U.S. Water News Online
LOS ALAMITOS, Calif. -- Certain trees, it seems, are heavy drinkers.
Poplar trees planted at the Joint Forces Training Base by an engineering firm are cleaning jet fuel out of the soil. Mature poplars drink 20 gallons of water a day.
Through a process called phytoremediation, the trees are breaking down and soaking up residual fuel that leaked from underground tanks when the base was a Navy air station.
Experts said the trees' roots release oxygen, sugars and alcohols that feed the bacteria in the soil that in turn break down the contaminants. The bacteria or microbes in the soil would eventually remove the contaminants, but that could take thousands of years.
Organic contaminants that get past the roots and into the tree are either contained in the tree or metabolized and released as oxygen or carbon dioxide into the air.
The jet fuel leaked when the base was a naval air station from 1942-1972. One of the three 210,000-gallon underground fuel tanks leaked fuel, creating a contaminant plume up to 5 feet thick.
Cleanup started seven years ago with construction of a trench to capture contaminated water. A pump-and-treat system was installed to take out the contaminants. These efforts removed 36,000 gallons of fuel in nine months.
A vacuum extraction system was then installed, reducing contaminant levels to residual or nonmeasurable concentrations.
Scientists planted 160 Italian hybrid poplar trees two years ago to help soak up any remaining pollutants. Poplars were chosen for their deep roots and thirst.
"They're very enthusiastic water-seekers," said Troy Hardin, environmental scientist at the base.
The mechanical pump system will continue to operate for two to four years, then the trees will replace the pumps. The phytoremediation program will save the military $900,000 over 10 years, officials said.
Return to the U.S. Water News' Archives page Or Return to the U.S. Water News Homepage
Editor@uswaternews.com
*Your Name:
*Your Email:
*Friend's Email:
Use a comma to separate e-mail addresses:
*Your Comments:
Hi, I thought you might like to read this article.
*Required Fields