List of Tables and Figures
List of Acronyms
Report
II. Methodology
III. Problems/Issues Encountered
Table 1. Population in the Border Area of US and Mexico States: 1990 and 1995
Table 2. Population Growth in the California-Baja California Region: 1930-1995
Table 3. Border Crossings between California and Mexico: 1991-1995
Table 4. Truck Border Crossings between California and Mexico: 1991-1995
Table 5. San Diego Energy Use: Industrial Sector
Table 6. San Diego Energy Use: Commercial Sector
Table 7. San Diego Energy Use: Residential Sector
Table 8. San Diego Energy Use: Transportation Sector
Table 9. San Diego Energy Use: Summary of All Sectors
Table 10. Baja California Energy Sources: 1993
Table 11. Baja California Fuel Use
Table 12. Point Sources of Emissions in San Diego and Imperial Counties
Table 13. Emission Factors for Cd. Juárez using MOBILE-Juárez Computer Model
Table 14. Emission Factors for El Paso using MOBILE 5a Computer Model
Table 15. Vehicle Kilometers Traveled (VKT) for Cd. Juárez and El Paso
Table 16. Air Quality information for the US-Mexico Border Region
Table 17. Ambient Air Quality Monitoring Sites: San Diego and Tijuana Region
Table 18. Ambient Air Quality Monitoring Sites: Imperial Valley, Yuma and Mexicali
Table 19. Ambient Air Quality Standards for the US and Mexico
Table 20. Ambient Air Quality Data for the San Diego-Tijuana Area
Table 21. Ambient Air Quality Data for the Imperial Valley-Mexicali Area
Table 22. Ambient Air Quality Data for Particulate
Matter less than 10 Microns (PM10) in the California-Baja California Border
Region
Table 23. Ambient Air Quality Data for Carbon
Monoxide in the California- Baja California Border Region
Figure 1. Emissions of Carbon Monoxide: San Diego County
Figure 2. Emissions of Nitrogen Oxides: San Diego County
Figure 3. Emissions of Sufur Oxides: San Diego County
Figure 4. Emissions of Total Organic Compounds: San Diego County
Figure 5. Emissions of Particulate Matter less than 10 Microns (PM10)
Figure 6. San Diego Ambient Air Quality Monitors
I. Objectives of the research
The objectives of this research were to develop a binational database that can be used to identify the principal sources of air pollution along the USMexico border, with a particular focus on the energy producing sector and the California-Baja California region. Data collection was not envisioned as an end in itself, but rather to be used as an important tool for policy makers and government agencies responsible for air quality on both sides of the border. Local, state and federal agencies both in Mexico and the US have expressed a need to have appropriate data on emissions to the atmosphere and criteria air pollutants in the border zone. This is especially the case on the Mexican side of the border.
A related objective was to build the needed human and technical infrastructure
required to establish data collection methods and procedures, particularly
in the Mexican border cities of Tijuana and Mexicali.
II. Methodology
Data was collected on two types of emissions; point and mobile sources. Point source emissions for San Diego and Imperial County were extracted from the California Air Resources Board data base. For Mexico, emissions were estimated from known fuel inputs to power plants in the region. For mobile sources such as cars and trucks, results of mobile emissions models were used, such as the EPA MOBILE models, adapted for use in the Mexican city of Cd. Juárez.
Data were collected from a wide variety of sources including CFE, PEMEX, the State of Baja California, the Secretary of Transportation, the cities of Tijuana and Mexicali, SEMARNAP, the USEPA, CARB, the San Diego Association of Governments, the San Diego Air Pollution Control District, and others.
Some of the data bases generated by this project have been posted on
the SCERP website and much of the data is stored both in at SDSU and UABC.
III. Problems/issues encountered
Most of the problems encountered in this project dealt with obtaining the relevant information from various agencies. This was true on both sides of the border. On the US side, the information may be available in theory, but considerable time had to be spent locating the appropriate person in the particular agency or company who had access to the material. Even then, access to the data was idiosyncratic. On the Mexican side of the border, less information was accessible, and access depended very much on personal contacts and inclusion of the agency into the project in some way. In Mexico, just providing data is generally not done, unless it is in some agreed upon context.
The research results reported here consist primarily of tables and charts that contain data related to sources of emissions in the border region. Upon analyzing the data, one important conclusion is that mobile sources (cars and trucks) are a very large source of total emissions in the San Diego-Tijuana portion of the border. Thus, programs aimed at reducing emissions from cars and trucks will go a long way to improve air quality in the border area. This will become more important as more trucks travel on California roads as a result of NAFTA.
In Mexicali-Calexico area, however, particulate matter from a variety of activities, such as agriculture, are a significant contributor to the emissions inventory, in addition to emissions from cars and trucks.
Another finding is that the best short term hope to reduce air pollution from large point sources, such as the large power plant at Rosarito south of Tijuana, is to switch the fuel from oil to natural gas. In fact, introduction of natural gas for electricity production and industrial processes in the border regions will significantly reduce air emissions (mostly SOx and CO) in the border area.
Close coordination between US and Mexican entities is absolutely essential to develop an adequate emissions inventory in the border region. This includes cooperation from agencies in Mexico City as well as local branches.
Emissions modeling, using models such as MOBILE5-Juárez, are very
useful in estimating emissions from mobile sources for Mexican border cities.
V. Conclusions and Recommendations
Based on the information developed in this report, we provide a summary of some of our conclusions and recommendations.
1. Developing an adequate emissions inventory for Mexican border areas is a long term problem. Continuing work will be required to obtain an appropriate inventory and to keep it up to date.
Recommendation
Human and technical infrastructure needs to be maintained if emissions inventories are to be kept up to date. Data quickly becomes out-dated and looses its value unless continually maintained.
2. The energy producing sector is the main point source of air pollution in the San Diego-Tijuana region. In particular, the large, 640 MW power plant located in Rosarito is the single largest point source of oxides of sulfur in the whole binational region.
Recommendation
High priority should be given to converting this power plant so that it can burn natural gas as a fuel instead of fuel oil. Conversion to natural gas will result in significant reductions in sulfur oxides for the whole border region.
3. Mobile sources, such as cars, light and heavy duty trucks, account for the majority of emissions in the San Diego-Tijuana region. Particulates from agriculture related activities are a large source of particulates in the Mexicali-Calexico area.
Recommendation
More work needs to be done developing adequate emission models for Mexican border cities. This should build on the work of the TNRCC in Cd. Juárez. Testing of Mexican vehicles needs to be carried out to obtain accurate emission factors and transportation models need to be developed to better understand Mexican driving habits and vehicle kilometers traveled.
