A. United States/California
The United States environmental policy can be found in the United States Code at Title 42 (Public Health and Welfare) section 4321 et seq. This contains the national environmental policies and goals, the establishment of environmental agencies, commissions, and councils; governs appropriations for environmental studies, research, clean-up and prevention, among many other tasks. Includes organization and formation of the Environmental Protection Agency and the Council on Environmental Quality.

Border Smog Reduction Act of 1998
Public Law 105-286 112 Statutes at Large 2773
  Applies only to the San Diego metropolitan area and amends the Clean Air Act to prohibit certain foreign-registered, noncommercial vehicles from entering the area more than twice a month. GAO focuses on measured ozone levels and the impact of the North American Free Trade Agreement on ozone in the San Diego area. The GAO has concluded that the act, under which violators can be fined or refused entry into the U.S., will reduce cross border smog by less than 0.5 percent a year. A San Diego air quality official told the GAO that even small sources of pollution must be addressed if the area is to combat ground level ozone, a component of smog. Many of the cars that pass through customs on their way into the U.S. spend at least 20 minutes idling while waiting in line, increasing local concentrations of air pollutants. The GAO notes that commercial truck traffic has increased since the implementation of the North American Free Trade Agreement in January, 1994, and that trucks contribute more air pollution than cars.
http://ens.lycos.com/ens/jul99/1999L-07-06-09.html
A congressional committee report on the Act’s impact on ozone levels is available at the USD Legal Research Center at KF6236.A85 R44 RCRED-99.

Clean Air Act
http://www.epa.gov/oar/oaq_caa.html
  Under this law, the EPA sets limits on how much of a pollutant can be in the air anywhere in the United States. The law allows individual states to have stronger pollution controls, but states are not allowed to have weaker pollution controls than those set for the whole country. The 1990 law covers pollution that originates in Mexico and Canada and drifts into the United States and pollution from the United States that reaches Canada and Mexico.

Water Resources Development Act, Public Law 102-580 (1992)
  Includes state dumping requirements for hazardous wastes.

The State of California has some of the extensive an far-reaching environmental laws and regulations of any state in the United States. The California Code contains many laws relating to environmental concerns with our neighbor to the south. Among them include:
  Clean Water Act, Public Resources Code sec. 5096.600-5096.683 (2002)
  Environmental Protection Program [generally]. Health & Safety Code sec.71000 et seq.
  Environmental Protection Program [for California-Mexico Border]. Public Resources Code sec. 71100-71104.
  Hazardous Waste Cleanup. Health & Safety Code sec. 25221 et seq.

California EPA at http://www.calepa.ca.gov/
  California’s regulatory agency administers California’s numerous environmental laws and regulations ; web site contains links to agency resources. Has a link to its California-Baja California Border Environmental Program at http://bep.calepa.ca.gov. Project documents include the Tijuana Industrial Wastewater Monitoring Reports and a California-Baja California Border Environmental Infrastructure Needs Assessment from 1998.


B. Mexico/Baja California Laws
  Constitution & Codes
The Mexican Constitution, enacted in 1917 and amended over the years, does not mention environmental issues. In 1988, the General Law of Ecological Balance [sometimes translated as Equilibrium] and Environmental Protection was passed., which for the first time governed environmental protection. After years of regulatory improvements to the General Law, the Mexican Government took another look at environmental protection issues in the mid-1990s. The result was the Amended General Law of Ecological Balance and Environmental Protection of 1996. This establishes the framework and authority for all environmental regulation in Mexico.

  SEMARNAT (Secretaria de Medio Ambiente y Recursos Naturales) governs Mexican environmental policies.
http://www.semarnat.gob.mx/legislacion_ambiental/index.shtml
This site has an extensive list which includes the text of Mexican environmental laws. The page is organized by International Law and Federal Law sections, and includes a breakdown of laws by topic (e.g., fishing, forestry, sea and ocean). Some links are not reliable; some documents are "unavailable," perhaps due to unreliable servers. In Spanish.

  You may request Mexican laws translated in English for a fee at http://www.mexicanlaws.com/
The sample translations seem well done.

