Border Affairs Program  |  Programa de Asuntos Fronterizos

The California Environmental Protection Agency Border Affairs Program promotes cooperation to help ensure a cleaner, safer, healthier, and more prosperous border region.  The program is a collaborative effort between CalEPA and our boards and departments to address environmental issues on multiple fronts and coordinate efforts with other California state agencies, Tribal Nations in the border region, and federal, state, and local governments in the U.S. and Mexico.

California-Mexico Border Relations Council

The CalEPA Secretary chairs the California-Mexico Border Relations Council, which serves as the central organizing body overseeing California-Mexico border issues. The Council is comprised of eight secretaries or directors of state agencies and publishes an Annual Report that is sent to the Legislature.  

Recent State Investments in the Border Region

Senate Bill 170, Statutes of 2021, appropriated $20 million to the State Water Resources Control Board (Board) to address water quality problems arising in the rivers that come across the border from Mexico.  In 2022, Assembly Bill 154 appropriated an additional $15M for this purpose.  On July 19, 2022, the former Secretary of CalEPA appeared before the Board to state his support for this border funding to move forward to important projects.  CalEPA will continue to work with our counterparts to encourage additional State investments in the border region to improve the health and environment for all Californians.

Community Science at the Border

CalEnviroScreen is a screening tool used to identify California communities disproportionately burdened by multiple sources of pollution. To improve the accuracy of border-region data, CalEPA works closely with community partners to understand and address CalEnviroScreen data gaps. The following community science projects are examples of ground-truthing government data at the border:

  • The San Ysidro Air Study was a 2-year collaboration between the San Ysidro community in San Diego, state government, and academia to collect neighborhood air pollution data using advanced low-cost technology. The partnership was critical to the success of the project. Through community science and civic participation, residents were decision makers.
  • Water Quality Assessment for Rural Communities in Imperial County: The California Office of Environmental Health Hazard Assessment and CalEPA are working with Comite Civico Del Valle, Inc. to assess canal water used for domestic purposes. Efforts are tailored to community concerns and to inform CalEnviroScreen.

Air Quality

CalEPA’s Border Affairs Program works with the California Air Resources Board to improve air quality at the border by collecting data on interagency air quality activities across agencies, and serves in an advisory role to the California Air Resources Board Imperial County-Mexicali Air Quality Work Plan and its respective working group (more information can be found on the California Air Resources Board’s California-Mexico Border Activities webpage).

Water Quality for Transboundary Rivers

To address water quality issues that arise from transboundary flows of waste, sedimentation and polluted water, CalEPA works closely with the San Diego and Colorado River Basin Regional Water Quality Control Boards and local communities. 

Tijuana River:  The CalEPA Border Affairs Program serves on the US EPA USMCA Eligible Public Entities Group to identify projects to address transboundary pollution.  CalEPA also serves on the Steering Committee of the Tijuana River Valley Recovery Team, a collaboration of more than 30 government agencies, property owners, academic and research institutions, and non-profit organizations from California and Baja California who work to improve environmental conditions in the Tijuana River Valley. 

New River:  In order to address New River pollution, CalEPA has been working to implement the New River Improvement Project and its respective update.  In October of 2017, local entities signed a MOU agreeing to long-term operation and maintenance of the project.  Three structural components of the project have received funding for construction, set to begin in 2022. The Project infrastructure components now include 1) installing a trash screen just downstream from the Mexico border; 2) piping polluted water away from Calexico to wetlands and aeration structures for remediation; and 3) replacing polluted water in the river channel with treated wastewater from the City of Calexico’s treatment plant.  The Project is complementary to the New River Parkway Project, which envisions a bike path, a park and recreational fields along the river.


The CalEPA Border Affairs Program serves as a member of the Border Region Solid Waste Working Group established by Senate Bill 83 (Committee on Budget and Fiscal Review, Chapter 24, Statutes of 2015) under the California-Mexico Border Relations Council (an update can be found here).  The group works to coordinate solutions to remediate problems associated with waste tires, solid waste, and excessive sediment that threaten water quality and public health in the California-Mexico border region.  The group is working to implement the Solid Waste and Waste Tire Strategic Plan published in January 2017. The group also oversaw publication of a study detailing The Flow of Used Tires from California to Mexico and Waste Tire Disposal Issues in Baja California.

Federal and Binational Partnerships

CalEPA continues to work closely with our federal partners on border region investments, including the North American Development Bank and US EPA.  CalEPA also works closely with our partners in Mexico, including Mexico’s National Water Commission, CONAGUA, and Mexico’s Ministry for the Environment and Natural Resources, SEMARNAT, and the governments of Baja California Norte and Baja California Sur. 

Border 2025:  The U.S. EPA Border 2025 U.S.-Mexico Environmental Program is the latest environmental program implemented under the 1983 La Paz Agreement.  The Border 2025 Environmental Program emphasizes regional, bottom-up approaches for decision making, priority setting, and project implementation to address the environmental and public health problems in the border region, and is designed to encourage meaningful participation from communities and local stakeholders.  CalEPA is a key Border 2025 partner and serves as a Co-Chair of the California-Baja California Regional Workgroup, which includes U.S. EPA, Mexico’s Ministry of Environment and Natural Resources, Secretaría del Medio Ambiente y Recursos Naturales, and the Secretatriat for Environmental Protection of Baja California, Secretaría de Protección al Ambiente de Baja California.

California-Mexico Memorandum of Understanding on Climate Change and the Environment (2014-2018):  The Border Affairs Program coordinated activities under the California-Mexico Memorandum of Understanding to Enhance Cooperation on Climate Change and the Environment.  The MOU was signed in July 2014 by California Governor Edmund G. Brown Jr, Rodolfo Lacy, Undersecretary of the Ministry of Environment and Natural Resources of Mexico, and Jorge Rescala Perez, General Director for the National Forestry Commission of Mexico.  The Joint Action Plan called for collaboration on climate change, air quality, wildfires and clean vehicles to reduce greenhouse gas emissions, protect public health and natural resources, and promote a clean economy.  CalEPA published a Summary Report of accomplishments under the MOU.  

Contact Information

Border Affairs
California Environmental Protection Agency
1001 I Street, 25th Floor
Sacramento, CA 95814
(916) 324-8741