You've heard of the “Superfund” environmental cleanup law. It's called the Comprehensive Environmental Response, Compensation and Liability Act, or CERCLA, and it allows the EPA to designate locations as hazardous waste sites that are uncontrolled or abandoned, set up plans to clean them up, and seek out the responsible parties for help with the cleanup.

What if the EPA's plan for a CERCLA site isn't going to get the job done? Nearby landowners and future buyers of the site may want it cleaned up to a higher standard than the EPA requires. In such a case, would these third parties have the right to demand a cleaner cleanup under state law?

That's the question before the Montana Supreme Court right now, after oral arguments earlier this month. The case involves a site near Anaconda in western Montana and the nearby communities of Crackerville and Opportunity. The Atlantic Richfield Company had operated a smelter for nearby copper mines on the parcel, pumping out fumes containing arsenic and lead which settled into the land and water before the smelter closed in 1980.

The EPA approved a cleanup plan in 1988. It required Atlantic Richfield to replace up to two feet of dirt wherever the concentration of arsenic within 125 feet of any home in Opportunity or Crackerville exceeded 250 parts per million.

Yet according to the landowners, the cleanup requirement is far too generous to Atlantic Richfield. In most other cleanup operations, the EPA has required arsenic to be reduced to levels between 25 to 40 ppm. Tests on their properties found that in most, the soil concentration level is at least 110 ppm — although some are as high as 1,000 ppm.

The U.S. Department of Health and Human Services says ingesting inorganic arsenic such as that found in Crackerville and Opportunity can cause cancer of the skin, liver or bladder. Breathing it increases the risk of lung cancer. It's not clear what level causes the increased risk, but the landowners sued in 2008 to get the land cleaned up so that arsenic levels never exceed 15 ppm.

They assert that the Montana Constitution guarantees the right to a “clean and healthy environment” for residents. In the past, the high court has allowed property owners to seek damages when a cleanup exceeded regulatory standards.

Is there a conflict between CERCLA and Montana law?

When state and federal laws conflict, federal law prevails, except in highly unusual circumstances. If the justices find that there is indeed a conflict, the Montana landowners will lose.

It's not clear that there is, though, although the laws do overlap. Atlantic Richfield and the EPA argued that only EPA experts are capable of establishing appropriate cleanup standards, and that 250 ppm was sufficient.

If landowners are unsatisfied with an EPA plan, they argued, they can challenge it during the development or comment period. The EPA's attorney pointed out that CERCLA completely prohibits challenges to cleanup plans in federal court after they have been finalized.

Justice James Shea chided the attorney for assuming, without statutory support, that state court challenges would also be prohibited.”CERCLA sets the floor for environmental cleanup, not the ceiling,” argued the landowners' attorney. “CERCLA was designed to act in conjunction with state law requirements.”

Moreover, the reason federal challenges are prohibited once a cleanup plan is finalized, he contends, is that congress wanted to prevent polluters from suing to lower the EPA's standards — not to keep pollution victims from suing for a more thorough cleanup. And, in fact, several Montana cases have pointed this out.

What would a ruling for the landowners mean?

If the Opportunity and Crackerville landowners win, damages paid by Atlantic Richfield would go into a trust to pay for the cleanup. Each landowner would have to petition for the funds in court. However, Atlantic Richfield says that could mean multiple, possibly conflicting plans would have to be reviewed and renegotiated.

“Even the state couldn't do what the plaintiffs are trying to do,” said their attorney. “If the remedy needs to be modified to be more protective, the EPA can do that.”