  Spanish versions of many Mexican laws are available on the Internet Law Library at http://www.priweb.com/internetlawlib/

  All 31 states in Mexico now have enacted their own comprehensive environmental laws. Many municipal governments have adopted laws addressing a broad range of environmental matters, including Baja California. This state’s web site is at http://www.bajacalifornia.gob.mx/entrada.htm


C. Environmental Agreements Between the U.S. and Mexico
Several agreements between the United States and Mexico relate to the border environment, natural resources and the species that live there: migratory birds and game mammals, cooperative fisheries programs, forestry development, wetlands and wildlife preservation. These bilateral conventions and agreements are all available at the Legal Research Center at the University of San Diego in a number of resources, including the Congressional Information Service and the United States Statutes at Large.

The following environmental agreements are listed because of their scope, importance, and relation to border issues.

  Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), signed by the U.S. in 1973 and by Mexico in 1991. CITES establishes a worldwide system of import and export regulations to prevent the overexploitation of plants and animals listed in the three appendices to the Convention. The text can be found at http://www.cites.org 

  Treaty of 1889 and Water Treaty of 1944
The United States and Mexico signed a treaty in 1889 creating the International Boundary Commission (IBC). The mandate of the IBC was to resolve problems of boundary demarcation between the two countries caused by changes in the courses of the Colorado and Rio Grande rivers. In 1944, the two nations signed the Treaty of Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande (the Water Treaty) changing the IBC into the International Boundary and Water Commission (IBWC). The Water Treaty extended the IBC’s purview to include maintaining the land boundary and apportioning the waters in all these rivers.

  International Boundary Commission, United States and Mexico / Title 22 United States Code sec. 277 et seq.
Originated in 1924 to study the "equitable use of waters" between Mexico and the U.S., it covers not only shared water use, but also border waters sanitation projects, construction of roads and highways and dams to facilitate water use and sanitation, and creating new river channels for increased population on the border.

  1983 United States-Mexico Agreement on Cooperation for the Protection and Improvement of the Environment in the Border Area - La Paz Agreement - TIAS 10827 (signed in 1983; entered into force 1984)
In 1983 in La Paz, Baja California, the United States and Mexico signed the Agreement on Cooperation, also known as the La Paz Agreement. This established a framework for cooperation between the two countries to prevent, reduce and eliminate sources of air, water, and land pollution in the zone extending 100 kilometers along each side of the international boundary. The La Paz Agreement creates a procedure for establishing annexes which facilitate cooperation on specific environmental issues.

  Integrated Environmental Plan for the U.S.-Mexican Border Area (IBEP)
This plan grew out of a meeting between the President of Mexico and the President of the United States on November 27, 1990 in Monterrey, Mexico, on the potential economic benefits and environmental effects of trade liberalization between the two countries. The IBEP reflected the idea that long-term economic growth is not possible without environmental protection and long-term environmental protection is not possible without economic growth. The plan’s goal: to protect human health and natural ecosystems along the border.

   The North American Free Trade Agreement - NAFTA
19 United States Code sec. 3 et seq.
NAFTA contains a number of environmental provisions and an additional trilateral environmental agreement was negotiated to supplement it. Subsequently, a bilateral agreement was signed to address the deficiencies in water and waste infrastructure in the border area. Many environmental side agreements have been enacted and may be found at the USD Legal Research Center.

  The North American Agreement on Environmental Cooperation (NAAEC)
This was signed by the United States, Canada, and Mexico on September 13, 1993 and entered into force with the NAFTA trade agreement on January 1, 1994, to promote sustainable development through mutually supportive environmental and economic policies. The Commission for Environmental Cooperation (CEC) located in Montreal was created under the NAAEC to protect and improve the environment through increased cooperation among the parties.

  U.S.-Mexico Agreement on the Border Environment Cooperation Commission and the North American Development Bank (BECC-NADBank Agreement)
This was the second environmental agreement negotiated after NAFTA to target environment problems in the border region to remedy transboundary environmental or health problems. It establishes two institutions to address these issues:

The Border Environment Cooperation Commission (BECC)  
Located in Ciudad Juarez, Mexico, helps to form solutions to border region environmental problems; has a staff of professionals from both countries.

  The North American Development Bank
The second institution was the NADBank, which exists to arrange for public and private investment in environmental infrastructure projects. It is capitalized and governed equally by Mexico and the United States.