What would America be like without the Environmental Protection Agency? To hear liberals tell it, the nation would be plunged into a new Gilded age, in which robber barons despoil the pristine wilderness.

Corporations, after all, seek profits, and government is supposedly best-placed to hold economic actors accountable for the negative externalilties they create.

This notion has some truth to it, and it can be honestly debated. Surely, the EPA's existence has played some role in creating the modern reality in which major polluters (BP, for example) are appropriately highlighted, excoriated, and held financially responsible for their messes.

On the other hand, the agency is nowadays more often noticed for its power grabs, its persecution of small landowners, and its quixotic obsession with strangling the country's energy supply by regulating non-pollutants like carbon dioxide. There is a strong argument that this agency's role is already too great, and that its power-hungry bureaucracy outlived its usefulness several years ago.

That much is up for debate. What is not debatable that President Obama's EPA — currently in the midst of trying to expand its jurisdiction over more of the waters of the United States — has just caused the greatest water-based environmental catastrophe since the BP spill.

By releasing 3 million gallons of toxic mining sludge into the Animas River in southwest Colorado, the agency has made other recent disasters pale in comparison – including the contamination of the Elk River in West Virginia last year. This disaster threatens both nature and humanity, and on top of that it is costing many local economies millions of dollars in lost tourism and recreation.

Before EPA contractors breached a debris wall earlier this month, sending a tidal wave of acid, arsenic and lead into the Animas, the historic Gold King mine (closed since 1923) had not been polluting the immediate area. EPA got involved there after they had made it unstable by plugging a smaller leak at a different but connected mine to it. This is how they came to release decades' worth of accumulated acids and heavy metals downstream.

In the West, water is critical, and it is probably more critical in these affected areas than in most parts of the West. Drinking wells near the river and downstream in Utah, New Mexico, and Arizona are now under threat and will have to be tested frequently. The affected waters will eventually flow through Lake Powell and the Grand Canyon as well. The long-term effects remain unknown.

EPA administrator Gina McCarthy has said she takes full responsibility for the spill. If she really meant it, she would have resigned already. But people in government can afford to say such things and take them lightly, as neither she nor anyone else involved will be fired. That's how government works. We hope this issue will be raised when EPA's attempt to expand its control over navigable waters and wetlands is challenged.

The EPA did not pollute the mine in the first place — that was the job of the robber-barons from whom they supposedly protect the public. But with an EPA this incompetent, who needs robber-barons?