Border Environment Research Reports (Number 1 - June 1996)

Environmental Issues of the California-Baja California Border Region

by Paul Ganster
San Diego State University

I. Introduction

The purpose of this paper is to provide a brief overview of the important environmental issues of the California-Baja California border region within the social, economic, political, and administrative framework of the transborder zone.(1) First, by way of introduction, the major economic, demographic, and political features of the region are sketched. Next, border environmental administration and regulation is discussed. Finally, the key environmental issues for the border region are presented and briefly detailed.

This paper is meant to provide a concise introduction to border environmental issues and the context within which they occur. It is not an exhaustive analysis. It is designed to help concerned citizens, students, members of the private sector, and government officials better understand transborder environmental problems of the most dynamic region of the U.S.-Mexican border.

II. The California-Baja California
Border Region

Demographic and Urban Growth

The California-Baja California border region includes the California counties of San Diego and Imperial and the Mexican municipalities of Tijuana, Tecate, and Mexicali.(2) Together they constitute the most populous and rapidly growing regions of the entire U.S.-Mexican border area. The population of the region is concentrated in large urban areas, particularly in the San Diego-Tijuana region. On the eastern end of the California-Baja California border, Mexicali is the great urban area, but has numerous small populations dispersed throughout the fertile Mexicali Valley agricultural area. Across the border, the Imperial Valley is characterized by a number of rapidly growing communities, including the border town of Calexico (23,708), Imperial (6,121), Brawley (21,738), Holtville (5,576), and the center of county government, El Centro (36,717).(3)

In addition to the rapid rate of growth in the region, due in large part to continuing migration to the border area from both countries, the key characteristic of population is its concentration in urban areas along the border. The urban areas have grown so rapidly that it has been impossible to provide adequate infrastructure on the Mexican side and to keep up with the deterioration of the infrastructure on the U.S. side. The growing population size and concentration, along with associated industrial development, has put considerable pressure on the natural resources of the region and has resulted in an increasing number and intensity of environmental problems, many of them transborder in nature. Many of the environmental problems of the San Diego-Tijuana region are linked quite directly to the chronic infrastructure deficit in the transborder area.

Table 1. Average Annual Population Growth Rates,
San Diego and Tijuana,
Imperial Valley and Mexicali, 1940-1995
City 1940-50 1950-60 1960-70 1970-80 1980-90 1990-95
San Diego 6.96 6.38 2.84 3.20 3.01 1.31
Tijuana 11.44 9.83 7.46 3.08 4.92 6.75
Imperial Valley .53 1.36 .31 2.2 1.78 5.09
Mexicali 10.85 8.51 3.49 2.57 1.66 2.94
Source: Calculated from Table 2.

Table 2. Population Growth in
San Diego and Tijuana,
Imperial Valley and Mexicali
Year San Diego County Tijuana Imperial Valley Mexicali
1930 209,659 11,000 60,903 29,985
1940 289,348 22,000 59,740 44,399
1950 556,808 65,000 62,975 124,362
1960 1,033,011 166,000 72,105 281,333
1970 1,367,200 341,000 74,400 396,324
1980 1,873,300 462,000 92,500 510,664
1990 2,520,500 747,000 110,400 601,938
1995 2,690,255 1,035,415 141,500 695,805
Source: For San Diego and Imperial Valley: California Statistical Abstract, 1979; California Statistical Abstract, 1994; San Diego Association of Governments (1995 data); Valley of Imperial Development Alliance (1995 data). For Tijuana and Mexicali: Instituto Nacional de Estadística, Geografía e Informática, XI Censo General de Población y Vivienda. Datos por Localidad, Baja California and updates. Rosarito is included in the 1995 Tijuana data.

Economic Characteristics

Although the economies of San Diego and Imperial counties are now emerging from the recession of the early 1990s and the economies of Mexicali, Tecate, and Tijuana have been substantially insulated from the Mexican economic crisis that began in late 1994, each side of the transborder region still faces significant economic challenges. San Diego, for example, experienced serious dislocation with the economic restructuring away from the aerospace and defense industries caused by the end of the Cold War and the decline in defense spending. The new jobs that have been created to replace jobs lost are generally in low skill, low pay occupations. This has increased the gap between the rich and the poor and has expanded the size of the low income population. Both Tijuana and Mexicali, and presumably Tecate, have seen significant job creation in the last decade through the maquiladora industry, but this has not been accompanied by an increase in real income. Thus, in northern Baja California, the gap between the rich and the poor is also widening. In both San Diego-Imperial and Tijuana-Mexicali, provision of social services by the government has stagnated or has been reduced, thus accelerating the impacts of the economic difficulties on the poorer residents of the region.

Both sides of the California-Baja California border region experienced periods of rapid economic expansion in the period after World War II which attracted large numbers of people to the region. The Baja California economy is relatively isolated from the national economy of Mexico and has developed largely through its connections to the U.S. economy. Over the past decade, the economy of Baja California has been stimulated by the expansion of the maquiladora industry. With the economic crisis in Mexico in the 1980s, real wages fell by as much as 50 percent, making Mexican labor rates competitive on a global scale and bringing considerable growth to the number and size of assembly operations. The Mexican economic crisis of late 1994 and the implementation of the North American Free Trade Agreement (NAFTA) have combined to boost maquiladora investment. With NAFTA, the economic linkages across the California-Baja California border have grown and intensified.

The California-Baja California border region is characterized by strong economic contrasts. San Diego is one of the wealthiest regions of the United States; the Imperial Valley, although now in a period of economic growth, has persistent pockets of poverty and a chronic high unemployment rate. Tijuana and Mexicali are among the wealthiest regions of Mexico in terms of per capita incomes and standard of living.