4. Emissions from heavy duty trucks will likely increase in the California-Baja California region, because of increased cross border traffic as a result of increased trade and phasing in of NAFTA regulations with respect to truck operations in the border region.
Recommendation
Basic information about emission factors for Mexican trucks operating in the border region needs to be developed. Sample testing of Mexican trucks should begin as soon as possible. On-road emissions from Mexican trucks crossing the border should be determined on a random basis. Mexican trucks crossing into California should meet the same emissions standards as California registered trucks.
5. It appears to be possible to use emissions models for certain Mexican border cities, such as Cd. Juárez. It also may be possible to adopt these models for use in Tijuana and Mexicali.
Recommendation
More testing of MOBILE models needs to be carried out in Mexican border
cities. This means information will be required pertaining to characteristics
of Mexican border vehicle fleet.
6. Demand side management programs, such as those of the CFE in Mexicali, could help reduce electric demand in the summer peak periods, thereby reducing peak power needs resulting in less pollution.
Recommendation
Energy efficiency programs are the most cost effective way to reduce emissions from the energy sector. Programs such as developing energy efficient building standards, energy efficiency ratings for appliances, such as air conditioners and refrigerators, should be supported and encouraged in Mexican border cities.
7. Data from this project and other related activities could form the basis for a Border Environmental Information effort. This could be located on the internet and produce information for use on both sides of the border.
Recommendation
A large amount of air quality information pertaining to the US-Mexico border is becoming available. The time is right to develop a comprehensive Border Environmental Information program to gather, organize, analyze and disseminate this growing quantity of information.
VI. Recommendations for further research
Further research should be directed to maintaining the human and physical infrastructure needed to keep up-to-date the data bases and models developed in this and related projects. Specifically, an arrangement between SDSU, UABC and for example, SEMARNAP and EPA should be developed that provides resources for at least one full time person to maintain a web site, enter data and provide hard copy output. Overseeing this person should be a binational advisory board which determines what type of information should be collected and the extent of data collection needed. If this is not done, in a very short time all the information collected in this and similar projects will become outdated.
What is called for here is an ongoing relationship between the SCERP
institutions, EPA and the appropriate Mexican entity, such as SEMARNAP or
INEGI.
VII. Benefits of research project
Sound policy regarding air pollution reduction in the border region cannot
be developed without the necessary data and information regarding emissions
into the atmosphere. This project has provided some of these data that can
be used to develop more fully an emissions inventory in the California-Baja
California portion of the border. Besides the gathering, organization and
dissemination of the information, important ties have been developed with
Mexican researchers and local officials working in the municipal and environmental
agencies in Tijuana and Mexicali. In the long run, these human contacts
may prove equally or even more important than the actual data bases developed.SOURCES
OF AIR POLLUTION IN THE US-MEXICO BORDER REGION: DEVELOPMENT OF DATA AND
INFORMATION
The objectives of this research were to develop a binational database that can be used to identify the principal sources of air pollution along the USMexico border, with a particular focus on the energy producing sector and the California-Baja California region. Data collection was not envisioned as an end in itself, but rather to be used as an important tool for policy makers and government agencies responsible for air quality on both sides of the border. Local, state and federal agencies both in Mexico and the US have expressed a need to have appropriate data on the sources of air pollution in the border zone. This is especially the case on the Mexican side of the border. These data will be used to develop an emissions inventory for the border region.
A related objective was to build the needed human and technical infrastructure
required to establish data collection methods and procedures, particularly
in the Mexican border cities of Tijuana and Mexicali.
The data gathered for this report are from those sectors that relate to activities that impact air quality in the border region, such as:
1. fuels used in the transportation sector in Baja California
2. fuels used for non-transportation related activities
3. fuels used for power production
4. electricity consumption by sector and municipality
5. number and type of power plants
6. population
7. point sources of emissions
8. cars and trucks
9. border crossings and waiting times
The information was collected by a variety of means. Most come from official sources on both sides of the border. On the Mexican side, agencies such as the Baja California State Economic Development Commission, CFE, PEMEX, INEGI, SEMARNAP, the Energy Regulatory Commission in Mexico City, and the Secretary of Energy were used. In addition to these official sources, the relevant literature was utilized where appropriate. Most of the information reported here is not generally available to the general public in Mexico or published. Much of it was gathered by personal contacts with Mexican officials in the agencies noted.
On the US side of the border, agencies such as the San Diego Association of Governments (SANDAG), the CARB and APCD, the USEPA, San Diego Gas and Electric, Southern California Gas Company, and others were consulted. For the US, there is more information available in the literature and other open sources.
In addition to collecting data on activities that generate emissions,
we also report information on actual measurements of some criteria pollutants
on the Mexican side of the border. These data have recently become available
via the CICA webpage which reports readings from recently air monitors in
Tijuana, Mexicali and Cd. Juárez. These data are QA/QC by CARB and
EPA.
III. Problems/issues encountered
Most of the problems encountered in this project dealt with obtaining the relevant information from various agencies. This was true on both sides of the border. On the US side, the information may be available in theory, but considerable time had to be spent locating the appropriate person in the particular agency or company who had access to the material. Even then, access to the data was idiosyncratic. On the Mexican side of the border, less information was accessible, and access depended very much on personal contacts and inclusion of the agency into the project in some way. In Mexico, just providing data is generally not done, unless it is within some agreed upon context.
One issue encountered was the confidentiality of the information supplied
by the various agencies we dealt with throughout the course of the project.
In Mexico, releasing information to the public is not as much as a tradition
as in the United States. This does not mean, however, that information cannot
be obtained. Our experience has been that to obtain information of the type
discussed here, personal contact between the principal investigators
and appropriate Mexican officials is a necessity. This should come as no
surprise to anyone who has worked in Mexico, but it should be kept in mind
as more US scientists and officials become more involved with agencies dealing
with environmental issues in Mexico.
The results of this project are presented in a series of tables and charts
containing information needed to understand the origin of emissions in the
border region as well as ambient air quality data for the border area.
Human population is a critical element when considering sources of air pollution. The population of the US-Mexico border region is about 10 million, with almost half located in the California-Baja California region, as seen in Table 1.
The population centers are grouped around "twin" cities with
the inevitable result that most air quality problems arise in the regions
where the cites are located. Along the US-Mexico border, the Mexican cities
have a greater population than the cities on the US side, with the important
exception of the San Diego-Tijuana region, where San Diego is the larger
of the two cities. The population of this region has grown rapidly over
the years, as shown in Table 2. The population
of the California-Baja California region is approaching 5 million, and is
expected to be about 5.5 million within the next ten years. It is this large
population concentrated in a relatively small geographical area, and its
rapid growth, that has been, and will continue to be, the main cause of
environmental problems, including air quality, in the border region.
