PROJECT REPORT
The US
Environmental Protection Agency( EPA) and Mexico’ s
Secretariate of Environment and Natural Resources are working together to clean up the chronic pollution of the 120-mile Tijuana
River.
By Lyndsey Denton-Fray, Valve World
The Tijuana River Project
Background
The Tijuana River is a river running near the Pacific coast in northwestern Mexico and Southern California in the western United States. The lower part of the river is heavily polluted with raw sewage and is a matter of concern due to flooding risks. The river has been used as a wastewater canal, with raw sewage blocking and overflowing on the Mexican side, with over 143 million gallons of sewage entering the river in 2017 and multiple beach closures over the years. This sewage crisis is a cross-border environmental and infrastructure challenge, affecting communities in both Mexico and the United States. Addressing it requires improvements to wastewater collection and treatment systems, alongside measures to manage river flows and reduce pollution reaching the Pacific coast. The ongoing project encompasses several infrastructure upgrades intended to improve wastewater management and protect public health and the surrounding environment.
The Parallel Gravity Line
The multiple structural collapses of the Parallel Gravity Line are one of the main issues regarding the sewage crisis of the Tijuana River. The failures of the Parallel Gravity Line, the critical wastewater pipeline that carries raw sewage through Tijuana in Mexico, have caused millions of gallons of untreated sewage to be leaked into the Tijuana River, causing extensive damage to beaches and surrounding areas, severe odours and health concerns for the South San Diego County. One of the goals is to complete the reconstruction of the Parallel Gravity Line. By restoring a critical part of the sewage conveyance system, the work
Part of the Tijuana River channel in Mexico.
is intended to reduce the risk of further releases of untreated wastewater into the river.
New improvements
According to the updates on the US Environmental Protection Agency news releases, the Parallel Gravity Line repairs have been completed, construction began on Phase 2 of the Tijuana River Gates, the first major construction contract was awarded for the next expansion of the South Bay International Wastewater Treatment Plant, and crews cleared approximately 16,622 feet of the Tijuana River pilot channel to prepare for upcoming rainy season. Alongside improvements to wastewater conveyance, the South Bay International Wastewater Treatment Plant in San Diego is set for a further expansion. Following an increase in capacity to 35 million gallons per day in 2025, a new expansion aims to raise capacity to 50 million gallons per day. The additional capacity is intended to strengthen the region’ s ability to treat wastewater crossing the border and reduce the volume of untreated sewage reaching the surrounding environment.