The greatest economic contrasts in the region are from one side of the border to the other. The gross regional product of San Diego is about $70 billion; that of the municipality of Tijuana is approximately $3 billion. Minimum wages in Southern California are approximately eight times those of Baja California. This basic fact of economic asymmetry colors all aspects of life in the region. Mexico is a developing country and its government agencies have very small budgets with which to provide the necessary urban and social services. City and state governments in Baja California often lack the basic resources or information to address environmental issues in the border region. Table 3 clearly shows the different levels of funding resources availability for local governments in the San Diego-Tijuana region.

Table 3. Local Government Budgets, 1992-1996
Year County of San Diego
(fiscal year
July 1-June 30)		 City of San Diego
(fiscal year
July 1-June 30)		 Municipality
of Tijuana
(pesos)(fiscal year
March 1-end of Feb)		 Municipality
of Tijuana
(dollars)*(fiscal year
March 1-end of Feb)
1992 1,171,000,000 1,160,785,595 190,106,829 61,523,245
1993 1,932,000,000 1,350,000,000 240,096,754 76,172,828
1994 1,950,000,000 1,273,000,000 270,458,184 90,152,728
1995 2,091,000,000 1,272,251,515 405,000,000 54,000,000
1996 2,197,000,000 1,176,970,208 401,000,000 53,466,667

* Pesos per dollar: 1992, 3.09; 1993, 3.152; 1994, 3; 1995, 7.5; 1996, 7.5.
Source: County of San Diego, City of San Diego, and annual Informes of the Municipality of Tijuana

Political and Administrative Context

Two very different political systems meet at the border, which makes cooperation on mutual problems much more complicated. Mexico is highly centralized. Political power flows from the presidency in Mexico City as do economic resources. Thus, local governments are relatively weak in Mexico. Traditionally, Mexican municipalities have had no secure and adequate source of funding so they have relied on state and federal governments. There is no civil service in Mexico, so with each new municipal president, governor, or president, there is massive turnover in administrative staff. This makes continuity in programs difficult and works against continuity in transboundary cooperation. Although the decentralization process is moving forward slowly, it will likely be many years before significant resources and administrative authority reside at the municipal level in Mexico and its border region.

There are few direct governmental and administrative counterparts across the border. Areas that are local responsibilities on the U.S. side are often state or federal responsibilities in Baja California. California local governments are able to raise financing for infrastructure through bonding and taxing mechanisms, but these options are extremely limited in Baja California and Mexico.

A complicating factor is that transborder cooperation has generally not been a high priority of local governments in San Diego and Imperial counties. For example, in 1993, the San Diego County Board of Supervisors abolished the very successful Department of Transborder Affairs, even though binational issues were increasingly impacting the region and economic linkages with Mexico were growing rapidly. However, the City of San Diego has recently taken a strong leadership role to assure that city departments are engaged in relevant cooperation with counterparts on the other side of the border.

III. Border Environmental Administration and Regulation(4)

Border environmental administration and regulation in the California-Baja California border region is a confusing mosaic of international, federal, state, and local agencies and jurisdictions. New international agencies, created in conjunction with the North American Free Trade Agreement (NAFTA), and the emergence of specific environmental agencies in Mexico at the state and local level add to the complex and dynamic nature of environmental administration and regulation in the border region. Often, in the border region, it is not easy to determine which agency is responsible for which environmental problems.

While transborder environmental problems are legally the responsibility of the two federal governments, Washington, D.C., and Mexico City traditionally have devoted minimal attention and few resources to resolving the issues of the border region. Consequently, state and local entities have been forced to take initiatives. In recent years, nongovernmental organizations (NGOs) from both countries have also become increasingly active on border environmental issues.

Over the years, the legal and administrative framework of both countries has evolved to address increasingly severe border environmental problems, but always lagging behind the growing concerns. Mechanisms and institutions simply have not kept pace with reality. The following section briefly sketches the government actors involved in addressing border environmental issues in the California-Baja California border area.

International Agencies and Actors

International Boundary and Water Commission (IBWC)

In 1944, the International Boundary and Water Commission was constituted in its present form to maintain the international boundary, partition waters, and deal with border sanitation issues. It has a Mexican section (Comisión Internacional de Límites y Aguas--CILA) and an American section, IBWC. Each section is headed by a commissioner who has ambassadorial status and reports to the respective department of foreign relations. Since IBWC has authority to operate on both sides of the border and to spend money on both sides of the border, the agency is often involved with other domestic agencies for transborder work addressed to sanitation issues. IBWC has limited its work on border environmental matters to some activities relating to sewage issues and water quality concerns. For example, IBWC carried out the construction and operation of the desalination plant constructed in Arizona to reduce total salt content of the waters delivered to Mexico, it carried out work on Mexicali's sewage treatment system, and, most recently, has been overseeing the design and construction of the international wastewater treatment plant in the San Diego-Tijuana region.

Border Environment Cooperation Commission (BECC)

The BECC was established as part of a side agreement to the 1993 North American Free Trade Agreement (NAFTA) between Mexico and the United States. It was prompted by the promise by U.S. NAFTA proponents, including the president and the majority of Congress, that the border environmental problems would not get worse under a regime of free trade and that the two federal governments should move to also address existing problems. BECC is a binational commission, funded jointly by Mexico and the United States.

The principal function of BECC is to evaluate and certify border environmental infrastructure projects in the border region as necessary and viable. This certification is required for the projects to obtain loans from the North American Development Bank (NADBank) or from a commercial lender. The first projects certified were municipal sewage treatment systems for Ensenada and Brawley. It is important to note that BECC does not award grants, but certifies projects for loans that must be repaid. Consequently, all projects must have an income stream to make them viable economically for loan repayment.