Related to the population growth has been the rapid increase in the number
of maquiladora plants. There are now 1,585 plants, employing about
549,000 people in the entire US-Mexico border region. In the California-Baja
California region, there are 777 plants employing 164,470 people. These
plants require water and power and contribute to point sources of emissions
in the border area.
Border crossings by cars and trucks give an indication of the economic activity in the border area and have an impact on air quality. The number of cars and trucks circulating in the border area as well as the waiting time to cross the border are factors that contribute to the mobile emissions in the region. The number of vehicles (cars, trucks and busses) crossing the California-Baja California border is given in Table 3. One can see the very large number of cars and trucks that cross the border annually, over 27,000,000 vehicles in 1995, with similar volumes during the previous four years.
Heavy-Duty trucks using diesel account for a disproportionate amount
of emissions, especially particulate matter. Table
4 gives the number of trucks crossing the border from 1991 to 1995.
During the period, truck traffic increased by 37 percent, reaching almost
700,000 crossings in 1995. All indications are that the number of trucks
crossing the border and operating within the border region will continue
to increase. Emissions from these trucks, especially particulate matter,
could become a significant problem in the border region, unless emissions
are reduced from both the US and Mexican truck fleets.
The production and utilization of energy for power, industrial processes and transportation is the largest source of air pollution in the border region. Therefore, information related to the energy sector on both sides of the border is an important element in developing an emissions inventory for the region. The following tables present data related to the energy sector for San Diego and Baja California.
Table 5, Table 6, Table 7, and Table 8 give comprehensive energy data for the residential, commercial, industrial and transportation sectors in San Diego County. These data were compiled as part of an extensive study of the energy sector in the region, in which one of the principle investigators (Dr. Sweedler) was a participant. The cooperation of local governments such as SANDAG is a good example of how SCERP projects interact with local government agencies.
The principal characteristic of the energy sector in San Diego is its almost total dependence on energy sources from outside the region. All transportation fuels and over 60 percent of electricity are imported from outside the area. Mobile sources account for approximately 60 percent of air emissions in the San Diego region, the result of the consumption of over 1.1 billion gallons of gasoline, 202 million gallons of diesel fuel and over 25 billion vehicle miles traveled in 1996. For San Diego the transportation sector is the largest consumer of energy, accounting for almost 60 percent of total energy consumption.
Table 9 summarizes the energy sector data for San Diego. It is clear from these data that improving air quality in the region will require directing strategies and resources to the transportation sector. A combination of cleaner burning fuels, such as compressed natural gas, increased emission controls, programs to reduce miles traveled, introduction of electric vehicles and improved bus and rail service will be needed to continue the improvement in air quality obtained in San Diego during the past few years.
Policies adopted in San Diego tend to influence trends on the Mexican side of the border. Although there is usually a time lag, eventually a certain degree of harmonization is reached. A good example is the introduction of unleaded gasoline in Tijuana. Over the past decade, unleaded gasoline was gradually introduced on the Mexican side of the border partly in response to its widespread use in San Diego. Today, most gasoline consumed in Tijuana is unleaded. This has greatly reduced the emissions of lead to the atmosphere in Tijuana.
We now turn to the energy sector in Baja California. Baja California derives its energy from basically two sources; petroleum products and geothermally generated electricity. All of the petroleum products are imported to the region from other parts of Mexico, especially from north-central Mexico and the Peninsular Area. For example, fuel oil used at the large (620 MW) Rosarito thermoelectric power plant, located 24 km south of the border, is transported by tanker from Pemex's Salina Cruz refinery 2400 km to the south and also from foreign sources. This power plant is the largest single source of sulfur dioxide emission in the entire border region, and possibly on the entire west coast of North America.
Geothermal energy from the geothermal fields at Cerro Prieto, located south of Mexicali is used to power Baja California's other principal power station.
The transportation sector uses leaded and unleaded gasoline and diesel. Liquid petroleum gas (LPG) substitutes for natural gas and is used mostly in the residential sector, but also in the industrial and commercial sectors.
There are no oil refineries in Baja California and most petroleum products enter the region via a products terminal at Rosarito, brought there by tankers. Between Rosarito and Mexicali there is a 10 inch pipeline to transport petroleum and refined products and a similar 8 inch pipeline between Rosarito and Ensenada. Liquid petroleum gas (LPG) is brought into the region by truck or rail and distributed by truck.
Baja California's energy supplies are shown in Table 10 for 1994. Petroleum-based products accounted for 69% of total energy supply, geothermally generated electricity accounting for the rest. Details of fuel consumption are given in Table 11 which covers the various fuels used in Baja California. These include diesel, nova (leaded gasoline), magna sin (unleaded gasoline), combustoleo (heavy fuel oil) and liquid petroleum gas. Data such as these can be useful in estimating emissions from use of liquid fuels.
Baja California's electrical energy infrastructure consists of two large power generating facilities, one using heavy fuel oil and the other utilizing geothermal energy, several smaller generating plants and appropriate transmission lines. The power grid is connected to San Diego via two 240 KV lines, one near Tijuana and the other Mexicali.
Demand for electricity in Mexico has increased at a much higher rate than in the US. During the 1980s electricity demand in Mexico grew at a rate of 6% per year, although the annual population growth rate was only 2.5% and the gross domestic product grew at 1.4% per year. In Baja California, electric energy demand growth averaged about 6% per year between 1982 and 1990. For the United States, demand growth during the 1980s averaged only about 2% per year, and in San Diego about 3% per year. Demand for electricity in Baja California will continue to grow faster than in San Diego and meeting this demand could have a major impact on air quality for the entire San Diego-Tijuana region.
Current expansion plans by CFE call for adding 450 MW by the year 2002 to the already existing 620 MW at the Rosarito plant, 100 MW at the geothermal plant at Cerro Prieto by 1999, and combined cycle plant to 225 in Mexicali by 2004. If the Rosarito plant is expanded and oil is used for fuel, this power plant will present a major source of air pollution in the border region.
