Nation's First Large-Scale
Desalination Plant Delivers Drought-Proof Water Supply |
2/20/2008 |
Clearwater, FL — The nation's first large-scale seawater desalination
plant is delivering drinking water to more than 2.5 million residents of the
Tampa Bay area. It's a timely solution as continued drought is forecast
across the southeastern United States.
While parts of Alabama, Georgia and North Carolina are facing exceptional
drought conditions, officials in west-central Florida say their residents
are benefiting from the nation's first drought-proof drinking water supply,
a project pioneered by the area's regional utility, Tampa Bay Water.
"Nearly a decade ago the Tampa Bay region suffered from an extreme drought,
just as we are currently, and at that time we explored how we might
drought-proof our system so that this didn't have catastrophic
consequences," said Jerry Maxwell, General Manager of Tampa Bay Water, "As
we did so seawater was a natural place for us to look. We live in Florida,
we are on a peninsula, surrounded by seawaters, and even though it hadn't
been undertaken on a large-scale, it seemed the natural thing to do."
Cost was the reason the utility had not considered seawater desalination in
the past, Maxwell said. But when technology advances brought the cost of
desalinated water down significantly, the utility felt the time was right.
The Tampa Bay Seawater Desalination Plant can produce up to 25 million
gallons per day of drinking water. The process works like this:
About 44 million gallons of water from a nearby power plant cooling system
is diverted to the plant. There, it goes through pretreatment steps to
remove algae and other particles. Using reverse osmosis filters, 25 million
gallons per day of freshwater is separated from the seawater.
This leaves behind a twice-as salty byproduct that is blended with a large
amount of cooling water from the power plant. That dilution is why
environmental studies show no measurable salinity change in Tampa Bay
related to plant production.
"In the rest of the world they don't always have as high or as strict of
standards as it relates to the environment as we do here in the US, so
working in a real natural, sensitive ecosystem meant that we had a very high
bar to clear in terms of environmental stewardship," said Maxwell.
The plant faced its share of early problems. Officials say the original
developer failed to deliver a plant that met specifications. So Tampa Bay
Water engaged two companies with worldwide desalination experience to bring
the plant up to specifications. They were American Water, and Acciona Agua
of Spain.
"I don't think any public utility has the kind of expertise in house that it
takes to undertake a project of this magnitude. In our in instance we
partnered with American Water and with Acciona because they had both North
American and worldwide experience in the construction of water treatment
plants," said Maxwell.
While the plant is designed to produce up to 25 million gallons per day, it
can be expanded to produce up to 35 million gallons per day in the future.
That, Tampa Bay Water officials say, gives them comfort that public water
supply will not be an issue during the next drought.
American Water's Don Correll, sees more such projects on the horizon.
"Beyond providing a reliable supply of drinking water to the residents of
this region and leading the way for other, similar projects across the
United States, this plant is an excellent example of what a successful
public-private partnership can accomplish," he said.
"We've already had folks from other coastal areas around the United States,
in from in fact around the world, come visit us, to visit this site, see
what we have been able to accomplish, understand how it works, and we know
it is just a matter of time before other s are able replicate what we have
done and in fact, improve on it and advance the science of seawater
desalination," Maxwell said.
Acciona Agua's Luis Castilla sees the plant as a demonstration to the world
that desalination is a practical solution. "I think personally that this
plant is one of the most important plants in the world. The success of this
plant is going to have far great impact not only in America but also in the
rest of the desalination markets in the world," he said.
"As growth and drought continue to strain the public water supply, it's
really good to know that we have a safe and sustainable way to harvest water
from the sea," said Maxwell.
SOURCE: Tampa Bay Water |