Commission on Environmental Cooperation (CEC)

The CEC was created by the North American Agreement on Environmental Cooperation that was concluded among Canada, Mexico, and the United States. The objectives of CEC are to improve the environment in the North American region through improved cooperation, harmonization, and compliance efforts; to foster sustainable development; to promote public participation; to support the environmental goals and objectives of NAFTA; to promote pollution prevention practices; and to improve conservation. Among other things, an important charge of CEC is to work to avoid creating additional trade barriers or trade distortions. Because the CEC is just beginning to implement programs, it is not yet clear what specific actions the CEC will bring to the border region other than some of its research activities.

International Agreements

1944 Treaty

The 1944 Treaty, which established the IBWC in its present form, also divided the surface waters of rivers that cross the international boundary between Mexico and the United States. Specific minimum quantities of water are detailed in the treaty, but there is no definition of quality of water delivered to Mexico, nor is there any requirement as to when water has to be delivered. Over the years, Mexicans have frequently made the point that the division of waters is unfair and that declining quality of water is a problem. As well, Mexicans have pointed out that the Colorado River is managed not to deliver optimum water supply for agricultural and domestic uses downstream in Mexico, but to optimize hydroelectric power production. This results in irregular and inefficient water deliveries to Mexico.

A number of the concerns expressed by Mexico have been dealt with in minutes negotiated and attached to the 1944 Treaty. For example, Minute 242 was negotiated and signed in 1973 in response to Mexican concerns about deteriorating quality of Colorado River water delivered to Mexico and provided for minimum standards.

1983 La Paz Agreement

In 1983, the "Agreement between the United States of America and the Mexican United States on Cooperation for the Protection and Improvement of the Environment in the Border Area" (referred to as the La Paz Agreement) was negotiated and is a framework agreement for addressing border environmental issues. It established a national coordinator for each country, regular meetings, and constituted working groups that now include the Air Work Group, the Contingency Planning and Emergency Response Work Group, the Hazardous Waste Work Group, the Pollution Prevention Work Group, the Water Work Group, and the emerging Environmental Information Management Group. The working groups include mainly U.S. and Mexican federal agency representatives and state representatives. Although the agreement contemplated broader participation in the process, including university researchers and nongovernmental representatives, so far they have been mostly excluded from the activities of the work groups. Since 1983, a number of annexes to the agreement have been negotiated. Those that impact the California-Baja California border region include the following:

Integrated Environmental Plan for the Mexican-U.S. Border Area, First Stage (1992-1994) (IBEP)

In 1990, Presidents Bush and Salinas instructed their respective environmental agencies to prepare a comprehensive plan to protect the environment along the border. A Boston consulting firm drafted the plan that was then presented in 1991 in a series of public hearings along the border. Despite intense criticism from NGOs and border communities, IBEP as a continuation of the La Paz Agreement represented a milestone in joint cooperation on border environmental matters. Developed to address environmental concerns about NAFTA, IBEP summarizes specific actions relative to protecting the border environment that the two governments would take over the next three years. The two governments committed over $500 million to border environmental protection projects through IBEP, but very little of that funding has been allocated or spent.

Border XXI

Border residents and authorities of both countries have recognized that a new vision is needed to address border environmental issues into the next century. This approach needs to broaden the scope of issues to be dealt with and increase the coordination among local, state, and federal governments and border communities. This approach also aims to increase public participation in the process of identifying environmental priorities and spending of scarce resources.

After a series of public forums in the border regions of Mexico and the United States, the two governments were scheduled to release a draft Border XXI document in the spring of 1996. Public comment will then be incorporated into this document before it is finalized. Border XXI will be a key framework for addressing border environmental issues into the foreseeable future.

U.S. and Mexican Federal Agencies

Many agencies of both federal governments are active in the border region, but in recent years the U.S. Environmental Protection Agency (EPA) and Mexico's Secretaría de Medio Ambiente, Recursos Naturales y Pesca (SEMARNAP) have taken the lead for each country on border environmental issues. While the working relationship between these two agencies is increasingly direct and productive, technically they still must work through their respective foreign relations ministries. Or, in the case of specific joint border infrastructure projects, they frequently work through the IBWC. SEMARNAP has delegations in each of the Mexican border states while EPA has regional offices in Dallas (for the Texas and New Mexico border region) and in California (for the California and Arizona border area). Most importantly, in 1995 EPA established Border Liaison Offices in San Diego (for California and Arizona) and in El Paso (for New Mexico and Texas) to enhance its work on border issues.

Many other U.S. federal agencies have duties that involve border environmental issues, including the Department of Commerce, the Department of the Interior, the Department of Housing and Urban Development, the Attorney General, the Department of the Treasury, the Department of Defense, the Department of Health and Human Services, the Department of Energy, and the Department of Agriculture. On the Mexican side, entities such as the National Water Commission, the Secretariat of Health, the Secretariat of Agriculture, the Secretariat of Energy, and the Secretariat of the Treasury all are involved in some way in border environmental issues.

Competing jurisdictions and inadequate cooperation at the federal level in both countries have frustrated the efforts at resolution of border environmental issues for many years. This is one of the issues that Border XXI aims to address.

California and Baja California State Agencies

The involvement of California state agencies in border environmental issues is significant and is growing rapidly. Taking the lead is the California Environmental Protection Agency (Cal-EPA), with a number of departments that deal with specific border environmental issues and coordinate with their federal and local counterparts. These include: Cal-EPA is increasing its border and transborder activities significantly. Recently, it took the lead to develop a listing of border environmental infrastructure projects for presentation to BECC for certification and possible funding by the North American Development Bank, the Preliminary California-Mexico Border Environment Needs Assessment (April 20, 1995).

