Construction of Santos-Guarujá Tunnel demands a study to prevent release of contaminants

Before dredging for tunnel installation, soil material will be collected for analysis and implementation of control measures, says Cetesb (Reproduction)

The construction of the submerged tunnel between Santos and Guarujá will depend on a new environmental licensing process, including assessments of the port channel, despite reference to work done over ten years ago. This statement comes from the São Paulo State Environmental Company (Cetesb).

The licensing includes studies on sediments prior to dredging for tunnel construction. "Dredging must be preceded by material analysis and the proposal of control measures to prevent the release of contaminants," explains Cetesb.

The disposal of dredged material will be determined based on the analysis results, with the company already indicating a likely option. "Typically, dredged material for operations at the Port of Santos is disposed of in the Oceanic Disposal Polygon (PDO), located 12 kilometers offshore."

Chemical engineer Élio Lopes emphasizes that the study must comply with Resolution 454 of the National Environment Council (Conama). This document outlines general guidelines and reference procedures for managing dredged material in waters under national jurisdiction.

"Depending on the concentrations of pollutants found, the final disposal location for these sediments will be chosen. Therefore, we need to await the results of the analyses to address this," argues Lopes.

When approached, APS also stated in a note that engineering alternatives for the construction of the Santos-Guarujá tunnel, as well as the required environmental permits, will be defined during the development of the executive project.

Seabed will receive concrete slabs to level the floor and accommodate tunnel modules, situated 21 meters below sea level (Reproduction)

Construction

The first of nine planned stages in the construction involves preparing the seabed. A trench will be dredged for the future placement of concrete slabs, effectively leveling the floor to accommodate the tunnel modules. This trenching phase is expected to take 14 months, without interruptions to navigation channels, according to the Port Authority of Santos (APS). The modules will be installed 21 meters below the waterline.

Cetesb adds that all studies and analyses supporting the issuance of the 2014 license will be utilized, as it serves as the foundation for the current project. "Updates and potentially new studies will be requested as needed based on the project presented," affirms the environmental company in a statement.

Current Status

Currently, implementation, as per the APS timeline, is in the legal modeling phase for the proposed public-private partnership (PPP).

Three public hearings were held between April 18 and 19, with an online public consultation. The tender announcement is expected in March of next year, with bidding in July.

The State Secretariat for Partnership Investments (SPI) stated in a note that the subject "will still be specifically addressed and further studies will be conducted," adding that the project is not yet finalized and subject to changes.

Interruptions

For soil surveying, the Porto channel was partially closed 13 times in 2014, each time for 12 hours from 11 AM to 11 PM. This totaled 156 hours, equivalent to 6.5 days of closures. These closures were necessary for the work but affected ship traffic and terminals at the time.

In 2014

A Tribuna reported on the construction of the Santos-Guarujá tunnel in 2014. In April of that year, the State Council for the Environment (Consema) unanimously authorized Cetesb to issue the preliminary environmental license (LP) for the tunnel construction.

In May 2014, Dersa, then responsible for the project, began soil surveys in the navigation channel. Conducted by a consortium of designers, the surveys aimed to assess the estuary soil conditions at depths where tunnel modules would be installed. Two vessels were used for this task.

Equipment on these vessels drilled up to 50 meters deep to collect sediment samples for analysis. These activities were a form of "biopsy" to study sediments for contaminants. Cetesb states that this previous study will be taken into account, although new surveys will be conducted on the soil.

Work depends on license

The start of the Santos-Guarujá tunnel construction, including soil surveys, depends on the issuance of the preliminary environmental license (LP) by the São Paulo State Environmental Company (Cetesb). However, approval from the State Council for the Environment (Consema) is required beforehand.

On June 12 at the Palácio dos Bandeirantes in the capital, Governor Tarcísio de Freitas (Republicanos) and Mayor Rogério Santos (Republicanos) held a meeting on the topic. The intention is to soon submit the environmental impact study to Cetesb so that the LP can be issued before the end of the year.

The aim is to launch the tender with the LP to attract investors with legal certainty. The governor assured that the contract for the Santos-Guarujá tunnel works will be signed in 2025.

The tunnel, valued at R\$ 6 billion, will be jointly funded by the state and federal governments. The dry connection between Santos and Guarujá has been planned by the state administration since February 2023, when the project was qualified under São Paulo's Investment Partnership Program (PPI-SP). The total length of the dry connection in Baixada Santista will be 1.5 km, with an immersed tunnel segment of 870 meters beneath the port channel.

The tunnel will consist of six pre-modulated concrete modules, constructed in a dry dock and transported by floaters for immersion, fitting, and fixation on the channel bed, which will also be deepened.