UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
^ San Francisco, CA 94105
June 2001
San Diego Hazardous Material Commodity Flow Study
Fact Sheet
Chemical Emergency Prevention and Preparedness Office
US EPA Region 9, San Francisco, California
In June 2001, the United States Environmental Protection Agency, Region 9, issued the final
report on a hazardous material commodity flow study of the San Diego, California area. A
commodity flow study is an analysis of the goods that are moving through a particular area. In
March, the study was presented to the California Border Emergency Planning and Response
Task Force. The study describes the identity and quantity of hazardous materials traveling through
San Diego, and provides recommendations for reducing risks that these materials pose to the
community. The study identifies the nature, quantities and routes of hazardous substances
transported in or near San Diego, including exports to and imports from Mexico.
Purpose of the study. USEPA conducted this study to create a useful reference document for
hazardous material emergency planning, prevention and response efforts at the US/Mexico border.
A better understanding of the chemical safety risks posed by transportation in San Diego will
enable federal, state and local officials to make more informed decisions on the allocation of
resources and the management of hazardous substances in the community.
The cities of San Diego, California, and Tijuana, Baja California, are one of the six Sister City
pairs designated for contingency planning and emergency response assistance under USEPA
Region 9's US/Mexico Program.
Data sources. Commodities are tracked as imports and exports through two federal agencies,
U.S. Customs Service (imports) and U.S. Bureau of Census (exports). Import and export
information is available by type of commodity, mode of transportation, port of entry/exit, volume,
shipment weight, and value. Hazardous waste import quantities are available through the Haztraks
database. Haztraks was created jointly by the USEPA and the Mexican Environmental Ministry
to track the movement of hazardous waste between the U.S. and Mexico.
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Traffic data included daily truck counts at key local intersections provided by the California
Department of Transportation. The study also considered data from the U.S. Department of
Transportation, Bureau of Transportation Statistics. Geographic and environmental data came
from San Diego city and county publications, a visit to the city by study personnel, and interviews
with local authorities.
Key results. Tables 1 -5 below show the annual number of trucks and railcars carrying hazardous
materials through San Diego, divided between imports and exports and the ports of entry (Otay
Mesa, Tecate and San Ysidro). According to the data, no hazardous materials were imported
through San Ysidro (the only rail link) in 1998 or 1999. Hazardous material exports through San
Diego are significantly more numerous than hazardous material imports, measured by the number
of trucks. This is because exports are often raw materials or partial products intended for the
maquiladoras or production plants, in Tijuana. Finished goods returning to the US dominate
imports. Finished goods are less likely to be hazardous than the raw materials used in production.
Exports may pose a greater risk to the San Diego area than imports for other reasons. Materials
to be exported tend to remain in the region longer than imports. Imports cross the border and
proceed immediately north on Interstates 5, 15 and 805 or east on Interstate 8 to their final
destination, simply passing through San Diego. In contrast, exports often remain in San Diego
warehouses or parking lots for consolidation or export clearance. This extended time in the
region increases the risk of an incident occurring locally.
The traffic network in the region was analyzed in order to identify problem areas or hot spots. The
areas of most concern are the intersections along the interstates most traveled by trucks. The
top two intersections are I-8 with I-5, and I-805 with 1-15. These intersections are located within
densely populated areas of San Diego.
The most sensitive parts of the environment in the San Diego region are the local water resources.
Many waterways in San Diego drain into the harbor and Pacific Ocean. Up to 20 percent of the
drinking water supply is from local sources captured in local reservoirs. For example, the Upper
Otay Reservoir and the Lower Otay Reservoir cover over 1,000 surface acres when full. Located
between the Tecate and Otay Mesa ports, they are two of the reservoirs for the City of San Diego's
municipal water supply system.
