East Side 'water wall' set to go

A.E. Araiza / Staff
Jerry Fordham of URS Construction, left, and Ray Murray, city environmental project manager, stand in front of one of the four treatment tanks near the Wilmot branch library.

System will block contaminated Broadway North landfill plume
By Scott Simonson

A treatment system to keep East Side well water pure is expected to start up in the next few weeks.

Ground water at the old Broadway North landfill, north of Broadway, between Pantano Wash and Prudence Road, is laced with tetrachloroethylene, also called perchloroethylene or PCE. The contamination has moved west toward Tucson Water wells on the East Side.

The new treatment system is designed to halt the spread and contain the threat of contamination so that it doesn't reach the wells, according to state and city officials.

The treatment system is anticipated to start up in mid-January and become fully operational by early February, according to Michael Fulton, Superfund programs unit supervisor for the Arizona Department of Environmental Quality.

"It's nowhere near over, but all of us are excited to see something happening," said Judy Burns, co-chairwoman of the community advisory board for the Broadway-Pantano Water Quality Assurance Fund Cleanup.

"It takes a long time," Burns said, "but we hope we see data within the next year or so that shows us that something is happening."

Built by the city with money from the state, the treatment system is called the Western Groundwater Containment System.

The containment system is designed to pump ground water through filters that remove PCE and other harmful chemicals.

A series of 20,000-pound, carbon-filled tanks does the filtering. The tanks work like giant versions of water-filtering pitchers found in many Tucson refrigerators, said Jerry Fordham of URS Construction, the engineering company overseeing the project for the city.

"This (carbon filtering) does a good job," Fordham said. "The method of treatment has been around a long time."

Building the containment system was a $2 million project for the state, county and city to address a 15-year-old problem.

In 1987, Tucson Water said the defunct Broadway North landfill, which closed in the late '60s, was leaking PCE.

PCE is a solvent for dry cleaning and metal de-greasing. Health effects of drinking water containing low levels of PCE are unknown, according to the Centers for Disease Control and Prevention. The U.S. Department of Health and Human Services says PCE "may reasonably be anticipated to be a carcinogen."

PCE from the defunct landfill mixed with ground water. Ground water flows like a river, only much slower.

A plume of polluted ground water has spread about two miles west of the landfill, forcing shutdown of four city wells between 1987 and 1998.

If the plume continued to spread, it could contaminate the heart of Tucson Water's system, according to research by the state Department of Environmental Quality.

Tucson Water's central well field serves 60 percent of its customers.

To prevent contamination from reaching central wells, the containment system will create an underground "wall" of water, said Ray Murray, environmental project manager of the city of Tucson.

Filtered water will be injected into the ground and pumped east, where it should block the tainted plume from moving farther west, Murray said.

The new system alone won't solve ground-water problems created by the old landfill, said Fulton of the ADEQ.

"It won't necessarily clean up all the contamination to be known there at the site," Fulton said. "Its function is to contain it and keep it from getting any worse."

Measures are in place at the old landfill to clean up the source of the pollution, he said.

The large filtering tanks for the project have been built behind the Wilmot branch of the Tucson-Pima Public Library, 530 N. Wilmot Road.

The injection well used to build the ground-water "wall" is near the intersection of Rosemont Street and Alamo Avenue, Murray said.

* Contact reporter Scott Simonson at 434-4097 or simonson@azstarnet.com.

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