
ecological areas (SEAs) that provide habitat for endangered species and unique recreational
opportunities. These natural resources and the variety of beneficial uses they support are described
more fully below.
Degree and Sources of Toxics Impairment
Of the Region 4 waterbodies assessed, bays and estuaries suffer disproportionately from
toxics pollution. Over 90 percent of the assessed bays and estuaries in the Region are impaired by
toxics. Conversely, the region's rivers, lakes, and reservoirs appear to be relatively free from
impairment by toxics pollution. Exhibit A-15, derived from the WQA database, illustrates the
percentage of waterbodies surveyed in each group that were found to be impaired by toxics.
17 Los Angeles Region Water Quality Control Plan (Basin Plan), California Water Quality
Control Board, June 1994.
A-24
-------
V' _; t-s*/i».'?*i;'e;w
LOS ANGELES REGION(4)
SOURCES
KF3 USPA 1992
V
WnerHmioe CoMni Bond
303(«I) b
use
USEPA Itogiai « CB
27. I99S
0 5 10 15 KILOMETERS
-------
JUNE 1997
»MIT*«*
MiwMflf y MJFTW
Morro Bay
MofS Landing Harnaf
Cvpintma Manh
FJIthom Slough
Goteta Stough/ Estuary
Walsonville Slough
Nacimiento Reservoir
Salinas River
San Lorenzo River
Espinosa Slough
More Cojo Slough
Salinas River Refuge
Lagoon (South)
Tembladcro Slough
Ethlbll A-14
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY VYATERBODIES
M.ittjal
*•**•>
X
X
X
•nwAcMUatt
A^M^K^^B^BAA
^i^pW^iilt^ar^
X
X
X
t
K
X
X
X
•••••••f
»
*
X
X
X
fim*
• «a— «
1
X
• x
X
•
1
X
X
X
X
X
X
X
X
X
X
X
X
X
*Mf«Mf<
«w>
la.ni.iti.
«
X
X
X
X
X
X
X
X
X
X
X
X
X
Cm.f mi
*****
X
X
X
X
wmnif.
H.MM
X
X
X
X
X
X
X
X
X
X
X
X
X
Freshwater
HabHal
X
X
X
X
X
X
X
X
X
X
Fish
Mlgratln
X
X
X
X
X
Fish
Spiw.hl|
X
X
X
X
X
X
X
X
Pmerralloi »'
BMogleal Iliblliti
of Special
Slgninca.ce
X
X
X
X
X
X
S.pporH
Ran er
Ciidanfcncl
Specie*
X
X
X
X
X
X
X
X
X
X
X
X
X
Source Water Quality Control Plan, Central Coastal Basin. Region 3. California Regional Water Quality Control Board, November, 1989, Table 2-2, Attachment E.
A-26
-------
JUNE 1997
Exhibit A-15
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREA
REGION 4: LOS ANGELES REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
14,070
14,293
98.44%
Estuaries
(acres)
1,678
1,816
92.40%
Lakes & Reservoirs
(acres)
461
13,897
3.32%
Rivers & Streams
(miles)
115
874
13.16%
Saline Lakes
(acres)
0
0
NA
Wetlands
(acres)
0
0
NA
Source: U.S. EPA analysis of WQA database.
The major sources of toxics pollution in the region include agricultural activities,
hydro/habitat modification, municipal wastewater discharges, urban runoff, and other nonpoint
discharges. Nonpoint source pollution has a wide-reaching impact, contributing to the impairment
of a large share of affected waterbodies. In particular, estuaries and rivers are significantly affected
by nonpoint discharges stemming from agricultural activities. Municipal point sources contribute
significantly to toxic pollution of bays, while unspecified point sources are associated with pollution
of both bays and estuaries. Industrial point sources affect a significant share of river miles, but are
otherwise a minor contributor. Exhibit A-16 shows the impacts of different pollution sources on the
waterbodies in the region.
Key Waterbodies Affected
Exhibit A-17 presents data on the significant waterbodies in Region 4 that are impaired by
toxics, as identified in California's 1994 303(d) report. Most of the waters on the list are ranked as
medium to low priority; only Mugu Lagoon achieved a rank of relatively high priority.
With respect to the areal extent of toxics contamination, Los Angeles Harbor and Mugu
Lagoon are the largest waterbodies affected by toxics. The WQA database shows that both
waterbodies are contaminated with pesticides and trace elements. Los Angeles Harbor is
contaminated by PCBs, priority organics, and metals.
In addition, California's Bay Protection and Toxic Cleanup Program (BTPCT) provides
another source of information on waterbodies affected by toxic pollution. The State's assessment
of known and potential hot spots in Region 4 corresponds with the 303(d) list. Known hot spots
include Mugu Lagoon, Santa Monica Bay, portions of Inner Los Angeles and Inner Long Beach
Harbors, and San Pedro Bay. The State has also identified Port Hueneme Harbor, Marina Del Rey
A-27
-------
JUNE 1997
Harbor, and portions of Inner Los Angeles and Long Beach Harbors as potential hot spots.18
Additional waterbodies added to the 1996 303(d) list include the San Gabriel River (lower) and the
Los Angeles River (upper).
Natural Resources and Beneficial Uses Affected
Toxics-impaired waters in Region 4 support a wide range of ecological and recreational uses.
Exhibit A-18 summarizes beneficial use information from the Basin Report for Region 4.
As Exhibit A-18 shows, all of the impaired waterbodies provide opportunities for both
contact recreational activities, including swimming and fishing, and non-contact activities such as
boating and hiking. In addition, the affected waterbodies provide a source for industrial and
agricultural water intake, support commercial shellfishing, and serve as navigation channels. Certain
of these waters also contribute to groundwater recharge and freshwater replenishment.
Additionally, nearly all of the waterbodies provide wildlife habitat for fish, waterfowl, and
other aquatic animals. In particular, several of the lagoons, estuaries, and woodlands provide refuge
for rare and endangered species. Harbor Park Lake, one of the areas included on the 303(d) list, has
been designated as a significant ecological area (SEA) by Los Angeles County. Waterbodies
designated as SEAs contain unique habitats that support threatened or endangered species.
18 Bay Protection and Toxic Cleanup Program, Staff Report; State Water Resources Control
Board, State of California, November 1993, p. 111, Figure 9
A-28
-------
JUNE 1997
Exhibit A-16
MAJOR SOI RO S OF TOXIC POLLUTANTS
RH;io>4: i.osANr.F.i.ES REGION
Agriculture
llyilro /Habitat Modification
Industrial
Land Development
Land Disposal
Mining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Urban Runoff
HIM
(•creM
220
2.100
0
0
0
0
10.700
13.785
12.890
0
2.739
shitr •(
l»iil f«»lc«
Impaired
Am
2",,
IS'.,
0",,
o-:,
O'/,:
0%
76%
98%
92%
0%
19%
Fttvarlrt
-------
JUNE 1997
Exhibit A-17
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN LOS ANGELES BASIN (REGION 4)
Waterbody
Mugu Lagoon
Ballona Wetlands
Colorado Lagoon
Long Beach Harbor (Inner)
Los Angeles Harbor (Inner)
Ventura River (Lower)
Calleguas Creek
Harbor Lake
Los Anpeles River (Upper)
Manna Del Rev Harbor
Revolon Slough
San Gabnel River (Lower)
San Gabnel River Tidal Basin
Ron Humane (Harbor)
Beardsle% Wash
Dominpuc? Channel Tidal Basin
Pollutants
Pesticides, trace elements
Metals
Pesticides, trace elements, lead
PCBs, PCP, pesticides, metals, priority organics
PCBs, pesticides, metals, trace elements, priority
organics
Metals, priority and nonpriority organics
Pesticides
PCBs, pesticides
Trace elements, priority and nonpriority organics
Pesticides, metals
Pesticides
Metals, priority and nonpriority organics,
unspecified toxics
Metals
PCBs, metals, priority organics
Pesticides
PCBs, pesticides, metals, priority organics
303(d)
Priority
2
3
3
3
3
3
4
4
4
4
4
4
4
5
unknown
unknown
Area
Affected
1500 acres
ISO acres
13 acres
840 acres
1260 acres
6 miles
11 miles
50 acres
25 miles
354 acres
9 miles
18 miles
3 miles
121 acres
5 miles
8 miles
Sources 1994 303(d) list; WQA Database
A-30
-------
JU1SE 1997
Eshtblt A-18
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY WATERBODIES
WiKMktd
Ballona
Wetlands
Bcardslcy
Wish
Calleguas
Cteek
Colorado
Ligoon
Dominguer
Channel
Tidal Bisin
Harbor
Lake
Long Bcacti
Harbor
(Inner)
Loi Angeles
Harbor
( loner 1
Lof Angeles
Rjver
(Upperl
Marina Del
Rry Harbor
Mug»
Ligoon
ran
Humane
IHarbor)
Revolon
Slough
Sin Gabriel
Rim
(Lower)
Sin Glbriel
River Tidal
Basin
Ventura
River
(tower)
MUN
X
X
X
X
X
X
X
IND
X
X
X
X
X
X
PROC
X
AGR
X
X
X
GWR
X
X
X
X
FRSH
X
X
*
X
NAV
X
X
X
X
X
X
X
MCI
X
X
X
X
X
X
X
X
X
X
X
X
X
X
RIC1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
COMM
X
X
X
X
X
X
X
X
X
WARM
X
X
X
X
X
X
X
X
COLO
X
X
BT
X
X
X
X
MAD
X
X
X
X
X
X
WILD
X
X
X
X
X
X
X
X
X
X
X
X
X
•IOL
X
X
X
RARI
X
X
X
X
X
X
X
X
X
MICK
X
X
X
X
srwN
X
X
X
X
X
SHILL
X
X
X
X
X
X
X
WET
X
X
X
X
.
X
X
X
X
Source: Wwtr pyalio Conlrol HOT. Lot Angtlti latin frpoa 4. California Water 0»llily Control Board, June. l»4 Table 1-1
Key MUN - Municipal and Domenii Supply
IND * Industrial Service Supply
PROC - Indnlriil Process Supply
AGR =• Agricultural Supply
GWR - Ground Wun Recharge
FRSH Freshwater Replenishment
NAV Navigation
RECI: Water Contact Recreation
RfC! Non-Contact Recreation
COMM Commercial and Spon Fishing
WARM Warm Freshwater Habitat
COLD Cold Freshwater Habitat
EST Ciuarine Habitat
MAX Marine Habitat
WILD Wildlife HaM*
BIOL rVeservMiori or Biological Habiui
RARE Rare. Threatened, or Endangered Specie.
M1GR- Mipitjonof Aquatx Organicmf
SPWN- Spawning or Reproduction
SHELL Shellfish Harvesting
WET Wetland Habiiai
-------
JUNE 1997
Region 5; Central Valley Region
Hydrologic Setting
The Central Valley Region extends approximately 400 miles from the California - Oregon
border southward to the headwaters of the San Joaquin River.18 It is bound by the Sierra Nevada
Mountains on the east and the Coast Range and Klamath Mountains on the west. The Region
encompasses over 50,000 square miles of land, about 40 percent of the total area of the State,
including four major drainage basins. The southernmost basin is arid and contains little surface
water. The other three basins — the Sacramento River Basin, the Sacramento-San Joaquin Delta
Basin, and the San Joaquin River Basin — contain some of the most heavily utilized waterbodies in
the State. Figure A-5 presents a map of the Central Valley Region.
The Sacramento River Basin is the northernmost section of Region 5. It covers nearly 26,500
square miles of land, varying in topography from valleys in the center of the basin to mountains on
both the eastern and western sides. Precipitation falls mainly in the mountains, either as rain or
snow. The basin encompasses the Sacramento River upstream of the City of Sacramento and the
river's tributaries, including the Pit, Feather, and American Rivers.
The Sacramento-San Joaquin Delta Basin extends from the source of the Mokelumne River
in the Sierra-Nevada mountains westward to the confluence of the Sacramento and San Joaquin
rivers. The basin experiences hot dry summers and cool wet winters, with precipitation levels
increasing to the east. The major waterbodies in the basin are the lower reaches of the Sacramento
and San Joaquin Rivers and the many interconnected channels in the Delta.
The San Joaquin River Basin lies directly below the Delta Basin, extending from the Sierra
Nevada mountains to the Coast range. Precipitation in the basin increases with elevation and is
greater in the northern sections. The principal rivers are the San Joaquin and its major tributaries,
including the Stanislaus, Tuolumne, and Merced.
Degree and Sources of Toxics Impairment
Agricultural activity, urbanization, and other factors have contributed to the impairment of
Region 5's surface waters. Examination of the WQA database reveals the following information:
18 Most of the discussion of the hydrologic setting of Region 5 is taken from two documents:
Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River
Basins, California Regional Water Quality Control Board, December, 1994; and Draft California
305(b) Report on Water Quality, State Water Resources Control Board, October 1994.
A-32
-------
LKC
USPA Rcpo* « CHS
Sept. 27. 1995
CENTRAL VALLEY RECKONER)
0 10 20 30 MILES
0 1O20 3O KILOMETERS
SOURCES
Sbcnic REJ USEPA 1992
W«
303
-------
use
USPA Figira 9 CBS
S^X. Z7. 1995
CENTRAL VALLEY REGION(5S)
0 10 20 30 MILES
I • 'i ' i H '
0 1020 30 KILOMETERS
SOURCES
Stem RF3 USPA 1992
Co*nl Bood
303(
-------
CENTRAL VALLEY REGION(5F)
Fnduad fcy
UKC
USEPA Rcgn 9 OB
Sept 27, 1995
0
h
10 20
30 MILES
0 10 20 30 KILOMETERS
SOURCES
SbenK RF3 USPA 1992
Wrtcr Rwucc CaMDl Baad
303(d)to S-1844
CoMinl Banl
-------
JUNE 1997
As summarized in Exhibit A-19, toxics impair a significant area of Region
5 waterbodies, including 48,000 acres of estuaries (100 percent of assessed),
120,156 acres of lakes and reservoirs (23 percent of assessed), 1,217 miles
of rivers (21 percent of assessed), and 8,227 acres of wetlands (16 percent of
assessed).19
Exhibit A-20 shows that agriculture and mining are the most significant
sources of toxic pollutants. Agriculture affects large portions of estuaries,
rivers, and wetlands, while mining discharges affect estuaries, lakes, and
rivers. Unspecified nonpoint sources, hydrologic modification,
municipalities, storm sewers, and urban runoff also add to toxic impairment.
Exhibit A-19
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREAS
REGION 5: CENTRAL VALLEY REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
0
0
NA
Estuaries
(acres)
48,000
48,000
100.00%
Lakes & Reservoirs
(acres)
120,156
514,074
23.37%
Rivers & Streams
(miles)
1,217
5,770
21.09%
Saline Lakes
(acres)
0
0
NA
Wetlands
(acres)
8,227
51^42
16.06%
Source. EPA analysis of WQA database
Key Waterbodies Affected
Based on California's 303(d) report, many of the waterbodies impaired by toxics in Region
5 are of significant priority. Twenty-eight waterbodies in Region 5 appear on the 303(d) priorities
list, 26 of which are impaired by toxics. Exhibit A-23 presents the pollutant types, 303(d) report
ranking, and area of impairment for the 26 toxics-impaired waterbodies.20
As shown in Exhibit A-21, the Delta Waterways, Clear Lake, the lower sections of the
American and Feather Rivers, and sections of the Sacramento River are all listed as highest priority
to the State. Metals, pesticides, and unspecified toxics combine to impair these waters. Shasta Lake
and the Grasslands Marshes lie in the second tier of state priorities, while Berryessa Lake,
Whiskeytown Reservoir and the lower section of the Stanislaus River fall into the third highest
category. Fifteen other waterbodies were ranked as lower priority.
19 The Delta Waterways account for the entire area of assessed estuaries.
20 California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May
1994.
A-36
-------
JUNE 1997
Exhibit A-20
MAJOR SOURCES OF TOXIC POLLUTANTS
REGION 5: CENTRAL VALLEY REGION
Agriculture
Hydro./Habitat Modification
Industrial
Land Development
Land Disposal
Mining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Urban Runoff
Bays
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Estuaries
(acres)
48,000
48,000
0
0
0
48,000
48,000
48,000
0
0
* 48,000
Share of
Total Toxics-
Impaired Area
100%
100%
0%
0%
0%
100%
100%
100%
0%
0%
100%
Lakes &
Reservoirs
(acres)
0
0
295
0
0
97,386
0
10,576
0
0
295
Share of
Total Toxics-
Impaired Area
0%
0%
0%
0%
0%
81%
0%
9%
0%
0%
0%
Rivers &
Streams
(miles)
533
0
186
19
0
690
185
514
0
185
178
Share of
Total Toxics-
Impaired Area
44%
0%
15%
2%
0%
57%
15%
42%
0%
15%
15%
Saline
Lakes
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wetland
s (acres)
8,226
0
0
0
0
2
0
1
0
0
0
I
Share of
Total Toxics-
Impaired Area
100%
0°/,
0%
0%
0%
oy,
0%
0%
0%
0%
0%
Source: U.S. EPA analysis of WQA database.
A-37
-------
JUNE 1997
Exhibit A-21
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN THE CENTRAL VALLEY REGION (REGION 5)
Waterbodv
Delta Waterways
Beach Lake
Berryessa Lake
Clear Lake
Davis Creek Res.
Keswick Res.
Marsh Creek Res.
Shasta Lake
Whiskeytown Res.
American River, Lower
Feather River, Lower
Kings River, Lower
Little Backbone Creek
Little Grizzly Creek
Merced River, Lower
Mokelumne River, Lower
Mud Slough
Sacramento River, Shasta Dam to Red
Bluff
Sacramento River, Red Bluff to Delta
Sacramento Slough
Salt Slough
Stanislaus River, Lower
Tuolumne River, Lower
Grasslands Marshes
Mormon Channel
Mormon Slough
Pollutants'
Pesticides, Metals, Unspec. Toxics
Pesticides, Metals
Metals
Metals
Metals
Metals
Metals
Metals
Unspec. Toxics
Pesticides, Metals, Unspec. Toxics
Pesticides, Metals, Unspec. Toxics
Pesticides, Metals, Trace Elements
Metals
Metals '
Pesticides, Unspec. Toxics
Metals
Pesticides, Trace Elements, Unspec. Toxics
Metals, Unspec. Toxics
Pesticides, Metals, Unspec. Toxics
Metals, Unspec. Toxics
Pesticides, Trace Elements, Unspec. Toxics
Pesticides, Unspec. Toxics
Pesticides, Unspec. Toxics
Trace Elements
Pesticides, Metals
Pesticides, Metals
303(d)
Priority
1
5
3
1
5
4
5
2
3
1
1
4
5
5
4
4
4
1
1
5
4
3
4
2
5
5
Area Affected
48,000 acres
295 acres
20,700 acres
43,000 acres
290 acres
450 acres
375 acres
20 acres
3,251 acres
23 miles
60 miles
30 miles
1 mile
10 miles
60 miles
28 miles
16 miles
50 miles
1 85 miles
1 mile
1 5 miles
48 miles
32 miles
8,224 acres
1 acre
1 acre
Sources: 1 994 303(d) list; WQA Database
1 An aquatic life criterion of 5 ng/\ for selenium is already in effect in portions of Region 5.
A-38
-------
JUNE 1997
Natural Resources and Beneficial Uses Affected
The surface waters of the Central Valley Region are essential to the diverse human activities
and wildlife resources in the Region. The Sacramento and San Joaquin Rivers alone furnish over
50 percent of the State's water supply. Together, the Region's waters support one of the most
productive agricultural centers, a growing population, and many wild and scenic areas. Exhibit A-22
presents a summary of the beneficial uses associated with the toxics-impaired waterbodies listed in
the 303(d) report.21
As shown in Exhibit A-22, all of the waterbodies listed in the 303(d) report for which
beneficial use information exists support both contact and non-contact water recreation, including
swimming, boating, hiking, and nature-watching. The American and Kings River are noted as
popular recreational areas, and the upper reaches of the Kings River are classified as Wild and
Scenic, protecting these reaches from the construction of dams and other water diversion devices.22
All but the Kings River supply water to municipalities, and most are used for agricultural purposes.
Many of the waterbodies supply industry, while a few serve as navigational channels.
All of the waterbodies listed in the 303(d) report also support wildlife habitats. Most are also
areas of fish spawning, while many serve as paths for fish migration. In particular, the Sacramento
River is home to rare and endangered species of salmon.
Region 6: Lahontan Region
(I \drologic Setting
Region 6, the Lahontan Basin, runs nearly 570 miles along California's eastern boundary and
encompasses over 33,000 square miles' of area. Its topography is diverse and includes the highest
(Mount Whitney) and the lowest (Death Valley) points in the contiguous United States. Also
included are the eastern slopes of the Warner, Sierra Nevada, San Bernardino, Tehachapi, and San
Gabnel mountains, as well as topographic depressions such as the Madeline Plains and the
Bridgeport, Owens, and Victor Valleys. The Region lies generally in a rain shadow, but
mountainous areas receive high levels of precipitation (up to 70 inches per year), mostly as snow.
Runoff from the mountains, generally from intermittent streams formed by melting snow, carries
significant amounts of toxic metals to the larger waterbodies of the Region. The high natural
concentration of toxics exacerbates the effects of toxic pollutants from human activity.23
:' The Region 5 Basin Report provided most of the beneficial use information but lacked
individual listings for many of the water bodies contained on the 303(d) report. The WQA
SITEDATA file was employed to augment the Basin Report.
- Draft California 305(b) Report on Water Quality; State Water Resources Control Board,
October 1994, pp. 12-13.
2) Water Quality Control Plan, Central Coast Basin; California Regional Water Quality
Control Board, Lahontan Region, Region 6, October, 1994, pp. 13-15.
A-39
-------
JUNE 1997
fiMMt A-»
wAti n o nr MM m r< AM> ursrru ui. I'SES
ASMX lAirnwtiHKry HATFRBODIES
Waltrbody
Delta Waterways
Beach Lake*
Berryessa Lake
Clear Lake
Davis Creek Res.
Keswick Res '
Marsh Creek Res *
Shasta Lake
Whiskeytown Res.
American River, Lower
Feather River, Lower
Kings River, Lower*
Little Backbone Creek*
Little Grizzly Creek*
Merced River, Lower
Mokelumne River, Lower
Mud Slough*
Sacramento River, Shasta Dam to Red
Bluff
Sacramento River, Red Bluff to Delta
Gaframf»ntn *51niloh**
Beneficial Vtn
Municipal
Supply
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Agriculture
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Industrial
X
X
X
X
X
X
X
X
X
X
X
NA
Wttrr
Contact
Recreation
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Non-Contact
Water
Recreation
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Freshwater
Habitat
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Fish
Migration
X
X
X
X
X
X
X
X
X
X
NA
Fish
Spawning
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Wildlife
Habitat
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
Navigation
X
X
X
X
MA
A-40
-------
Exhibit A-22 '
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY WATERBODIES
(continued)
^***^*^l^*^^^^***llll*^—^^***lmmmmm*^^mmmm^^^^^^^^^^^^^^^^^^^^
Waterbody
Salt Slough*
Stanislaus River, Lower
Tuolumne River, Lower
Grasslands Marshes*
Mormon Channel**
Mormon Slough**
••••••••av^v^^HmMH^H^^HM^
Municipal
Supply
X
X
X
X
NA
NA
M»*--«^^^^^^MIMMBMIII*^H^^H^M
Agriculture
X
X
X
X
NA
NA
Industrial
X
NA
NA
mmiiiiii*imimiiiiiim*mm******iiim*miiiim
Water
Contact
Recreation
X
X
X
X
NA
NA
Beneficial Uses
••••••^^^••••••••••••••••••••••••••••••i
Non-Contact
Water
Recreation
X
X
X
X
NA
NA
•••••••••••••^•^^^^^^^^^M
Freshwater
Habitat
X
X
X
X
NA
NA
••^^••••••••••^•^•^•B
Fish
Migration
X
X
X
X
NA
NA
••••••••••••••••••^•••^^•^H
Fish
Spawning
X
X
X
X
NA
NA
^^BBHHHHHHHHMHBBqaBBBaH,^HBHfl
Wildlife
Habitat
X
X
X
X
NA
NA
^^^^^^^•^•^^^^^^^^•M
Navigation
NA
NA
* The Region 5 Basin Report did not contain individual listings for these waterbodies. The beneficial uses were taken from the WQA database, SITEDATA.
** Neither the Region 5 Basin report nor the WQA contained beneficial use listings for these waterbodies.
Sources: Water Quality Control Plan. Central Valley Region. Sacramento River and San Joaquin River Basins, California Regional Water Quality Control Board, December, 1 994, Table II-l .
Water Quality Assessment Catalog, State Water Quality Control Board, December, 1994.
A-41
-------
JUNE 1997
The waterbodies in the Lahontan Region have proven essential to urban development in the
area; a number of the Region's waterbodies are diverted to supply energy and drinking water for the
cities of Los Angeles and Reno, Nevada. The Region's 700 lakes are utilized for many human
beneficial uses and include a number of saline lakes, such as Alkali Lake and Honey Lake. In
addition, Lahontan Region waterbodies attract millions of visitors for recreation each year. Much
of the Region is in public ownership, with land use controlled by the Los Angeles Department of
Water and Power, the National Park Service, Bureau of Land Management, and other Federal and
State agencies.24 Figure A-6 shows the location of major waterbodies in Region 6.