Instead of increasing generating capacity within Baja California to meet
future demand, an argument can be made to purchase electricity from the
North American power system. As noted earlier, the Baja California power
grid is isolated from the Mexican national system, but is connected to the
California system at two points. This permits power transfers between the
whole North American system and Baja California. As deregulation of the
California and US electric sector gains momentum, electric customers and
energy brokers will be searching all over North America for the cheapest
power available. It may prove cost effective for CFE in Baja California
to both buy and sell power within this very large electric market. Large
consumers of power in Baja California, such as industrial parks, may find
it cheaper to purchase power from the US than from CFE. Similarly, customers
in San Diego may find it less costly to obtain power from CFE in Baja California
or from independent power producers located in Mexico, than from their local
utility or from the statewide power exchange to be established under deregulation.
3. Baja California Natural Gas Market
Baja California has no natural gas distribution or transmission pipeline network. The state therefore cannot utilize the abundant natural gas resources of Mexico. There is, however, a growing recognition that natural gas would be an ideal fuel to meet the region's growing demand for industrial heat and electric generation, provided the high cost of constructing a pipeline system can be met.
The Chamber of Commerce for the manufacturing sector in Mexicali, CANACINTRA, has undertaken a survey to locate probable consumers of natural gas if the service were available. A total of 37 companies in diverse industries were identified as potential users of natural gas.
In addition to the industrial sector, the use of natural gas for power generation in Baja California is potentially of great importance. As noted above, the principal thermal power plant in the state is the 640 MW facility located in Rosasrito, just 24 km south of the border. CFE plans to add 450 MW of additional capacity by the year 2002. Currently the plant burns heavy fuel oil and is the main point source of air pollution in Baja California. If expansion plans are realized, the Rosarito plant will be the largest thermal power plant on the west coast of North America by the turn of the century.
The existing boilers at the Rosarito plant, as well as future generating units, could be major users of natural gas, if it were available to Tijuana. If expansion plans for the Rosarito plant are completed, its installed capacity will be 1090 MW by the year 2002. Assuming a fuel requirement of 240 mcfd of natural gas per 1000 MW of installed capacity, the Rosarito plant would require approximately 262 mcfd, by the year 2002. To put this quantity of natural gas into perspective, total natural gas usage for the whole San Diego region in 1995 was 252 mcfd. Thus, to supply natural gas to the Rosarito power plant implies a doubling of the natural gas supply to the whole region. Clearly, this is a significant undertaking, but one that also promises significant benefits, financial and environmental, to the region.
In March 1996, the Mexican government through its Energy Regulatory Commission called for bids to construct a pipeline system to supply natural gas to Mexicali. The project is to be carried out in three phases: an engineering phase, procurement and actual construction of the pipeline system. The result of the bidding process were announced on 12 August 1996. The winning bid went to a consortium of three companies based in southern California and Mexicali: Enova (the parent company of SDG&E), Pacific Enterprises (the parent company of Southern California Gas Company) and Pr-xima, and Mexican company in Mexicali. The consortium, known as Distribuidora de Gas Natural de Mexicali (DGN) will have a 12 year exclusivity on the distribution of natural gas to over 25,000 users in Mexicali.
The possibility that Tijuana could also develop a natural gas project
similar to Mexicali has been under discussion by business leaders, although
no specific plan has yet emerged.
1. San Diego and Imperial Counties
Major point sources of air emissions for San Diego and Imperial Counties are given in Table 12. These data are based on the California Air Resources Board's reporting requirements which we have modified to allow incorporation into a GIS data base. We have identified the coordinates of each point source in universal coordinates and state plane projection. These data were then used to create an ARCINFO data base which could used to display the various pollutants in a GIS framework.
Figure 1, Figure 2, Figure 3, Figure 4, and Figure 5 show the location and amount of emissions for COx, NOx, SOx, PM (total) and PM10 for San Diego County. Figure 6 shows the location of air monitoring stations maintained by the San Diego Air Pollution Control District.
From Table 12, one sees that emissions for total and reactive organic gases for San Diego and Imperial Counties were 21,130 and 5,008 tons per year, respectively, in 1995. For COx, NOx, SOx, PM and PM10, total emissions were, 2752, 7014, 559, 4615 and 2116 tons per year, respectively.
Power plant operations are the major point sources of oxides of nitrogen,
carbon and sulfur. They also are the principal source, along with agricultural
activity and quarry operations, of particulate matter.
Data on point source emissions are very difficult to obtain for the Mexican side of the border region. Most of the information is confidential and whatever is supplied to the authorities, mostly SEMARNAP and PROFEPA, is not generally available to researchers or the public.
Attempts have been made, however, to estimate emissions from point sources using known inputs to various industrial operations. These approaches are, of course, only rough estimates based on engineering calculations. They are fraught with uncertainties about actual plant operations and depend on many unverifiable assumptions. Until actual measurements of emissions take place in the Mexican border region and the results are released to the research community, these engineering calculations are all that are available
One such set of calculations have been performed by Mej'a et al. They calculated SO2, CO, emissions from central power plants in the border region. Of particular interest to us is their estimation of emissions from the large thermoelectric plant located in Rosarito, Baja California, just 24 km from the border. For SO2 and CO, Me'ja et al. estimate 5,000 and 12,000 tons per month, respectively. These are very high emissions and must be considered an upper limit, since they do include any emission control devices installed on the plant. The monthly estimated (calculated) emissions from this one plant far exceed the total yearly emissions for the whole of San Diego County.
Another Mexican study finds much lower emissions than those just noted. Quintero et al., find 5,900 tons of SO2 , 870 tons of CO, 420 tons of particulates and 820 tons of hydrocarbons per year.
Very large discrepancies such as these, clearly point to the need for
actual measurements of plant emissions which will then be made available
to the research community. Despite the lack of availability of measured
emissions from the Rosarito plant, there can be no doubt that this single
plant, which uses relatively high sulfur fuel oil (the exact composition
of the fuel is not available), is the largest point source of sulfur oxide
and CO emissions in the region. A strong case can be made for switching
this plant to natural gas on environmental grounds alone.
E. Mobile Sources of Emissions
Emissions from mobile sources, such as cars, light and heavy duty trucks, buses and motorcycles, account for approximately 60 percent of total emissions in San Diego County. The estimation of mobile source emissions is usually determined by the use of computer models developed by the EPA or CARB. California bases its estimates on the models developed by CARB (know as the Motor Vehicle Emissions Inventory or MVEI models), while the rest of the nation uses the MOBILE series of models developed by EPA. When dealing with mobile emissions in the California-Mexico border region, one immediately runs into a question of which models to use. We have chosen to utilize the MOBILE series for two reasons. First, comparisons can be made with other Mexican border cities, notably Cd. Juárez, where the MOBILE models have been utilized and second, there is developing a convergence between the newer versions of MOBILE and MVEI models.