Other California state agencies engaged in activities relating to the environment of the border include the California Coastal Commission, the Department of Health Services, the Department of Energy, the Department of Fish and Game, the Department of Transportation, and the Department of Commerce.

Direct involvement of Baja California state agencies in border environmental issues is relatively recent. As part of the national plan to decentralize environmental administration, Baja California now has the Law of Environmental Equilibrium and Environmental Protection and a set of enabling regulations. It also has the Dirección General de Ecología (DGE) that has among its duties the enforcement of the environmental regulations, overseeing preparation and public access to environmental impact studies for construction projects and other activities, and maintaining a registry of environmental laboratories and environmental services firms. As a new agency, the specific duties of DGE are still evolving.

Local and Municipal Agencies in the Border Region

At the local level in California's border region, a number of county and city agencies are actively involved in border environmental matters. San Diego County's Environmental Health Department, Hazardous Materials Management Division, Department of Health Services, and Department of Public Works all have programs that involve the border. In the City of San Diego, the Environmental Services Department, Environmental Programs Division, is working with the Municipality of Tijuana to develop a binational market in recyclable materials from the regional solid waste stream. The Metropolitan Wastewater Department has a long history of work on the transborder sewage flows issues and the Fire Department's Hazardous Materials Emergency Response Team works with Tijuana on coordinated emergency response. In 1993, the cities of San Diego and Tijuana signed a memorandum of understanding to create a binational advisory board, including an environmental advisory committee. This mechanism was designed to add depth and continuity to the transborder relationship.

Local governments in the Imperial Valley are now actively involved in border environmental matters. The Imperial County Board of Supervisors, and especially Supervisor Wayne Vandergraff, have developed cordial relationships with government leaders in Mexicali. These relationships have facilitated increasing coordination with Mexicali on important topics such as public health, hazardous materials and emergency response, emergency services, fire department cooperation, and other areas. The Imperial Irrigation District has a long record of collaboration with Mexican agencies across the border on water-related matters. The City of Calexico, located on the international boundary across from Mexicali, has also developed a close working relationship with Mexicali through the efforts of its mayor, city council, and city manager.

Tijuana's municipal environmental efforts are centered in the Dirección de Planeación del Desarrollo y Ecología, which deals mainly with land use planning issues. The duties of this agency will expand when a new environmental regulation is approved in the near future. Also important at the municipal level is the Department of Public Works, which deals with water supply and quality issues.

The Municipality of Mexicali is also beginning to develop local capacity for environmental planning through its Dirección de Catastro, Control Urbano y Ecología. Mexicali, while developing a local environmental ordinance, is moving forward with development of an environmental planning document for the municipality and an urbanization project along the New River. As the federal government and the state government of Baja California move to decentralize environmental responsibilities, Mexicali is preparing to become more active in this area, including transborder cooperation on the environment.

Nongovernmental Organizations

Over the last few years, communities, citizens, and particularly nongovernmental organizations (NGOs) in the border region have come to play a more important role in the formulation of environmental policy and in environmental enforcement and administrative activities. These groups have also played a key role in raising public awareness about environmental issues in the region. The Environmental Health Coalition advocates environmental justice and pollution prevention in San Diego and Tijuana and has been particularly outspoken about hazardous waste associated with maquiladoras in the region. NGOs such as the Sierra Club, the Surfrider Foundation, Baykeepers, and Citizens Against Recreational Eviction (C.A.R.E.) participated in a lawsuit challenging aspects of the international wastewater treatment plant that is being built at the border to deal with renegade sewage flows from Tijuana across the border. The U.S.-Mexico Border Progress Foundation is a binational borderwide NGO that works with communities and companies on issues relating to environment, sustainable development, and public health. The United Nations Association Environmental Committee of the Tijuana-San Diego Border Region serves to link concerned groups and individuals on both sides of the border. There are also a number of active NGOs in the Imperial Valley-Mexicali Valley region.

Although participation of nongovernment groups was contemplated in the 1983 La Paz Agreement, significant citizen and NGO involvement in border environmental policy emerged on a broad scale with the public hearings related to IBEP in 1992. The establishment of the NAFTA environmental institutions, particularly BECC, unfolded with an unprecedented amount of involvement by citizens and NGOs from the border communities of Mexico and the United States. It is clear that the active work of border NGOs, communities, and citizens has assured that these actors will continue to play an important role in border environmental policy and administration.

Border Environmental Management Authority

Despite some successes, the U.S. federal government has been slow to respond to transboundary pollution problems which are a federal responsibility but which have local impacts. Mexico does not have the financial resources to deal with border pollution issues, except when subjected to significant pressure from the U.S. government, and the U.S. Congress is unwilling to allocate funding in adequate amounts for border environmental problems. Thus, U.S. border entities are forced to lobby the federal government through whatever means possible, or to attempt to deal with the problems themselves. For some years there has been discussion of developing new approaches to dealing with binational border environmental problems.

It has been suggested that there is the need for a border management authority to take a multidisciplinary approach to assure uniformity of regulation and compliance with respect to environment. Such an authority is needed to oversee the various border environmental programs, both state and federal, to assure coordination and eliminate duplication, providing a more cost-effective approach. A more unified authority is also needed for a comprehensive ecosystems management approach.

