Works in Guanabara Bay are delayed, but interventions signal improvements

The initial schedule for the depollution work in Guanabara Bay, in Rio de Janeiro, is nine months behind schedule, compared to that provided for in the concession of basic sanitation in the state.

The delay is due to the delay by Agenersa (Regulatory Agency for Energy and Basic Sanitation) in approving the preliminary project presented in February by Águas do Rio, the concessionaire responsible for the works.

The documents on the interventions are still in the first stage of processing at the agency, which should have been closed in March. The end of the analysis at the agency was scheduled for September, when the necessary licenses would be requested for the construction of the belt that aims to prevent the discharge of sewage into the waters of Guanabara Bay.

All deadlines are provided for in the Tender Specifications for the concession.

Since the beginning of full operation of Águas do Rio, in November 2021, small interventions in the sewage system have led to some signs of improvement in the waters. Survey of Sheet showed that, for the first time, a beach in the bay was classified as good — Praia da Ribeira, on the island of Paquetá. There were also signs of improvements on the beaches of Botafogo and Flamengo.

However, the definitive solution for the entire bay depends on the belt to be built.

In a joint note, the agency and the state government state that the delay “does not mean impacts on the final schedule”. They say that the five-year term estimated a delay of one year to obtain licenses, when the average is five months.

The seven-month “fat” of the schedule, however, is already less than the nine-month delay. According to the state government, the five-year period for building the belt around the bay began on November 1, 2021, when the concessionaire completely took over sanitation services in the region.

Águas do Rio, in a note, states that it is already speeding up the detailing of the projects to advance the next stages of processing at the agency.

“The concessionaire reaffirms its commitment to the deadlines stipulated in the contract, such as five years for the creation of a protection belt around Guanabara Bay.”

The new promise to clean up Guanabara Bay is part of the concession for basic sanitation in Rio de Janeiro, signed in August last year. The contract provides for the treatment of 90% of sewage in the state by 2033, in line with the new regulatory framework for the sector.

An emergency investment of BRL 2.7 billion over five years by Águas do Rio, winner of the auction in the region, is expected to accelerate the end of the dumping of waste in the bay.

The bet in this period is the so-called dry weather collector, which is faster to implement. Instead of new pipes connecting houses to the exclusive sewage network, the pollution continues to be drained through the rain drainage network and will be blocked before flowing into the rivers that reach the bay. From there, it will be directed to the currently idle treatment stations.

The project for building the collectors, however, depends on Agenersa’s approval.

The documents also show that the estimated expenditure of BRL 2.7 billion for the works, made by the state, is lower than that calculated by the concessionaire. Águas do Rio’s preliminary project forecasts R$ 71 million more than the cost of the works, 2.6% more than described in the concession contract. The meeting of accounts, however, will only occur when the executive projects are analyzed.

While waiting for the approval of the works, small interventions made by the concessionaire after one year of service indicate the positive potential of the belt to be made.

The improvement in conditions on Ribeira beach, in Paquetá, is due, according to Águas do Rio, to an action that stopped the illegal spillage of six Olympic sewage pools per month into the sea. Among the measures are improvements in the treatment plant and in the four pumping stations in Paquetá.

Interventions by the concessionaire also allowed for two rare consecutive weeks of bathing on Botafogo beach in August, a shore that was polluted in 99.8% of the measurements taken between 2015 and 2019.

The main one was the cleaning of the oceanic interceptor, a storm sewer that crosses the entire south zone. The polluted Carioca, Banana Podre and Berquió rivers stopped flowing into Guanabara Bay and were diverted to the structure that takes water to the oceanic outfall of Ipanema. The drought during the winter also contributed to the improvement.

“Águas do Rio, in partnership with Inea, is already carrying out inspection actions to put an end to clandestine connections and ensure that the rivers, in the future, are able to flow cleanly into the bay”, says the concessionaire.