Mussels Fouling Nation's Largest Desalination Plant
In south Florida, tiny mussels are so badly gumming up Tampa Bay's $110-million desalination plant that its builder is now seeking help from former competitors to finish the project.
Asian green mussels are the culprit, contaminating the water going into the plant and fouling its works, said Beth Leytham, a spokeswoman for Covanta the New Jersey company building the plant in Apollo Beach, Fla.
``They're clogging the filters,'' Leytham said, and so far the company has been unable to figure out how to deal with the problem.
Covanta, whose parent company went bankrupt last year, has been struggling to complete the nation's largest desalination plant for its client, Tampa Bay Water. Covanta missed its initial deadline in January, then failed a critical test in May and appears headed for a default on its contract this Tuesday.
Frustrated Tampa Bay Water officials already have begun talking to companies capable of replacing Covanta if it does fail.
Now Covanta itself is negotiating with former competitors, including U.S. Filter, to get more money and staffing.
The plant is supposed to take 40 million gallons of seawater every day and force it through 10,000 tightly woven membranes to produce 25 million gallons of potable water and 15 million gallons of brine. The water comes from Tampa Electric Co.'s Big Bend plant, one of the first places the Asian green mussels were discovered in the United States.
To cool its generator, the plant pumps in millions of gallons of bay water through intake pipes covered with mesh screens. In 1999, Tampa Electric discovered the mollusks covering the screens, forcing the pumps to work harder than usual. Divers cleaned the screens, but the mollusks returned worse than before.
The Asian green mussel is native to the Indian and Pacific oceans. Ten years ago green mussels cropped up in Caribbean waters in Trinidad. Scientists think they traveled there in the ballast water of a bulk cargo ship, and they suspect that's how they arrived in Tampa Bay.