IV. Environmental Issues of the California-Baja California Border Region

This section provides an overview of the most obvious border environmental issues of the California-Baja California border region. This list has been developed through examination of IBEP, the ongoing activities of the EPA-SEMARNAP working groups under the 1983 Border Environmental Agreement, the research and community forums undertaken by the Southwest Center for Environmental Research and Policy (SCERP), and the Border XXI community meetings organized in the fall of 1995 by EPA.

There is no standard with which to evaluate overall progress on resolution of border environmental problems. There are not even baseline indicators for the region's transborder environmental problems that would permit measurement of resolution or growing severity of particular problems.

A related issue is that of prioritization of steps to resolve border environmental issues. Given the context of scarce resources on both sides of the border, how should priorities be set for dealing with the different pollution problems in the transborder region? Should the basic criterion be protection of human populations from negative health consequences of environmental pollution? How should health risks of pollution be measured? Should small communties with fewer technical and financial resources receive special consideration? Should decisions be made only on the basis of how many people benefit? What about the protection and restoration of endangered species and ecosystems?

Water Supply and Water Quality Problems

The California-Baja California border is an arid region. In a typical year, San Diego imports 90 percent of its water and Tijuana imports an increasingly large percentage of its water. The 1944 Treaty fully allocated all surface waters in the border region, and as a result the Imperial Valley has a generous supply of Colorado River water. Due to upstream evaporation and return flow from agricultural use, the Colorado River water diverted for the Imperial Valley has a relatively high content of suspended solids. The Mexicali Valley has a much smaller allocation of Colorado River water that is of even poorer quality than that for the Imperial Valley. Also, during low rainfall years in the Colorado Basin, there is insufficient water for full agricultural production in the Mexicali Valley, given current water use practices. In addition to the increased levels of suspended solids, including salts, there are also elevated levels of pesticide residues and fecal coliforms (indicator bacteria for contamination by human waste) in the river water as it reaches the Mexican border.

Although the California-Baja California border region depends upon imported water for urban and agricultural uses, there is adequate water available in the larger region for the foreseeable future. For example, in California transfer of a small percentage (as little as 5 percent) of the state's water from agricultural to urban uses would provide sufficient water for the future. However, the San Diego region depends upon an inadequate storage system and a system of aqueducts from the north that is vulnerable to natural hazards such as earthquakes. In order to expand the supply of local water, in recent years there has been significant effort to enhance water reclamation in the region. The cost of providing infrastructure for water reuse is high and the energy cost for reclamation and distribution of reclaimed water is significant, which has financial as well as pollution considerations. Currently, and for the near future, water reuse offers only limited possibilities for supplementing the regional supply and the most economical alternative is the development of water markets for transfer of water from agricultural to urban uses.

It has also been suggested that development of an international water market along the California-Baja California border would help resolve the water supply problem in Baja California. There are also current discussions between the San Diego County Water Authority, the Metropolitan Water District, and authorities in the Imperial Valley for direct transfer of Colorado River water from the Imperial Valley to San Diego.

At present, there is limited capacity for water reuse in the region. There is a small water reuse facility in Tijuana known as Ecoparque that could supply a limited amount of water for irrigation of green areas. There are also reclamation projects in Escondido and Del Mar.

The Bureau of Reclamation is working on plans and design of a parallel canal to the All American Canal that brings water from the Colorado River to the Imperial Valley. There is a significant water loss from the present canal through seepage, but the new canal would reduce the amount of water available in aquifers on the Mexican side of the border. In addition to the development of an environmental impact statement, there are also diplomatic discussions over the issue.

Surface and groundwater supplies are threatened everywhere along the California-Baja California border due to raw sewage dumping, agricultural runoff, and industrial and hazardous waste pollution. Such contamination reduces the supply of water for human use and has other serious consequences for plants, animals, and human health. The most important water pollution problems are indicated below.

The New River

The New River is actually a drainage canal that flows through the Mexicali Valley, through urban Mexicali, and then north across the border through the Imperial Valley and empties into the Salton Sea. In Mexico, the New River is contaminated with agricultural chemicals, industrial waste, raw sewage, and lightly treated sewage from Mexicali's treatment lagoons so that by the time it passes into Imperial Valley it is perhaps the most contaminated river in the United States. A large number and variety of disease pathogens, heavy metals, and toxic chemicals have been identified in the waters of the New River. Exposure to New River waters presents a serious health threat to human populations on both sides of the border. The actual number of cases of illnesses specifically attributable to contact with waters of the New River is likely small, but the potential for negative impacts on human health is large.

Some concerns have been raised about the impact of the New River discharge into the Salton Sea, an important wildlife habitat and recreation area. Increasing salinity levels and growing concentrations of selenium contamination are apparently more related to agricultural practices in the Imperial Valley than to the New River.

A related issue is that of the transborder impact of Mexicali sewage. The present Mexicali treatment system consists of a number of large ponds to the west of the urban core and the treated effluent is discharged into the New River, just south of the international boundary line. Mexicali has had difficulty in the maintenance and operation of this system and chronic problems with poorly treated effluent being discharged into the New River, adding to the contaminant load of that body of water. The aeration systems have had design and maintenance problems so the treatment system has produced a considerable concern regarding odors in the region. Some discussions for channeling the flow of effluent southward to the Laguna Salada have not led to any specific plans.

Although Mexico and the United States have worked on the problem for years, the New River remains a serious concern and a top priority for residents of the region. The New River remains a contentious issue for the two neighbors.

