The Investigators

Jul 6, 2013 2:31 AM by Tom McNamara

Leaking underground storage tanks remain an unseen threat

TUCSON - It's a hidden threat that has plagued thousands of towns and neighborhoods for decades - leaking underground storage tanks.

There may be one or more near where you live. That's why the threat they pose is still taken seriously, all these years later.

The Environmental Protection Agency estimates there are more than 500,000 releases of hazardous materials from underground storage tanks across the country.

As the news 4 Tucson Investigators uncovered, some of those tanks are buried right here in Tucson.

Most of the underground storage tanks that leak potentially hazardous materials contain petroleum - gasoline - which can seep into the soil, and eventually into our aquifer.

"With the petroleum getting into the soil and then migrating into the groundwater, yes, that is an issue, especially, you know, in Tucson, and groundwater issues, we take that very seriously," says Fernando Molina, with Tucson Water.

It's up to the Arizona Department of Environmental, ADEQ, quality to keep tabs on gas station operators, to make sure they're maintaining their tanks, or properly sealing and destroying their old tanks.

One gas station that reported a leaking underground storage tank was C & T Oil on East 5th Street at Alvernon Way, a busy midtown intersection.

The cleanup there is underway, and for now, the station remains closed.

When a gas station does close, it's up to the operator to make sure the tank is secure.

ADEQ tells the News 4 Tucson Investigators, there are steps you can take as well.

"If they do see their local gas station suddenly chained up, to actually call ADEQ and give us the name and the address. That way, we can check our list and make sure that the owner has put it into either temporary closure, that we understand. We do have inspectors out all the time," says Laura Malone, with ADEQ.

While those state inspectors keep tabs on tank operators, Tucson Water also works to make sure your drinking water is free from potential hazards.

"Even though we are utilizing more and more of our Colorado River allocation and pumping from the Avra Valley, we still have to protect and maintain the aquifer in the central basin, so we spend a lot of time monitoring," says Molina.

Since 1987, ADEQ received more than 8,500 reports of leaking underground storage tanks. More than 7,500 have been cleaned up so far.

Most tanks used to be made of bare steel, which could corrode over time. ADEQ says since the late 1990's most tanks have been upgraded to newer tanks, which are less prone to corrode and leak.

"Us as citizens of Arizona, and we travel, and it's a big state, you know, we want to make sure that we have gas stations, and we want gas stations, but also that the gas stations are being operated appropriately, and that they stay in compliance with the regulations. That's the bottom line, there are requirements, and owners and operators of tank systems have that responsibility," Malone says.

ADEQ maintains an online database, where you can check on reports of leaking underground storage tanks in your area.

If you have something you'd like the investigators to check out, please send us an e-mail to


Most Popular

Top Videos

1 2 3 4