The MOBILE model has been modified for use in Cd. Juárez by the Texas Natural Resources Conservation Commission (TNRCC) in a project under the direction of Carl Snow of the TNRCC. The resulting model is known as MOBILE-JUÁREZ. We have worked closely with Snow in learning how to use the model and to investigate its applicability to other Mexican border cites, such as Tijuana. A two day workshop on MOBILE use was conducted by Snow at the campus of SDSU in which our researchers as well as APCD, CARB and Mexican staff participated.
The MOBILE model has been adapted for use in Cd. Juárez by conducting tests on a representative fleet of Mexican cars in that border city. Emissions test were performed and the results incorporated into the MOBILE model. These tests replaced those usually used for the US fleet of cars. Although MOBILE-JUÁREZ has been developed based on the vehicle fleet in Cd. Juárez, it should be applicable for use in other Mexican border cities as well. The reason is that there is a greater similarity among the fleets of Mexican border cites than between a US and Mexican border city.
Table 13 gives the results of a representative
output of MOBILE-JUÁREZ for Cd. Juárez. For comparison, results
for El Paso are given in Table 14. One needs
to have an independent estimation of the vehicle miles (or kilometers) traveled
for each vehicle class in order to obtain actual emissions to the atmosphere
for the mobile fleet. These were obtained in a separate study for Cd. Juárez,
and are listed in Table 15. Total vehicle miles
traveled for the Cd. Juárez fleet in 1993 was 3,393,949, about one
third the VMT for El Paso. Using the emission factors calculated from the
MOBILE-Juárez model, one can estimate total hydrocarbon and CO emissions
in Cd. Juárez from mobile sources. The results are 34.5 metric tons
of hydrocarbons and 13.4 metric tons of CO emitted to the atmosphere in
Cd. Juárez by the vehicle fleet.
F. Ambient Air Quality Data for the Border Region
1. Monitoring sites
Measurements of ambient air quality is well established in San Diego and Imperial Counties. In San Diego, the Air Pollution Control District has stationed monitors throughout the region. For most Mexican border cities, however, monitoring of air quality has not taken place on a regular basis. Recently, however, Tijuana, Mexicali and Cd. Juárez have had installed air quality monitors as part of a cooperative program between USEPA, SEMARNAP and CARB. For the first time, it is now possible to obtain quality assured and quality controlled measurements of air quality in these border cities.
The posting of these data is available on the internet at a site maintained by the EPA. We have downloaded these data and reorganized the format in order to input the data into a GIS data base and to make comparisons between US and Mexican border cities. The type of data available are given in Table 16.
Table 17 lists the monitoring stations in San Diego and Tijuana. There are 12 sites, 8 in San Diego and 4 located in Tijuana. Table 18 shows the monitoring sites in the Imperial Valley, Yuma, Arizona and Mexicali. Fourteen sites are operating in this area, 8 in the US and 6 in Mexico. The pollutants measured at each site are also listed.
The installation and quality assured operation of these sites are very
important as it they allow for continual measurement of air quality in the
border region and opens the possibility to test emission and atmospheric
models.
2. Results of Air Quality Monitoring
Ambient air quality data can be compared with ambient air quality standards in the US and Mexico. Both countries have established similar ambient air quality standards for carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), particulate matter of 10 micrometers or less in diameter (PM-10), and lead (Pb). Table 19 compares the Mexican and US health-based ambient air quality standards. There is no current guidance in Mexico by which to determine "nonattainment" with Mexican air quality standards. Additionally, there is insufficient air quality monitoring data to determine if Mexican cities meet the Mexican air quality standards.
We have summarized and condensed the ambient air quality date from the air monitoring sites in the California-Baja California border region. We also have created an ARCINFO data base with the monitoring sites as a data layer. The locations of the air monitors is shown in Figure 6. Keep in mind that by having the air monitors as a coverage in a GIS data base, one can relate information on air emissions and location of monitors to any variable in the GIS data base. For example, at-risk populations and their proximity to point sources of emissions and ambient air quality monitoring stations could be determined. This could be useful in sitting facilities such as hospitals and health care facilities.
Table 20 and Table 21 gives the ambient air quality data for the San Diego-Tijuana and Imperial Valley-Mexicali regions. Table 22 and the accompanying figure compares PM10 ambient air quality measurements from sites in San Diego, Tijuana, Imperial Valley and Mexicali. The highest levels are seen to occur in the Imperial Valley and Mexicali, with levels in Mexicali generally higher than in Imperial Valley. The highest readings can be six times greater than the lowest recorded values (300 PPM compared to less than 50 PPM), reflecting the wide variation of particulate matter in the air in the border region. The high levels in Imperial Valley and Mexicali are generally thought to be caused by the heavy concentration of agricultural activity in the area and the lack of paved roads.
Table 23 shows ambient air data for carbon
monoxide in the border region. In this case, the highest readings were recorded
in Calexico, with high values also occurring in San Diego. The high values
in Calexico may be due to idling cars at the border waiting to cross into
California. Interestingly, the relatively low values recorded at Otay Mesa
may be due to the fact that this is primarily a crossing for heavy trucks
with diesel engines, which tend to produce low CO emissions. The abnormally
low value for the UABC site in Mexicali is probably due to the very low
number of observations at the site, so we do not regard it as meaningful.
V. Conclusions and Recommendations
Based on the information developed in this report, we provide a summary of some of our conclusions and recommendations.
1. Developing an adequate emissions inventory for Mexican border areas is a long term problem and continuing work will be required to obtain an appropriate inventory and to keep it up to date.
Recommendation
Human and technical infrastructure needs to be maintained if emissions inventories are to be kept up to date. Data quickly becomes outdated and looses its value unless continually maintained.
2. The energy producing sector is the main point source of air pollution in the San Diego-Tijuana region. In particular, the large, 640 MW power plant located in Rosarito is the single largest point source of oxides of sulfur in the whole binational region.
Recommendation
High priority should be given to converting this power plant so that it can burn natural gas instead of oil. Conversion to natural gas will result in significant reductions in sulfur oxides for the whole border region.
3. Mobile sources, such as cars, light and heavy duty trucks, account for the majority of emissions in the San Diego-Tijuana region. Particulates from agriculture related activities are a large source of particulates in the Mexicali-Calexico area.
Recommendation
More work needs to be done of developing adequate emission models for Mexican border cities. This should build on the work of the TNRCC in Cd. Juárez. Testing of Mexican vehicles needs to carried out to obtain accurate emission factors and transportation models need to be developed to better understand Mexican driving habits and vehicle kilometers traveled.
