Rural Residents Find Riches in Saltwater
By Adalberto Marcondes - Tierramérica*
farming and growing forage crops resolve the problem of dealing
with the waste left by water desalination in a thirsty community
of the Brazilian Northeast.
SÃO JOSÉ DO SERIDÓ, Brazil, Apr 23 (Tierramérica)
- A village in Brazil's dry Northeast region is putting to the test
a project that began with machine to desalinize the little water
available, and has ended up creating food and income and promoting
Caatinga Grande, founded in 1989 on land affected by agrarian reform
near the town of São José do Seridó, in the northeastern state of
Rio Grande do Norte, aims to be a showcase for innovative technologies
of the Programa Água Doce (fresh water program, launched in 2004
by several state and non-governmental entities.
Some 200 kilometers from Natal, the state capital, this modest village
with the Santa Rita church as a backdrop has households that have
scared off misery. Situated in the middle of Brazil's semiarid region,
it was chosen to test a new technique for making use of waste from
its well of saltwater, one of thousands in the Northeast.
The Caatinga Grande desalination apparatus produces 10 liters of
potable water daily for each of its 355 residents -- enough for
their drinking and cooking needs.
But, "for each liter of potable water, we obtain a liter of water
saturated with salts," technician Odilon Juvino de Araújo, of the
Brazilian agricultural research agency EMBRAPA, told Tierramérica.
And that salty wastewater contaminates soil and kills plants, explained
resident José Anselmo Filho.
What to do with the wastewater became a problem that caused some
disputes with neighboring towns, until a new approach came from
EMBRAPA, which was researching a possible solution in the nearby
state of Pernambuco.
"We came to resolve an environmental problem" and ended up creating
a "virtuous cycle" with the desalinator, said Araújo.
Less than 300 meters away from the village are three holding tanks
that form part of that solution -- but they were initially seen
with skepticism by the local population. "Since they have promised
so many things, we have learned to distrust. But now it's different.
There are results," Netinha, a resident, tells Tierramérica as she
points to the fish swimming in one of the tanks.
The potable water flows from the desalinator into a tank that supplies
the community, while the wastewater is channeled to two other tanks
where a resistant and tasty fish is raised: the red tilapia, a hybrid
variety of the Oreochromis genus that adapts well to environments
with high mineral content.
A third tank accumulates the used water from the two fish pools,
which is rich in minerals and organic material -- and is potentially
a serious contaminant. But that liquid doesn't go to waste either.
It is used to irrigate plots of saltbush (Atriplex nummularia),
a forage crop of Australian origin that absorbs the salt and serves
as food for the sheep and goats in the area.
The land where the tanks and the saltbush crops are located is set
up with underground protection to prevent the salt from filtering
into the deeper soils and groundwater.
"I had a hard time believing in this, but now the fish are fat and
are going to provide a good yield," says Cícero Martins da Costa,
one of the people responsible for the fish farm. He hopes to get
800 kilograms of fish that the community will be able to sell, or
eat it themselves.
"It's a source of income that didn't exist before," he says.
Tilapia take six months to reach maturity. But the fish farm tanks
are staggered by a three-month difference. This way, the community
has four fish harvests per year.
According to João Bosco Senra, water resources secretary at the
Environment Ministry, this technology could be implemented soon
for many of the 2,000 desalinators installed on the wells in the
"sertão", the semiarid region in eastern Brazil extending from the
Jequitinhonha Valley in the southeastern state of Minas Gerais,
through Bahia, Pernambuco, Sergipe, Alagoas and Rio Grande do Norte,
"We are developing new materials to make it easier and cheaper to
maintain the desalinators," Senra told Tierramérica.
The Programa Água Doce's financial backing comes from the Banco
do Brasil Foundation. The cost of each unit installed is about 35,000
dollars, and includes repairs and updating of the desalinators,
construction of the holding tanks, pumps to move the water, planting
of saltbushes and technical assistance.
"The money is very well spent. It's about 50 cents (0.27 dollars)
per person, per day, to ensure quality potable water, sanitation,
food, income and a stimulus for goat and sheep production," says
Foundation president Jacques de Oliveira Pena.
The Foundation will earmark 1.4 million dollars for expanding the
initiative across Brazil's semiarid region. In total, the partners
in the Programa Água Doce will provide 6.76 million dollars to replicate
the endeavor in 22 communities in 11 states.
"The important thing is to have something concrete to show to the
people of the sertão," who will want to see results if they are
to be convinced, says Pena.
* Adalberto Marcondes is the director of