Possible actions. Many communities have improved the safety of their residents by placing
restrictions on truck traffic carrying hazardous materials, and by enacting zoning measures to
prevent the storage and shipment of hazardous materials in sensitive or high risk areas. The San
Diego region has few options to affect the current movement of hazardous materials through
residential areas in the city. Hazardous material traffic flows on major interstates. Essentially all
of the interstates travel directly through densely populated areas of San Diego. There are no real
alternatives to these routes. Restricting hazardous material traffic on the interstates would
effectively transfer the trucks onto local surface roads, which would increase the risk of a spill.
Awareness of the nature of hazardous material flows, and the nature and location of spills, will
assist emergency preparedness by San Diego County's existing Hazardous Materials Incident
Response Team and other local authorities.
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Table 1 - Truck Imports by Commodity Description for Otay Mesa in 1998 and 1999
Description
Inorganic chemicals
Organic surface-active agents
Miscellaneous chemical products
Paints
Explosives
Ores, slag, and ash
Fertilizers
Mineral fuels
Organic chemicals
Photographic or cinematographic goods
TOTALS
1998 Annual
# of Trucks
2,429
1,351
70
57
66
2
0
2
0
0
3,976
1999 Annual #
of Trucks
1,771
1,104
126
61
43
6
2
1
0
0
3,113
Table 2 - Truck Imports by Commodity Description for Tecate in 1998 and 1999
Description
Explosives
Ores, slag, and ash
Organic surface-active agents
TOTALS
1998 Annual
# of Trucks
2
0
0
2
1999 Annual #
of Trucks
180
0
0
180
[No hazardous materials were imported through San Ysidro in 1998 or 1999.]
Table 3 - Truck Exports by Commodity Description for Otay Mesa in 1998 and 1999
Description
Petroleum, petroleum products and related materials
Gas, natural and manufactured
Plastics in primary forms
Inorganic chemicals
Crude minerals (excluding coal and petroleum)
Fertilizers
Organic chemicals
Chemical preparations for photographic uses
Chemical materials and products
Dyeing, tanning and coloring materials
Perfume materials, polishing and cleansing preparations
Ash and residues containing metals and metallic compounds
Coal, coke and briquettes
TOTALS
1998 Annual
# of Trucks
8,764
4,933
3,058
492
412
487
288
175
119
132
19
6
0
18,885
1999 Annual #
of Trucks
7,907
5,836
3,958
732
567
551
268
238
196
172
30
11
2
20,468
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Table 4 - Truck Exports by Commodity Description for Tecate in 1998 and 1999
Description
Petroleum, petroleum products and related materials
Plastics in primary forms
Dyeing, tanning and coloring materials
Inorganic chemicals
Fertilizers
Organic chemicals
Coal, coke and briquettes
Chemical materials and products
Perfume materials, polishing and cleansing preparations
TOTALS
1998 Annual #
of Trucks
760
78
53
30
17
9
0
9
2
958
1999 Annual #
of Trucks
308
89
40
40
21
16
13
9
3
538
Table 5 - Rail Exports by Commodity Description for San Ysidro in 1998 and 1999
Description
Plastics in primary forms
Chemical materials and products
Petroleum, petroleum products and related materials
Inorganic chemicals
Organic chemicals
Gas, natural and manufactured
Dyeing, tanning and coloring materials
Ash and residues containing metals and metallic compounds
Perfume materials, polishing and cleansing preparations
Fertilizers
Chemical preparations for photographic uses
Crude minerals (excluding coal and petroleum)
TOTALS
1998 Annual #
of Railcars
557
19
69
25
20
10
5
3
0
1
0
5
715
1999 Annual #
of Railcars
225
47
16
15
13
11
3
3
1
0
0
0
334
For more information about chemical safety and US EPA's US/Mexico Border Program, please consult
the following:
1. http://www.epa.gov/usmexicoborder/ef.htm
2. http://www.epa.gov/swercepp/ip-bopr.htmtfmexico
3. USEPA Region 9 San Diego Border Office: Tel 619.235.4765
4. USEPA Region 9 Chemical Emergency Prevention & Preparedness Office:
Tel 415.744.2405.
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