4. Emissions from heavy duty trucks will likely increase in the California-Baja California region because of increased cross border traffic as a result of increased trade and phasing in of NAFTA regulations with respect to truck operations in the border region.
Recommendation
Basic information about emission factors for Mexican trucks operating in the border region needs to be developed. Sample testing of Mexican trucks should begin as soon as possible. On road emissions from Mexican trucks crossing the border should be determined on a random basis. Mexican trucks crossing into California should meet same emissions standards as California registered trucks.
5. It appears to be possible to use emissions models for certain Mexican border cities, such as Cd. Juárez. It may be possible to adopt them for use in Tijuana and Mexicali.
Recommendation
More testing of MOBILE models needs to be carried out in Mexican border
cities. This means information will be required pertaining to characteristics
of Mexican border vehicle fleet.
6. Demand side management programs, such as those of the CFE in Mexicali, could help reduce electric demand in the summer peak periods, thereby reducing peak power needs resulting in less pollution.
Recommendation
Energy efficiency programs are the most cost effective way to reduce emissions from the energy sector. Programs such as developing energy efficient building standards, energy efficiency ratings for appliances, such as air conditioners and refrigerators, should be supported and encouraged in Mexican border cities.
7. Data from this project and other related activities could form the basis for a Border Environmental Information effort. This could be located on the interment and produce hard copy information for use on both sides of the border.
Recommendation
A large amount of air quality information pertaining to the US-Mexico border is becoming available. The time is right to develop a comprehensive Border Environmental Information program to gather, organize, analyze and disseminate this growing quantity of information.
VI.
REDUCING AIR POLLUTION IN THE BAJA CALIFORNIA BORDER REGION
Dr. Norris C. Clement, Department of Economics
San Diego State University
Introduction.
Air pollution in Baja California appears to be a serious and growing problem for residents there and occasionally, during certain meteorological conditions, for Southern California residents as well. Additionally, Mexican vehicles crossing the border into Southern California may import significant air pollution as an unwanted side effect of what might otherwise be a favorable impact on the local economy.
This short essay explores how air pollution might be reduced in an area that not only is relatively poor and technologically backward but shares an international border and an air basin with one of the world's richest and technologically advanced metropolitan areas.
The general approach here will be to first identify some of Baja California's most salient characteristics vis-à-vis the issue of air pollution and then to identify the main options available to policy makers that could be employed to mitigate the pollution. In the third section the rapidly changing environmental regime adopted by environmental agencies on the US-Mexican border is presented along with some thoughts on formulating a long term strategy for addressing the problem as framed in previous sections.
Given the scarcity of data on air emissions in Baja California, the essay
should be viewed as a tentative set of propositions that could both inform
readers who are unfamiliar with the topic and provide a point of departure
for further discussion among researchers and policy makers.
I. The unique situation of Mexico's northern border region
As noted in the introduction all of the communities of Mexico's Northern border region, which extends approximately 2000 miles from San Diego-Tijuana in the west to Brownsville-Matamoros in the east, are, in comparison with their "twin -cities" on the US side, relatively poor economically and backward technologically. Nevertheless, the region is relatively prosperous in the Mexican national context, having taken advantage of its proximity to US through tourist spending since the Prohibition era of the 1920s and industrial investment since the implementation of the maquiladora (assembly plant) program in the 1960s.
A large portion of the population, approximately 80%, lives in twin-city urban areas while the rest live in small settlements scattered throughout the arid environment where agriculture exists almost exclusively at the mercy of irrigation projects originating from rapidly depleting underground aquifers and a few surface rivers.
The relatively high rate of population growth, over 5% in recent decades, due in large part to internal migration from the more backward parts of the interior of Mexico, is another defining characteristic of the region.
The region has been governed by an extremely centralized federal system where a very large proportion of local revenues and public works are provided at the pleasure of government officials in Mexico City, hundreds of miles to the South. Although Mexico is now moving towards a more decentralized democracy the asymmetries with the US still limit the ability of local authorities to collaborate with agencies on the other side of the border. Until recently, cross border interaction between twin cities was carefully regulated by the federal government and still depends more on informal relationships than formal agreements and/or institutions.
Historically, Mexico's arid Northern border region was regarded as a convenient barrier between the expansionist behemoth to the North. However, in recent decades the region has generated most of the country's new jobs and provided an escape valve for the surplus labor force of the interior into the rapidly expanding, mainly low paying, maquiladora sector.
During the post W.W.II period (1950-76) Mexico's economy grew rapidly, based on an "inward-oriented" strategy that stressed protectionism and building a domestic industrial capacity shepherded by a strong state sector. However, by 1976 (marking the first in a series of currency devaluations which saw Mexico's peso go from 12.5 pesos = $1 in 1976 to approximately 8,000 pesos = $1 in 1997) that strategy had outlived its effectiveness. New oil discoveries in that year provided an oil boom (1976-81) that temporarily boosted the economy and also provided an abundant source of oil and gas that in turn undermined any efforts to increase energy efficiency.
A second major economic crisis in 1982, triggered by Mexico's virtual default on its external debt and another major devaluation, marked the beginning of the end for the old development strategy and stimulated a series of market-oriented reforms that eventually led to sharply reduced protectionism, open doors to foreign investment, a lesser role for government in the economy and in 1994, implementation of the North American Free Trade Agreement (NAFTA) with the US and Canada in order to guarantee market access to the large and prosperous US market. Nevertheless, the period since 1982 has been marked by restrictive monetary and fiscal policies, a series of peso devaluations, low or negative economic growth rates, falling living standards for most Mexicans and, consequently, dramatic reductions in government financed infrastructure and social services.
The main implication of these events is that the peso devaluations reduced Mexican labor costs in dollar terms which in turn stimulated foreign investment, mainly in the maquiladora industry, which is largely concentrated in the Northern border region. The maquiladora "boom," which was partially fueled by lax enforcement of environmental regulations, stimulated increased demand for labor, increased migration from the interior of Mexico and increased the need for infrastructure and social services in the region to accommodate the rapidly growing population. Due, however, to the recession at the national level, which serve as the major source of local government revenues, an infrastructure deficit emerged in the northern border region that left communities struggling to keep up with the rising demands for public expenditures. As urban areas expanded streets went unpaved, sewer and water systems were left unfinished and environmental regulations were largely unenforced, mainly because of a shortage of public resources but also because officials were fearful of scaring off the foreign investors who were fueling the economic expansion of the region.
