📋 Tender Overview
Sector
Wastewater
Sponsor
Local water utility, Tijuana State Commission of Public Services (CESPT).
Benefitted Population
688,000 people
Certification Date
14 / Dec / 2023
Background
In coordination with NADBank, the U.S. Environmental Protection Agency (EPA), the Mexican National Water Commission (CONAGUA) and the U.S. and Mexican Sections of the International Boundary and Water Commission (IBWC/CILA), CESPT and the State of Baja California have been working to address incidents of untreated wastewater discharges to the Tijuana River basin and the Pacific Ocean. As part of a binational commitment formalized through the Statement of Intent (SOI) signed by EPA and CONAGUA, as well as IBWC Minute 328, specific wastewater infrastructure rehabilitation and replacement projects are scheduled for implementation over the next few years with cost-share commitments from both countries.
The project proposed for certification is included in the SOI and will address two key components of the wastewater collection and conveyance system in Tijuana: (i) replacement and abandonment of the old sewer main known as the International Collector and rehabilitation of the PB1B lift station; and (ii) rehabilitation of the Tijuana River diversion system, which includes works to improve the operation and increase the capacity of the PBCILA lift station and rehabilitate the PB1A lift station.
On July 30, 2022, the parallel conveyance system related to PB1A and PB1B, which convey Tijuana River water to the Pacific Ocean and wastewater to the San Antonio de los Buenos Wastewater Treatment Plant (WWTP), respectively, experienced major breaks in both force mains, which caused both lift stations to be shut down. While the PB1B force main has been replaced and regular operations have resumed, repairs on the PB1A force main have not been completed, impairing the operations at the PB1A lift station. As a result, excess wastewater flows have been conveyed to the South Bay International WWTP, severely impacting its operation. Moreover, due to the condition of the PBCILA lift station and its river intake, the diversion system was not functioning adequately to prevent transboundary flows in dry-weather seasons.
Description
The project consists of replacing and abandoning the deteriorated International Collector, rehabilitating PB1A, PB1B and PBCILA lifts stations, increasing the capacity of PBCILA from 1,008 to 1,490 liters per second (lps) or 23 million to 34 million gallons a day (mgd) and constructing a new intake from the Tijuana River channel to PBCILA. The improvements to each of these components are described below:
Tijuana River Diversion System – construction completed by CONAGUA
Tijuana River in-take: Installation of 289 ft of 48-inch fiberglass reinforced
PBCILA Lift Station improvements: Sand and grit removal (Vortex), fine and coarse mechanized screen, effluent flow meter, conveyor belts for automatic trash and debris collection, a new 125-HP C
