Skip to content (press enter)


Surfrider’s No Border Sewage Policy

July 13, 2017

Executive Summary of Sewage Problem

Brief Background

The Tijuana River Valley and South Bay border communities of San Diego have experienced contamination due to untreated raw sewage from Tijuana since the 1930s. Incidents of contamination have increased over the last 50 years due to Tijuana’s rapid increase in population, a growing Mexican middle class and the high cost of housing in San Diego counties. As a result, Tijuana’s sewage infrastructure has not been able to cope with the needs of its quickly expanding population. The problem has been made worse by the increase in unpredictable rain events seen in the last few years.


Mexican Sewage Diversion Operates During Dry Weather

Located in Mexico, Pump Station CILA (PS CILA) was constructed in 1991 as a diversion structure and pumping facility located in the low flow channel of the Tijuana River. It collects sewage flow in the Tijuana River during dry weather and then conveys the sewage to Pump Station 1 located in Tijuana. During periods of rain, PS CILA is turned off due to operational concerns. PS CILA was constructed to operate during dry weather and for an estimated capacity of 23 million gallons per day.


Treated Wastewater and Rain affect Sewage Diversion

The Tijuana River is also now a discharge point for discharge from two Mexican wastewater treatment plants, Arturo Herrera and La Morita. These treatment plants contribute up to 10 mgd of effluent which is captured by PS CILA. The result of this is that it reduces the amount of sewage flow that PS CILA can pump. This is made worse during rainfall events when PS CILA is turned off.


A Secondary Wastewater Treatment Plant

The South Bay International Wastewater Treatment Plant (SBIWTP) was constructed as a secondary wastewater treatment facility in 1997 to treat raw sewage flows from the Tijuana collection system and surface flows from canyon collectors in Tijuana. SBIWTP can only treat a maximum of 25 million gallons per day of Mexican flows.


The Big Spill

In 2017, January and February were periods of extraordinary rain in San Diego. From February 1-4 the Mexican water authority (CESPT) intentionally bypassed raw untreated sewage into the Tijuana River as a result of an emergency repair on a collapsed collector in Tijuana. There was no notification provided to the United States. In mid-February, Imperial Beach residents began reporting visible sewage and stench in the vicinity.  On Feb. 24, 2017, the International Boundary and Water Commission (IBWC) in San Diego officially reported a sewage spill to local leaders. According to preliminary reports between 143 to 230 million gallons of Tijuana’s raw sewage had been discharged into the Tijuana River which funnels into Imperial Beach. Plumes of sewage were visible off of the Imperial Beach coastline. Mexican officials report that the spill was estimated to be 28 million gallons over the course of 4 days.


Imperial Beach residents have been both angered and motivated by the February 2017  sewage spill. As a result, residents have formed two groups: The IB Clean Water Movement and Stop the Poop. Both groups are active in letter writing, advocacy, information dissemination and community organization. Further, other stakeholders such as Border Patrol and government officials have voiced the need to solve the sewage problem. Since the February 2017 spill there have been around a dozen smaller scale spills in the Tijuana River Valley though lack of data make its difficult to determine if this sewage made it from the Tijuana River and into local beaches.


The Aftermath

On March 2, 2017 the Binational Core Group (BCG) established by Minute 320 convened in Tijuana to discuss the sewage spill. The BCG contained representatives from the United States, Mexico and nonprofits organizations on both sides of the border. Another meeting was held on May 23, 2017.


CILA (the IBWC’s Mexican counterpart) and CESPT (Mexican water authority) have taken short to medium term steps towards solutions. Mexico has purchased equipment to respond to incidents like that of February 2017. Mexico has commenced an investigation of its collector system as well as repairs to its collector system and acquired some funding for this purpose.


The IBWC and CILA have reached a notification protocol that in summary requires immediate notification in emergency situations that will be updated as information is made available as to quantities of sewage and timelines for repairs.