Meanwhile, the rapidly expanding Mexican border population became acquainted with US living standards and consumer habits. An important cross-border market developed for used building materials, vehicles and tires, as well as refrigerators and other large appliances while considerations of energy efficiency and air/water pollution were largely ignored. For the very poor a lower purchase price is usually much more attractive than lower monthly energy costs, especially when those are held artificially low through subsidies. Similarly, in the absence of public pressure, governments tend to emphasize economic growth and higher levels of prosperity while environmental impacts are largely ignored.
In very general terms the environmental movement is still in its incipient stage in Mexico. While important environmental groups emerged in Mexico during the 1980s the environmental movement on both sides of the border was stimulated by the debates surrounding the ratification of the North American Free Trade Agreement (NAFTA) in the early 1990s. These debates resulted in the formulation of new North American environmental institutions and a new level of transborder cooperation on border environmental issues.
The main point here is that despite these new institutions, the general level of public awareness of environmental problems in the Mexican border region remains relatively low in comparison with the US. Additionally, local governments still lack the resources necessary to adequately ameliorate such problems and even if they did have adequate resources, the lack of continuity in local government results in a lack of institutional memory which forces each new government to begin anew from a very low level of knowledge and experience in its efforts to deal with such problems.
Finally, the lack of basic statistical data on the economic, demographic
and environmental characteristics of the region, represents a formidable
obstacle to effective environmental management.
II. The problem and its solution: mitigation options.
Air pollution imposes costs upon the general population in terms of added health problems and lower worker productivity. Additionally, air pollution adds to global environmental problems such as acid rain, the receding ozone layer and the greenhouse effect which can lead to global warming.
A. The Traditional Approach
The mainstream approach to pollution control utilized in the US and other advanced countries is to identify the specific sources of the pollution and their respective social costs and through specific programs achieve the highest reduction of pollution at the lowest cost. The overall goal is somehow to hold pollution at some acceptable level by internalizing the social costs of pollution (i.e., the negative externalities,) to those who through production and/or consumption are responsible for the pollution.
Essentially there are three ways that governments can achieve this goal:
1. Pollution Controls (Command and Control). By imposing a system of (maximum) pollution standards on businesses and/or consumers and then constructing an enforcement system to monitor compliance with standards. Those not complying with the standards then are fined and obligated to remedy the violation in the future.
2. Taxes and Subsidies. In this situation taxes are imposed on the polluter in accordance with the amount of pollution, thereby increasing the firm's costs and eventually the price charged to end users. Higher prices will then, in most cases, reduce the quantity demanded of the polluting good and therefore reduce pollution. Subsidies can be used where it is expected that they will result in less pollution by perhaps defraying the firms' cost of pollution control equipment or new, alternatively, less pollution production techniques.
3. Tradeable Permits. Here the government issues each firm a permit to emit a specified level of pollutants into the atmosphere. Environmentally efficient firms who do not pollute the allowable level then can sell their permits to other firms thereby providing an incentive to find the least costly form of pollution control.
A fourth way that pollution controls can be imposed is via negotiated
agreements either between private parties or between governments and private
parties.
B. Limitations of The Traditional Approach in Baja California
There are several limitations to utilizing the traditional-mainstream approach in Baja California. Most conspicuous is the lack of data on the sources of air pollution in the region comparable to those which exist in San Diego and California. Such data would permit a comprehensive analysis of the sources of air pollution and their magnitude. Without such data it is not possible to carry out a thorough analysis of the costs of pollution and appropriate mitigation policies.
Another limitation relates to the low incomes of most Baja California residents (i.e., consumers and business owners). Per capita income there has been estimated at approximately $4,000, as compared to approximately $25,000 for San Diego residents. If we assume, as this report has done, that mobile sources, such as light and heavy duty trucks, account for the majority of emissions in the San Diego-Tijuana, then it could be extremely difficult to impose the burdens of pollution control equipment on vehicles of low income consumers or small, marginal business owners.
It is true, however, that many residents are able to pay as they have incomes that permit them to enjoy a standard of living commensurate with that of, for example, San Diego. Similarly, many businesses, especially those foreign corporations in or associated with the maquiladora sector, have costs and revenues comparable to those in the US. Thus, it is clear that some consumers and some businesses have both the environmental awareness and economic resources sufficient to understand, purchase and maintain pollution abatement equipment. The problem is how to devise a system that would be equitable with respect to all consumers and businesses and also be efficient (i.e., produce significantly lower pollution at a reasonable cost).
Low incomes also present other problems. Even if low cost pollution abatement equipment were available for vehicles:
an effective monitoring and enforcement system would have to be created; however the cost of such a system would, at this time, probably strain the resources of the state and local government, and
extremely low income families, who are among those most likely to drive the most polluting vehicles, would have the highest incentive to evade pollution controls.
Finally, because of the extremely centralized governance system in Mexico
it may be difficult to maintain the flexibility necessary to apply the most
effective blend of the available policies, especially negotiated agreements.
In this context the fact that government owned facilities may be among the
heaviest producers in the region, e.g., the Rosarito power plant, can introduce
complications into market-based policies.
III. Pollution mitigation in Baja California
Given the limitations of the traditional approach to air pollution mitigation
in Baja California the next question is, What kind of approach is appropriate
in Baja California and other Northern border states and communities? Specifically,
what blend of available tools might be employed and over what period of
time in order to equitably and efficiently reduce air pollution in the region.
A. Border Environmental Institutions
At this point it may be helpful to point out that environmental management on both sides of the US-Mexican border is a process increasingly subject to international agreements and evolving patterns of binational, transborder cooperation.
In modern times such treaties go back to 1944, when the International Boundary and Water Commission (IBWC) was created in its present form to deal with what its title implies, international boundary and water issues on the US-Mexican border. Subsequently, the 1983 La Paz Agreement on "Cooperation for the Protection and Improvement of the Environment in the Border Area" provided a framework for addressing a broader range of border environmental issues. Then in 1991 an "Integrated Environmental Plan for the Mexican-US Border Area, First Stage (1992-1994)" (IBEP) built on the La Paz Agreement and took joint cooperation on border environmental issues to a higher stage. Finally, "Border XXI" was presented in 1996 in order to broaden the scope of collaborative issues and increase coordination among all levels of government and border communities.
Meanwhile the debates surrounding NAFTA stimulated the negotiation and subsequent ratification of the NAFTA Environmental Supplemental Agreement which is administered by a three country Commission for Environmental Cooperation. Since NAFTA's implementation two additional organizations have been established to deal specifically with US-Mexican border environmental issues. The first, the Border Environment Cooperation Commission (BECC), authorizes research and action projects related to "cleaning up" the border environment while the North American Development Bank (NADBank) is to provide financial support for large environmental infrastructure projects, which have been certified by the BECC.
