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Metropolitan outflow
for the treatment of
wastewater
The metropolitan area of
the city of San José in Costa
Rica requires the treatment
of wastewater which is
currently discharged into
several rivers. As a result
of this situation, there is an
initiative by the Instituto
Costarricense de Acueductos
and Alcantarillados (AyA),
of executing a mega-project
for treating wastewater and
reducing the level of
contamination of the rivers
that flow through the city.
FCC Construcción is currently building the
metropolitan outflow of the city of San José
which will make it possible to transport was-
tewater to the collectors in the north and
south of the plant for its treatment in the Los
Tajos WWTP. This mega-project will benefit
the more than 450,000 residents and will
provide a flow of 7,281 litres per second.
Oscar Rodríguez, the project manager, ex-
plained that this outflow will have a “length
of 3,100 meters parallel to the Torres River”.
The engineer added that “contribution of the
outflow to the communities in the metropo-
litan area of San Jose is significant since it
is a pioneer program nationwide for the
A pioneer project in Costa Rica
treatment of wastewater since the aim is to
treat the wastewater from the city which is
contaminating the neighbouring rivers”.
Safety, health and environmental plan
The head of the Health, Safety and Envi-
ronment department of the Outflow Project,
Rodrigo Lazo, explained that the project is
based on FCC’s General Safety Plan. Lazo
said that the outflow project is simple, but
important because of the hazards entailed
since it is necessary to perform excavation
work and also work at heights as well as
other tasks that require strict controls.
The safety measures implemented include
talks aimed at the employees who enter the
project site for the first time; weekly training
courses of safety; preliminary inspections of
the sites where work is going to be perfor-
med, and the installation of signals.
In addition, during the execution of the
work, several environmental measures will
be implemented, including a reforestation
plan and a humidifying plan to minimise the
amount of dust to which workers in the field
are exposed to as well as the population li-
ving 100 to 200 metres from the project site.
Social responsibility
Since the project involves channelling
through the centre of the city of San José,
FCC and AyA meet periodically to inform the
neighbours of Carvajal, Solar, and Flor Nata-
lia of when the traffic will be interrupted and
on the work schedule to mitigate any possi-
ble inconveniences for the residents caused
by traffic congestion and noise.