The IBWC and other members of the Minute 320 are interested in developing a water quality monitoring program to develop a baseline and identify pollutants that reach local beaches. The IBWC is also exploring options that will either reduce or eliminate the amount of sewage dumped into the Tijuana River. It will also look at options that will reduce or eliminate sewage that reaches local beaches.


Policy Objectives and Implementation:

The border sewage problem has long existed in Imperial Beach and Coronado. However, the problem worsened over the last 30 years as Tijuana’s population increased beyond the city’s capacity to respond with adequate infrastructure. Border sewage from Tijuana is a routine occurrence in Imperial Beach as are regular beach closures. Surfrider’s No Border Sewage Committee recognizes the dangers posed and endeavors to work with public agencies and other non-profits organizations to avoid future sewage spill contamination.


Upon a review of a decade’s worth of news and media coverage on border sewage in Imperial Beach, several themes continually reoccurred:

  1. Raw sewage contamination is most likely to occur during periods of heavy rain.
  2. Public notification of contamination fails to occur because of regular “breakdown(s) in communication.”
  3. The Tijuana sewer/wastewater management system is failing.
  4. Little has been done to remediate recurring problems.


As such, Surfrider supports the following policy objectives:


  • The development of policies that would ensure a regular system of communication with respect to water quality, contamination and sewer works between the IBWC, CILA (IBWC’s Mexican counterpart) and the public.


Based on previous incidents, known deficiencies in the Tijuana sewer system and weather patterns, it is likely that another sewage spill will occur. Surfrider applauds the new Notification Protocol between CILA and the IBWC. However, Surfrider will advocate for a system of daily communication and exchange of information with respect to water quality and sewer system updates between CILA and the IBWC. Surfrider will also advocate for better communication between the IBWC and the public.


Information regarding water quality and sewage spills should be easily accessible to the public and ideally disseminated via the plethora of social media platforms now available. To achieve this objective, Surfrider will collaborate with the IBWC San Diego, CILA, public agencies, non-profit organizations and community groups.


  • Support the development of a water quality monitoring program along the Tijuana River Valley and local beaches.


The IBWC and the City of San Diego conduct weekly testing of water samples at the Tijuana River and at local beaches. However, the events of the last few months have highlighted that there is little or no baseline data concerning the sewage or other pollutants that enter the Tijuana River and those that actually reach local beaches.


Surfrider recommends the following:

  1. The development of a 12 week - baseline study to identify the pollutants present in the Tijuana River Valley.
  2. The development of a more frequent and thorough long-term water quality monitoring program based on the 12 week baseline study.
  3. A quicker turnover of water testing results and dissemination of information.
  4. Implementation of programs that will reduce the pollutants in the Tijuana River Valley.

To achieve this objective, Surfrider will collaborate with the IBWC San Diego, CILA, public agencies, non-profit organizations and community groups.


  • Promote the development of a plan that will address Mexico’s deficient infrastructure issue and the environmental impact it has on local beaches.


There is a need to openly address Mexico’s failing infrastructure with concrete, measurable, and actionable solutions because this has health and economic impacts.  Surfrider looks forward to engaging with public entities to discuss all feasible solutions with the end goal of working collaboratively to reach necessary solutions and funding goals.  There are various  ideas available to eliminate sewage flows into the ocean and Surfrider strives to support the exploration of these aggressively.


  • Advocate for the use of Federal and State resources to address pollution in the Tijuana River Valley and to remediate the pollution that has already occurred.


Surfrider supports the use of Federal and State resources to address and eliminate the sewage, trash, sediment and chemical waste that plagues our ocean, waves and beaches in the border region. The current system is failing and the infrastructure in Mexico is deficient. Much of the aggravation and lack of action has resulted from the fact that Imperial Beach has been alone in attempting to solve this problem which at its core is an international problem. Surfrider supports the implementation of programs that will remediate the pollution that has plagued the Tijuana River Valley.


To achieve this objective, Surfrider will collaborate with the IBWC San Diego, CILA, public agencies, non-profit organizations and community groups.