San Diego Sewage Treatment System

Over the decades, San Diego has failed to upgrade and maintain its wastewater treatment system. For many years, San Diego has been involved in litigation with the federal government for its failure to meet statutory sewage treatment standards as set by the Clean Water Act. San Diego's response to pressure and the fine imposed by the Environmental Protection Agency has been to seek a waiver from federal standards on the theory that sewage treated at a lesser standard can be safely discharged into the ocean. Available scientific research, although somewhat limited, seems to support San Diego's position and recently San Diego obtained a waiver through federal legislation. However, San Diego's sewage collector and treatment system is old and in poor repair. Frequent breakdowns result in numerous discharges of untreated sewage into streams and bays and onto beaches along the ocean. This produces a continuing threat to human health and closure of prime recreation areas for varying periods of time.

Within the San Diego region, there have been fierce debates regarding solutions to San Diego's sewage treatment problems. On the one hand, various environmental groups have argued that the solution lies in reducing the per capita consumption of water in San Diego through conservation efforts and in the expansion of water reclamation projects and the use of low cost alternative treatment technologies. Some groups point out that large scale water reclamation and reuse will involve significant capital costs and energy use which adds to the cost of the reclaimed water and produces pollution from energy production. Others argue that the best alternative is significant capital investment and upgrading and expanding the traditional technologies. The supply, distribution, and treatment of San Diego water and wastewater is critical for the future growth and quality of life in the region, yet litigation by the opposing sides and lack of decisive political leadership have frustrated solutions.

Tijuana Sewage Treatment

For 50 years Tijuana has struggled to provide sewage collection and treatment facilities for the exploding urban population and the flow of untreated sewage across the international boundary into San Diego. This has been a significant issue on the bilateral policy agenda. United States' concerns regarding the sewage flows have been several. First, the flow of untreated sewage down the Tijuana River channel and down the side canyons from Tijuana colonias into the river valley has contaminated the valley, making farmland unsuitable for production of food crops. Second, the flow of sewage into the ocean has resulted in chronic contamination of the waters adjacent to the beach and continuing closure of prime recreation areas. The ocean from Imperial Beach to Rosarito Beach is simply unsafe for human contact. Finally, the flow of the Tijuana River has been altered by urbanization from a stream with a seasonal flow during the rainy part of the year to a permanent flow of approximately 15 million gallons per day. This has had significant negative effects on the Tijuana National Estuarine Reserve, an important salt water marsh ecosystem at the mouth of the river that is home to many rare and endangered plant and animal species.

The United States has opposed proposals by Mexico to install sewage treatment facilities upriver in the Tijuana basin because the treated discharge would add to the impacts on the Estuarine Reserve. Instead, in 1987, Tijuana built a 25-million gallon per day capacity wastewater treatment plant near the coast some 5.6 miles south of the international border. This plant quickly reached capacity and discharges sewage that is minimally treated into the surf to the north of Rosarito Beach, adding to the nearshore marine pollution problem along the beach.

After intense political pressure by activists on both sides of the border, particularly those from Imperial Beach and the Tijuana River Valley, the two federal governments agreed to build an international joint sewage treatment plant to handle Tijuana's sewage. Slowly, the necessary funds have been allocated by the United States and Mexican governments and by early 1996, construction was under way at this plant, which is scheduled to come into service in 1997. Although this is a significant step, unresolved issues remain. These include protection and restoration of the wetlands, construction of an ocean discharge, disposal of sludge generated by the plant, and insistence by environmental groups that an adequate water reuse program be developed for the plant.

Marine Pollution

Marine pollution has been a persistent problem in the California-Baja California border region, but one that has largely been ignored in public discussions of transborder environmental issues. Urban runoff from San Diego and Tijuana transports various hazardous materials into the nearshore marine environment where they enter the marine food web and offer the potential for negative human health effects. Most marine species in San Diego Bay, for example, are unsafe for human consumption. Monitoring programs have detected a growing problem with heavy metals, pesticides, and other chemical contaminants from San Diego to Ensenada. And this problem is growing with increased industrialization and population in the region. Biological contamination is likewise serious along the coast, making shellfish unfit for human consumption, and water contact unadvisable for humans.

Concerns have also been raised regarding the impact of increased salinity and agricultural chemicals in the Colorado River on the Gulf of California. As well, the natural regime of the river has been radically altered with a series of dams upstream with water releases timed for power generation purposes. It is not clear what the environmental effects of these practices are.

Hazardous and Industrial Waste

With growth of urban populations and domestic manufacturing and associated activities, and with the expansion of the maquiladora industry, there has been a great increase in industrial waste and pollutants in the border region. While maquiladoras are often singled out by critics as responsible for significant pollution in the border region, there is a notable lack of reliable data and studies to support this assertion. For example, a limited analysis of hazardous waste in Mexicali maquiladoras carried out recently by EPA failed to turn up significant polluting by these companies. Mexican domestic industries and businesses in Tecate, Tijuana, and Mexicali, ranging from automobile repair shops, to small furniture manufacturers, or to large chemical plants, produce significant pollution, both non-point source and point-source. Only a portion of this waste is disposed of properly; the rest is discarded into the sewer systems, solid waste dumps, or simply dumped on the ground in canyons or other areas. This type of pollution is picked up from the flushing action of rains or the normal operation of the sewage system and is transported by rivers and washes and then to the Pacific Ocean or Salton Sea. The pollution from urban runoff is also a significant problem in San Diego and other urban areas on the U.S. side of the boundary.

Maquiladoras also produce some industrial and hazardous waste in Mexico's border cities that has important transborder effects. While many of Baja California's 500 or so maquilas produce no significant waste, certain sectors such as those involved in electronics, plating operations, and so forth do generate important quantities of hazardous waste. Even when, according to Mexican regulations, some portion of the waste generated is returned to the country of origin--usually the United States--the rest is being stored (often improperly), dumped in municipal landfills, or discharged into the wastewater collector system. Solvents used in the electronics industry and heavy metals associated with metal finishing operations seem to be the most common problems.