Degree and Sources of Toxics Impairment
Much of the toxic pollution found in Region 6 waterbodies originates in the many mountain
streams that serve as tributaries to the Region's major rivers and lakes. Many desert waters also have
naturally high concentrations of toxic metals, including selenium. Additional toxics, including
metals, pesticides, priority organics, and trace elements, result from human activities, particularly
land development, agriculture, and urban development. The high natural baseline, combined with
human contributions, leads to a large areal extent of toxic impairment. Examination of the WQA
database reveals the following information:
• As summarized in Exhibit A-23, toxics impair a significant portion of most
of the waterbody types assessed, including 35,878 acres of lakes and
reservoirs (19 percent of assessed), 66,182 acres of saline lakes (34 percent
of assessed), and 372 miles of rivers and streams (13 percent of assessed).
However, only 468 acres of wetlands (1 percent of assessed) are considered
to be impaired by toxics.
• Exhibit A-24 demonstrates that natural sources are among the primary
contributors to toxic pollution in Region 6, particularly for rivers, lakes, and
reservoirs. In addition, agricultural activities are associated with the
impairment of 34 percent of affected rivers and streams and 100 percent of
affected saline lakes, while land development is connected with the
impairment of 70 percent of affected lakes and reservoirs area and 16 percent
of affected saline lakes. Mining contributes significantly to river
contamination. The relatively small area of wetlands that is impaired by
toxics is affected by urban runoff and miscellaneous nonpoint sources.
24 Ibid.
A-42
-------
LAHONTAN REGION(6SLT-A)
LKC
USPA Hip«B 9 OB
Stpt 27. 199$
10
20
30 MILES
0 10 20 30 KILOMETERS
SOURCES
Steam RF3 USEPA 1992
WrterRnouoe Co*»J Bond
303(
-------
LAHONTAN REGION(6SLT-B)
LKC
USEPA Rcgn 9 CBS CC*B
SffL 27. 1995
10 15 MILES
0 !
I • •! ' i H '
0 5 10 15 KILOMETERS
SOURCES
SteOK RF3 UffiPA 1992
Watr Reran Co*ml Bo«i
303(
-------
/
IXC
UffiPA R<«n 9 OB
S^t 27. 199S
IJ\HONTAN REGiON(6V)
0
t-
15 30
45 MILES
0 15 30 45 KILOMETERS
SOURCES:
Stem RF3 IREPA 1992
Wafer brace OMOD! Bond
303(d) m S-1W4
-------
JUNE 1997
Exhibit A-23
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREA
REGION 6: LAHONTAN REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
0
0
NA
Estuaries
(acres)
0
0
NA
Lakes &
Reservoirs
(acres)
35,878
189,059
18.98%
Rivers &
Streams
(miles)
372
2,893
12.86%
Saline Lakes
(acres)
66,182
193,082
34.28%
Wetlands
(acres)
468
43,545
1.07%
Source: U.S. EPA analysis of the WQA database.
Key Waterbodies Affected
Based on California's 303(d) report, a number of the waterbodies affected by toxics in Region
6 are of significant priority. Twenty-seven waterbodies in Region 6 appear on the priority list, 14
of which are affected by toxics. Exhibit A-25 presents the pollutant types, 303(d) report ranking,
and area of impairment for these 14 waterbodies. Included are the Truckee River, Owens River,
Honey Lake, Eagle Lake, Topaz Lake, and a small segment of Lake Tahoe.25 Metals and trace
elements are the most common types of toxics, with pesticides and priority organics also present.
As shown in Exhibit A-25, Lake Tahoe is listed as among the state's highest priorities (a
ranking of "1"), but the area affected by toxics (according to the WQA database) is limited to only
0 1 percent of the total area of the lake. In contrast, the WQA data suggest that toxics impair the
entire assessed area of the waterbodies ranked in the second tier, including Eagle Lake, Owens River,
Truckee River, and Honey Lake.
1994.
2' California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May
Based on 1996 data, Lake Tahoe has been removed from the 303(d) list.
A-46
-------
JUNE 1997
Exhibit A-24
MAJOR SOIWES OF TOXIC POLLUTANTS
REGION «: I.AHONTAN REGION
Agriculture
Hydro /Habilat
Vlodiflcation
Industrial
Land Development
Land Disposal
Mining
Municipal
Other Nonpoint
Sources
Other Point
Sources
Storm Sewers
Urban Runoff
RIM
(itrwl
0
0
0
0
0
0
0
0
0
0
0
Miirt •!
TM*I Tiittv
Imttilrtd Art*
N\
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Fttvirtn
(•cm)
0
0
0
0
0
0
0
0
0
0
0
Shirt •» T«*l
1*lk*-ln»f»llrt4
Arta
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
lahnA
Rn*r**lr«
(a»r«)
J.JOO
0
0
25.000
0
2.300
0
35.878
0
0
4,670
Shirt «f
Tt*ll Tnkt-
linpib-H Art!
6r,
OT4
0%
70%
0%
6%
0%
100%
0°/«
0%
13%
River* A Strctmi
(miles)
127
0
0
7
1
94
4
245
4
0
117
Shirt of Total
Toilcs-
Impilrcd Are*
34%
0%
0%
2%
0%
25%
1%
66%
1%
0%
31%
Sillne Lakes
(icres)
66,182
0
0
10,855
0
0
0
10.855
0
0
0
Share of
Total Toxics-
Impaired Area
100%
0%
0%
16%
0%
0%
0%
16%
0%
0%
0%
Wetlands
(acres)
0
0
0
0
0
0
0
468
0
0
468
Share of
Total Toxics-
Impaired Area
0°/e
0%
0%
0%
0%
0%
0%
100%
0%
0%
100%
Source: U.S. EPA analysis of WQA database.
* Natural Sources are a subset of Other Nonpoint Sources.
A-47
-------
JUNE 1997
Natural Resources and Beneficial Uses Affected
The waterbodies of the Lahonton Basin support a diverse wildlife population, including
species and subspecies of plants and animals exclusive to the Region. Notable fish species include
the Eagle Lake trout, Lahontan and Paute cutthroat trout, and Mojave Chub. Exhibit A-26
summarizes available information on the beneficial uses supported by Region 6 waters that have
been identified as impaired by toxic pollutants. As the exhibit indicates, all of the waterbodies
included on the 303(d) priority list are categorized as either freshwater or inland saline habitats, and
all support wildlife. Most are fish spawning areas, while many support fish migration and rare or
endangered species. Eagle Lake and Lake Tahoe are both considered essential for the preservation
of biological habitats of special significance.26
In addition to providing important wildlife habitat, all of the freshwater resources listed in
Exhibit A-26 supply water to municipalities. The waters of the Truckee, Carson and Walker Rivers,
and of Lake Tahoe, are allocated among water users in California and Nevada, while water from the
Owens and Mono Rivers is diverted, via the Los Angeles Aqueduct, for use in the Los Angeles area.
Most of the waterbodies also support agriculture, while many are used for navigation. Only four of
the waters are utilized for industrial purposes.
Many of the waters identified in Exhibit A-26 play a critical role in the Lahontan Region's
tourist economy According to the Basin Report, all of the waterbodies support both, contact and
non-contact uater recreation, including swimming, boating, hiking, and nature-watching. Most of
the waterbodies also support commercial and sport fishing. Segments of the East Fork Carson and
West Walker Riven ire included in the State Wild and Scenic River system, which prohibits the
construction of dams and other water diversion facilities on the specified waterbodies. Lake Tahoe
and Eagle Lake art noted tourist sites, while the Truckee river is a popular rafting stream and wild
trout fishery 1 nhuunes of the Owens river also support heavy recreational use.
Based on 1996 data. Lake Tahoe is no longer on the 303(d) list.
A-48
-------
JUNE 1997
Exhibit A-25
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN THE LAHONTON REGION (REGION 6)
Waterbody Name
Eagle Lake (2)
Fallen Leaf Lake
LakeTahoe1
Topaz Lake
Bryant Creek
Carson River, E. Fork
Carson River, W. Fork
East Walker River
Owens River
Susan River
Truckee River
West Walker River
Alkali Lake, Lower
Honey Lake
Pollutants
Metals
Trace Elements
Metals, Pesticides
Trace Elements
Metals, Trace Elements
Metals, Trace Elements
Trace Elements
Metals, Priority Organics
Trace Elements
Metals, Trace Elements
Metals, Trace Elements, Priority Organics
Metals, Trace Elements
Trace Elements
Trace Elements
303(d)
Priority
2
3
1
4
5
3
4
3
2
4
2
3
3
2
Area Affected
25,000 acres
1,4 10 acres
160 acres
2,300 acres
10 miles
46 miles
6 miles
Smiles
120 miles
7 miles
106 miles
1 mile
10,855 acres
55,327 acres
Sources: 303(d) list; 1994 WQA Data Base
1 Based on 1996 data, Lake Tahoe is no longer on the 303(d) list.
A-49
-------
JUNE 1997
WilerbiMly
Eagle Like
(2)
Fallen Leaf
Lake
LakeTahoe
Topaz Lake
Bryant Creek
Carson River,
E Fork
Carson River.
W Fork
East Walker
River
Owens River
Susan River
Trackee River
West Walker
River
Alkali Lake.
Lower
Honey Lake
Exhibit A-16
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY WATERBODIES
Beneficial (Jsei
Municipal
Supply
X
X
X
X
X
X
X
X
X
X
X
X
Agriculture
X
X
X
X
X
X
X
X
X
X
X
X
Industrial
X
X
•
X
X
Commercial
and Span
Fishing
X
X
X
X
X
X
X
X
X
X
X
Navigation
X
X
X
X
X
X
X
X
X
Water
Contact
Rtertatlon
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Non-Contact
Water
Recreation
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Growtdwatcr
Recharge
X
X
X
X
X
X
X
X
X
X
X
X
Wildlife
Habitat
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Freshwater
Habitat
X
X
X
X
X
X
X
X
X
X
X
X
X
Inland
Sallnt
Habitat
X
X
Fliti
Migration
X
X
X
X
X
X
Fish
Spawning
X
X
X
X
X
X
X
X
X
X
X
X
Sourrt: Water Quality Control Plan. Lahonlan Basin. Region 6. California Regional Water Quality Control Board, October, 1994, Table 2-1
Preservation
of Biological
Habitats of
Special
Stgnlllcanct
X
X
Supports
Rare or
Endanger*
Spedes
X
X
X
X
X
X
A-50
-------
JUNE 1997
Region 7; Colorado River Basin
Hydrologic Setting
"Region 7, the Colorado River Basin, encompasses approximately 20,000 square miles of
southeast California.27 It is bordered on the north and west by several mountain ranges, on the south
by Mexico, and on the east by the Colorado River and the state of Arizona. As shown in Figure A-7,
the major waterbodies in this region are the Colorado River, the Salton Sea, and a variety of smaller
rivers and conduits that feed the Salton Sea.
The hydrologic features of Region 7 are heavily influenced by the Colorado River and
agricultural activity in the area. Water from the Colorado River is used to irrigate land in the Palo
Verde Valley, the Imperial Valley, and the Coachella Valley.
The Salton Sea was formed early in this century by overflow from the Colorado River and
now is fed primarily by irrigation drainage from the Imperial and Coachella Valleys. It is
California's largest inland waterbody, covering approximately 220,000 acres, and supports a number
of wildlife species and recreational activities (see below). Agricultural drainage is transported to the
Salton Sea via several natural and man-made conduits. The Alamo River, New River, and Coachella
Valley Storm Water Channel are the Sea's major water sources and are fed primarily by agricultural
runoff. San Felipe Creek and Salt Creek are natural waterways that also feed the Salton Sea.
Degree and Sources of Toxics Impairment
Unlike many of California's other water regions, toxics pollution in the Colorado River Basin
is relatively homogenous in nature and source: pesticide and trace element contamination caused by
agricultural drainage. Analysis of the WQA database yields the following information:
• Of the total river miles assessed in Region 7, approximately 60 percent
(1,433 miles) are impaired by toxics.
• Where pollutants are specified in the database, pesticides account for
essentially all of the toxic pollution that impairs rivers, while trace elements
(primarily selenium) are the primary pollutants for the Salton Sea.
• Agriculture is listed as the source of toxic pollution for nearly 100 percent of
the Region's impaired waters. Border pollution from Mexico (agricultural
runoff and municipal sewage) is a minor contributor as well.
27 Water Quality Control Plan - Colorado River Basin Region, State Water Resources Control
Board, California Regional Water Quality Control Board, Colorado River Basin Region, November
17, 1993.
A-51
-------
COLORADO RIVER BASIN REGION(7)
LKC
USEFA Rtfgm 9 OSS
Sept 27, 1995
10 20
30 MILES
0 10 2O 30 KILOMETERS
SOURCES.
Stan RF3 UXPA 1992
WMBT Room CoMBl Bond
303(d) b> S-IM4
-------
JUNE 1997
Key Waterbodies Affected
Available water quality data indicate that, apart from the Salton Sea, the extent of waters
impaired by toxics in Region 7 is relatively limited. Exhibit A-27 presents information on the
Region 7 waterbodies that California's 303(d) report identifies as impaired.28 These include the
Salton Sea as well as several rivers or channels that carry agricultural runoff. Despite the fact that
these waters are identified in the 303(d) report, only the Salton Sea is listed as being of "high
priority" (based on beneficial uses and severity of pollution) relative to other state waters.29
With respect to the areal extent of toxics contamination, the Salton Sea and the Imperial
Valley Drains are the two most significant waterbodies impaired. The WQA database indicates that
trace elements (including selenium) are the most significant toxics problem in the Salton Sea. This
is consistent with a 1986-1987 U.S. Geological Survey investigation of the area that found elevated
concentrations (a median of 19 ppb) of selenium in tile drain effluent. The study also found elevated
selenium and boron in aquatic bird tissues.30 The WQA database indicates that both trace elements
and pesticides are present in the Imperial Valley Drains.
•*' California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May
1994.
•"According to the WQA data, the Colorado River itself has no toxic pollution. Salinity
levels, however, are high in the lower portions of the river. In addition, the flow of the Colorado has
been greatly diminished by diversions for agricultural, industrial and municipal use (Running Dry:
Why Some of the World's Great Rivers No Longer Reach the Sea, World Watch, May/June, 1995.)
K An Overview- of Irrigation Drainwater Techniques, Impacts on Fish and Wildlife
Resources, and Management Options, U.S. Fish and Wildlife Service, May 1992, p. 63.
A-53
-------
JUNE 1997
Exhibit A-27
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN COLORADO RIVER BASIN (REGION 7)
Watcrbody
Salton Sea
Alamo River
Coachella Valley Storm
Channel
Imperial Valley Drains
New River
Palo Verde Outfall Drain
Pollutants
Trace elements
Pesticides, Selenium
Pesticides
Pesticides, Selenium
Pesticides, Trace
elements
Pesticides
303(d)
Priority
1
4
5
5
5
5
Area Affected
220,000 acres
52 miles
20 miles
1,305 miles
60 miles
16 miles
Sources 303(d) list: 1994 WQA database.
Natural Resources and Beneficial Uses Affected
The surface waters of the Colorado River Basin, including those impaired by toxics pollution,
support diverse wildlife resources as well as a variety of beneficial human uses. Exhibit A-28
summarizes beneficial use information from the Basin Report for Region 7. As shown, all of the
waterbodics impaired by toxics support habitat, fish, and wildlife.31 Moreover, all support some
form of rare, threatened or endangered species. The Basin Report for Region 7 provides the
following additional information on fish and wildlife in the Region:
• Fish: Virtually all fish species found in Region 7 have been introduced into
the Region. The irrigation canals support large- and smallmouth bass,
catfish, bullhead, bluegill, sunfish, crappie, carp, striped bass and other
species The Salton Sea supports large sportfish, including orangemouth
corvina, gulf croaker, sargo, and tilapia.
31 Regional officials list the Salton Sea as a warm freshwater habitat for lack of a more precise
categorization The Salton Sea is actually of somewhat greater salinity than ocean water. Personal
communication with Kenneth Coulter, Senior Engineering Geologist, California Regional Water
Quality Control Board, Colorado River Basin Region, July 27,1995.
A-54
-------
JUNE 1997
Waterfowl: The Salton Sea National Wildlife Refuge and state waterfowl
management areas are located in and around the Salton Sea. Currently, more
than 90,000 migratory waterfowl, as well as other aquatic birds, use the
refuge each year.32
Rare, Threatened, Endangered Species: Critical species supported by
surface water in the Region include the desert pupfish, razorback sucker,
Yuma clapper rail, black rail, least Bell's vireo, yellow billed cuckoo, and
desert tortoise.
Mammals and Reptiles: Large portions of Region 7 are inhabited by
rodents, coyotes, foxes, and assorted reptiles.
32 An Overview of Irrigation Drainwater Techniques, Impacts on Fish and Wildlife
Resources, and Management Options, p. 63.
A-55
-------
JUNE 1997
Exhibit A-28
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY WATERBODIES
Waterbody
Salton Sea
Alamo River
Coachella Valley Storm
Channel
Imperial Valley Drains
New River
Beneficial Uses
Aquaculture
X
Water
Contact
Recreation
X
X
X
X
X
Non-
Contact
Water
Recreation
X
X
X
X
X
Freshwater
Replenishment
X
X
X
X
Warm
Freshwater
Habitat
X
X
X
X
X
Wildlife
Habitat
X
X
X
X
X
Supports
Rare,
Endangered
Species
X
X
X
X
X
Note: Beneficial use information not available for Palo Verde Outfall Drain.
Source: WQA data, as summarized in Water Quality Control Plan Colorado River Basin Region, p. 2-12 through 2-13.
A-56
-------
JUNE 1997
The ecological impacts attributable to pollution in Region 7's surface waters include adverse
effects on waterfowl. Concentrations of selenium are highest in the drainage channels and tests have
found elevated tissue concentrations in birds and other species that feed in these areas. In addition,
the Saitoh Sea was the site of one of the largest bird kills on record (approximately 180,000 eared
grebes), although this event was associated with red algae blooms partially caused by nonpoint
source runoff, rather than direct exposure to toxics.33
Apart from supporting wildlife, the Region's impaired surface waters are used for recreation
and other human activities. The WQA database shows that the beneficial use of these waters include
swimming, fishing, and non-contact recreation such as boating and hiking.34 It should be noted that
all the affected rivers are used for the collection and transport of agricultural drainage; however, the
Clean Water Act does not recognize this application as a beneficial use.
Toxics contamination in the region has had an impact on recreational activity in recent years,
but only to a small degree. Because of selenium levels in the Salton Sea, a fish consumption
advisory is in effect. Recreational anglers and sensitive subpopulations such as pregnant women are
encouraged to limit intake offish caught in the Salton Sea. Regional officials note that the advisory
is highly conservative, and that recreational fishing is still popular in the area. Furthermore, a
number of other recreational activities are freely pursued; for example, no beach closures have ever
been issued for the Salton Sea.35
Region 8; Santa Ana River Basin
Hydrologic Setting
The Santa Ana River Basin is approximately 2,800 square miles in size and is located just
south of Los Angeles and north of San Diego.36 It is bounded by the San Gabriel and San
Bernardino mountains to the north and east, the San Jacinto Mountains in the southeast, and the
Pacific Ocean to the west. As the Region's name suggests, the Santa Ana River and its tributaries
11 Personal communication with Kenneth Coulter, Senior Engineering Geologist, California
Regional Water Quality Control Board, Colorado River Basin Region, July 27,1995.
14 CWA, 40 CFR Section 131.10 (a).
" Personal communication with Kenneth Coulter, Senior Engineering Geologist, California
Regional Water Quality Control Board, Colorado River Basin Region, July 27,1995.
* The majority of the material on Region 8 was taken from the Water Quality Control Plan -
Santa Ana River Basin, State Water Resources Control Board, California Regional Water Quality
Control Board, Santa Ana River Basin Region, January 1995.
A-57
-------
JUNE 1997
comprise the largest waterbody system in the area, which also includes the San Jacinto River and
other rivers that interlace the mountains. Lake Elsinore in the south and Lake Mathews in the center
of the Region are its largest standing waterbodies (see Figure A-8).
The climate in the Santa Ana River Basin is dry and warm. The region receives an average
of only 15 inches of rainfall per year, and is technically classified as "near-desert". The attractive
climate has encouraged settlement, making the Region the most densely populated in California.
Moreover, the area continues to grow. A 1985 land use report for the upper Santa Ana basin
indicates that the amount of land used for agricultural activities declined by 30 percent from 1975
to 1984, while land use for urban and suburban development increased by 23 percent during that
period.37
The search for adequate water to supply the needs of such a densely populated area has
affected the hydrology of the Region. In particular, the Santa Ana, San Jacinto, and other rivers have
been diverted for use in irrigation and urban water supplies. These activities have resulted in a
cessation of the groundwater recharge cycle; in some areas, artesian wells no longer pump water to
the surface. At the same time, the area has been forced to exploit its remaining groundwater
reservoirs as surface water sources dry up. Despite the use of sophisticated water retrieval
techniques to access remaining local water supplies, the Region now must import over half of its
water from other sources to meet the needs of the population. As a result, the Santa Ana River is an
effluent-dominated river system; as its upstream waters are siphoned for other uses, downstream
outfalls have become the largest contributor to the river's flow. These conditions contribute to
elevated concentrations of pollutants, which have been only partially addressed by recent efforts to
improve prctreatment and reduce the quantity of pollutants entering the Region's waters.
Degree and Sources of Toxics Impairment
Based on areal extent of impairment, toxics have the greatest impact on the bays and
estuaries of Region 8. All of the bays whose waters have been assessed are impaired by toxics.
Similarly, of the estuaries assessed, 91 percent are contaminated with toxics. Wetlands and rivers
appear to be relatively less polluted, revealing rates of contamination of roughly 3 and 11 percent,
respectively. Exhibit A-29 presents the percentages of assessed waters in Region 8 that have been
found to be toxic-impaired.
r Upper Santa Ana River Drainage Area Land Use Survey, 1984, California Department of Water
Resources, Southern District, June 1985, Table 3, pp. 11
A-58
-------
SANTA ANA REGION(8)
P»dM»i by
LKC
UffiPA Begin 9 GJS
Sept 27, 1995
10
15 MILES
0 5 10 15 KILOMETERS
SOURCES
RF3 USEPA 1992
Waer Rcvuce CoMni Bond
3Q3(d)l- S4844
Hyilmhigic Till !•• r»iif
SMC W^er Known CoMnl Bond
-------
JUNE 1997
Exhibit A-29
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATERBODY AREA
REGIONS: SANTA ANA RIVER REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
1,030
1,030
100.00%
Estuaries
(acres)
2,726
2,996
90.99%
Lakes & Reservoirs
(acres)
4,100
15,167
27.03%
Rivers & Streams
(miles)
49
463
10.58%
Saline Lakes
(acres)
0
0
NA
Wetlands
(acres)
400
15,017
2.660/,
Source: EPA analysis of WQA database.
The primary source of toxics pollution in Region 8 is nonpoint source runoff from both urban
and agricultural areas. Land development has contributed significantly to the impairment of
estuaries and lakes, while land disposal has primarily affected wetlands. Aside from the effects of
mining on lakes and reservoirs and the effects of POTWs on rivers, point source contamination is
minor. Exhibit A-30 shows the impacts of different point and nonpoint sources on the various
waterbodies in the region.
Key Waterbodies Affected
Exhibit A-31 presents data on the Region 8 waterbodies that appear on California's 303(d)
list and are impaired by toxics (based on WQA data). Included are two portions of the Santa Ana
River, as well as Lake Elsinore and certain Pacific coastal harbors. As shown, most of the waters
are of lower priority (although several did not receive a ranking in the 303(d) list). Metals and
pesticides are the most common categories of pollutants affecting these waters. The California Bay
Cleanup Program lists several potential "toxic hot spots" in the Santa Ana basin. These include
Anaheim Bay, Huntington Harbor, Bolsa Bay, and Newport Bay.38
Natural Resources and Beneficial Uses Affected
As shown in Exhibit A-32, the toxic-impaired waters of Region 8 provide a variety of
beneficial services to the area. All of the waterbodies listed provide recreational opportunities for
both contact activities, such as swimming and fishing, and non-contact activities such as boating and
hiking. Certain of these waters also provide for commercial and recreational fin- and shellfishing.
38 Bay Protection and Toxic Cleanup Program, Staff Report; State Water Resources Control
Board, State of California, November 1993, p. 111, Figure 9.