At this point a myriad of governmental agencies and non-governmental
organizations are involved in defining and managing US-Mexican border environmental
issues. Nevertheless, the general objective of this new constellation of
organizations is that bringing together technical monitoring, academic analysis,
and grass-roots participation with governmental processes and financial
leverage can result in a politically acceptable and environmentally sound
set of policies. Because the process is relatively new it is still too early
to assess its overall performance. Still, the concept represents a great
deal of progress over the traditional top-down processes dictated by the
two nations' capitals that prevailed for so many years.
B. A strategy for reducing air pollution
All public policies are based upon certain implicit and explicit assumptions. The approach here is based on three explicit assumptions.
That Mexico's long term economic prospects are better than recent actual economic performance. Specifically, that the Mexican economy will continue to grow at a rate of 5-6% per year thereby increasing general prosperity levels and employment opportunities and providing a stable economic environment.
That current trends to increase political democratization and administrative decentralization will continue and grow. These trends are essential if community organizations are to express their views and participate in the political-technical process of moving toward sound environmental policies at the local level.
As prosperity increases and is more equally divided among all sectors of the population and as democratic political processes widen and deepen the populace will have more confidence in its government and will be more likely to accept environmental measures that today might be totally unacceptable.
Given these assumptions it is possible to formulate some of the major
elements of an overall air pollution mitigation policy. The list of recommendations
builds on policies currently in place. Many of these can be implemented
in the short run and completed in the short term while others must be on-going.
The basic logic of the approach is that in the short term air pollution
abatement policies must be simple, cheap and easily administered. However,
over the longer term as the economic and political situation improves more
sophisticated, market based policies can be implemented.
Recommendation
That the current efforts of the US Environmental Protection Agency (EPA) and Mexico's Secretaria de Medio Ambiente, Recursos Naturales y Pesca (SEMARNAP) continue. These include:
1. Continued development of air quality improvement programs
2. Building institutional infrastructure and expertise in the border region
3. Encouraging ongoing involvement of local communities
4. Review of air pollution abatement strategies that do not require extensive technical evaluations
5. Study of the potential for economic incentive programs for reducing air pollution more quickly and at less cost than conventional "command and control" methods that require specific technologies and/or emissions reductions.
Based on the background information presented in this appendix it is clear that these efforts recognize the lack of data for the region as well as the many economic, technological and administrative asymmetries that exist between the US and Mexico.
While all of these efforts are essential to building a solid program,
in the long term it is important that research on "best practice techniques"
be carried out (i.e., finding out what has worked best in other areas) and
such information communicated to practitioners in the border region. Frequent
conferences on all of these efforts increases one-to-one contact that is
also an important element in building transborder networks.
Recommendation
That research be carried out on environmental education efforts throughout
the border region to determine what is and is not being taught to both school
age population and adults and the results be communicated to the appropriate
education officials. Clearly the ultimate success of environmental policies
will be based on public understanding and acceptance of them and education
seems to be a key factor.
Recommendation
That research be carried out on how other countries and regions undergoing
the transition from developing to developed status have successfully dealt
with the introduction of environmental controls.
Recommendation
That environmental organizations in both countries monitor and support
the efforts of Mexican and US government agencies to modernize and speed-up
vehicle inspections at border ports of entry. Recent innovations at
the San Ysidro-Tijuana port indicate that effective inspection procedures
are consistent with short delays. In addition, new technology is becoming
available which can facilitate vehicle and commercial inspections thereby
reducing idling times. Such efforts could significantly reduce air pollution
and therefore deserve the support of other agencies on both sides of the
border.
Recommendation
That the use of negotiated settlements be pursued more actively, especially
in the case of large scale polluters such as the Rosarito power plant. There
seem to be two important impediments to cleaning up the Rosarito plant:
government ownership of the facility, which is also the owner of the supplier
providing the fuel oil, and the high cost of switching to natural gas. Across
the border in San Diego the Enova-SDGE firm is known to want to supply gas
to that and other facilities. Some preliminary discussions along these lines
have begun, and they should be encouraged by local, state and federal authorities.
Recommendation
That the feasibility of supporting the "greening of industry" in the Mexican border region through fiscal incentives and the development of cross border networks be explored. The greening of industry refers to pollution prevention techniques defined in footnote #2 above. Currently a study is being carried out on these processes in the San Diego-Tijuana region which apparently is becoming a leader in the development of this type of technology.
Publications:
1. Sweedler, Alan 1994. "Energy Sector of Baja California",
in San Diego Regional Energy Plan, San Diego Association of Governments,
San Diego, 1994
2. Sweedler, Alan 1995. "Energy and Environment in the California-Baja
California Border Region, in Energy and Environment in the California-Baja
California Border Region, Alan Sweedler, Paul Ganster, and Patricia
Bennett, eds., Institute for Regional Studies of the Californias, San Diego
State University, San Diego, CA.
3. Sweedler, Alan, Paul Ganster, and Patricia Bennett, eds., Energy
and Environment in the California-Baja California Border Region, Institute
for Regional Studies of the Californias, San Diego State University, San
Diego, CA.
4. Sweedler, Alan, Margarito Quintero Nú-ez and Patricia Bennett,
"Energy Sector in the California-Baja California Border Region"
in Boundaries and Energy: Problems and Prospects, International Boundaries
Research Unit, University of Durham, Durham, UK. (Forthcoming)
5. Rey, Serge, Paul Ganster, Gustavo del Castillo, Juan Alvarez, Ken
Shellhammer, Alan Sweedler, and Norris Clement, "The San Diego-Tijuana
Region" in Integrating Cities and Regions: NAFTA and the Caribbean
Face Globalization, James Wilkie and Clint Smith (forthcoming)
6. Ganster, Paul, Alan Sweedler, James Scott, and Wolf-Dieter Eberwein,
Borders and Border Regions in Europe and North America, San Diego
State University Press and Institute of Regional Studies of the Californias,
San Diego, 1997
Workshops conducted:
1. Emissions Inventory Development in the Border Region. San Diego,
September, 1996. One day workshop with 30 participants from US and Mexico.
Discussed point and mobile source emission inventory development in border
region.
2. Using MOBILE Models in Mexican Border Cities. San Diego, March
1997. One day workshop conducted by Carl Snow of the Texas Natural Resource
Conservation Commission on the use MOBILE-Juárez. Attended by staff
from San Diego APCD, CARB, and SDSU and UABC personnel.
Other personnel who have participated in project: