Almost one in 10 of the nation's 1,230 Superfund toxic waste sites (search) lack adequate safety controls to ensure people and drinking water won't be contaminated, according to data from the Environmental Protection Agency (search).

Another 13 percent of the sites lack enough data for officials to assess the safeguards, the EPA says.

Together, the two findings mean that agency officials are confident only that about four-fifths of the worst-contaminated sites won't make people sick or foul drinking water supplies (search).

But that doesn't mean people are actually drinking contaminated water or "rolling around in contaminated soil" at a fifth of the sites, said Randy Deitz, an attorney in the Superfund program.

The agency began using a new measure in 2002 — called "human exposure under control" — to assess risk at the sites. The last complete tally was in September 2003, though the agency's web site offers more recent data on certain sites.

Deitz and other EPA officials confirmed the figures available on the agency's Web site. They reflect site risk assessments in varying degrees of completion.

At "about 80 percent (of the sites) we feel we have exposures under control," said Superfund program analyst Melanie Hoff, who oversees the new measures. At the remaining sites it "doesn't mean that there's exposure, it means there's the potential for it to occur."

Environmentalists said Tuesday those figures show the Bush (search) administration is failing to protect public health, and Congress and the White House should reinstate a special tax to help fund the Superfund program.

"Without an effective funding mechanism for Superfund cleanups, dangerous chemicals will continue to seep into our air, water and soil," said Ed Hopkins, the Sierra Club's environmental quality program director, who wrote a report on the data.

But Deitz and other EPA officials called it misleading to suggest a connection between the figures and the $3 billion Superfund program's overall funding levels.

"Until the work is done, there might be some potential for exposure," Deitz said. "Even if we had all the money in the world, you wouldn't just put backhoes in there and start digging before you had studied the site and designed a remedy."

Phil Angell, an EPA consultant, said, the sites at issue "all have some contamination, but none ... presents an imminent risk to human health" because of either emergency cleanup measures in place or the posting of fish advisories and other official warnings.

"It would be incorrect to assume that any of those sites are a raw, uncontrolled site for which the public could be exposed to harmful contaminants," wrote Angell in an e-mail, clarifying the EPA's view of the issue.

In what has been a popular rallying cry among environmental groups and some Democrats, the Sierra Club urged Congress and the White House to reinstate the tax that was put into a Superfund trust fund and used to pay for cleanups at about 30 percent of the sites.

Congress let the tax expire in 1995, and has been appropriating about $1.3 billion yearly in general tax revenues to make up for it. That money goes into the trust fund, which has used up the money from the tax. The trust fund had received about $1.5 billion a year from an excise tax on the sale of petroleum and some chemical feedstocks and from a corporate environmental income tax, all of which expired.

The cleanup of the other 70 percent of the sites typically is paid for by polluters under orders from EPA to clean up messes they made. Those commitments plus the tax revenues have kept the program at about $3 billion yearly, according to EPA officials.