A-60
-------
JUNE 1997
Exhibit A-30
MAJOR SOURCES OF TOXIC POLLUTANTS
REGIONS: SANTA ANA REGION
Agriculture
iydro./Habitat Modification
ndustrial
.and Development
.and Disposal
fining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Urban Runoff
Bays
(acres)
700
0
0
0
0
0
0
1,030
20
0
350
Share of
Total
Toxics-
Impaired
Area
68%
0%
0%
0°/0
0%
0°/0
0%
•100%
2%
0%
34%
Estuaries
(acres)
752
0
0
752
0
0
0
1,974
0
752
1,974
Share of
Total
Toxics-
Impaired
Area
28%
0%
0%
28%
0%
0%
0%
72%
0%
28%
72%
Lakes &
Reservoirs
(acres)
0
0
0
1,500
0
500
0
4,100
0
0
2,600
Share of
Total
Toxics-
Impaired
Area
0%
0%
0%
37%
0%
12%
0%
100%
0%
0%
63%
Rivers &
Streams
(miles)
12
0
0
0
0
0
12
16
0
0
24
Share of
Total
Toxics-
Impaired
Area
24%
0%
0%
0%
0%
0%
24%
33%
0%
0%
49%
Saline
Lakes
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total
Toxics-
Impaired
Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wetlands
(acres)
400
0
0
0
400
0
0
400
0
0
400
Share of
Total
Toxics-
Impaired
Area
100%
0%
0%
0%
100%
0%
0%
100%
0%
0%
100%
Source: U.S. EPA analysis of WQA database.
-------
JUNE 1997
Several of the waterbodies listed in Exhibit A-32 also contribute to water supplies in the area.
The majority of freshwater entities are identified as a source for groundwater replenishment. Several
of these waterbodies provide water for municipal systems and agricultural enterprises.
Region 8 waters that are impaired by toxics also support a variety of wildlife. All of the
surveyed waterbodies provide either salt- or freshwater habitat for aquatic organisms, including some
rare and endangered species. Certain of the waters are spawning areas for fish and other aquatic
wildlife. In addition, Anaheim Bay and the Upper Newport Bay Ecological Reserve are designated
as biological habitats of special significance that require special protection.
Exhibit A-31
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN SANTA ANA RIVER BASIN (REGION 8)
Waterbody
Upper Newport Bay Ecological Reserve
Anaheim Bay
Big Bear Lake
Newport Bay. Lower
Lake Elsinore
Santa Ana River. Reaches 3 and 4
Grout Creek
Huntington Harbor
Knickerbocker Creek
San Diego Creek.. Reaches 1 and 2
Pollutants
Pesticides, trace elements
Metals, pesticides
Metals
PCBs, pesticides, metals, trace elements
Various toxics
Metals, various toxics
Metals
Pesticides, metals
Metals
Pesticides, metals, various toxics
303(d)
Priority
2
3
3
3
4
4
NA
NA
NA
NA
Area
Affected
1500 acres
1 80 acres
2970 acres
700 acres
2600 acres
30 miles
2 miles
150 acres
2 miles
12 miles
Sources: 30?ldi list 1994 WQA Database
A-62
-------
JUNE 1997
Exhibit A-32
NATURAL RESOURCES AND BENEFICIAL USES
ASSOCIATED WITH KEY WATERBOD1ES
Walerbody
Anaheim Bay
Big Bear Lake
Lake Elsinore
Grout Creek
Huntirtgton Harbor
Knickerbocker Creek
Newport Bay, Lower
San Diego Creek,
Reaches I and 2
Santa Ana River,
Reaches 3 and 4
Upper Newport Bay
Ecological Reserve
MtN
X
X
X
AGR
X
X
GWR
X
X
X
X
X
NAV
X
X
REC1
X
X
X
X
X
X
X
X
X
X
REC2
X
X
X
X
X
X
X
X
X
X
COMM
X
X
X
WARM
X
X
X
X
COLD
X
X
X
BIOL
X
X
WILD
X
X
X
X
X
X
X
X
X
X
RARE
X
X
X
X
X
X
SPWN
X
X
X
X
X
MAR
X
X
X
X
SHEL
X
X
X
EST
X
X
Key MUN - Municipal and Domestic
Supply
AGR * Agricultural Supply
GWR - Ground Water Recharge
NAV Navigation
RECI Water Contact Recreation
REC2: Non-Contact Recreation
COMM Commercial and Sport
Fishing
WARM Warm Freshwater Habitat
COLD: Cold Freshwater Habitat
EST Esluarine Habitat
MAR Marine Habitat
WILD: Wildlife Habitat
BIOL Preservation of Biological Habitat
RARE: Rare, Threatened, or Endangered
Specie)
SPWN: Spawning or Reproduction
SHELL: Shellfish Harvesting
Source: Water Quality Control Plan - Santa Ana River Basin, State Water Resources Control Board, California Regional Water Quality Control Board, Santa Ana River Basin Region, January 1995, pp. 3-7 to 3-24.
A-63
-------
JUNE 1997
Region 9; San Diego Basin
Hydrologic Setting
The San Diego Basin (Region 9) forms the southwest comer of California and encompasses nearly
3,900 square miles of surface area. The Region is bound to the west by the Pacific Ocean, and to the east
by the Laguna Mountains and mountains located in the Cleveland National Forest. To the north lies a
hydrologic divide that begins near Laguna Beach and extends inland through El Toro; to the south is the
United States and Mexico border.39 Figure A-9 shows the location of major waterbodies in Region 9.
Topographically, the San Diego Region is divided into a coastal plain, a central mountain-valley
area, and an eastern mountain-valley area. The San Diego Region is characterized as semi-arid; precipitation
is lowest on the coast, higher inland. In general, Region 9 water resources are limited, with only about
20,000 acres of bays and estuaries, 15,000 acres of lakes, and about 600 miles of rivers assessed in the WQA
database. Scarcity of rainfall and increased urbanization of the Region have led to increased amounts of
water importation from eastern sections of the state and alterations in many of the region's stream flows.
Degree and Sources of Toxic Impairments
The effects of toxic pollutants in Region 9 are greatest in the San Diego Bay area. The areal extent
of toxics impairment in Region 9 is limited, with most pollution the result of increasing urbanization. The
WQA data support the following observations:
• As summarized in Exhibit A-33, only 38 of the 576 river miles assessed (6.6
percent) are impaired by toxics. Toxics impair a small percentage of bays (2.2
percent of assessed) and estuaries (14.4 percent of assessed) as well.
• Exhibit A-34 demonstrates that industry, storm sewers, and miscellaneous nonpoint
sources are the principal sources of toxic pollutants in bays, while land disposal
activities have led to the contamination of estuaries. Toxic pollution in rivers is
associated with agricultural and urban runoff, as well as industrial sources.
39 Water Quality Control Plan, San Diego Basin (Region 9); California Regional Water
Quality Control Board, San Diego Region, September, 1994, p. 1-3.
A-64
-------
Pmtaecd by
LKC
USPA Regk» 9 CHS Cater
Sept 27, 1995
SAN DffiGO REGION(9)
10
15 MILES
5 10 15 KILOMETERS
SOURCES
StmnK RF3 USEFA 1992
m ; _ j m — ._ J ___ »; __ T^-J.
mpMOBfl wBCfDOfDEK JIMTT
Wiler ROOUBC OMbal Band
303(d) M 5-1844
Coitni uouo
-------
JUNE 1997
Exhibit A-33
TOXICS-IMPAIRED SHARE OF TOTAL ASSESSED WATER BODY AREA
REGION 9: SAN DEEGO REGION
Toxics-Impaired
Total Assessed
Share
Bays
(acres)
308
13,965
2.21%
Estuaries
(acres)
937
6,523
14.36%
Lakes & Reservoirs
(acres)
0
15,185
0.00%
Rivers & Streams
(miles)
38
576
6.60%
Saline Lakes
(acres)
0
0
NA
Wetlands
(acres)
0
0
NA
Source: U.S. EPA analysis of WQA database.
Key Waterbodies Affected
Based on California's 303(d) report, a number of the waterbodies affected by toxics in Region
9 are of significant priority.40 Fifteen waterbodies in Region 9 appear on the priority list, seven of
which are affected by toxics. Exhibit A-35 presents the pollutant types, 303(d) report ranking, and
area of impairment for these seven waterbodies. Included are the North and South sections of San
Diego Bay, Oceanside Harbor, Central Mission Bay, and the Tijuana River. Metals are a
contaminant in all of the waterbodies, with pesticides, trace elements, and priority organics also
present in some areas.
The North and South sections of San Diego Bay were rated among the state's highest 301(d)
priorities. The North section receives metals, pesticides, and priority organics from industrial
sources and, to a limited extent, storm sewers. Industry also discharges toxic metals to the South
section, accompanied by priority organics from nonpoint sources. The State has also assigned
relatively high 301 (d) priority to the Tijuana River Estuary (ranked in the second tier), while Central
Mission Bay, Oceanside Harbor, Arroyo Trabuco Creek, and the Tijuana River are all considered
medium priority.
California's Bay Protection and Toxic Cleanup Program (BPTCP) provides an additional
indicator for key coastal waterbodies affected by toxic pollutants. BPTCP lists areas of significant
toxicity, high levels of bioaccumulation, and impairment of ecologic beneficial uses as toxic "hot
spots". While there are no known toxic hot spots identified in Region 9, many "potential" toxic hot
spots (areas exhibiting elevated toxic concentrations in water or sediment) are listed. The Tijuana
River Estuary was the only waterbody included on the 303(d) list not considered a potential hot spot;
conversely, Central San Diego Bay is targeted by BPTCP, but is not on the 303(d) list.41
40
California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May
1994.
41 Bay Protection and Toxic Cleanup Program, Staff Report; State Water Resources Control
Board, State of California, November, 1993, p. 111, Figure 9.
A-66
-------
JUNE 1997
» iMM »-M
MIHMIUN IN Ml* lOXH «H 1 ITANT*
unaoN* *AimrM>ftF(aoN
Agriculture
Hydro /Habitat Modification
Industrial
Land Development
[.and Disposal
fining
Municipal
Other Nonpoint Sources
Other Point Sources
Storm Sewers
Jrban Runoff
Bays
(acres)
0
0
305
0
0
0
I
308
0
165
63
Shirr of
Total Todcs-
Impalrrd
Are*
0°/«
0%
99»/.
or,
VA
0%
0%
100%
•0"/<
54%
20"/<
Estuaries
(tcres)
1
0
1
0
936
0
0
1
0
0
1
Share of
Total Toilet-
Impaired
Arti
0%
0%
0%
ov.
100%
0%
0%
0%
0%
0%
0%
Lakes &
Reservoirs
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share ef
Total Toiles-
Impalred
Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Riven &
Streams
(miles)
II
0
6
0
0
0
0
2
0
0
6
Share of
Total Toilcs-
Impilred
Are*
29°/i
0%
16%
0%
0°/,
0%
0°/«
5%
0%
0%
16%
Saline
Likes
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired
. Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wetlands
(acres)
0
0
0
0
0
0
0
0
0
0
0
Share of
Total Toxics-
Impaired
Area
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Source: U.S. EPA analysis of WQA database.
A-67
-------
JUNE 1997
Natural Resources and Beneficial Uses Affected
Exhibit A-36 summarizes available information on the beneficial uses supported by Region
9 waters that are identified as impaired by toxic pollutants. As the exhibit shows, all of the
waterbodies impaired by toxics are either freshwater or marine habitats, and most support rare,
threatened, or endangered plant or animal species. All are also wildlife habitats, and several are
recognized as aiding in the preservation of biological habitats of special significance.
In addition to supporting wildlife and maintaining ecosystems, the toxic-impaired
waterbodies are also used for contact and non-contact water recreation, including swimming, fishing,
boating, and camping. In addition, all of the marine waterbodies support commercial fishing and
shellfish harvesting. Many of the waterbodies are also used as a source of water for industrial
purposes.
Exhibit A-35
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN SAN DIEGO REGION (REGION 9)
\Vilerbodv Name
Central Mission Bay
Oceanside Harbor
San Dtc?o Bay, North
San Diego Bay, South
Tuuaiu River Estuary
Arrow Trabuco Creek
Tttuana River
Pollutants
Metals, pesticides
Metals, pesticides, trace elements
Metals, pesticides, priority organics
Metals
Metals, pesticides
Metals
Metals, pesticides, trace elements
303(d)
Priority
3
4
1
1
2
5
5
Area Affected
1 acre
1 acre
239 acres
4 acres
1 acre
1 mile
7 miles
Sources 303(d) list; 1994 WQA Data Base
A-68
-------
JUNE 1997
^•••••^•V^^VH^^HWIM^^^^^^^^^^
Waterbody
Central Mission Bay
Oceanside Harbor
San Diego Bay, North
San Diego Bay, South
Tijuana River Estuary
Arroyo Trabuco
Tijuana River
^^HMWM^V^^^M^^H-M
Agriculture
X
Industrial
X
X
X
X
X
X
^•••••^••••^•••••••••••MM
Shellfish
Harvesting
X
X
X
X
X
N
••^••(•••••^•^••••••••••••^•••••••i
Ocean
Commercial &
Sport Fishing
X
X
X
X
X
ATURAL RESC
ASSOCIATE!
Waler
Contact
Recreation
X
X
X
X
X
X
X
Exhibit A-36
>URCESANbl
) WITH KEY V
^^••^•WH^^^^HH^l^lfe
Non-
Contact
Water
Recreation
X
X
X
X
X
X
X
IENEFICIA1
fATERBOD
^••^^•••MI^^HA^M
Marine
Habitat
X
X
X
X
X
.USES
IES
•••••••••^•••••••••H
Wildlife
Habitat
X
X
X
X
X
X
X
^•••••^••••••••••••••••••Hl
Freshwater
Habitat
X
X
^•••••^•••^^•^••^^•^
Fish
Migration
X
X
X
X
X
MBBB^W«»^M
Fish
Spawning
X
i
^^^•••••M^pifllpHlflB^MmvMHMIH^t^B
Preservation of
Biological Habitats
ofSpeeM
Significance
X
X
X
••{•^•••^•••••••••••MIIIIMPIBl
Support!
Rare or
Endangered
Species
X
X
X
X
- x
X
Source: Water Quality Control Plan, San Diego Basin, Region 9, California Regional Water Quality Control Board. September, 1994, Tables 2-2, 2-3.
A-69
-------
APPENDIX B
CALIFORNIA FISH TISSUE CONTAMINANT DATA BASES
Bl: Freshwater
B2: San Francisco Bay
-------
JUNE 1997
FISH TISSUE DATABASES
To analyze the baseline health risks faced by anglers in California in support of the
California Toxics Rule, we constructed two fish tissue contaminant databases. The first database
includes information on contaminant concentrations in fish from rivers and lakes located throughout
California. We apply these data to the analysis of health risks faced by California's freshwater
anglers. The second database contains information on contaminant concentrations in fish from San
Francisco Bay. These data serve as the basis for a case study of potential health risks facing anglers
who consume fish caught in enclosed bays and estuaries, as represented by the health risks faced by
anglers consuming fish from San Francisco Bay.
Bl; Freshwater Fish Tissue Database
Fish Tissue Data Source
The freshwater database contains fish tissue contaminant information collected by
California's Toxic Substances Monitoring Program (TSMP). The TSMP is administered by the State
Water Resources Control Board and is conducted jointly with the California Department of Fish and
Game. This on-going program monitors the occurrence of toxic pollutants in California's waters
through sampling and analysis of fish tissue. Since its inception in 1976, more than 70 species of
fish have been sampled under the TSMP. Samples of largemouth bass, channel catfish, and carp ~
all species which are commonly caught and consumed by California's angling population ~ have
been collected with the highest frequency. Fish tissue samples are collected between May and
December of each year, thereby minimizing the potential impacts of seasonal variation on
contaminant concentrations. Each sample is analyzed for up to 10 metals and 68 organic
compounds.
Although the TSMP collects freshwater tissue samples throughout the state, sampling
locations are targeted to waterbodies with known or suspected water quality impairments. The data,
therefore, may not provide a representative assessment of overall water quality. To the extent that
California's anglers fish in less contaminated lakes and streams, the TSMP data may overstate
contaminant concentrations in the fish they consume. Exhibit B-l provides a list of the TSMP
sampling locations included in the freshwater database.
B-2
-------
JUNE 1997
A review of the TSMP sampling stations included within this analysis indicates that the
program's potential bias may not be significant. First, across the entire state, approximately 53
percent of the waterbodies (encompassing 51 percent of the fish tissue samples) included in the
freshwater analysis comply with applicable water quality standards and designated use criteria.
Second, each of the California Water Quality Control Board regions samples impaired water bodies
at different rates. Regions 4, 6, and 8, for example, collect between 75 and 95 percent of their
samples from impaired water bodies. The six remaining regions collect between eight and 38
percent of their samples from impaired sources. Analysis of sample size by region, however,
indicates that regions with a large number of unpaired samples are not likely to exert a
disproportionate impact on average tissue concentrations because the number of samples collected
in these regions is generally equal to or less than the number of samples collected in other regions.
Similarly, comparison of TSMP sampling locations to areas where California's OEHHA has
issued health advisories warning against fish consumption shows that less than three percent of the
samples (12 out of more than 360 samples) used in this analysis were collected from locations where
advisories have been issued. These results also suggest that any bias toward higher fish tissue
contaminant levels introduced by this targeted sampling effort may be limited.
B-3
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
v-.'/:. • •";**?• ..,• .- f-s.,,:.. • , . ;>•.;•!((;';•:.••"••.',"•'•*- 1 •—•:. •.,:...',?»»•.< ,-,>.-' .-;;.- ' .-' . ,*•?„-,.,.»'=•:;:,,-;
v.-Ksr-ivwSv--^ - . • .-- - •.-....'.. . Region! * .-... --.j-.-. •.-.• :.- . . x»*-~ ,:.^:jv. .v
Station Name
Beaughton Creek d/s Highway 97 Bridge
Big Sulfur Creek
Carrville Pond
Hardscrabble Creek
Indian Creek
Iron Gate Reservoir
Janes Creek
Klamath River u/s Copco Reservoir
Lake Mendocino
Lake Pillsbury
Lake Pillsbury/Eel River Arm
Lake Sonoma -
Lost River/Canal D
Mark West Creek
Russian River/Odd Fellows Park Bridge
Shasta River
Smith River
Trinity River/East Fork
Trinity Rrver'Willow Creek
Tnmrv River d's Burnt Ranch
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
>led for
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Region 2
Station Name
Alameda Creek/Niles Canyon Road
Alamiux Creek d/s Almaden Reservoir
Almaden Reservoir
Bear Gulch Reservoir
Coyote Creek'Brokaw Road
Coyote Creek/Percolation Pond
LakeChabot
Los Gatos Creek
Napa River/Napa
New York Slough
Santa Fe Dam Park
•
Stevens Creek
Sampled for
Metals
X
X
X
X
X
X
X
X
X
X
X
X
Organics
X
X
X
X
X
X
X
X
B-4
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
•• '-f *~~ , Region 2 (continued) ' ;; 5 ' /'-.**- 'V^^cl
Station Name
Stevens Creek Reservoir
Vasona Lake
Walker Creek
Walnut Creek
Sam
Metals
X
X
X
X
pled for
Organics
X
X
X
••••'•- Region* £•*• •'••-*S-&-:'%?- '.:sfc:.;-.;^l-i ;•
Station Name
Alisal Slough u/s Tembladero Slough
Bean Creek/Conference Drive
Bean Creek/Graham Hill Road
Big Sur River
Bixby Creek
Cborro Creek
Chorro Creek u/s Chorro Reservoir
EILuero
Elkhora Skwgh
Golcta Slough WestTecolotico Creek
JamnoB Lake
KUw Mtar Pood
Lake Vacmuento/Dip Creek
Lair Sacararato.'Las Tablas
Lair San Amooio/San Antonio River
LmlrSarRfveT
l«% (Hat Crrek a's Los Osos
***tr* » Lakr
(K»f Uco Lake
HotvruLaLr
Sakmod Crrrk
San LormzD Rjver'Big Trees
S«n Luis Obupo Creek d/s SLO
S*u Um Obupo Creek u/s SLO
Small T»v Lake
Uaddel Creek
U atsonville Slough/Lee Road
While Rock Rrservoir
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
B-5
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
"v ' • •.-.<:*•<;/•:-* -••!/. "::•..• •' ' /' Region 4 ;...- •" .'•"••^'.' '• -*,-•'- *, " ,
Station Name
Arroyo Conejo
Arroyo Conejo d/s Forks
Ballona Creek
Calabasas Lake
Calleguas Creek
Casitas Lake
Echo Park Lake
El Dorado Park Lake
Eleanor Lake
Harbor Park Lake
Legg Lake
Lincoln Park Lake
Lindero Lake
Los Angeles River/Sepulveda Basin
Malibou Lake
Malibu Creek
Oxnard Drainage Ditch 2
Peck Road Lake
Puddingstone Reservoir
Revolon Slough
Rio de Santa Clara/Oxnard Drain
San Gabriel River
San Gabriel River/Coyote Creek
Santa Clara River/Santa Paula
Sherwood Lake
Simms Pond
Ventura River
Westlake Lake
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Region 5
Station Name
American River N.F./Highway 49
American River d/s Folsom Reservoir
American River d/s Highway 160 Bridge
American River d/s Watt Avenue Bridee
Sampled for
Metals
X
X
X
X
Organics
X
X
B-6
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
• : *> --•-••' -- Region 5 (continued) .~
Station Name
Bounde Creek/Norman-Princeton Road
Bullards Bar Reservoir/Willow Cr
Bollards Bar Reservoir/Willow Cr
Butte Creek/Colusa Highway
Cache Creek
Cache Creek d/s Davis Creek
Camp Far West
Camp Far West/Rock Creek Arm
Central Drain/Norman-Princeton Road
Colusa Drain/Abel Road
Colusa Drain/Yolo-Colusa County Line
Courtright Reservoir/Dusy Creek
Cross Canal
Dallas Warner Reservoir
Dry Creek/Spenceville
Feather River d/s Highway 99 Bridge
Feather River d/s Oroville Reservoir
Glenn-Colusa Canal
Huntington Lake/Rancherio Creek
Kem River/Bakersfield
Lake Kaweah
Lake Wildwood
Logan Creek/Norman-Princeton Road
Mendota Pool
Merced River/Hatfield St Recreation Area
Mud Slough
New Hogan Reservoir
Paradise Cut/Tracy
Pardee Reservoir
Reclamation Slough
Rollins Reservoir
Sacramento River/Hood
Sacramento River/Keswick
Sacramento Slough
Salt Slouph
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
B-7
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
^v.- , ,--. -. ,.^---;: - -v < -^ -> Region 5 (continued]
Station Name
San Joaquin River/Mossdale
San Joaquin River/Newman
San Joaquin River/Vemalis
Stanislaus River
Stockton Deep Water Channel
Sycamore Slough/Knights Landing
Sycamore Slough/Yolo-Colusa County Line
Willow Creek/Norman-Princeton Road
Wishon Reservoir N.FTKings River
Yuba River N.F. d/s Bullards Bar Res
1, •'•'•• t, • .-^ .- .v ,.
;. ••.":, "•::.'.. -J,. .--•• •••". ,. . " -•" •
Sampled for
Metals
X
X
X
X
X
X
X
X
Organics
X
X
X
X
X
X
X
X
, . - , . Region 6
Station Name
Bishop Creek Canal d/s Bishop
Boca Reservoir
Bodie Creek/Flying M Club
Carson River W.F. d/s Paynesville
Convict Lake
Crowley Lake
Deep Creek u/s Mojave River
Donner Lake
Eagle Lake
East Walker River/Bridgeport
Grant Lake
Grass Valley Lake
Gull Lake
Haiwee Reservoir
Hot Creek
Hot Creek d/s Hatchery
June Lake
Lake Tahoe/Homewood
Little Rock Creek Reservoir
Long Valley Creek/Honey Lake
Lundy Lake
Mammoth Creek
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
x
pled for
Organics
X
X
X
X
X
X
X
X
X
X
B-8
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
• ' - -.-'•. -'-":-• • r;\;.:' Region 6 (continued) ..••-.»-;'''• .-..-.; '•-?-..- •','?."
Station Name
Martis Creek d/s Martis Creek Reservoir
McGee Creek
Monitor Creek
Owens River Gorge
Pine Creek/Bishop
Robinson Creek
Sabrina Lake
Silverwood Lake
Slinkard Creek
Squaw Creek
Stampede Reservoir
Susan River d/s Piute Creek
Topaz Lake
Trout Creek/Tahoe d/s Meeks Lumber
Trout Creek/Tahoe u/s Meeks Lumber
Trout Creek/Truckee d/s Meeks Lumber
Trout Creek/Truckee u/s Meeks Lumber
Twin Lakes
Virginia Creek/Dog Town
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
Region 7
Station Name
Alamo River/Brawley
Alamo River/Calipatna
Alamo River/Holtville
Alamo River/International Boundary
Central Drain
Colorado River/International Boundary
Colorado River/Needles
Colorado River u/s Imperial Dam
Fig Drain
Fig Lake
Fig Lake Outlet
Greeson Drain
Holtville Main Drain
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
tied for
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
B-9
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
•V" '*• v^^v'^Vwr^^''^' 'Region 7 (continued) •-••'.<:;'?-.: ••••-.&'<•; ,•<,,>'."