This chemical pollution of surface waters and groundwater has potentially serious consequences for the region's water supply. Reclamation is made impossible or prohibitively expensive when the water to be reclaimed has significant chemical pollution. Cleaning up polluted aquifers is particularly problematic and expensive.

Another problem related to hazardous and industrial waste is that of illegal dumping. Given the high costs to properly dispose of some hazardous wastes, there is a long history of illegal dumping in the border region. Smuggling of hazardous wastes into Mexico is a potentially lucrative criminal activity and has been a sporadic problem along the California-Baja California border.

Continued problems with hazardous and industrial waste are related to lack of adequate infrastructure in Mexico and in the California border region, the high cost of proper disposal, and the lack of enforcement of existing regulations by Mexican authorities. Collaborative binational efforts to track the movement of hazardous waste across the international boundary have been only partially successful as a computerized tracking system has been slow to come on line and has significant limitations. Even though there has been progress, it will be some time before illegal movement of hazardous materials in the region is largely curtailed.

Pesticides and Agricultural Chemicals

While there is some evidence of agricultural chemicals and pesticides entering surface streams and the ocean in the Tijuana-San Diego area through the sewage systems and through urban runoff, the problems are relatively minor. However, in the Mexicali and Imperial valleys there is considerable concern about contamination of surface streams and aquifers by these chemicals. More specifically, in many areas in the Mexicali Valley and a few in the Imperial Valley, canal water is used for domestic purposes--for cooking, drinking, and bathing. These practices most likely have quite negative health effects on the human populations of the region.

There is also a growing concern in the two valleys about drifting pesticides and herbicides from aerial applications. Obviously farm workers are affected by agricultural chemicals transported by winds, but since producing agricultural areas are often directly adjacent to residential areas, this is a matter of concern in urban areas as well.

Occupational Health

There are some significant environmental health and safety problems in some Mexican border manufacturing plants. Partly, this is due to lax enforcement of existing codes but cost savings concerns on the part of management and lack of training of workers regarding proper procedures and use of safety devices are contributing factors. There are a few cases of plants relocating from the United States to Mexico because of lax environmental enforcement in Mexico. Several plants using asbestos products, some using exotic gases and acids, and, more recently, a dozen or so furniture companies from the Los Angeles area that do not want to comply with stricter emission control regulations imposed in the regional air basin are cases in point. There is little factual evidence to suggest that there has been massive relocation of U.S. firms in order to avoid environmental regulations.

Municipal and Solid Waste

Everywhere in the California-Baja California border region, municipal and solid waste disposal is an important concern. Communities on both sides of the border have inadequate landfill space for the future. Baja California has additional problems related to the design of landfills and control of what goes into them, endangering aquifers that contribute to the region's scarce water supply. Municipal landfills produce quantities of greenhouse gases as part of the decomposition of organic matter of waste materials. No border landfills are using these gases for electric power generation.

The border region problems associated with landfills will be resolved through a combination of capital investment and reduction of the amount and kind of materials that go into the landfills. Some areas of the California border region currently have in place recycling programs for green waste, for cans, bottles, and plastics, and for paper. Recycling programs on the Mexican side of the border are less extensive. A bottleneck for these efforts is the lack of well-developed markets for recyclable materials. The City of San Diego and the Municipality of Tijuana currently have under way a pilot project to develop regional, transborder markets for recycled materials both to stimulate more recycling activities, and to create jobs in the region using reclaimed materials. Another benefit of this program will be the reduction of amounts of solid waste entering the landfills of the region.

Air Pollution

Air pollution is a growing problem for the California-Baja California border region. Air pollution comes from different sources, but ultimately is linked to growing human populations in the region. The exact transborder linkages of air pollution are not well understood. It is not clear to what extent San Diego's air quality is affected by pollutants transported from Tijuana sources and vice versa. At the same time, it is not clear how pollutants generated in the Imperial/Mexicali valleys move back and forth across the border. Also, air pollution sources from outside the region are important. It has been documented that a significant part of the failure of San Diego to meet minimum air quality regulations for a certain number of days each year is caused by the transport of pollutants by winds and air currents from the Los Angeles basin. This may also affect Tijuana.

The pollutants of major concern in the California-Baja California border region include solid particulates (PM10), sulfur dioxide (SO2), carbon monoxide (CO), and ozone. Currently, San Diego exceeds U.S. ambient air quality standards in carbon monoxide and in ozone.

Major sources of pollution include point source and non-point source. In terms of point source pollution, the major contributors are permanent installations such as electricity generating plants and large industrial plants such as cement plants. The major point source for air pollution in the region is the Rosarito power plant, which uses fuel oil for generating electricity for Baja California. Similar plants on the San Diego side of the region were converted to cleaner burning natural gas some years ago.

Rapid growth of the number of vehicles in the border area has been the largest contributor to air pollution problems in the region. The vehicle fleet for San Diego County numbers 1,894,567 (September 1995), that for Imperial County is 112,523 (September 1995), that for Mexicali is 228,297 (December 1992), that for Tecate is 20,591 (December 1992), and that for Tijuana is 241,581 (December 1992). Although there are fewer vehicles in Baja California than in San Diego and Imperial counties, the Mexican vehicle fleet is characterized by poor maintenance and by older vehicles that do not have catalytic converters as well as by use of leaded gasoline. Consequently, the Mexican vehicles contribute a disproportionately large share of the total pollution of the region.

Management of the ports of entry along the California-Baja California border exacerbates the air pollution problem by excessive waiting times for vehicles to cross. The long lines of idling vehicles produce significantly more pollution than vehicles traveling along the highways.

A growing source of air pollution in the region is the increasing number of heavy duty diesel vehicles that transport cargo across the border. This fleet has expanded considerably with the growth of the maquiladora industry and the implementation of NAFTA. Although hard data are not available regarding the precise amounts of pollution produced by these vehicles, it is likely an important part of the regional air pollution picture.

Solid particulate matter--dust, ash from open burning, and so forth--which is known as PM10 is also of concern in the California-Baja California border region. Recent research suggests that particulate matter is a more serious problem for human health than previously thought. High levels of exposure to PM10 are associated with increased emergency room visits, hospital admissions, and early deaths. Children, the elderly, and people with asthma and chronic pulmonary disease are particularly affected by PM10. Agricultural activities, including plowing and burning of field stubble, are serious pollution problems in the Imperial Valley and Mexicali Valley. Moreover, unpaved streets and roads, particularly on the Mexican side, are contributors to PM10 pollution. The Imperial Valley is designated by EPA as an area that exceeds U.S. ambient air quality standards in PM10. While less of a problem in the San Diego-Tijuana region, dust from unpaved streets is still a matter of concern.

Uncontrolled burning in urban areas is another element in the air quality problems of the border region. Use of scrap materials for domestic purposes and for manufacturing of bricks produces significant air pollution. While the solution is to convert to natural gas or liquefied petroleum gas, these are distributed on the Mexican side by monopolistic concessionaires and the artificially high cost of these clean fuels assures the continued use of scrap materials, including wood, particle board, and even tires.

Bioresources

There are a number of endangered species and ecosystems in the California-Baja California border region. Examples include the coastal chaparral complex of plants and animals along the Pacific Coast, Tijuana National Estuarine Reserve and Baja California salt water estuaries, Cleveland National Forest and the Sierra de Juárez, and the Sonoran desert natural areas from Borrego southward into Baja California. All of these ecosystems and their associated plant and animal species need to have binational cooperation for conservation and protection to assure their long-term sustainability. Because of greater growth along the U.S. side of the border, there is often a greater presence of undisturbed habitats and ecosystems on the Mexican side. The San Diego region is attempting to protect key habitats through the Multi-Species Conservation Plan, which would protect vital corridors and would maintain large enough habitat areas for survival of important species. The plan is under attack by land developers and their allies because of the restrictions that this conservation approach puts on private property. Ironically, U.S. developers have argued that it is acceptable to eliminate coastal chaparral in Southern California because the ecosystem and associated plant and animal communities extend well into Baja California. The implication is that a less developed country should be forced to eventually forgo development to protect these natural resources.

Currently, San Diego State University, along with Mexican universities, is facilitating a binational effort to create a biosphere reserve in the transborder Tijuana River Basin. The goal of this broad-based effort is to develop mechanisms to permit economic development in the region, yet conserve important natural resources and to improve the quality of life in the region.

The Imperial Valley-Mexicali region includes several natural areas of importance that are threatened by human activities. The lower Colorado delta region, although not directly on the border, is directly affected by the quality and quantity of water provided by the Colorado River. Imperial Valley includes sensitive desert protected areas that reach the border.

V. Conclusion

The California-Baja California border region is extremely dynamic, with expanding economies and increasing industrialization. Population in the region is growing rapidly and urban areas are spreading, often in a chaotic fashion. Unmanaged growth in the region has produced serious transborder environmental problems, including air and water pollution, contamination from improper disposal of hazardous and solid wastes, and urban and development impacts on plant and animal species and critical ecosystems.

The two federal governments have made progress in addressing transborder environmental issues, and state and local governments are becoming more involved in these problems. Individuals and nongovernmental organizations from the communities of the California-Baja California border region are also taking a more active role with regard to environmental problems of the area. At the same time, cooperation on environmental matters across the border has increased significantly, beginning with the 1983 La Paz Agreement and as seen in the Border XXI process. With decentralization in Mexico of more responsibilities for environmental issues to the municipal governments, a new window of opportunity is opening for more local transborder cooperation on resolution of border environmental problems.

  1. The author expresses appreciation to Mark Spalding, Bill Jones, Kimberly Collins, Alan Sweedler, Karen Riveles, Cliff Metzner, and others who read drafts of this paper and provided valuable comments.
  2. The new Mexican municipality of Rosarito, located along the coast below Tijuana, with a population of about 80,000, was created in 1995 and is not reflected in this discussion nor in the tables. Its population is still aggregated with that of the municipality of Tijuana.
  3. 1994 data.
  4. The Institute for Regional Studies of the Californias at San Diego State University is currently developing a guide to border environmental administration that will be available in late 1996.
For more information: There are many sources of information about environmental issues of the California-Baja California border region. The World Wide Web site of the Southwest Center for Environmental Research and Policy and the Institute for Regional Studies of the Californias at San Diego State University contain information and references of use. The U.S. Environmental Protection Agency Border Liaison Office in San Diego has a collection of recent government reports and publications on border topics. The research libraries at San Diego State University and the University of California, San Diego, have excellent collections of materials touching on border environmental topics.
Additional copies of this report may be obtained from the Institute for Regional Studies of the Californias, San Diego State University, San Diego, CA 92182-4403; tel. (619) 594-5423; Fax (619) 594-5474; e-mail irsc@mail.sdsu.edu
Copyright © 1996 by Paul Ganster
Published by Institute for Regional Studies of the Californias, San Diego State University, San Diego, CA 92182-4403
ALL RIGHTS RESERVED
ISBN 0-925613-19-3

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