Station Name
New River/International Boundary
New River/Westmorland
Palo Verde Outfall Drain
Pumice Drain
Reservation Main Drain
Rose Drain
South Central Drain
Verde Drain
Wiest Lake
Sam
Metals
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
X
X
X
Region 8
.
Station Name
Big Bear Lake
Bolsa Quca Channel/Westminster Ave
Canyon Like
Chino Creek d/s Euclid Ave
E.G.G Wintenburg Channel/Gothard St
PradoLake
Santa Ana River Hamner Ave
Santa Ana River/Pndo Dam
Santa Ana River TJSGS Gage
Sam
Metals
X
X
X
X
X
X
iled for
Organics
X
X
X
X '
X
X
X
X
X
Region 9
Station Name
BLM Reservoir Buena Vista Mine
Cannon Lake 'Carlsbad
Escondido CreekCountry Club Drive
Escondtdo Creek'Elfin Forest Park
Forester Creek/Billy Mitcbel Road
Guajome Lake
Keys Creek
Lake Hodges
Lake Mission Viejo
Lake San Marcos
Sam
Metals
X
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
X
X
X
B-10
-------
JUNE 1997
Exhibit B-l
FRESHWATER FISH TISSUE SAMPLING LOCATIONS BY CALIFORNIA
STATE WATER RESOURCES CONTROL BOARD REGION
--•-•^::vyV r *-, Region 9 (continued) .vV't^>;*V . VP'-^'^t?;
Station Name
Los Penasquitos Creek/Highway 15
O'Neill Lake
Oso Reservoir
Otay River/Apache Service Pond
Rainbow Creek
San Diego River/Mission Center Drive
San Diego River/Old Mission Dam
San Luis Rey River/Foussat Road
San Luis Rey River/Highway 1 5
San Luis Rey River/Highway 76
San Luis Rey River/Pankey Road
San Marcos Creek
Sao Marcos Creek/Gibralter
Santa Margarita River/Willow Glen Road
Santre Lake No. 5
S»-err»ater Reservoir
Sam
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
pled for
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Abbreviations:
dt Downstream
» t upstream
N F North Fork
W F West Fork
B-ll
-------
JUNE 1997
Freshwater Database Structure
The freshwater database provides information on contaminant concentrations for five metals
and 26 organic compounds. Exhibit B-2 lists the contaminants included. The contaminants were
selected for inclusion in the database based on the following three criteria:
(1) The proposed water quality standards contained human health or aquatic life
criteria for the contaminant;
(2) TSMP samples were analyzed for the contaminant; and
(3) The contaminant was observed above method detection limits (MDLs) hi at
least one tissue sample.
Exhibit B-2
CONTAMINANTS INCLUDED IN THE
FRESHWATER DATABASE
Metals
Organics
Copper
Mercury
Nickel
Selenium
Zinc
Aroclor 1248
Aroclor 1254
Aroclor 1260
Dieldrin
Endrin
Endosulfan I
Endosulfan II
Endosulfan Sulfate
HCH-alpha
HCH-gamma
Hexachlorobenzene
Toxaphene
o,p'-DDT
p.p'-DDT
o,p'-DDE
p,p'-DDE
o,p'-DDD
p,p'-DDD
p,p'-DDMU
alpha-Chlordane
gamma-Chlordane
Cis-Chlordane
Trans-Chlordane
Cis-Nonachlor
Trans-Nonachlor
Oxychlordane
B-12
-------
JUNE 1997
In addition to the criteria listed above, the freshwater database includes only those samples
collected between 1988 and 1993. Data were limited to this period to best reflect current water
quality conditions. In addition, all tissue concentrations in the database are measured in fish fillets
without skin — the most commonly consumed portion offish caught by anglers.
The database includes more than 360 composite samples of 32 different species offish. Each
composite contains tissue from an average of six fish of a single species. The number offish per
composite sample ranges from one to 65. As a result, the number of fish samples actually
incorporated into the analysis is substantially greater than the number of composites.
We have grouped the composite samples into one of five general species categories based
on family level taxonomy. These categories include bass, trout, catfish, panfish, and other. The
species included within each of these groupings are listed in Exhibit B-3. For each species category
the number of samples and the number of samples containing contaminants at concentrations above
the MDL are summarized in Exhibit B-4.
San Francisco Bay Fish Tissue Database
Fish Tissue Data Source
In 1994, California's Water Resources Control Board - San Francisco Bay Region undertook
a study of contaminant levels in edible fish tissues collected from San Francisco Bay.1 The main
goal of the study was to identify the contaminants, fish species, and geographic areas within San
Francisco Bay that pose the greatest health risk to Bay anglers. The San Francisco Bay fish tissue
database constructed for this analysis contains a subset of the contaminant data collected during the
1994 study.
The San Francisco Bay study includes fish tissue samples collected from 16 stations located
throughout the Bay. Thirteen of these stations were classified as "geographically discrete," or
stations providing contaminant data for well-defined areas of the Bay. These stations were selected
to obtain data that were proximate to commonly fished shorelines and piers, and either known to be
contaminated or thought to be contaminant free. Furthermore, the stations were selected because,
together, they provide geographic coverage of the entire Bay. Three additional sampling locations
1 Contaminant Levels in Fish Tissue from San Francisco Bay, Final Draft Report, December,
1994.
B-13
-------
JUNE 1997
Exhibit B-3
FRESHWATER SPECIES CATEGORIES
Common Name
BASS:
Largemouth bass
Smalhnouth bass
White bass
TROUT:
Brook trout
Brown trout
Coast cutthroat trout
Eagle lake trout
Kokanee
Lahontan cutthroat trout
Rainbow trout
Steelhead rainbow trout
CATFISH:
Black bullhead
Brown bullhead
Channel catfish
Flathead catfish
White catfish
Yellow bullhead
f AN FISH:
Bluegill
Green sunfish
Redear sunfish
Sacramento perch
White crappie
OTHER:
Carp
Goldfish
Hardhead
Hitch
Mozambique tilapia
Redbelly tilapia
Sacramento squawfish
Sacramento sucker
Santa ana sucker
Stnped mullet
Genus
Micropterus
Micropterus
Morone
Salvelinus
Salmo
Oncorhynchus
Oncorhynchus
Oncorhynchus
Oncorhynchus
Oncorhynchus
Oncorhynchus
Ameiurus
Ictalurus
Ictalurus
Pylodictis
Ameiurus
Ictalurus
Lepomis
Lepomis
Lepomis
Archoplites
Pomoxis
Cyprinus
Carassius
Mylopharodon
Lavinia
Tilapia
Tilapia
Ptychocheilus
Catostomus
Catostomus
Mugil
Species
salmoides
dolomieu
chrysops
fontinalis
trutta
clarki clarki
mykiss aquilarum
nerka
clarki henshawi
myidss
mykiss gairdneri
melas
nebulosus
punctatus
olivaris
catus
natalis
macrochirus
cyanellus
microlophus
intemtptus
annularis
carpio
auratus
conocephalus
exilicauda
mossambica
zillii
grandis
occidentalis
santaanae
cephalus
B-14
-------
JUNE 1997
Pollulint
Copper
Mercury
Nickel
Selenium
Zinc
Total Chlordane3
Total DDT'
Dieldrin
Total Endosulfan'
Endrin
HCH alpha
HCH gamma
Hexachlorobenzene
Total PCBs'
Toxaphene
Exhibit B-4
SUMMARY OF FRESHWATER FISH TISSUE OBSERVATIONS
ToUl
N*mhrr •!
Simpln
12
369
50
289
12
247
247
247
233
247
247
247
247
249
247
Namtwr »f
S*mplr«
Atwte MDI.1
II
359
2
283
12
72
190
50
41
2
6
21
24
41
26
BlM
N«mtwf of
Simpltt
3
108
12
77
3
64
64
64
62
64
64
64
64
64
64
N«n»h»f of
SiMptet
Atwte MDL
2
108
0
76
3
10
42
0
1
0
0
3
0
7
0
Trout
limtor •(
Stmpln
4
78
11
76
4
36
36
36
35
36
36
36
36
37
36
Ninthrr »f
S«mpl«
Ate** MDL
4
75
0
76
4
5
22
0
0
0
0
1
0
2
0
Catfish
Nambtr of
Simple*
0
71
8
40
0
47
47
47
42
47
47
47
47
47
47
Number of
Simples
Above MDL
0
70
1
36
0
21
47
20
16
0
4
6
8
12
9
Panflsh
Number of
Simples
1
35
9
32
1
24
24
24
22
24
24
24
24
24
24
Number of
Simples
Above MDL
I
35
1
32
1
1
9
1
0
0
0
1
0
1
0
Other
Number of
Simples
4
77
to
64
4
76
76
76
72
76
76
76
76
77
76
1 MDL = Method Detection Limit
: Total Chlordane = alpha-Chlordene + gamma-Chlordene + cis-Chlordane + trans-Chlordane + cis-Nonachlor + trans-Nonachlor + Oxychlordane
' Total DDT = o.p'-DDT + p,p'-DDT + o,p'-DDE + p,p'-DDE + o,p'-DDD + p,p'-DDD + p,p'-DDMU
4 Total Endosulfan = Endosulfan 1 + Endosulfan II + Endosulfan Sulfate
5 Total PCBs = Aroclor 1248 + Aroclor 1254 + Aroclor 1260
Number of
Simples
Above MDL
4
71
0
63
4
35
70
29
24
2
2
10 .
16
19
17
B-15
-------
JUNE 1997
were classified as "non-discrete regions," or areas of open bay. These regions were used to collect
shark samples and were denned as North Bay, Central Bay, and South Bay. Exhibit B-5 lists all 16
sampling locations. (See Exhibit 3-12 for a map of these locations).
The study's collection protocol targeted fish species with high probability of catch and
consumption by Bay area anglers, and high potential for contaminant accumulation due to feeding
behavior or habitat range. Specific species collected included white croaker, shiner surfperch,
walleye surfperch, white surfperch, leopard shark, brown smoothhound shark, striped bass, sturgeon,
and halibut.
Fish collected at each station were combined into single-species composite samples for
chemical analysis. Depending on the species, the number offish required to obtain a standard 200
gram composite varied. White croaker, walleye surfperch, and white surfperch required five fish for
a composite. Shiner surfperch required 20 fish. Composites of shark, halibut, sturgeon, and striped
bass each required three fish.
Contaminant analyses were conducted on fish fillets. To reflect common fish preparation
methods, white croaker and all surfperch fillets analyses included the skin; shark, halibut, sturgeon,
and striped bass were analyzed without skin. Each composite sample was analyzed for trace metals,
polychlorinated biphenols (PCBs), pesticides, and polycyclic aromatic hydrocarbons (PAHs).
Selected samples were analyzed for dioxins and furans.
B2: San Francisco Bay Database Structure
The San Francisco Bay database includes contaminant concentrations for five metals, PCBs,
21 pesticides, three PAHs, and Dioxin. The contaminants included in the database are listed in
Exhibit B-6. To be included in the database, each contaminant satisfied the following three criteria:
(1) The proposed water quality standards contained human health or aquatic life
criteria^ for the contaminant;
(2) The San Francisco Bay study analyzed for the contaminant; and
(3) The contaminant was observed above MDLs in at least one tissue sample.
B-16
-------
JUNE 1997
Exhibit B-5
SAN FRANCISCO BAY STUDY SAMPLING LOCATIONS
Discrete Sampling Locations:
1. San Mateo Bridge
2. Dumbarton Bridge
3. Fremont Forebay
4. Richmond Inner Harbor
5. Berkeley Pier
6. Oakland Inner Harbor
7. Oakland Middle Harbor Pier
8. Double Rock
9. Islais Creek Channel
10. Point Molate
11. Rodeo Pier
12. San Francisco Pier #7
13. Vallejo Pier-Mare Island Straight
Non-Discrete Sampling Regions:
14. South Bay
15. Central Bay
16. North Bay
(West shoreline near pier)
(East shoreline near pier)
(East of the Freemont Landfill)
(Friendship Shamada Park)
(Fruitvale)
(Candlestick)
(San Pablo Strait)
(Carquinez Stait)
(Municipal Pier)
(Knight Island)
(South of Oakland Bay Bridge)
(Between Oakland and San Rafael Bridges)
(North of San Rafael Bridge)
B-17
-------
JUNE 1997
Exhibit B-6
CONTAMINANTS INCLUDED IN THE
SAN FRANCISCO BAY DATABASE
Metals
Organics
Cadmium
Copper
Mercury
Silver
Zinc
PCBs 5,8,18,28,29,31,44,49,
52, 66,70,74, 87,85,97,99,
101,105,110,118,128,132,
137,138, 149,151,153,156,
157,158,170,174,177,180,
183,187, 189,194,195,201,
203,206,209
Dieldrin
HCH-alpha
HCH-beta
HCH-gamma
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
o,p'-DDT
p,p'-DDT
o,p'-DDE
p.p'-DDE
o,p'-DDD
p.p'-DDD
p.p'-DDMU
p,p'-DDMS
gamma-Chlordene
Cis-Chlordane
Trans-Chlordane
Cis-Nonachlor
Trans-Nonachlor
Oxychlordane
Fluoranthene
Fluorene
Pyrene
Dioxin (as 2,3,7,8-TCDD)
B-18
-------
JUNE 1997
More than 450 individual fish from seven species comprise the 64 composite samples
included in the San Francisco Bay database developed for this analysis. We have grouped the
composite samples into one of four general species categories based on family level taxonomy.
These categories include white croaker, perch, striped bass, and shark. The species included within
each grouping are listed in Exhibit B-7. For each species category, the number of samples and the
number of samples containing contaminants at concentrations above the MDL are summarized in
Exhibit B-8. Samples of halibut and sturgeon were collected during the San Francisco Bay study
but are not included in our database due to limited sample sizes.
Exhibit B-7
SAN FRANCISCO BAY SPECIES CATEGORIES
Common Name
Genus
Species
WHITE CROAKER:
White croaker
PERCH:
Shiner surfperch
Walleye surfperch
White surfperch
STRIPED BASS:
Striped bass
SHARK:
Brown smoothhound shark
Leopard shark
Genyonemus
Cymatogaster
Hyperprosopon
Phanerodon
Morone
Mustelus
Triakis
Hneatus
aggregate
argenteum
fiircatus
saxatilis
henlei
semifasciata
B-19
-------
JUNK 1997
Exhibit B-8
SAN FRANCISCO BAY FISH TISSUE OBSERVATIONS
Pollutant
Cadmium
Copper
Mercury
Silver
Zinc
Total Chlordane:
Total DDT'
Total PCBs4
Dieldrin
HCH alpha
HCH beta
HCH gamma
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Fluoranthene
Fluorene
Pyrene
Dioxin
Total
Number
of
Samples
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
17
Number of
Samples
Above MDL1
14
64
64
5
64
61
64
64
49
22
1
17
4
12
23
10
4
1
9
White Croaker
Number
of
Samples
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
9
Number of
Samples
Above MDL
4
25
25
0
25
25
25
25
24
18
1
12
3
8
13
0
1
0
8
Surf Perch
Number
of
Samples
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
3
Number of
Samples
Above MDL
2
18
18
4
18
18
18
18
14
3
0
0
0
1
3
9
2
0
0
Striped Bass
Number
of
Simples
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
2
Number of
Simples
Above MDL
1
9
9
0
9
9
9
9
9
1
0
5
1
3
7
1
1
1
1
Shark
Number
of
Simples
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
3
Number of
Simples
Above MDL
7
12
12
1
12
9
12
12
2
0
0
0
0
0
0
0
0
0
0
1 MDL = Method Detection Limit
: Total Chlordane = gamma-Chlordene + cis-Chlordane + trans-Chlordane + cis-Nonachlor + trans-Nonachlor + Oxychlordane
' Total DDT = o,p'-DDT + p,p'-DDT + o,p'-DDE + p,p'-DDE + o,p'-DDD + p,p'-DDD + p,p'-DDMS + p,p'-DDMU
• Total PCBs = PCB congeners 5 + 8 + 18 + 28 + 29 + 31 +44 + 49 + 52+66 + 70 + 74 + 87 + 85 + 97 + 99+101 + 105+ 110+118 + 128+132+137+ 138+149+ 151 +153+156+157+ 158 + 170 +
174+ 177+ 180+ 183+ 187+ 189+ 194 + 195 + 201 +203 + 206 + 209
R-?n
-------
APPENDIX C
FISH CONSUMPTION RATES
-------
JUNE 1997
FISH CONSUMPTION RATES
The quantity offish consumed is an important factor in this report's analysis of health risks
associated with current levels of toxic contaminants in tissue of non-commercially caught freshwater
and San Francisco Bay fish. Since the analysis evaluates the risks for anglers, the consumption rate
reflects the habits of mis segment of the population, rather than those of the population as a whole.
EPA estimates fish consumption among the general population at 6.5 grams per person per day;
however, studies of consumption rates among anglers estimate substantially higher rates for this
specific group. EPA offers default values to be used in evaluating potential risks from fish
consumption, but recommends using local consumption data whenever they are available.1
Following EPA's guidance, we have conducted this analysis based on the results of a 1994
survey of fish consumption patterns among anglers in Santa Monica Bay that provides recent
estimates of consumption rates for California anglers.2 Specifically, we assumed that a "typical"
California angler would consume between 21.4 and 49.6 grams of fish per day. This range is
bounded by the median (21.4 g/day) and the mean (49.6 g/day) from the Santa Monica Bay study.
Since this range covers the central portion of the study's fish consumption distribution, we assumed
that the vast majority of California anglers would consume fish within these rates. We present all
estimates of individual and population risks based on this range.
We also provide individual risk estimates for anglers at the high end of the fish consumption
distribution. Based on the Santa Monica Bay study, we use the 90th percentile consumption rate of
107.1 g/day to represent these high consumption anglers. The 90th percentile value may also be
representative of subgroups of anglers, such as those relying on their fish catch for subsistence, or
those from a specific ethnic group, whose diets contain substantially more fish than other anglers'.
These values are listed along with those from several other studies in Exhibit C-l. This
exhibit shows that the consumption rates from the Santa Monica Bay Study are within the range of
other reported values.
1 See USEPA, Guidance for Assessing Chemical Contamination Data for Use in Fish
Advisories. Volume 1: Fish Sampling and Analysis, Office of Water, EPA 823-R-93-002, August
1993.
2 Santa Monica Bay Restoration Project, Santa Monica Bay Seafood Consumption Study,
prepared by Southern California Coastal Water Research Project and MBC Applied Environmental
Sciences, June 1994.
C-l.
-------
JUNE 1997
Exhibit C-l
SELECTED FISH CONSUMPTION ESTIMATES
Source
Consumption
Rate(g/day)
Santa Monica Bay Study of anglers1
mean
median
90th percentile
49.6
21.7
107.1
California Office of Environmental Health Hazard Assessment (average
value used in assessing human health risks)2
23
USEPA default values for recreational anglers3
median
90th percentile
30
140
Sport-Caught Fish in Michigan4
Low-income minority
Other minority
Other sport fishers
43.1
11.1
16.7
Sources
Santa Monica Bay Seafood Consumption Study, June 1994.
California Environmental Protection Agency, Office of Environmental Health Hazard
Assessment, "Food Consumption Value," Memorandum from R.K. Brodberg to Dave Morry,
May 24, 1995.
USEPA, Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories, August
1993
West, et al., 1993, as reported in USEPA's Regulatory Impact Analysis of the Final Great Lakes
Water Quality Guidance, March 1995.
C-2
-------
APPENDIX D
SUPPLEMENTAL INFORMATION FOR THE
ANGLER RISK ASSESSMENT
-------
JUNE 1997
SUPPLEMENTAL INFORMATION FOR
THE ANGLER RISK ASSESSMENT
This appendix provides background information for the calculation of angler cancer and
noncancer risks. In addition, it describes the specific carcinogenic and noncarcinogenic effects of
contaminants that pose potentially significant risks to freshwater and/or San Francisco Bay anglers.
Much of the text presented in this appendix has been adapted from EPA's March 1995 Regulatory
Impact Analysis of the Final Great Lakes Water Quality Guidance.
CARCINOGENIC EFFECTS: NON-THRESHOLD CALCULATIONS
AND SUBSTANCE-SPECIFIC CARCINOGENIC EFFECTS1
Part of EPA's assessment of carcinogenic substances is a rating of the "weight of evidence"
concerning carcinogenicity. The evidence from human and animal studies is cross-tabulated into
one of five categories: (1) sufficient evidence, (2) limited evidence, (3) inadequate evidence, (4) no
data concerning carcinogenicity, and (5) no evidence of carcinogenicity. The classification scheme
is presented in Exhibit D-l.
Exhibit D-l
EPA CLASSIFICATION SCHEME FOR CARCINOGENS
Group
A
Bl
B2
C
D
E
Description
Human carcinogen; sufficient human evidence.
Probable human carcinogen; limited human evidence.
Probable human carcinogen; sufficient animal evidence, inadequate or no human
evidence, or no human data.
Possible human carcinogen; limited animal evidence, inadequate or no human
evidence, or no human data.
Not classifiable as to human carcinogenicity; inadequate human and animal evidence
or no data available.
Evidence of noncarcinogenicity for humans.
Source: U.S. EPA, Guidelines for Carcinogen Risk Assessment, 51 FR 33992-34054, 1986.
1 For more detailed information on EPA's method for estimating cancer risks, see U.S. EPA,
Risk Assessment Guidance for Superfund, Volume I: Human Health Evaluation Manual, December
1989.
D-l
-------
JUNE 1997
In addition to the qualitative rating assigned to potentially carcinogenic substances, EPA
develops substance-specific cancer slope factors (CSFs) for potential carcinogens. A CSF gives the
increase in lifetime cancer risk for an individual continuously exposed to a substance, from birth to
death, per unit increase in the substance's concentration.2 CSFs provide estimates of risks associated
with low-dose exposure to suspected or known carcinogens. They are estimated from data on high
dose human exposures and/or high dose laboratory exposure to animals. The CSF for an agent with
an "A" rating will be based - at least in part - on human data, while one with a "B2" rating will be
based entirely on animal data.
Generating a Cancer Slope Factor
In deriving a CSF, EPA evaluates available toxicological information about a chemical and
selects an appropriate data set. In choosing appropriate data sets, human data of high quality are
preferred to animal data. If animal data are used, the species that responds most similarly to humans
is preferable. If there is no clear choice among species for which data exist, data for the most
sensitive species is given the greatest emphasis. Occasionally, when no single study is judged to
be most appropriate, EPA may derive a CSF based on the geometric mean of slope factors from
several studies that collectively support the estimate.
Concept of Nonthreshold Effects
Carcinogens are assumed to have no threshold, i.e., there is no level of exposure that does
not pose some probability, however small, of generating a carcinogenic response. Therefore, the
development of a CSF usually involves extrapolating from the high doses administered to
experimental animals to the lower exposure levels expected for human exposure in the environment.
Because the extrapolation of the dose-response is to a range where data are not available, the actual
CSFs are uncertain. Hence, a large margin of safety is built into the slope factors. Generally, EPA
takes a conservative approach in estimating a CSF by calculating the slope factor as the highest value
that can be justified with 95 percent confidence. Thus, given the data, it is unlikely that the CSF is
greater than that reported.
2 U.S. EPA, Integrated Risk Information System, 1995.
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Assessing Carcinogenic Risks
A substance-specific CSF is multiplied by the substance-specific daily dose to estimate the
incremental probability of a person developing cancer over a lifetime (70 years) as a result of
exposure to the potential carcinogen. A cancer risk of 1 x 10'6 implies a probability of one in a
million of developing cancer. Risk managers generally consider a cancer risk of 1 x 10~6 sufficient
to protect the general population.
Combined Risks for Multiple Substances
To determine the overall potential for carcinogenic effects from exposure to more than one
substance, the sum of substance-specific cancer risks is calculated. This risk summation assumes
that there are no antagonistic or synergistic interactions and that all substances produce the same
effect (i.e., cancer). If these assumptions are incorrect, the actual multiple-substance risk may be
over- or under-estimated.
Carcinogenic Effects Associated with Fish Tissue Contaminants
A summary of the carcinogenic effects for contaminants that pose potentially significant
cancer risks to freshwater or San Francisco Bay anglers is provided below. Unless otherwise
indicated, descriptions of the carcinogenic effects of these contaminants are based on data obtained
from EPA's Integrated Risk Information System, Forth Quarter, 1996.
Chlordane — Chlordane is classified as a B2 probable human carcinogen. Although human
carcinogenicity data are inadequate, there is sufficient evidence of carcinogenicity in studies in
which benign and malignant liver tumors were induced in four strains of mice of both sexes, as well
as in male rats. This compound is structurally related to other known liver carcinogens. The
quantitative estimate of the CSF, 1.3 (mg/kg-day)"1, is derived from the geometric mean of several
data sets, based on the incidence of liver tumors in mice and rats.
DDT - DDT is classified as a B2 probable human carcinogen. No case studies or
epidcmiologicaJ investigations are available concerning the carcinogenic effects of DDT in humans
following oral exposure. However, DDT is one of the most widely studied pesticides in animals,
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and numerous carcinogenicity studies are available for several animal species. The CSF of 0.34
(mg/kg-day)"1 is derived from the geometric mean of several data sets, based on the incidence of liver
tumors in mice and rats after exposure to 4,4'-DDT.
Dieldrin - Dieldrin is a B2 probable human carcinogen with a unit risk factor of 16 (mg/kg-
day)"1. There is inadequate evidence of human carcinogenicity for this contaminant. Two studies
of workers exposed to aldrin and dieldrin reported no increased incidence of cancer. However, both
studies were limited in their ability to detect an excess of cancer deaths because exposure levels for
workers were not quantified. In addition, the number of workers studied was small, the mean age
of the cohort was young, the number of expected deaths was not calculated, and the duration of
exposure and of latency was relatively short. EPA's basis for its B2 classification is the
carcinogenicity of dieldrin hi seven strains of mice when dieldrin is administered orally. Dieldrin
is also structurally related to other compounds (aldrin, chlordane, heptachlor, heptachlor epoxide,
and chlorendic acid) that produce tumors in rodents. Therefore, EPA classifies the animal
carcinogenicity data for this contaminant as "sufficient." At different dose levels, the effects range
from benign liver tumors, to liver carcinomas with transplantation confirmation, to pulmonary
metastases.
Dioxin — The EPA has classified dioxin (2,3,7,8-TCDD) as a B2 probable human carcinogen
when considered alone, and a Bl carcinogen (limited human evidence in addition to sufficient
animal evidence of carcinogenicity) when considered in association with phenoxyherbicides and/or
chlorophenols. The estimated CSF for dioxin is based on a study showing increased incidence of
tumors of the lungs, liver, hard palate, and nasal turbinates in female rats maintained on diets
containing dioxin for two years. The EPA estimated the CSF from the results of two different
pathologic examinations that produced differences in tumor incidence, and hence, slightly different
values.' The final slope factor of 1.5 x 10s (mg/kg-day)"1, is the average based on these separate
calculations.4
•
PCBs — PCBs have been classified as B2 probable human carcinogens based on a 1996 study
that found liver tumors in female rats exposed to Aroclors 1260,1254,1242, and 1016, and in male
rats exposed to Aroclor 1260. Human data are currently inadequate yet suggestive of carcinogenic
5 Agency for Toxic Substances and Disease Registry, lexicological Profile for 2,3,7,8-
Tctrachlorodibenzo-p-Dioxin, June 1989.
* US EPA, Health Effects Assessment Summary Tables: Annual Update FY-1994, March
1994.
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effects in the liver and lungs via ingestion, inhalation, or dermal exposure. The CSF for PCBs of
2.0 (mg/kg-day)'1 used in this analysis is based on EPA's 1996 guidance for assessment of health
risks resulting from exposure to PCBs.5 EPA's guidance recommends a tiered approach that uses
PCB CSFs ranging from 0.04 to 2.0 mg/kg-day depending on the characteristics of the exposure
pathway and congener composition of the PCB mixture. EPA notes that bioaccumulated congeners
ingested through the food chain (e.g., consumption of recreationally caught fish) tend to exhibit the
highest chlorine content and persistence. Therefore, EPA recommends using the highest PCB CSF
of 2.0 mg/kg-day for food chain exposure pathways where environmental processes tend to increase
risk.
The data regarding occupational and accidental exposures of humans to PCBs are
inconclusive due to confounding exposures, lack of exposure quantification, and small sample sizes.
In one such study, male workers at a capacitor manufacturing plant in Italy exhibited a statistically
significant increase in gastrointestinal tract cancer over local and national rates. Hematologic cancer
incidence in female workers exceeded local but not national rates. Another study of 2,588 capacitor
plant workers in New York and Massachusetts with occupational exposure to Aroclor 1254,1242,
and 1016, showed a statistically significant increase in death from cancer of the liver, gall bladder,
and biliary tract.
An occupational cohort study of 3,588 capacitor plant workers in Indiana analyzed the health
effects of varying levels of exposure to Aroclor 1242 and 1016. At the end of the follow-up period,
workers showed a significant increase in malignant melanomas compared to national rates. A cohort
study of 142 male Swedish capacitor plant workers who had been exposed to PCBs for an average
of 6.5 years did not indicate any excess mortality of cancer incidence; however, the follow-up time
was limited and the cohort was small.6
Statistical!) significant excess risk of liver cancer has been reported in a 16-year follow-up
of patients who consumed PCB-contaminated rice oil in the Yusho, Japan incident. However, there
were a number of serious limitations in this study. First, there was a lack of information concerning
job histories or the potential influence of alcoholism or smoking. Second, the information
5 USEPA. National Center for Environmental Assessment, Office of Research and
Development PCBs Cancer Dose-Response Assessment and Application to Environmental
Mixtures, EPA'600P-96/001F, September 1996.
6 Agency for Toxic Substances and Disease Registry, Toxicological Profile for Selected
PCBs (Aroclor-1260.'1254.-1248.-1242,-1232,-1221, and-1016), June 1989.
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concerning the diagnosis of liver cancer was obtained from the victims' families and may not have
been independently verified by health professionals. Additionally, there were confounding
exposures to polychlorinated dibenzofurans and polychlorinated quinones; thus, the findings are
considered tentative. In general, although studies of humans exposed to PCBs are suggestive of
excess risk of liver cancer, the available epidemiological data do not indicate a consistent
tumorigenic effect.
There also are a large number of animal studies that review the carcinogenic potential of
PCBs. A recent study of Sprague-Dawley rats compared carcinogenicity across different Aroclors,
dose levels, and sexes. Statistically significant increased incidences of liver adenomas or carcinomas
were found in female rats for all Aroclors and in male rats for Aroclor 1260. This study also
investigated tumor progression after exposure ended (stop-studies). Aroclors 1254 and 1242 resulted
in tumor incidences that were nearly proportional to exposure duration, while stop-study tumor
incidences for Aroclor 1016 were zero. The stop-study associated with Aroclor 1260 resulted in a
greater cancer incidence than the lifetime exposure.
A long-term bioassay of Aroclor 1260 with rats produced hepatocellular carcinomas when
100 ppm was administered for 630 days to 200 animals. In another study, female rats surviving at
least 29 months had a 91 percent incidence of liver carcinomas; however, male rats had only a four
percent incidence rate.
Toxiphrar — Toxaphene is classified as a B2 probable human carcinogen based on
inadequate human evidence and sufficient animal evidence. Oral exposure to this chemical has
resulted in dose-related increases in liver carcinomas in mice and thyroid tumors in rats. Based on
these data, EPA's estimated CSF is 1.1 (mg/kg-day)-'.
NONCARCINOGEMC EFFECTS: THRESHOLD CALCULATIONS
AND SUBSTANCE-SPECIFIC HEALTH EFFECTS7
Unlike carcinogenic effects, noncarcinogenic effects are assumed to occur only at exposures
above a threshold concentration below which protective mechanisms and function reserve capacities
prevent reactions to exposure. Therefore, a range of exposures exists from zero to some finite value
7 For more detailed information on EPA's method for estimating noncancer risks, see U.S.
EPA, Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual,
December 1989.
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that can be tolerated by the individual without the manifestation of an adverse effect. The reference
dose (RfD) is an estimate of a daily exposure level for humans, including sensitive subgroups, that
is not likely to cause adverse effects during a lifetime of exposure. To develop an RfD, it is
necessary to identify the upper bound of a tolerance range for the most sensitive populations.
Derivation of an Oral Reference Dose
To develop an oral RfD, EPA examines all available toxicity studies for a substance
following oral exposure. If adequate human data are available, this information is used as the basis
of the RfD. Otherwise, animal study data are used. When choosing the appropriate human or animal
study to use in deriving the RfD, EPA must make judgements regarding the relevance and quality
of the available experimental studies. In addition, EPA must identify the effect characterized by the
"lowest observed adverse effect" (LOAEL), which is referred to as the critical toxic effect, and
serves as the basis for the RfD.
After the study and critical toxic effect have been selected, EPA identifies the exposure level
that represents the highest exposure level tested in the study at which the critical effect was not
observed. This highest "no observed adverse effect level" (NOAEL) is used to develop the RfD.
Applying Uncertainty Factors
The RfD is derived from the NOAEL by consistent application of the following uncertainty
factors (UF):
• A factor of 10 is used to account for variation in biological response to
exposure among the general population and is intended to protect sensitive
subgroups, such as the elderly, from adverse effects.
• A factor of 10 is used when extrapolating from animals to humans to account
for interspecies variability.
• A factor of 10 is used when a NOAEL derived from a subchronic rather than
a chronic study is used as the basis for a chronic RfD.
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• A factor of 10 is used when a LOAEL rather than a NOAEL is used as the
basis for an RfD.
In addition to the UFs listed above, a modifying factor (MF) ranging from greater than zero
to 10 is used to reflect a qualitative professional assessment of additional uncertainties in the critical
study and in the entire toxicity database for the substance not specifically addressed by the preceding
UFs. The default value for the MF is 1.0.
Calculation of the Reference Dose
To calculate the RfD, the appropriate NOAEL (or LOAEL if a suitable NOAEL is not
available) is divided by the product of all of the applicable uncertainty factors and the modifying
factor. The calculation is as follows:
RfD = NOAEL or LOAEL/(UF, X UF2... X MF)
Oral RfDs are expressed in units of mg/kg-day.
Accessing the Potential for Noncarcinogenic Effects
The RfD assumes that there is an exposure threshold below which adverse effects will not
occur. If the exposure level (dose) exceeds this level, adverse effects could potentially occur. This
potential for adverse systemic effects is characterized by the hazard quotient (HQ). The HQ is
calculated according to the following equation:
HQ = Dose/RfD
The greater the value of the HQ above one, the greater the potential for adverse effects. However,
the HQ is not a statistical probability; a ratio of 0.001 does not mean that there is a one in one
thousand chance of the effect occurring. Furthermore, the potential for adverse effects does not
increase linearly as the RfD is approached or exceeded.
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Risks for Exposure to Multiple Substances
To determine the overall potential for noncarcinogenic effects from exposure to more than
one substance, EPA has developed a hazard index (HI) approach. Under this approach, EPA
assumes that simultaneous exposure to several substances below their respective threshold levels
could result in an adverse health effect. Thus, the HI is equal to the sum of the HQs.
Noncarcinogenic Effects Associated with Fish Tissue Contaminants
A summary of the critical systemic effects associated with exposure to the four contaminants
that pose potentially significant noncancer risks to freshwater or San Francisco Bay anglers is
provided below. These contaminants are the only ones among those considered in this analysis that
have an HQ greater than 0.5 under the typical or 90th percentile fish consumption rate scenarios.8
Chlordane — The oral RfD for chlordane is based on a chronic study in which rats were fed
chlordane at various dietary levels. The critical systemic effect observed was liver lesions in
females, at 0.27 mg/kg-day. The RfD of 6.0 x 10'5 mg/kg-day is based on a NOEL of 0.06 mg/kg-
day and an uncertainty factor of 1,000. An uncertainty factor of 100 was used to account for the
inter- and intraspecies differences; and an additional factor of 10 was used to account for the lack
of an adequate reproduction study and an adequate chronic study in a second mammalian species,
and the generally inadequate sensitive endpoints studied in the existing studies.
DDT — The oral RfD for DDT was determined from a chronic study in which rats were fed
DDT in their diet for 27 weeks. The critical effect was liver lesions. The RfD of 5 x 10"4 mg/kg-day
is based on a NOEL of 0.05 mg/kg-day and an uncertainty factor of 100. An uncertainty factor of
100 was selected to account for uncertainty associated with interspecies conversion and to protect
sensitive human subpopulations.
Dioxin — The oral reference dose for dioxin is based on a three generation reproductive study
in Sprague-Dawley rats receiving 0.001, 0.1 or 0.01 ug 2,3,7,8-TCDD/kg-day. The lowest
observable effect level (LOEL) was 0.001 ug 2,3,7,8-TCDD/kg-day based on a reduction in
8 We have included contaminants with HQs as low as 0.5. Given the uncertainties in the risk
estimates, an HQ as low as 0.5 suggests that exposure to a contaminant may be high enough to
produce an adverse health effect.
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gestation index, decreased fetal weight, increased liver to body weight ratio, and increased incidence
of dilated renal pelvis. An uncertainty factor of 1,000 was applied to account for interspecies
variation and for the use of a LOAEL, resulting in an RfD of 1 x 10'9 mg/kg-day.'
Mercury - The mercury RfD is derived from a study of citizens in rural Iraq that were
exposed to mercury-treated seed grain that was mistakenly used in bread. Adults and children who
consumed bread for two to three months showed latent toxicity, with infants exposed during
gestation being the most sensitive group. Infants exposed during fetal development exhibited
cerebral palsy, altered muscle tone, deep tendon reflexes, and delayed developmental milestones.
Adults exhibited neurological signs including paresthesia, ataxia, reduced visual fields, and hearing
impairment. Using mercury concentrations in hair and assumptions of steady-state conditions and
first-order kinetics, the study estimated that the individuals had a dietary intake of 65 yug/L mercury
per day. The resulting oral RfD of 1.0 x 10"4 mg/kg-day includes an uncertainty factor of 10.
PCBs - The liver is a principal site of systemic PCB toxicity in animals. Liver effects have
been observed in numerous studies with exposed rats, mice, guinea pigs, rabbits, dogs, and monkeys,
but rats have been tested most extensively. The effects appear to be reversible at low doses and are
similar among species. Nonmalignant proliferative lesions were observed in the liver at high
frequencies of PCB-treated rats and mice. Liver alterations were observed in monkeys fed diets
containing 2.5 and 5.0 ppm Aroclor 1248. However, these effects were examined by autopsy in only
one animal per dose level. In addition, rats exposed to Aroclor 1254 for four to 12 weeks
experienced thyroid alterations. Thyroid effects also appeared to be reversible after cessation of
exposure.10
Studies of PCB-exposed workers provide inconsistent but suggestive evidence for subclinical
increases in serum enzymes that are indicators of possible liver damage. Liver dysfunction has not
been demonstrated in PCB-exposed workers.
The RfD for PCBs is based on toxicity studies of the effects of long-term exposure to Aroclor
1254 on monkeys. Based on the LOAEL for changes in immune response, periocular tissue, and nail
bed formation, EPA has developed an RfD of 2 x 10'5 mg/kg-day.
9 Agency for Toxic Substances and Disease Registry, Toxicological Profile for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin, June 1989.
10 Agency for Toxic Substances and Disease Registry, Toxicological Profile for Selected
PCBs (Aroclor -1260, -1254, -1248, -1242, -1232, -1221, and-1016), June 1989.
i
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APPENDIX E
ECOLOGY AND ECOLOGICAL EFFECTS
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This appendix was adopted from Chapter 2, Ecological Risk and Decision Making
Workshop (1995), U.S. Environmental Protection Agency, Office of Sustainable Communities
and Ecosystems, Office of Policy, Planning and Evaluation, Washington, D.C. 20460
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2. ECOLOGY AND ECOLOGICAL EFFECTS UNIT
Contents
Summary of Ecology Unit 1
Basic Concepts in Ecology 4
Ecology Definition 5
Species 7
Populations g
Habitat 9
Community 10
Niche 11
Succession 12
Evolution 14
Food Web .-.-. 16
Ecosystem 18
Abiotic Factors 20
Photosynthesis 21
Decomposition 22
Nutrients and Biogeochemical Cycles 24
Carbon Cycle 26
Major Types of Ecosystems 28
Ecological Effects of Stressors 29
Stressor Types 30
Ecological Exposure to Chemical Stressors 32
The Nature of Chemical Stressors 34
Bioconcentration, Bioaccumulation, Biomagnification 35
The Nature of Physical Stressors 37
The Nature of Biological Stressors 39
Kinds of Effects Caused by Chemical Stressors 40
Eutrophication 44
Acid Deposition 45
Kinds of Effects Caused By Physical Stressors 46
Habitat Fragmentation 47
Kinds of Effects Caused By Biological Stressors 48
Ecological Significance of Effects 49
Natural Versus Human Stressors and Recovery 50
Key Concepts 51
Optional Exercise: A Simulation Model for the Hypothetical What-If Bug Population 57
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995
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Ecology Unit
Summary of Ecology Unit:
June Allotted
Approximately 2 hours are allowed for discussion and lecture.
Summary of the Unit
This unit presents a general overview of ecology to provide participants with the basic concepts and terminology
underlying ecological risk assessments. The information includes a discussion of the types of stressors and
related ecological effects.
Key Concepts
» Ecosystems are complex and dynamic, composed of interacting networks of biotic and abiotic compon-
ents. - ------ -
» Principal ecological components are individuals, populations, communities, and ecosystems.
» Critical to the function of an ecosystem is the flow of energy and nutrients through the system's producers
and consumers.
» Strcnon can affect individual organisms, population growth, community structure and function, and
ecosystem processes.
» Interactions among individuals in a population, and among populations in a community influence the
significance of a stressor's ecological effects.
» The combination of stressor, environmental, and biological characteristics dictates the nature, extent, and
magnitude of ecological effects.
References
Cockerham, L.G., and B.S. Shane, eds. 1994. Basic Environmental Toxicology. CRC Press, Ann Arbor, MI.
Crowder, L.B., J J. Magnuson, and S3. Brant 1 98 1 . Complementarity in the Use of Food and Thermal Habitat
by Lake Michigan Fishes. Can. J. Fish. Aquatic Sci. 38:662-668.
Dasmann. R.F. 1964. Wildlife Biology. John Wiley & Sons, Inc., New York.
Howell. D J. 1 994. Ecology for Environmental Professionals. Quorum Books, Westport, CT.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995 p~1
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Ecology Unii
References (Continued)
Kan, J.R., K.D. Fausch, P.L. Angermeier, P.R. Yarn, and IJ. Schlosser. 1986. Assessing Biological Integrity
in Running Waters: A Method and Its Rationale. Illinois Natural History Survey spec. publ. 5, Champaign,
IL.
Krebs, CJ. 1972. Ecology: The Experimental Analysis of Distribution and Abundance. Harper and Rowe,
Publishers, New York.
Moriarty, F. 1983. Ecotoxicology: The Study of Pollutants in Ecosystems. Academic Press, Inc., Orlando, FL.
Odum, EP. 1993. Ecology and Our Endangered Life-Support Systems. Sinauer Associates, Inc.,
Sunderland, MA.
Smith, R.L. 1990. Ecology and Field Biology. Harper Collins Publishers, New York.
Suter, G.W., II. 1993. Ecological Risk Assessment. Lewis Publishers, Chelsea, MI.
Terres, J.K. 1980. The Audubon Society Encyclopedia of North American Birds. Alfred Knopf, New York.
USEPA. 1993. A Review of Ecological Assessment Case Studies From a Risk Assessment Perspective.
EPA/630/R-92/005. U.S. Environmental Protection Agency, Risk Assessment Forum, Washington, DC.
p-2 Ecological Risk and Decision Making Workshop / Participant Manual / December 12.199
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Ecology Unit
ECOLOGY AND
ECOLOGICAL EFFECTS
UNIT
Ecological Risk and Decision Making Workshop /Participant Manual /December 12, 1995
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Ecology Unit
ECOLOGY AND ECOLOGICAL
crrtCTS
Basic Concept* In Ecology
Ecological Effects of Strassors
There are certain concepts that are important to understand to improve appreciation of ecological risk
assessments. This unit will provide a brief review of ecological concepts, and the ecological effects of man-
made activities and natural stressors.
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Ecology Unit
Basic Concepts in Ecology
Ecology — olkos ("house") logos
("governing rules")
Focus — the primary levels of
ecological organization: species,
populations, communities, and
ecosystems.
Basic Concepts in Ecology
The term "ecology" comes from the Greek phrase oikos ("house") logos ("governing rules"), literally "the rules
of the house." The "rules" refer to the array of relationships and interconnections through which organisms
interact with their environments.
Organisms do not live in isolation but occur in systems that exhibit a certain structure and function, such that
the behavior of the whole is greater than the sum of the parts and therefore, very difficult to predict
» Just as the cell and the entire individual organism represent levels of a system, so do populations of
individuals of the same species and communities of populations characterizing ecosystems (Howell, 1994).
» Ecology is the study of systems in which there are interactions among living organisms, and between those
organisms and the landscapes they inhabit. These relationships and interactions can generally be
characterized in the following manner:
• Among individuals within a population;
- Social interactions among members of a wolf pack, or breeding behavior among stoneflies in a
mountain stream.
• Between individuals of different populations;
- Predator-prey interactions between wolves and moose, or the importance of spottail shiners in the diet
of green herons.
Ecological Risk and Decision Making Workshop /Participant Manual/December 12, 1995
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Ecology (M
Basic Concepts in Ecology {Continued)
• Between organisms and their physical surroundings;
- The relationship between gopher holes and soil microorganisms, or the influence of river water levels
and muskrat populations.
This unit focuses on four primary levels of ecological systems:
» Species;
» Population;
*• Community; and
» Ecosystem.
In doing so, the materials introduce and define some of the ideas and terms commonly used in ecology.
p-6 Ecological Risk and Decision Malting Workshop/Participant Manual/Decemberl 2,1995
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Ecology Unit
ABA
SPECIES
A group of actually or potentially Intarbraadlng
organism that am rvproducttwly MM
othar organisms.
Two animals of Ac same species will not necessarily look exactly alike. Widely distributed species often have
different physical or behavioral characteristics. As a familiar example, consider the species homo sapiens.
Humans exhibit considerable variety in skin, hair and eye color, size, etc. This same type of variety also occurs
in plant and animal species.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995
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Ecology Unit
POPULATIONS
Populations are group* of organisms of the
same apaciaa occupying a particular apaca
over a glvan Interval of tima.
Populations are the next step up the systems hierarchy from the individual organism.
Population structure is the relative proportion of individuals within each stage, e.g., eggs, larva, juveniles, and
adults, or category, e.g., male or female.
A maximum population size can be reached for a limited area and time frame, given specific and limited
amounts of food, shelter, living space, and other resources. This carrying capacity varies from month to month
or even day to day with the seasons and other environmental circumstances.
Population density primarily is a function of three factors: birth rate, death rate, and distribution over time and
space.
Each organism occupies only areas that meet its requirements for life. As a result, a population generally has
a patchy distribution.
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Ecology Unit
HABITAT—WHERE AN
ORGANISM LIVES
Habitat providaa factors nacaasary tor survival,
such as:
• Hiding piacas
* Naating and birthing, anas
• Shatter from ambtant *>aathar conditions
Covar for tha growth and survival of ahada-
totorant apaeiaa of vagatatlon
Structural faaturaa naadad for song parchaa
Foodaourca
In a general sense, a habitat can be thought of as the "address" of an organism.
Habitat structure provides much of what is needed to sustain life. Habitats also need to be a particular size and
often, of a particular configuration to meet the living requirements of a particular species. Habitat size and shape
will vary depending on the quality of the habitat and the requirements of the species.
» For example, species that live at the edge of forests (transitional belts between the interior forest and a
different adjacent landscape) require a much different habitat type than interior forest species.
» For forest interior plants, the minimum area depends on the size at which moisture and light conditions
become sufficient enough to support shade-tolerant species.
Terrestrial habitats are often described in terms of vegetational type, such as a pine forest or a grassland.
Freshwater habitats are broadly classified as standing water or running water.
Literally standing between freshwater and marine habitats, and heavily influenced by both, are estuarine
habitats.
Marine habitats are generally classified as coastal and open ocean.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995
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Ecology Unit
COMMUNITIES
Populations of dMMvnt sp«clM Ito and Interact
wHh om another hi complex i
cofimiunftiea.
A community is an organized assemblage or association of populations in a prescribed area or a specific
habitat (Howell, 1994). No species in nature exists in isolation from all others. Communities, more specifically
biotic communities, are associations of interacting populations and are often defined by the nature of their
interactions or by their location.
Communities can be considered on both large- and small-scale levels. Since most species are distributed
independently according to environmental gradients (e.g., moisture or light levels, temperature, etc.), no clear-
cut boundaries delineate communities. A community could be identified as existing within an entire forest or
as existing within a hollow tree. Other examples of small-scale communities could be a decaying log, a pile of
dead leaves, or the gut of a deer. The adaptations of populations to their habitats, and the interactions between
and among populations determine the nature of a community.
Each community is composed of certain organisms that are characteristic of particular habitats. For example:
» Egrets in salt marsh habitats in eastern North America;
» Saguaro cactus in desert habitats in the southwestern United States; or
» Cattails in freshwater marshes.
Although the species within a community are, to some extent, replaceable by others over space and time, their
functions in the community are relatively fixed.
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Ecology Unit
NICHE
A niche is the role or function of
• species In a community.
Ecological niche is the role or function of a species in its community. The niche is the expression of the
relationship of an individual organism or population to the rest of the community.
An organism's ecological niche is expressed as its "job" in its give-and-take with its environment. More
specifically, an animal's activity pattern, its feeding location, and its place in a food web-^what it eats and what
eats h—•contribute to a description of its niche. For example:
» Red-eyed vireos hunt for food in trees; ovenbirds hunt on the ground.
» Red-tailed hawks are active by day; screech owls are active at night.
Some birds of related species within the same family occupy separate niches in parts of the same kind of tree.
» Bay-breasted, blackburnian, black-throated green, cape may, and yellow-rumpled warblers each live in a
different zone or part of a spruce tree. Each species nests in a different part of the tree and at a different
height above the ground. Each species gathers insects in a different part of the tree. These birds sometimes
overlap in tiie physical space they occupy in or about the tree, but their niches do not (Torres, 1980).
This example points out the importance of the diversity of species. Each species performs a particular function,
and the loss of a species will disrupt the community. This becomes especially important when endangered
species are at risk, because there is little or no reserve capacity for those species to fill vacated niches and
maintain community function.
Plants may form niches according to light levels. For example, in a tropical rain forest different plants live at
different heights—canopy (tall trees), understory trees, shrub layer, and ground layer of vegetation. Plants living
in each layer of the forest have adapted to different light levels.
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Ecology Uni
SUCCESSION
The gradual replacement of on* community
by another a* environmental conditions
change.
Communities exist in a continual state of flux. Organisms die and others are bom to take their place. When)
habitat ts disturbed—for example, by clear cutting, fire, or hurricane—the community slowly rebuilds. Thi
sequence of changes initiated by disturbance is called succession. The creation of any new habitat—a plowa
field, a temporary pond left by heavy rains—invites a host of species particularly adapted to be good pioneers
or to colonize the newly disturbed sites.
is the process whereby the pioneering species adapted to the disturbed habitat are progressive!;
replaced by other species, and so on, until the community reaches its former structure and composition. Fo
example, consider the following sequence of events:
• An oak-hickory community is burned.
» Annual and perennial herbs (pioneers) invade that area.
» Pine seeds blow in.
» The pines and herbs compete for resources.
• Within 30 years, the burned area has become a stand of pines.
• The forest floor (under the pines) shows many oak and hickory seedlings (pine seedlings grow poorly i
shade while competing for nutrients).
» A well-developed oak-hickory understory exists within 50 years.
» Oaks and hickories replace the pines as they die.
» Within 200 years, the burned area once again becomes an oak-hickory forest
This example illustrates that the microenvironment beneath a plant community differs significantly from th;
in the open. Temperature, humidity, soil moisture, and light are all affected by the canopy.
» A stable community consists of species whose seedlings can survive in its unique microenvironment whi
seedlings of other species cannot.
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Succession (Continued)
» If the stable community is removed by some disturbance, leaving the soil exposed to full sunlight, the first
species that colonize the site are not those of the old community; rather, they are seedlings of species
adapted to grow in full light intensity.
Succession has been classified into two types (primary, secondary) according to its origin. The terminal
community is known as the climax, although subtle changes in species composition continue after reaching the
climax growth form. Primary succession is the establishment and development of plant communities in newly
formed habitats previously without plants. Secondary succession is the return of an area to its natural
vegetation following a major disturbance. The characteristics of the dominant species change during succession:
*• Early-stage species are opportunistic, and capitalize on their high dispersal ability to colonize newly created
or disturbed habitats rapidly. These species, which include dandelions and milkweed, typically have small
wind-dispersed seeds. The seeds can remain dormant in soils of forested or shrub-covered areas for years
until fire or treefalls create the bare soil conditions they need for germination and growth of the early-stage
species.
» Climax species disperse and grow more slowly. Their shade tolerance as seedlings, and large size as mature
plants give them a competitive edge over early successional species.
It should be noted that communities do not always return to the climax state following a disturbance, especially
if there is an increasing impact of humans on the environment In some cases, humans might have modified an
area so extensively that the natural disturbance and succession regimes can no longer exist
An example can be seen in some of the southwestern portions of the United States, as well as the many other
arid or semi-arid regions of the world. In these areas, where local climates would normally allow grassland to
maintain itself, the influence of disturbances, such as overgrazing by livestock, have led to the long-term
conversion of productive, arable grassland to desert The same community in a region with a true desert climate
would be a natural condition; however, in "desertified" regions it can be seen as a "disclimax" — a disturbance-
caused climax community.
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Ecology Uni
PRINCIPLES OF EVOLUTION
- No two Individuate art exactly alike
» Them Is competition for survival
» Some Individuate have tnlta better suited for
survival In a particular environment
Evolution consists of changes in the genetic makeup of a population over time. This process occurs because
of several facts:
» All organisms show variation—no two individuals are exactly alike.
» All organisms produce more offspring than can survive to adulthood.
» There is competition for survival within and among species or populations for energy, sunlight, food,
nutrients, water, space, and mates.
» Under given conditions, individuals with certain characteristics have a better chance of survival and
reproduction than others because they can use the environment to better advantage. '
*• Some of those characteristics are inheritable over long time spans—geologic time or less.
The result is natural selection. The commonly used phrase to describe natural selection is "survival of the
fittest" However, this refers to genetic lines and not individuals. Fighting for survival is only a small part of
competition in natural selection.
» Darwin's finches on the Galapagos Islands of the Pacific developed a great variety of bill shapes, behaviors
and other features to facilitate feeding on different types of food (bugs, seeds, flowers, etc.). These
characteristics were developed to adapt to various environmental conditions, such as temperature, moisture
chemistry, light, etc.
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Ecotogy Unit oEPA
Principles of Evolution (Continued)
Artificial selection is the intentional breeding of a species such as livestock, pets, plants, etc. It may also be
the unintentional spread of a species or characteristics, such as resistance of insects to pesticides, or bacteria to
antibiotics. This results in very complex, self-sustaining communities finely adapted to the environment in
which they live. When it is that finely tuned, disturbances to the environment can have a tremendous impact,
from which they may or may not recover.
For most of its history, the human species was subject to the forces of natural selection. This has changed for
several reasons:
» A cultural evolution led to technology, freeing humans to a great extent from the effects of natural selection.
» Humans are still part of ecosystems, but we are now almost always the dominant factor, subjecting other
species to an array of stresses to which they are not adapted.
» For many species, even communities, the rate of introduction of new human stressors (physical, chemical
or biological) far outstrips the rate with which they can evolve adaptations.
» A shift is occurring on the planet from self-sustaining communities that have evolved over very, very long
periods of time, to very recently created communities that require artificial inputs of energy and materials,
e.g., agriculture.
If long-term or unprecedented environmental changes occur, the response by a species or population will be:
» Extinction;
» Survival unchanged; or
» Evolution or adaptation.
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FOOD WEB
Food Web
A food chain is the transfer of energy from one species to another. However, no organism lives wholly on
another, and many organisms share several different food sources. Consequently, food chains interlink and form
food webs (see diagram).
The term food web more accurately describes the complex, interrelated system of pathways through which
the flow of energy takes place in nature. A food web is the total set of feeding relationships among and between
species.
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Food Web (Continued)
The food web hierarchy is described by feeding, or trophic, levels:
> Producers — Producers, primarily green plants, are the trophic level that supports all others.
» Consumers — Consumers rely on producers as an energy source. Most consumers belong to one of three
groups:
• Herbivores, which consume plants.
• Carnivores, which consume meat
• Omnivores, which consume both meat and plants.
Many species are omnivores, living on mixed diets of plant and animal material. For example, black bears feed
on berries, nuts, insects, rodents, and other plant and animal material.
Many species change their feeding habits seasonally or have different food requirements at different life
stages. For example, seeds, nuts, and acorns are staple food items for turkeys during most of the year, but hi
summer, turkeys eat grasshoppers, other insects, frogs, toads, snakes, and other animals.
Trophic Levels and Energy Level
Consumers can be categorized into trophic levels. All organisms that share the same general source of nutrition
are said to be at the same trophic level. Consumers belonging to more than one trophic level are called
omnivoru.
Energy decreases as trophic levels increase — at each step in the food chain, energy is lost in respiration, and less
energ) is available for the next level up. Caloric energy stored by plants is passed through the community
through successive transfers between plants and herbivores, and prey and predators. At each step in the food
cham. a considerable portion of the potential energy transferred in the food is lost as heat. The longer the food
cham. the more restricted the amount of energy that will reach the terminal members. As a result, we rarely find
food chains of more than four or five steps in natural situations. Furthermore, the number of organisms involved
in the populations through which this energy passes becomes smaller with each new link.
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Ecology Unit
ECOSYSTEM
Generalized ecosystem diagram illustrating the systematic nature of
ecosystems and major components of the system
"1
Nulnvnn
An ecosystem includes the physical environment and its component plant and animal populations. In the
simplest of terms, all ecosystems consist of three basic components: the producers, the consumers, and abiotic
(or nonliving) matter (Smith, 1990).
» Producers and consumers make up the biotic (or living) components of an ecosystem and include plants,
algae, bacteria, and animals. As covered previously, populations of these organisms grouped into
recognizable aggregations are known as communities.
• Producers are the energy-capturing base of the system. Producers are largely green plants that are able
to Ax (or transform) the energy of the sun and manufacture food from simple inorganic and organic
substances.
p-ffl
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Ecosystem (Continued)
» Consumers use (eat) the food stored by the producers, rearrange it (through digestion), and finally
decompose the complex materials into simple, inorganic substances (assimilation into body tissues).
The structural elements of an ecosystem are the species, population, community, habitat, and food chain. The
functional elements include niche and the flow of energy through the system's producers and consumers.
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ABIOTIC FACTORS
Soils, sediment, water, solar
radiation, nutrl«ntm, and minerals.
Ecosystems are not dosed systems, existing within neatly defined boundaries. For example, picture a stream
flowing through a deciduous forest, then a grassland, then, gradually, a salt marsh, ultimately emptying into a
bay. Obvious gradations exist along this kind of continuum, yet the ecosystems are identifiable by general
landscape characteristics.
The elements that differentiate ecosystems are abiotic components that make up the physical environment,
such as soils, sediment water (moisture, salinity), solar radiation, and nutrients. These elements determine the
types of organisms that can inhabit a particular ecosystem.
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PHOTOSYNTHESIS
The process toy which plants
convert light energy Into chemical
energy, which Is stored as glucose.
; light energy from the sun is absorbed by photosynthetic organisms (plants, algae,
Ecosystems operate
and photosynthetic bacteria) and transformed into chemical energy in the form of glucose.
» Glucose is a sugar and an organic compound. Compounds that contain carbon and hydrogen are called
organic compounds. The glucose is used to synthesize (or produce) carbohydrates, amino acids, proteins,
fatty acids, fats, vitamins, pigments, etc.
Non-photosynthetic organisms (i.e., animals) get energy by eating this sugar or other substances, such as
carbohydrates, that the plants make from it.
» When an animal eats a plant, the animal gets energy and the carbon-compound that is storing the energy.
The animal uses the compound as a source of carbon to synthesize the substances it needs. In other words,
photosynthesis is important for generating both energy and essential substances in an ecosystem.
Photosynthetic organisms are producers, and non-photosynthetic organisms are consumers (because they must
consume producers to obtain energy).
In summary, organisms need energy to survive, and they need a source of carbon in order to synthesize carbon-
containing substances, such as proteins and fats.
» Photosynthesis supplies both needs by converting light energy into chemical energy, and by combining
carbon dioxide (COj) gas and water to form glucose, an organic compound. Glucose, then, is a source of
energy and organic carbon for making all the other substances organisms need for survival.
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DECOMPOSITION
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Decomposition
Organisms living in any ecosystem require a continual supply of energy and nutrients in order to survive.
Photosynthesis provides the energy, and decomposition provides the nutrients.
Decomposition of organic matter, such as what occurs to fallen leaves and logs, or roadkilied possums, consists
of breaking down organic compounds and returning basic chemical elements, such as carbon, to the soil. The
organisms most commonly associated with decomposition are bacteria and fungi. These microorganisms secrete
enzymes into plant and animal matter, causing them to decompose.
* Bacteria are the major decomposers of animal matter.
» Fungi are the major decomposers of plant material.
Once one group has exploited the material to its capabilities, another group of bacteria and fungi able to use the
remaining material move in. In this way, a succession of microorganisms acts on the organic material until it
is finally reduced to inorganic nutrients. Detritivores are invertebrates that aid decomposition by fragmenting
leaf litter, etc. Examples of detritivores, from smallest to largest size, are as follows:
» Protozoans;
» Mites, springtails, potworms;
» Nematodes, caddisfly larvae, mayfly nymphs; and
» Snails, earthworms, millipedes.
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Ecology Unit
NUTRIENTS AND
BIOOEOCHEMICAL CYCLES
Nutrtsnts am assantlal to plants and
animals and am ussd ovsr and over
again, cycling batwsan organisms and
th* anvtronmant
For an ecosystem to function, nutrients must be available to plants, and must be present in a consumer's diet
Of the many elements required, these eight are the most important:
» Carbon:
» Hydrogen:
» Oxygen:
» Nitrogen:
A basic part of all organic compounds, such as glucose. In the ecosystem, it exists as
carbon dioxide, carbonates, and fossil fuel, and as a part of living tissue.
Also a basic part of organic compounds and an important component of water.
A by-product of photosynthesis. It is used by microbes in the decomposition process, and
is used by animals in cellular respiration. Three major sources of oxygen are carbon
dioxide, water, and molecular oxygen.
An essential element of protein and DNA. It makes up about 79% of the atmosphere as
molecular nitrogen, but most plants can use it in a changed form, such as nitrates or
nitrites.
» Phosphorus: An element involved in photosynthesis. It plays a major role in energy transfer in plane
and animals.
•• Sulfur:
» Calcium:
Like nitrogen, a basic constituent of protein.
Element necessary for proper acid-base relationships, blood clotting, contraction anc
relaxation of the heart muscle, etc.
Magnesium: Element that helps certain enzymes function and is crucial to protein synthesis in plant!
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Ecology Unit
Nutrients and Biogeochemical Cycles (Continued)
These chemical elements are not destroyed upon the death of an organism. They can be used over and over
again, being transferred from organisms to the environment and back to the organisms, in more or less circular
paths, called cycles. Each element that is a nutrient follows its own unique pathway, called a biogeochemical
cycle or nutrient cycle, through the abiotic and biotic components of an ecosystem.
In contrast to energy, which is in constant supply from the sun, nutrients exist on earth in fixed amounts. Life
evolved the means to use mineral nutrients, release them to the abiotic environment, and then use them again.
Although energy eventually leaves the earth as heat, and nutrients remain on earth to be recycled, the pathways
of both are closely tied together. For some nutrients, going back and forth between the physical environmental
and living organisms entails changing from an inorganic element or compound to an organic compound.
The nitrogen cycle is one specific example of the many biogeochemical cycles. Gaseous nitrogen is converted
into ammonia, nitrates and nitrites by specific microorganisms. Plants convert these nutrients into proteins,
DNA, and other organic compounds. Animals obtain these nutrients by eating plants or other animals. When
plants and animals die, certain decomposer bacteria convert the nitrogen-containing organic compounds back
into ammonia, nitrates, nitrites, and gaseous nitrogen beginning the cycle over again.
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CARBON CYCLE
i V
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Ecology Unit
Carbon Cycle
«
The carbon cycle is another critical biogeochemical cycle. The recycling of carbon between the abiotic and
biotic elements of an ecosystem is linked inseparably to the flow of energy through photosynthesis and
respiration. The abiotic part of the carbon cycle involves carbon dioxide, a gas that makes up a small percentage
of the atmosphere (0.03 percent) and is dissolved in the waters of the earth.
» Producers convert solar energy into chemical energy, which they use to convert the carbon in carbon dioxide
into glucose.
» As plants respire (at night), they convert some of the carbon in organic compounds back to carbon dioxide,
which is released into the environment
» The rest of the converted carbon is stored in new plant tissue, which is transferred along a food chain.
» At each link in the food chain, more of the carbon converted by the producer is released by a consumer as
carbon dioxide.
» The release of converted carbon by respiration replaces much of the carbon incorporated into glucose during
photosynthesis.
» In breaking down organic waste and dead organisms, detritivores and bacteria return carbon to the physical
environment in the form of carbon dioxide.
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Ecology Unit
MAJOR TYPES OF ECOSYSTEMS
Tanvatrtal: Grassland*, diatrta. conMt
dacMuoua toraata, alplna, tundra,
ralnforMt
fonjeta.
Aquatic:
Lakaa and pond*. streams and nVaro,
it aatuartaa, opan aaa
There are two major types of ecosystems: terrestrial and aquatic.
Examples of terrestrial ecosystems include:
Rainforest
Deserts
Grasslands
Deciduous Forests
Coniferous Forests
Alpine
Tundra
Amazon, northeastern Australia
Mojave and Sahara
Serengeti, Great Plains of the U.S.
New England maples, Colorado aspens
Rocky Mountains, Mt St Helens
Swiss Alps
Greenland, Siberia
Aquatic ecosystems—freshwater and saltwater—include the following:
*• Lakes and Ponds
» Streams and Rivers
- Wetlands
»• Estuaries
» Open Sea
•• Coral Reefs
Great Lakes, Walden Pond
Ohio River
Florida Everglades
Chesapeake Bay
Pacific Ocean
Australian Great Barrier Reef
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Ecology Unit
AS*
ECOLOGICAL EFFECTS
ofSTRESSORS
Stressor Type*
Kinds of Ecological Effects
Factors Influencing Ecological Effects
Ecological Effects of Stressors
We just concluded a discussion of a few basic terms and concepts necessary to develop a cursory understanding
of the fundamentals of ecology. This section continues in the same manner by providing an overview of the
characteristics of man-made or anthropogenic stressors and their ecological effects.
A definition and description of the types of stressors that commonly are addressed during an ecological risk
assessment will be provided. Such stressors are those we (humans) have control over.
Next, we will discuss some stressor characteristics, followed by examples of the kinds of ecological effects
caused by stressors.
The section concludes with a brief discussion of the ecological significance of the effects caused by
anthropogenic stressors.
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STRESSOR TYPES
an Induttrial ehM
PtiyvlcftJ StivMora Looping* dred0tn0rflllifiQ
conHfucikMif etc.
Biological StraMon Introduce organism and
fMCfOOFMMMSfVIS SUCH Ml
Ecological risk assessments evaluate the effects caused by three general types (or categories) of
stressora-chemical. physical, and biological.
Chemical stresson include hazardous waste, industrial chemicals, pesticides, and fertilizers. These stressors
are by far the most frequently investigated during ecological risk assessments. This is evident in the focus of
most of the major pieces of environmental legislation and the EPA programs developed to enforce such
legislation. For example,
> CERCLA—Uncontrolled hazardous waste (Superftind).
» RCRA—Controlled hazardous waste.
» FIFRA—Pesticide registration.
» TSCA—Manufacture and use of toxic substances.
» CWA—Discharge from municipal wastewater treatment plants and industrial facilities.
Physical stresson are activities that directly remove or alter habitat Ranging from tilling soil to logging, road
construction, and the building of shopping malls, these stressors often are the most destructive because they can
result in total habitat loss as soils are compacted and organisms are lost
EPA's regulatory authority with regard to physical stressors pertains to filling waters of the U.S. including
wetlands (Section 404 of CWA), e.g., placing fill in water for constructing a bulkhead to shore-up waterfron
property.
Biological stressors are organisms or microorganisms that are introduced, or released, (intentionally o
accidentally) to habitats in which they did not evolve naturally. These organisms often are called "exotics.
Biological stressors become a concern when they compete against native species, replace them, and beconv
pests.
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Ecotogy Unit
Stressor Types (Continued)
With regard to ecological concerns, EPA's jurisdiction over biological stressors is limited essentially to the
regulation of genetically engineered microorganisms under the auspices of FIFRA and TSCA (for use in
commerce). The federal agencies primarily responsible for regulating exotics are the U.S. Department of
Agriculture and the U.S. Fish and Wildlife Service.
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Ecology Una
Contaminant
Source
ECOLOGICAL EXPOSURE TO
CHEMICAL STRESSORS
Contaminated
Medium
Bloavailabto
Contaminant
Contact with
Organism
Exposure is the route and extent of contact between a chemical stressor and the ecological component
Exposure includes three aspects:
» The chemical must reach the organism. This means that some medium must be contaminated, such as air,
water, soil, sediment, or other organisms.
» The chemical must be in a form that can cause effects. This is known as bioavailability.
» The chemical must reach a site on or in the organism where the chemical can cause effects. This means that
the organism must breathe, eat, drink, touch, or be touched by the contaminated medium.
Depending on the physical and chemical properties of contaminants, they are incorporated into the cycles of the
atmosphere, soil, and/or water, where ecological components become exposed. Once in the environment,
chemicals can undergo changes and/or move from one medium to another. This is called fate and transport.
Chemical stressors can be altered by physical and chemical processes. For example:
*• Light energy can alter a substance through a process called photolysis.
» Some substances react with water in a process known as hydrolysis. To illustrate, acetic anhydride, which
is corrosive and causes bums, is hydrolyzed to acetic acid (vinegar), a food substance.
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Exposure (Continued)
» Contaminants can react with other chemicals in the environment to produce new compounds. For example,
under the right conditions lead will bond with sulfide ions in sediment to form an insoluble, nontoxic
mineral, lead sulfide (galena).
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Ecology Unit
THE NATURE OF CHEMICAL
STRESSORS
Bioavailable chemicals exist in •
form that organisms can talc* up.
No bieavailability equals no uptake
and therefor* no effect
Before a chemical stressor can induce an effect in an organism or become incorporated into its tissues, the
chemical stressor most be bioavailable. That is to say, it must exist in a form that the organism will absorb.
The total amount of a substance detected in contaminated media is not necessarily bioavailable. A portion
of the chemical stressor might be sorbed (or adhered) to soil or sediment particles, or to particles suspended in
the water column or atmosphere. Some or all of the chemical might be chemically bound as an insoluble salt
or other biologically unavailable compound.
» Only the bioavailable portion of the total amount of contaminant in the environment is relevant to an
ccotoxicity evaluation. No bioavailability equals no uptake and therefore no effect.
» The bioavailability of a substance can change with changes in environmental conditions. For example,
an increase in the acidity of water or soil can increase the bioavailability of metals.
Biologically unavailable chemical stressors in ingested soil, sediment, or water may become bioavailable
during the digestive process. For example, a squirrel might inadvertently ingest lead-contaminated soil in the
process of opening an acorn. If the lead in the soil is not bioavailable (i.e., is strongly sorbed to the soil particle),
it can become bioavailable when the acid in the squirrel's stomach causes the lead to dissociate (or desorb) from
the soil particles. The lead is now available for uptake into the animal's bloodstream.
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Ecology Unit
BIOCONCEKTRATION
BIOACCUMULAT1ON
BIOMAGNIFICATION
When evaluating the potential for toxic effects from chemical stressors, we have to consider bioconcentration,
bioaccumulation, and biomagnification as factors. Note that these are factors, not effects. Even if a chemical
stressor is present at low concentrations in the environment, it might still pose a threat to ecological components
if it bioconcentrates or bioaccumuiates, and especially if it biomagnifies.
Bioconcentration - The absorption of a chemical by an organism to levels greater than the surrounding
environment
Bioaccumulatioo - Uptake and retention of a chemical by an organism through feeding and bioconcentration.
BiomagnificatioB • Increased concentration as a contaminant passes up the food chain.
A classic case of biomagnification is DDT. During the years of its use, the pesticide DDT caused eggshell
thinning in numerous birds of prey, including hawks and eagles. DDT occurred at low concentrations in water
as a result of runoff from agricultural fields. Because DDT is very persistent and because it accumulates in fat
tissue, it biomagnified in the food chain, beginning with aquatic plants and invertebrates, through fish, to fish-
eating birds. The lower concentrations occurring at the bottom of the food chain produced no adverse effects,
but the high concentrations in the birds caused eggshell thinning and reduced reproductive success.
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Ecology Urn
Bioconcentration, Bioaccumulation, Biomagnification (Continued)
A bioconcentration factor (BCF) is the concentration of the chemical in the organism, divided by the exposun
concentration. It is often used in ecological risk assessments to help characterize exposure.
BCFs for Daphnia magna (Water Flea)
Substance
Benzo(a)pyrene
Bis(2-ethylhexyl)phthalate
Manganese chloride
BCF
12762
5200
911
Bioconcentration varies among chemicals. Bioconcentration, bioaccumulation, and biomagnification depend
on bom the chemical and the species exposed to the chemical. As shown in the above table, bioconcentration
in one species varies with the chemical. Also, bioconcentration of the same chemical varies with the species.
Environmental conditions also affect bioconcentration and bioaccumulation, so in she-specific risk assessments,
we may sometimes want to calculate site-specific bioconcentration factors.
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Ecology Unit
THE NATURE OF PHYSICAL
STRESSORS
The severity of the impact of • physical
strsssor depends primarily upon:
» The size of the affected area.
» The frequency of the disturbance.
» The Intensity, or physical force, of the
distributing event
All ecosystems are dynamic and possess some degree of resilience to recover from a disturbance. Natural
disturbance is a normal part of ecosystem functioning. Occasional disturbances that cause fluctuations in
community structure and function are as much a part of natural processes as is the cycling of nutrients.
However, the addition of human-caused physical stressors often pushes a system's resilience to its limits because
they tend to be more frequent, more intense, and tend to impact larger areas than do natural disturbances. In
other words, they represent new types of disturbances to which the system has not evolved adaptations.
The extent to which this combination is overwhelming depends on the size of the affected area, the frequency
of disturbance, and the intensity of the disturbing event. Generally speaking, larger and more frequent
physical stressors result in more extensive and longer-lasting effects. Massive and intensive disturbances can
sometimes take centuries to recover. Sometimes recovery is apparent within years, a relatively short period of
time.
» Whether a two-lane country road or a superhighway, road construction means habitat loss. Often wetlands
are filled, hilltops are removed, and other changes are made. The movement of heavy machinery results
in the compaction of soil. During construction, rain washes exposed soil into streams and other bodies of
water. Also, use of the road will introduce some chemical stressors, such as oil and gas residues, and road
salt in northern climates.
» Surface mining removes habitat and increases erosion. Removing topsoil often exposes iron- and sulfur-
bearing strata to rain, resulting in highly acidic runoff that renders nearby water bodies lifeless. Surface
mining also exposes water tables, adding to the volume of runoff.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995
P-37
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Ecology Unit
The Nature of Physical Stressors (Continued)
» Clear-cutting, a common form of timber harvesting, removes large blocks of forested habitat The erosion
associated with logging occurs both from the newly exposed forest floor and from improperly constructed
logging roads.
» Clearing and plowing fields for agriculture disturbs the structure of the soil, exposing it to erosion by water
and wind. Water erosion often carries soil, fertilizers, and pesticides to nearby streams and rivers.
p-38 Ecological Risk and Decision Making Workshop / Participant Manual / December 12,
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Ecology Unit
THE NATURE OF BIOLOGICAL
STRESSORS
ilMngorgi
• (Including
mlcroorganlafna) accldanttHy or Intanttonally
Intioducad to an acoayalatn.
Unllka chamlcal and physical atraaaon. biological
•treason can raproduca, adapt, and apread, adding
dlmanalona to tha ecological aiaaaimant
Biological stressors are known as "exotics" because they have hot evolved along with the organisms that make
up a particular biotic community.
These ttrtnon add another dimension to the ecological risk assessment process because they are Irving and
reprodvctftf organisms that require the consideration of active biological and mechanical transport, passive
transport, or both.
» Microorganisms, some invertebrates, and some seeds have nearly the same capability for transport; they are
earned in the guts of animals, by wind, and by water.
» Mechanical transport (e.g., ships, trucks, airplanes) is as effective as biological transport in moving
organisms over long distances. Upon arrival in a suitable habitat, biological stressors use nutrient and
energy sources to grow and reproduce.
Ecological Risk end Decision Making Workshop /Participant Manual/December 12, 1995
P-39
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Ecology Unit
KINDS OF EFFECTS CAUSED BY
CHEMICAL STRESSORS
y, tehavtoral
dhparilon. local ueaatbon.
ctMngn (*.0i nfrht IOM), habttat dcMnwtlon.
Effects are measured and evaluated in terms of organisms, populations, communities, and ecosystems. For the
most pan. community-level effects translate into ecosystem effects, because communities make up the biological
portion of an ecosystem.
OrgMif B Level Chemical stressors matter because of their effects on populations, and, indirectly, on
communities, but chemical stressors act by their immediate effects on individual organisms (Moriarty, 1983).
Effects on individuals range from rapid death through sublethal effects to no observable effects. These effects
may be indirect, occurring as a result of elimination of prey base or habitat alteration. In the case of threatened
and endangered species, effects influencing a few individuals are likely to be significant because they are at or
near to the point of no return.
Population Level Usually, effects become ecologically significant when they affect the survival, productivity,
or function of a significant number of individuals such that population size is reduced, population structure
is altered, or total function is impaired (Cockerham and Shane, 1994).
» Population size can be reduced if stressors reduce mating* success or egg production; reduce survival of
offspring or reproductive-age adults; increase susceptibility to predation, parasitism, and disease; affect
recruitment through altered immigration or emigration rates; or reduce development or maturation rates.
» Population structure can be altered if stressors differentially affect one age group or developmental stage,
reduce development or maturation rates, or differentially affect one sex.
» Ecological function can be reduced if stressors impair photosynthesis, reduce organisms' efficiency in
converting food into energy, or cause organisms to slow or stop performing activities such as decomposition
of leaf litter or fixation of nitrogen.
P-40
Ecological Risk and Decision Making Wortehop / Participant Manual / December 12,1995
-------
Ecology Unit
Kinds of Effects Caused by Chemical Stressors (Continued)
Community/Ecosystem Level. Community/ecosystem-level effects are often the direct result of Stressors
affecting the ability of populations to interact with one another.
Two examples of a stressor affecting a population's ability to interact with other populations are an impaired
ability to avoid predators and a decreased ability to prey on lower trophic levels.
A population can suffer from indirect effects due to a stressor altering the dynamics of populations with which
it interacts, such as reduction in the abundance of a predator due to toxic effects on prey.
Stressors can result in changes in structural properties of a community, such as the number of species or
trophic levels, or changes in the functional properties of an ecosystem, such as photosynthesis.
Lethal and Sublethal Effects
Adverse effects on living organisms can be either lethal or sublethal.
» Lethal — Mortality of individuals due to exposure to chemical Stressors.
» Sublethal — Other adverse effects. These include reproductive impairment, disruption of certain functions
such as growth or photosynthesis, and induction of behavioral abnormalities such as hyper- or hypo-activity.
Frequently, the type of sublethal effect is characteristic of the chemical stressor of concern. For instance, lead
and mercury are associated with behavioral abnormalities in mammals.
Toxicity varies among chemicals. Toxicologists measure the lethal effects of a chemical by exposing test
animals to various concentrations or doses of the chemical and counting how many organisms die in a specified
period of time.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12,1995
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Ecology Unit
Kinds of Effects Caused by Chemical Stressors (Continued)
Lethality is usually expressed as the median lethal concentration or dose (LCW or LQ, ) which is the
concentration or dose at which SO percent of an exposed population dies. Notice that the lower the LCn or LD»
the more toxic is the chemical. It takes less to kill 50 percent of the population. As the table shows, lethal
concentrations vary among chemicals for a particular species.
Lethal effects are measured by Median Lethal Concentration (LCM) and Median Lethal Dose (LD*).
LC*s for Daphnia magna
Substance
Aroclor 1248
Cadmium chloride
Carbon disulfide
Sodium arsenhe
LC,.
2.6
65
2100
5278
As with lethal effects, ecotoxicologists test for sublethal effects by exposing organisms to different
concentrations or doses of a chemical, and counting how many exhibit the adverse effect Sublethal effects are
frequently reported as follows:
» Median effects concentrations or doses (EC*s or EDws) indicate the exposure at which 50 percent of
exposed organisms exhibited the effect being evaluated by the investigation.
» Lowest Observed Adverse Effects Level or Concentrations (LOAELs or LOAECs) indicate the lowest
exposure at which adverse effects were initially observed.
» No Observed Adverse Effect Levels or Concentrations (NOAELs or NOAECs) indicate the highest
exposure at which effects were not observed.
Sometimes the word "adverse" is left out, making these acronyms LOEL or LOEC and NOEL or NOEC. The
following tables show how sublethal effects vary according to the chemical, the species, and the effect.
p-42 Ecological Risk and Decision Making Workshop / Participant Manual / December 12,199!
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Eeotogy Unit
Kinds of Effects Caused by Chemical Stressors (Continued)
LOAECs for Phenanthrene
Species/Effects LOAEC (in pg/1)
Daphnia pu/ex/reproduction 110
Daphnia pn/ex/growth 360
Selenastnan capricornutwn (alga)/population 800,000
growth
LOAECs for Di-n-octyl phthalate in Fathead Minnows
—Effect- LOAEC (in ug/i)
Reduced Growth 8300
Reduced Hatching 1760
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995
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Ecology Unit
CHEMICAL STRESSORS:
AN EXAMPLE
Tlw
biological overproduction In
prtnwrily M • fMutt of
phosphonw
•tc.
Images of hazardous waste come to mind first when considering chemical stressora. However, mere are other
kinds of chemical stressors that are widespread and more damaging in terms of ecological impacts. OIK
example is nutrient loading or eotrophicatkra, which is the biological overproduction in aquatic ecosystems.
Treated sewage, drainage from agricultural lands, river basin development, runoff from urban areas, and
other factors, commonly increase the rate of nitrogen and phosphorus loading to aquatic ecosystems, and are
the major causes of biological overproduction, or entrophication.
Nitrogen and phosphorus are required in limited amounts by algae and aquatic plants. However, excess
amounts of these nutrients act as fertilizers and cause photosynthetic rates to increase dramatically. The
corresponding growth forms dense algal populations, increases turbidity and sedimentation, reduces the lighted
region where photosynthesis occurs, and prevents the growth of submerged aquatic vegetation.
Increased sedimentation reduces growth rates or resistance to disease, prevents successful development of eggs
and larvae, modifies natural movement or migration patterns, reduces the natural availability of food, and results
in more oxygen being consumed in the lower reaches of the water column and the sediments during the
decomposition of organic matter. The result often is a depletion or almost complete absence of dissolved
oxygen in the lower reaches of the water column.
P-44
Ecological Risk and Decision Making Workshop / Participant Manual / December 12.1995
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Ecology Unit
CHEMICAL STRESSORS:
ANOTHER EXAMPLE
Acid Deposition
The release of auttur dioxide and nttrogwi oxide to
the atmosphere (primarily n a result of foull fuel
combustion), where they form sulfurlc and nitric
add, which than fait* back to earth In all forma of
precipitation.
The major industrial sources of acid deposition are internal combustion engine, utility plants, etc. These
industrial sources produce sulfur dioxide and nitrogen oxides which are the precursors of acid deposition.
These substances readily react in aerosols to generate sulfuric and nitric acid, respectively. These acids and their
precursors are picked up and transported from one locale to others by the prevailing winds. Deposition then
occurs in precipitation in all its forms.
Eighty percent of sulfur dioxide released into the atmosphere is attributed to human activity—100 percent in
some regions. Of that, 85 percent is attributed to fossil fuel combustion. Nitrogen oxides also come from
combustion, the most notable source being motor vehicles.
For terrestrial ecosystems, the effects of acid deposition have been implicated in declines and die-back in
forests. In aquatic systems, changes in pH, or the acidity or alkalinity of a solution, can affect communities
of bacteria, algae, invertebrates, and fish, altering species composition and productivity, reducing numbers,
and impairing reproduction and decomposition. Acidic conditions can mobilize metals from a bound form in
which they are largely non-toxic to a free form in which they are toxic and readily available to organisms.
Acid deposition is thought to be the major cause of the destruction of populations of fish and other aquatic
organisms in many lakes, particularly in the northeastern United States (Cockerham and Shane, 1994).
Ecological Risk end Decision Making Worttshop /Participant Manual/December 12, 1995
P-45
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Ecology Unn
KINDS OF EFFECTS CAUSED BY
PHYSICAL 3TRES3ORS
Erosion Removal 'and transport of Mil material
by wster sno wind*
Slltetion
Soil ttwt to rsmovsd by erosion imkM
to wsy to strawm and rtvsi*.
U0M
Intensity
ibiMghsr
rs md
sett and wster temp
lowsr soil moisturs and rsMHw
hufitkUty.
Disturbances create conditions for erosion by destroying plants, their roots, and soil organic matter. Arid and
semiahd climates are especially prone to wind erosion. The soil in such areas has little moisture to hold it
together, and the small quantity of vegetation that grows in such areas does not provide stems and leaves
extensive enough to block the wind, or roots extensive enough to hold soil in place.
Ejf_mmnl« of natural causes*
of man-made causes:
Water flow (rivers and streams), heavy rains, flooding, drought followed
by rain storms or strong winds.
Agricultural practices (such as irrigation, plowing, clearing of land,
grazing), removal of vegetation (timber harvesting), construction of roads,
buildings, etc. 1
I
One of the major ecological problems associated with erosion is siltation. Siltation results in the deposition o!;
excess soil where stream and river currents are slow, smothering plants and bottom-dwelling organisms, anc
covering important fish habitat Some fish, such as salmon, require clean gravel streambeds in which to spawn
For them, the effects of siltation could result in the loss of critical breeding habitat. Salmon lay their eggs it
the small spaces between rocks on streambeds. Water circulating around the eggs supplies them with oxygen
which is dissolved in the water. If the spaces become filled with silt, water circulation around the eggs wil
decrease and the young will fail to develop.
When the vegetation along a stream or other water body is removed (e.g., by clear-cutting, house construction
etc.). the amount of sunlight reaching the water increases. As a result, water temperatures can increas
significantly, possibly having lethal effects on some of the resident aquatic organisms.
P-46
Ecological Risk and Decision Making Wortahop / Participant Manual / December 12,1%
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Ecology
Unit
HABITAT FRAGMENTATION
Physical streasora, such as road construction,
logging, dredging wetlands, etc, break larger areas
of habttat Into smaller patches, or fragments.
Habitat fragments can ulttonataly become so
Isolated that they function much like Islands.
Wildlife corridors are "natural highways" that link
habNat fragments, thereby allowing certain species
to survive a partial loss of habitat
In addition to disturbing or destroying the immediate habitats), activities such as road construction, logging,
dredging wetlands, and agriculture, whittle away piecemeal at larger, relatively intact areas. This results in
habitat fragmentation, the breaking up of larger areas into smaller patches or fragments of habitat
When habitat patches become isolated from similar habitat by different, relatively inhospitable terrain, they
essentially become islands.
If fragmentation continues, the remaining area is reduced to a critical size below which the habitat will not
provide the requirements of many of the original species, and a number of them will disappear.
Many species of terrestrial wildlife can live in fragmented habitats only if corridors link enough fragments to
provide both habitat requirements and interactions with others of the same species to perpetuate viable
populations.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12, 1995
P-41
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Ecology Unit
KINDS OF EFFECTS CAUSED BY
BIOLOGICAL STRESSORS
Introduced organisms act a» biological
•tremors through prsdation, parasitism,
pathogenssis, and competition for rssoureas.
Exotic organisms include domestic species, accidentally introduced species, non-native game and fish species,
biocontrol agents, and, quite recently, species modified by bioengineering. Through competition, predation,
and pathogenesa (disease), exotic organisms have extinguished native species or reduced them, and have
drastically changed the character of the invaded communities (Suter, 1993).
» Outbreaks of insects, such as the introduced gypsy moth and spruce budworm, defoliate large areas of forest,
which result* m the death or reduced growth of affected trees. The degree of gypsy moth mortality can
range from 10 to 30 percent in hardwood forests to 100 percent in spruce and fir stands.
When two a
Michigan.
species of plankton-feeding fish, the alewife and rainbow smelt, proliferated in Lake
native species offish with similar food habits declined drastically (Crowder et al., 1981).
Japanese honrytuckk. a garden escapee, and multiflora rose, widely planted in the past for soil conservation
purposes. na«t invaded old fields and forest edges, crowding out native plants and affecting the structure
and composition of animal life.
Virulent tree diseases have markedly changed the composition of North American forests. The chestnut
blight, introduced into North America from Europe, nearly exterminated the American chestnut and
removed it as a major component of the forests of eastern North America. With its demise, oaks and birch
increased (Smith. 1990).
P-48
Ecological Risk and Decision Making Workshop / Participant Manual / December 12,1995
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Ecology Unit
ECOLOGICAL SIGNIFICANCE OF EFFECTS
Nctuft snd im0nltudft of effects
Spatial and temporal pattern of cftacti
Ecological significance of effects or the types and extent of effects is an important consideration in assessing
ecological risk.
Nature and Magnitude of Effects
The nature of effects relates to the relative significance of effects especially when the effects of stressors on
several ecosystems within an area were assesssed. It is important to characterize the types of effects associated
with each ecosystem and where the greatest impact is likely to occur.
Magnitude of effect will depend on the ecological context, e.g., life history characteristics. Long-lived
vertebrates such as large mammals, predatory birds, and whales are more sensitive to mortality imposed on
adults that are short-lived, highly fecund (fertile) organisms such as quail and anchovies (Cockerham and Shane,
1994).
Spatial and Temporal Patterns of Effects
Spatial and temporal patterns of effects consider whether effects occur on large scales (e.g., acid rain) or will
be localized, and whether effects are short-term or long-term. Some effects take decades to manifest themselves
(e.g., ozone depletion effects on marine ecosystems).
Recovery Potential
Recovery relates to how easy it is to adapt to changes. For example, rainforests which are complex, highly
evolved ecosystems may take longer to adapt to perturbations than a pine forest, which can recover relatively
quickly from disturbances by rapidly re-seeding.
Ecological Risk and Decision Making Workshop / Participant Manual / December 12. 1995
P-49
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NATURAL VS. HUMAN STRESSORS
AND RECOVERY
It is important to remember that natural disturbances bring about diversity of the landscape. Wind, moving
water, drought, fire, and animal activity yield variation in habitats. These natural disturbances also cause
changes in the availability of open space for species to colonize. Ecosystems are adapted to disturbances that
have occurred with some frequency over the evolutionary history of the ecosystem and will usually eventually
recover and return to their original state.
Humans may introduce stressors to which the ecosystem has not been exposed during its evolutionary history
(synthetic chemicals, exotic species). Human-caused disturbances are usually more frequent, more intense and
impact larger areas. These larger-scale disturbances can have subtle as well as dramatic impacts on a habitat.
They often result in a situation that is overwhelming from which the ecosystem never recovers. Recovery is
sometimes apparent within years. However, a massive and intense disturbance can cause an ecosystem to take
centuries to recover. Even then, the original or "natural" ecosystem may never recur.
P-SO
Ecological Risk and Decision Making Workshop / Participant Manual / December 12,1S9!
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Ecology Unit
offA
Key Concepts
Ecosystems are complex and dynamic,
composed of interacting networks of
blotic and abiotic components.
Principal ecological components are
species, populations, communities, and
ecosystems.
Critical to the function of an ecosystem
Is the flow of energy and nutrients
through the systems's producers and
Key Concepts (Continued)
Stressors can affect individual
organisms, population growth,
community structure and function, and
ecosystem processes.
Interactions among individuals in a
population, and among populations in a
community influence the significance of
a stressor's ecological effects.
The combination of stressor,
environmental, and biological
characteristics dictates the nature,
extent and magnitude of ecological
Ecological Risk and Decision Making Workshop /Participant Manual/December 12, 1995
P-51
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SO*
Ecology Unit
Optional Exercise:
The following exercise illustrates how stressors affect a population.
A SIMPLE SIMULATION MODEL
Hypothetical WhaMf Population
Stage
Eggs
Larvae
Adults
Initial
Number
300
200
100
Maturation
Time
1 mo.
1 mo.
Percent
Survival
50
SO
SO per mo.
Percent
Females
SO
Eggs/
Female/Month
10
To illustrate the effects of stressors on populations, we will use a very simple simulation model. We'll call our
organism Hypothetical what-if, or the What-If Bug.
The What-If Bug has three stages: an egg, a larva, and an adult The eggs and larva each take one month to
complete their development, and SO percent survive to the next developmental stage (egg to larva, larva to
adult). Adult survival is SO percent per month. In other words, of the original 100 adults in our example, 50
will be alive at the end of 1 month, 25 at the end of 2 months, and so on. One lucky individual will live to the
ripe old age of 7 months. The What-If Bug has a sex ratio of 0.5; that is, 50 percent of the adult population is
female. Every month, each female lays 10 eggs.
Our simulations start out with 300 eggs, 200 larvae, and 100 adults. We then run the simulation for 25 "months,"
first with the parameters shown here, then changing one parameter to see the effect of reduced survival of a life
stage, reduced egg production, or changes in the sex ratio. The next four figures show the effects of hypothetical
stressors on our hypothetical population.
» In the first figure, we reduce egg survival from 50 percent to 45,40, and 35 percent.
» In the second figure, we reduce adult survival in the same manner.
» In the third figure, we reduce eggs per female from 10 to 9.7 and 5 eggs per female.
» In the fourth figure, we vary two parameters simultaneously. Both adult survival and the percent of the
population that is female are reduced from 50 percent to 45,40, and 35 percent.
Let's look at the results. You will note that the top curve in each graph represents the initial conditions that we
presented earlier. All the curves represent the total population (eggs, larvae, and adults) over the 25- month
period.
P-52
Ecological Risk and Decision Making Workshop / Participant Manual / December 12,1995,
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Ecology Unit
Optional Exercise (Continued)
Egg Survival
Assume that the What-If Bug lays its eggs in soil contaminated with a chemical that is slightly toxic. Suppose
that the toxic effects of the contaminant only reduce egg survival from its normal SO percent to 45 percent The
graph in Figure 1 shows that the population at the end of 25 months is about half what it would be with no
additional egg mortality, down from about 2400 to about 1200. If the contaminant causes egg survival to
decrease to 40 percent, the population does not grow at all, and if egg survival drops to 35 percent, the
population declines.
EGG SURVIVAL
220
50%
Fipxrt L Number of «s= of What-If Bug surmring over 25 months
-------
Ecology Unit
Optional Exercise (Continued)
Adult Survival
The adult What-If Bug feeds on flowers that grow along pesticide-treated vegetable fields. Drift from the
pesticide spraying lands on the flowers, killing some What-If Bugs (Figure 2).
» The population fails to grow at all when adult survival declines just to 45 percent
» Reductions in survival to 40 and 35 percent result in significant decline in the population.
ADULT SURVIVAL
12
MONTH
£3%
40% —B— ~~L
•^** «v — %!••, »4
Fiftxrt 2. Number of adult What-If B«j£ snrrmng over 2£ months
P-54
Ecological Risk and Decision Making Workshop / Participant Manual / December 12. 1995
-------
Ecology Unit __ SB*
Optional Exercise (Continued)
Eggs per Female
Along the roadway, another flower serves as a food source for adult What-If bugs. The soil is so compacted at
this site that the plants provide less nutrition and the female bugs produce fewer eggs.
*> Figure 3 shows that a reduction to nine eggs per female causes the population to grow at about half the rate
if egg production remains at 10 per female.
» At five eggs per female, the population is heading for extinction.
EGGS PER FEMALE
2520
24
10
Figore 3. Number of eggs per female What-If Bug over 25 months
Ecological Risk and Decision Making Workshop /Participant Manual / December 12. 1995
P-55
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Ecology Unit
Optional Exercise (Continued)
Adult Survival and Percent Females
The What-If bug survives best in partially shaded environments where the temperature is moderate in summer.
Females are more susceptible than males to high temperatures, but both suffer some additional mortality. In
Figure 4 both adult survival and the percent of the population that is female were reduced. To keep things
simple, we used the same numbers for each: 50,45,40, and 35 percent
» As seen in Figure 4, with just a 5 percentage point decline in the two parameters, the population declines.
At 40 and 35 percent, the population is quickly becoming extinct
ADULT SURVIVAL/% FEMALE
gerq
1500
icoa
so-
12
MONTH
£3% — 45% —- 4C% -s- 25%
Figare 4. Survival of adult What-If Bugs when percsat females change over 25 months
p-56
Ecological Risk and Decision Making Workshop /Participant Manual/December 12, 1995
-------
Ecology Unit
Optional Exercise (Continued)
The figures show that small differences in survival, reproductive rates, and sex ratios can produce large
differences in population size over the long term.
» You may have noticed that in some of the curves the population increased at first, then declined. How far
into the future can/should we consider when looking at effects?
» In several instances, the population increased, but not as much as with the original parameters. Should a
population actually decrease before the effects are considered significant? How much is too much?
Ecological Risk and Decision Making Workshop /Participant Manual/December 12, 1995 P-57
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APPENDIX F
LOADINGS DATA USED IN THE
APPORTIONMENT ANALYSIS
-------
JUNE 1997
This Appendix presents loadings data used in Chapter 7 of the California Toxics Rule (CTR)
Benefits Report to apportion benefits between point and nonpoint sources of pollutants in the
proposed CTR. Data are taken from NOAA, (June 1988) The National Coastal Pollutant
Discharge Inventory: Estimates for San Francisco Bay, Data Summary, Ocean Assessment
Division, National Oceanic and Atmospheric Administration, and J.A. Davis et al, (1991) Status
and Trends Report on Pollutants in the San Francisco Estuary, prepared by the San Francisco
Bay-Delta Aquatic Habitat Institute for the San Francisco Estuary Project, U.S. EPA.
F-l
-------
LOADINGS TO SAN FRANCISCO BAY
NOAA DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Chlorinated
Hydrocarbon
Pesticides
•
Notes:
Source:
roiM
WASH W All R
1RI A 1 MINI
PLAN IS
1724
11.79
2631
4808
35.38
4.31
j 32.45
0.56
SOURCE
TOTALS
SOI RMS
DIRK 1
INIM'SIRIAl
niSCIIARCiFS
091
0.91
5.44
4.54
6.35
0.07
9^98
0.00
308.85
POV.IR
PI .AN IS
•
0.91
2.72
*
0.91
•
1 ) All values are in metric tons per year.
URBAN
RUNOFF
635
181
10.89
43.55
183.25
o.ii
196.86
0.05
NO
CROPLAND
RUNOFF
31.75
0.91
246.76
1 10.68
56.25
0.34
266.72
0.41
NPOINT SOURi
FORESTLAND
RUNOFF
9.98
-
109.77
48.08
29.03
0.14
118.84
2) The NOAA data show large mercury loadings associated with riverine inputs to the Bay.
We classified 46.34 percent of these riv
the likely original source of the mercur>
1
erine loadings as poi
'. The 46.34 percent
nt sources given that upstream mines are
figure can be found in Exhibit 7-4.
NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for San Francisco Bay,
Data Summary, Ocean Assessments Division, National Oceanic and Atmospheric Administration,
June 1988. f
JES
PASTURE /
RANGELAND
RUNOFF
47.17
1.81
471.74
210.47
132.45
0.52
530.71
5,549.80
IRRIGATION
RETURN
FLOW
-
-
1.81
-
•
0.00
1.81
0.08
UPSTREAM
SOURCES
45.36
64.41
395.54
536.15
124.29
4.28
1,508.66
TOTAL
ALL
SOURCES
158.76
81.65
1,269.16
1,004.26
567.00
9.77
2,766.94
1.10
5,858.65
-------
LOADINGS TO SAN FRANCISCO BAY
DAVIS DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickef
Selenium
Zinc
Notes:
Source:
— - - — .
SOURCE
TOTALS
1) All values are
POINT SOURCES
~~l
MUNICIPAL &
INDUSTRIAL
DISCHARGES
Lower
Bound
1.50
1.80
12.00
19.00
11.00
0.20
19.00
" 2.10
77.00
143.60
in metric U
1 1
Upper
Bound
5.50
4.00
13.00
30.00
16.00
0.70
27.00
2.10
80.00
178.30
--
--
>ns per year.
1
URBAN
RUNOFF
Lower
Bound
1.00
0.30
3.00
7.00
30.00
0.03
-
34.00
75.33
Upper
Bound
9.00
" " 3.00
15.00
59.00
250.00
0.15
-
-
268.00
604.15
NONPOINT SOURCES
1
NONURBAN
RUNOFF
Lower
Bound
10.00
0.52
130.00
51.00
31.00
0.15
-
130.00
352.67
Upper
Bound
120.00
6.00
1,500.00
580.00
360.00
1.70
-
1,450.00
4017.70
872.37
Davis, J.A., el al., Status and Trends Report on Pollutants in the San Francisco
Estuary, prepared by the San Francisco Bay-Delta Aquatic Habitat Institute for
the San Francisco Estuary Project, U.S. EPA, March 1991
1
UPSTREAM
SOURCES
Lower
Bound
12.00
.
66.00
80.00
51.00
-
51.00
5.30
164.00
429.30
5,160.90
Upper
Bound
12.00
.
66.00
80.00
55.00
-
51.00
5.30
175.00
444.30
DREDGED
MATERIAL
Lower
Bound
•
0.02
•
1.00
1.00
0.01
2.00
-
3.00
7.03
Upper
Bound
•
0.20
-
10.00
10.00
0.10
20.00
-
30.00
70.30
ATMOSPHERIC
DEPOSITION
Lower
Bound
.
0.14
-
1.90
6.00
-
-
-
-
8.04
Upper
Bound
m
0.35
-
3.10
21.00
-
-
-
•
24.45
TOTAL
•
ALL SOURCES
24.50
2.78
211.00
159.90
130.00
0.39
72.00
7.40
408.00
1,015.97
146.50
13.55
1,594.00
762.10
712.00
2.65
98.00
7.40
2,003.00
5,339.20
-------
LOADINGS TO SANTA MONICA BAY
NOAA DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Chlorinated
Hydrocarbon
Pesticides
Notes:
Source:
POINT
WASTEWATER
TREATMENT
PLANTS
15.88
9.25
89.81
123.02
59.06
0.53
226.34
0.77
SOURCE
TOTALS
SOURCES
DIRECT
INDUSTRIAL
DISCHARGES
0.27
0.45
0.45
2.81
2.81
0.04
7.53
543.38
POWER
PLANTS
-
-
-
4.35
m
0.00
-
1) All values are in metric tons per year.
. J_ 1
URBAN
RUNOFF
0.91
m
0.91
4.54
19.96
0.01
21.77
0.01
NONPOINT SOURCES
CROPLAND
RUNOFF
-
-
-
-
-
-
-
0.00
125.28
NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for
Santa Monica Bay, San Pedro Bay, and San Diego Bay, Data Summary, Ocean
FORESTLAND
RUNOFF
-
-
-
-
-
.0.00
0.91
Assessments Division, National Oceanic and Atmospheric Administration, July 1988.
PASTURE /
RANGELAND
RUNOFF
0.91
-
10.89
10.89
10.89
0.07
42.64
m
IRRIGATION
RETURN
FLOW
-
-
-
-
-
-
-
UPSTREAM
SOURCES
-
-
-
-
-
-
-
TOTAL
ALL
SOURCES
17.96
9.71
102.06
145.60
92.72
0.65
299.19
0.77
668.66
-------
LOADINGS TO SAN DIEGO BAY
NOAA DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc .
Chlorinated
Hydrocarbon
Pesticides
Notes:
Source:
POINT
WASTEWATER
TREATMENT
PLANTS
6.17
9.89
16.69
26.40
10.70
0.11
90.81
0.14
SOURCE
TOTALS
SOURCES
DIRECT
INDUSTRIAL
DISCHARGES
0.27
1.18
1.1 8
2.45
2.54
0.02
4.99
174.63
POWER
PLANTS
»
-
»
1.09
-
-
-
1 ) All values are in metric tons per year.
URBAN
RUNOFF
0.91
-
0.91
4.54
19.05
0.01
20.87
0.00
NONPOINT SOURCES
CROPLAND
RUNOFF
.
-
-
-
-
0.00
09,
0.01
48.11
NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for
Santa Monica Bay, San Pedro Bay, and San Diego Bay, Data Summary, Ocean
Assessments Division, National Oceanic and Atmospheric Administration, July 1988.
FORESTLAND
RUNOFF
•
-
-
-
-
0.00
0.91
PASTURE/
RANGELAND
RUNOFF
-
•
-
-
-
-
-
IRRIGATION
RETURN FLOW
<•
-
-
V
-
•
-
UPSTREAM
SOURCES
-
-
-
-
m
-
•
TOTAL
ALL
SOURCES
7.35
11.07
18.78
34.47
32.30
0.15
1 18.48
0.15
222.74
-------
LOADINGS TO SAN PEDRO BAY
NOAA DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Chlorinated
Hydrocarbon
Pesticides
Notes:
Source:
POINT
WASTEWATER
TREATMENT
PLANTS
12.16
18.23
32.11
50.98
22.95
0.22
182.26
0.36
SOURCE
TOTALS
SOURCES
DIRECT
INDUSTRIAL
DISCHARGES
0.27
0.27
0.27
0.27
0.27
0.00
0.36
0.00
327.71
POWER
PLANTS
0.18
0.18
0.18
5.72
0.18
0.00
0.27
1 ) All values are in metric tons per year.
1
----
-
—
URBAN
RUNOFF
1.8J
-
2.72
13.6J
61.69
0.03
68.04
0.02
NONPOINT SOURCES
CROPLAND
RUNOFF
-
-
-
-
-;-
-
0.0 1
NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for
FORESTLAND
RUNOFF
-
-
1.81
1.81
1.81
0.01
8.16
161.55
Santa Monica Bay, San Pedro Bay, and San Diego Bay, Data Summary, Ocean
Assessments Division, National Oceanic and Atmospheric Administration, July 1988.
PASTURE /
RANGELAND
RUNOFF
-
-
-
-
-
0.00
0.00
IRRIGATION
RETURN
FLOW
-
-
-
-
-
-
-
-
UPSTREAM
SOURCES
-
-
-
-
-
-
-
TOTAL
ALL
SOURCES
14.42
18.69
37.10
72.39
86.91
0.27
259.10
0.38
489.27
-------
LOADINGS TO MONTEREY BAY
NOAA DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
- - •-
Notes:
Source:
POINT
WASTEWATER
TREATMENT
PLANTS
0.98
0.44
1.60
1.49
2.44
0.10
5.76
SOURCE
TOTALS
SOURCES
DIRECT
INDUSTRIAL
DISCHARGES
1.07
0.80
1.89
0.54
5.37
0.05
5.38
27.92
POWER
PLANTS
*
1 ) AH values are in metric tons per year.
URBAN
RUNOFF
0.50
0.14
6.70
3.27
13.80
0.01
15.31
NO
CROPLAND
RUNOFF
0.63
0.08
14.42
6.00
3.22
0.04
15.40
86.17
NOAA, The National Coastal Pollutant Discharge Inventory, Summary
of Pollutant Discharges in West Coast Study Area by Estuarine
Watershed, circa 1982/1984; obtained on disk from Mr. Percy Pacheco,
Office of Ocean Resources Conservation and Assessment.
N POINT SOURCES
FORESTLAND
RUNOFF
6.35"
0.01
3.65
1.12
1.08
0.00
4.35
•
PASTURE/
RANGELAND
RUNOFF
0.07
0.00
0.72
0.22
0.21
-
0.86
IRRIGATION
RETURN
FLOW
-
-
-
-
-
-
-
UPSTREAM
SOURCES
-
-
-
-
-
-
-
TOTAL
ALL
SOURCES
3.60
1.49
22.97
12.64
26.12
0.20
47.07
114.08
-------
LOADINGS TO HUMBOLDT BAY
NOAA DATA
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Notes:
Source:
POINT
WASfEWATER
TREATMENT
PLANTS
0.32
0.43
0.78
1.15
0.54
0.00
4.06
SOURCE
TOTALS
SOURCES
DIRECT
INDUSTRIAL
DISCHARGES
0.35
8.61
1.18
1.67
0.00
7.00
26.10
- - -
POWER
PLANTS
1 ) All values are in metric tons per year.
—
URBAN
RUNOFF
0.23
0.06
0.32
1.48
6.29
0.00
6.98
NO
CROPLAND
RUNOFF
NOAA, The National Coastal Pollutant Discharge Inventory, Summary
of Pollutant Discharges in West Coast Study Area by Estuarine
Watershed, circa 1982/1984; obtained on disk from Mr. Percy Pacheco,
Office of Ocean Resources Conservation and Assessment.
NPOINT SOURCES
FORESTLAND
RUNOFF
0.14
0.01
3.46
1.73
0.69
0.00
2.57
70.27
PASTURE /
RANGELAND
RUNOFF
0.08
0.01
1.94
0.97
0.39
-
1.44
IRRIGATION
RETURN
FLOW
-
-
-
-
-
-
-
UPSTREAM
SOURCES
0.94
0.55
11.88
7.21
1.83
0.09
18.96
I
„
TOTAL
ALL
SOURCES
2.07
1.06
26.98
13.73
11.41
0.10
41.00
96.37
-------
LOADINGS TO SACRAMENTO RIVER
CVRWQCB DATA
Arsenic
Cadmium
Copper
Lead
Zinc
Notes:
Source:
POINT
NPDES
0.38
0.01
1.15
0.38
10.12
SOURCE
TOTALS
SOURCES
MINES
1.72
1.81
63.91
0.56
261.18
341.22
NONPOINT SOURCES
URBAN
RUNOFF
2.40
0.22
8.16
12.70
59.42
1) All values are in metric tons per year.
AGRICULTURAL
DRAINAGE
4.90
0.19
16.65
1.71
41.25
147.61
Central Valley Regional Water Quality Control Board, Mass Emission
Strategy - Load Estimates, no date.
TOTAL
ALL
SOURCES
9.40
2.23
89.88
15.35
371.97
488.83
-------
LOADINGS TO SAN JOAQUIN RIVER
CVRWQCB DATA
. —
Arsenic
Cadmium
Copper
Lead
Zinc
Notes:
Source:
POINT
NPDES
0.08
0.00
0.24
0.08
2.14
SOURCE
TOTALS
SOURCES
MINES
0.00
0.0!
0.00
0.00
0.27
2.83
NONPOINT SOURCES
URBAN
RUNOFF
0.68
0.05
1.95
2.27
15.88
1 ) All values are in metric tons per year.
AGRICULTURAL
DRAINAGE
1.86
0.09
6.44
0.65
15.15
45.01
Central Valley Regional Water Quality Control Board, Mass Emission
Strategy - Load Estimates, no date.
TOTAL
ALL
SOURCES
2.62
0.14
8.64
3.00
33.44
47.84
-------
APPENDIX G
COMPARISON OF POSSIBLE POINT SOURCE
INDUSTRIAL PCB DISCHARGERS IN CALIFORNIA AND
THE GREAT LAKES REGION BY SIC CODE
-------
JUNE 1997
This Appendix compares industries (as organized by SIC codes) reporting PCB discharges
in the Great Lakes region and the existence and number of similar industries in California. This data
was developed in support of the document: Assessment of Compliance Costs Resulting from
Implementation of the Final Great Lakes Water Quality guidance, prepared for the U.S.
Environmental Protection Agency, March 13,1995, prepared by SAIC.
G-l
-------
Great Lakes-California PCB Cross Reference
Major SIC Number MAJOR NAMF Minor SIC Number MINOR Nam*
Great Lakes establishments reporting PCB Discharges
10 METAL MINING
1011 IRON ORES
1021 COPPER ORES
METAL MINING
1081 SERVICES
Census CA Firms PCS CA Firms TRI PCS MI+WISC
14 NONMETALLIC MINERALS
CRUSHED AND
BROKEN
1422 LIMESTONE
15
SAND AND
1440 GRAVEL
204
20 FOOD AND KINDRED PRODUCTS
BAKERY
2050 PRODUCTS
424
2063 BEET SUGAR
FLAVORING
EXTRACTS AND
2087 SYRUPS
47
24 LUMBER AND WOOD PRODUCTS
RECONSTITUTED
2493 WOOD PRODUCTS
27
-------
Great Lakes—California PCS Cross Reference
Major SIC Number MAJOR NAME Minor SIC Number MINOR Name Great Lakes establishments reporting PCB Discharges
Census CA firms PCS CA Firms TRI PCS MI+WISC
,""• I UWJillJf-M AMD F!« 'Ml-1
FURNITURE AND
7500 FIX TURFS 1764
or F ICE
FURNITURE.
2522 EXCEPT WOOD 77
DRAPERY
HARDWARE AND
BLINDS AND
2591 SHADES 88
tODUCTS
PAPER AND
ALLIED
2600 PRODUCTS
2611 PULP MILLS
2621 PAPER MILLS
PAPERBOARD
2631 MILLS
2640 NOT LISTED
PAPERBOARD
CONTAINERS AND
2650 BOXES
2651 MOXOJSTED
CONVERTED
PAPER
2670 PRODUCTS
634
4
9
15
N/A
243
N/A
363
0 2
5 4
0 1 13
0 7
0 1
0 1
0 1
0 1
-------
Great Lakes-California PCB Cross Reference
Mnjor ^IC Number MA inp riAMr M,rv>. r\r
MINOR N,
Great Lakes establishments reporting PCB Discharges
< 'i. i i 11 >
I .' I M'
ill ''I '. «
27 PRlNliNu Aril) rum isniNG
, i A
' /\ | „„,.. 7R| PCS MI+WISC
PRINT IN'1. Arm
2 TOO PUOllSMIN'i
2710 NEWSPAPERS
COMMERCIAL
2750 PRINTING
BLANKBOOKS
AND LOOSELEAF
2782 BINDERS
PRINTING TRADE
2790 SERVICES
28 CHEMICALS AND ALLIED PRODUCTS
CHEMICALS AND
ALLIED
2800 PRODUCTS
INDUSTRIAL
INORGANIC
2810 CHEMICALS
INDUSTRIAL
2813 GASSES
INDUSTRIAL
INORGANIC
2819 CHEMICALS, NEC
PLASTICS
MATERIALS AND
2820 SYNTHETICS
8423
690
5219
64
567
•
1367
125
52
65
57
0
0
0
0
0
0
0
2
18
0
1
3 _
2
1
1
.
2
2
1
1
2
-------
Great Lakes-California PCB Cross Reference
Major SIC Number MAJOR NAME Minor SIC Number MINOR Name
Great Lakes establishments reporting PCB Discharges
Census CA Finn:, PCS CA Firms TRI PCS MH-WISC
2830 DRUGS 217
SOAP, CLEANERS,
AND TOILET
2840 GOODS 337
PAINTS AND
ALLIED
2850 PRODUCTS 190
PAINTS AND
ALLIED
2851 PRODUCTS 190
INDUSTRIAL
ORGANIC
2860 CHEMICALS 57
CYCLIC CRUDES
AND
2865 INTERMEDIATES 12
AGRICULTURAL
2870 CHEMICALS 81
MISC. CHEMICAL
2890 PRODUCTS
ADHESIVES AND
2891 SEALANTS
CHEMICAL
PREPARATIONS,
2899 NEC
303
76
167
29 PETROLEUM AND COAL PRODUCTS
PETROLEUM AND
2900 COAL PRODUCTS
PETROLEUM
2911 REFINING
222
32
30
-------
Great Lakes-California PCB Cross Reference
Major SIC Number MAJOR NAME Minor SIC Number MINOR Name Great Lakes establishments reporting PCB Discharges
r<;nsusCA Firms PCSCAFirmr, TRI PCS MI+WISC
30 RUBBFR AMI) MISO PLASTIC PRODUCTS
GASKETS,
PACKING AND
3053 SEALING DEVICES
FABRICATED
RUBBER
3069 PRODUCTS. NEC
3079 N/A
MISC PLASTICS
3080 PRODUCTS, NEC
32 STONE, CLAY, AND GLASS PRODUCTS
GLASS AND
GLASSWARE,
PRESSED OR
3220 BLOWN
GLASS
3221 CONTAINERS
CEMENT.
3241 HYDRAULIC
READY-MIXED
3273 CONCRETE
3274 Ml^l
NONMETALLIC
MINERAL
3290 PRODUCTS
80
196
N/A
1736
88
12
22
436
3
194
0 1
0 3
0 4
0 11
0 3
4 1
0 1 5
5 1
0 1 1
0 1
-------
Great Lakes-California PCB Cross Reference
Major SIC Number MAJOR NAME Minor SIC Number MINOR Name Great Lakes establishments reporting PCB Discharges
Census CA firms PCS CA Firms TRI PCS MI+WISC
MINERALS,
GROUND OR
3^95 TRI.ATED 36 0 5
NONCLAY
3297 REFRACTORIES 7 1 2
33 PRIMARY METAL INDUSTRIES
BLAST FURNACES
3312 AND STEEL MILLS
ELECTROMETALL
URGICAL
3313 PRODUCTS
COLD FINISHING
OF STEEL
3316 SHAPES
STEEL PIPES AND
3317 TUBES
IRON AND STEEL
3320 FOUNDRIES
GRAY AND
DUCTILE IRON
3321 FOUNDRIES
MALLEABLE IRON
3322 FOUNDRIES
PRIMARY
3334 ALUMINUM
PRIMARY
NONFERROUS
3339 METALS, NEC
7
3
16
24
89
39
0
3
10
__ 3
0 1
0
0
0
1 2
0
0 2
0
6
1
5
1
1
10
2
t
1
SECONDARY
NONFERROUS
3340 METALS 37
-------
Great Lakes-California PCS Cross Reference
iber MAJOR NAME Minor SIC Number MINOR Name
SECONDARY
NONFERROUS
3341 METALS
ALUMINUM
EXTRUDED
3354 PRODUCTS
NONFERROUS
FOUNDRIES
3360 (CASTINGS)
ALUMINUM
3365 FOUNDRIES
COPPER
3366 FOUNDRIES
NONFERROUS
3369 FOUNDRIES, NEC
METAL HEAT
3398 TREATING
34 FABRICATED METAL PRODUCTS
FABRICATED
METAL
3400 PRODUCTS
METAL DOORS,
3442 SASH AND TRIM
FABRICATED
PLATE WORK
3443 (BOILER SHOPS)
MISC. METAL
3449 WORK
METAL FORGING
3460 AND STAMPING
' ensus CA Firms
37
31
216
82
41
9
79
4657
193
182
61
433
PCS C-A Film*
0
1
0
1
0
0
1
0
2
0
0
Great Lakes establishments reporting PCB Discharges
TRI PCS MI+WISC
1 1
1
1
1
2
1
6
5
1
1
t
-------
Great Lakes-California PCB Cross Reference
Major SIC Nti'iiho. MA.inr fjAPr Minor Sl<~ r.'umN • r.'ltK'P N.i
Great Lakes establishments reporting PCB Discharges
PCS CA Firms TR! PCS MUWISC
11
AU I "MOTIVE
13
PI A t ING AND
.W/1 I ('I ISMIN(i
METAL COATING
AND ALLIED
3479 &6£"CES
FABRICATED
METAL
3490 PRODUCTS
FABRICATED
METAL
3499 PRODUCTS, NEC
308
816
384
35 INDUSTRIAL MACHINERY AND EQUIPMENT
ENGINES AND
3510 TURBINES
INTERNAL
COMBUSTION
3519 ENGINES, NEC
CONSTRUCTION
AND RELATED
3530 MACHINERY
METALWORKING
3540 MACHINERY
SPECIAL DIES.
TOOL JIGS, AND
3544 FIXTURE
MACHINE TOOL
3545 ACCESSORIES
39
31
272
958
575
192
0 5
1 1
0 2
0 1
0 1
0 1
-------
Great Lakes-California PCS Cross Reference
Major SIC Number MAJOR NAMF Minor SIC Number MINOR Name
Great Lakes establishments reporting PCB Discharges
^t'f I l/Vt
!Nf»usiiJ»
•'<» MA< i "fj| r i
-------
Great Lakes—California PCB Cross Reference
>er MAJOR NAME Minor SIC Number MINOR Name
:>,7 IRANi'l ORlAllONEQUIPMtm
MOTOR VEHICLES
3710 AND EQUIPMENT
MOTOR VEHICLES
371 1 AND CAR BODIES
MOTOR VEHICLE
PARTS AND
3714 ACCESSORIES
MISC.
TRANSPORTATIO
3790 N EQUIPMENT
38 INSTRUMENTS AND RELATED PRODUCTS
SEARCH AND
NAVIGATION
3812 EQUIPMENT
MEDICAL
INSTRUMENTS
3840 AND SUPPLIES
DENTAL
EQUIPMENT AND
3843 SUPPLIES
Census t ;A I
648
57
451
115
163
752
259
Great Lakes establishments reporting PCB Discharges
inns PCS CA Firms TRI PCS MI'WISC
0 3
1 15
0 2 46
0 1
0 1
0 1
0 1
39 MISC. MANUFACTURING INDUSTRIES
TOYS AND
SPORTING
3940 GOODS
3970 NOT LISTED
512
N/A
0 1
0 1
MISC.
3990 MANUFACTURES 1054
-------
Great Lakes-California PCS Cross Reference
Major SIC Number MAJOR NAME Minor SIC Number MINOR Name Great Lakes establishments reporting PCB Discharges
'••-•iisusCA Firms PCr> CA fiims 1RI PCS MI+WISC
42 TRUCKING AND WAfH IIOUSING
TRUCKING
TERMINAL
4230 FACILITIES N/A 0 1
47 TRANSPORTATION SERVICES
INSPECTION AND
4785 FIXED FACILITIES 4
49 ELECTRIC, GAS, AND SANITARY SERVICES
ELECTRIC
4911 SERVICES 319 55 21
SEWERAGE
4952 SYSTEMS 221 275 24
4953 REFUSE SYSTEMS 371 16
50 WHOLESALE TRADE-DURABLE GOODS
MOTOR VEHICLE
SUPPLIES AND
NEW PARTS;
WHOLESALE
5013 TRADE 2758
65 REAL ESTATE
NONRESIDENTtAL
BUILDING
6512 OPERATORS 4495 24
-------
Great Lakes-California PCB Cross Reference
Major SIC Number MAJOP NAME Minor SIC Number MINOR Name
Great Lakes establishments reporting PCB Discharges
' • -MI- ! if- iTSCArirms TRI PCS MhWISC
COIN OPERATED
LAUNDRIES AND
7215 CLf ANING
1158
Mist Rf PAIR SERVICES
REPAIR
7699 SERVICES, NEC
3582
80 HEALTH SERVICES
8060 HOSPITALS
MEDICAL AND
DENTAL
8070 LABORATORIES
HEALTH AND
ALLIED SERVICE.
8091 NEC
199
2463
N/A
0 3
0 1
0
87 ENGINEERING AND MANAGEMENT SERVICES
RESEARCH AND
TESTING
8730 SERVICES
I' COMMERCIAL
PHYSICS
8731 RESEARCH
2155
802
0 10
1 1
TESTING
8734 LABORATORIES
615
-------
Great Lakes-California PCB Cross Reference
Kipr r,|r NumhT MAJOP NAMf "•' '- ~"~ Mum! ptjv»r ireal I akes eslablishments reporting PCB Discharges
.'•••Mums PC? C- ' in.". Ml PCS MHWI5C
Notes
PCS is Permit CompKnu <- Svstem
TRI is loxics release invenlory
MI+WISC is the sum of establishments with PCBs reported to the Michigan and Wisconsin toxics programs.
Derived from the- US HiiK.au of the Census 1992 Economic Cunsus.
-------
|