Can we go home now?

Have we done enough damage?

An environmental disaster is brewing in the heartland of Iraq's northern Sunni-led insurgency, where Iraqi officials say that in a desperate move to dispose of millions of barrels of an oil refinery byproduct called "black oil," the government pumped it into open mountain valleys and leaky reservoirs next to the Tigris River and set it on fire.

The resulting huge black bogs are threatening the river and the precious groundwater in the region, which is dotted with villages and crisscrossed by itinerant sheep herders, but also contains Iraq's great northern refinery complex at Baiji.

And why is this "black oil" there? Freedom. Or the spread of democracy. Or because Saddam Hussein had WMD. Or the GWOT. Or....

As much as 40 percent of the petroleum processed at Iraq's damaged and outdated refineries pours forth as black oil, the heavy, viscous substance that used to be extensively exported to more efficient foreign operations for further refining. But the insurgency has stalled government-controlled exports by taking control of roadways and repeatedly hitting pipelines in the area, Iraqi and American officials have said.

So the backed-up black oil — known to the rest of the world as the lower grades of fuel oil — was sent along a short pipeline from Baiji and dumped in a mountainous area called Makhul.

A series of complaints handed up the Iraqi government chain were conveyed to oil industry officials, and as of last weekend the fires had at least temporarily stopped, but black oil was still being poured into the open valleys, according to Mr. Younis, who works in the province's Department of Environment and Health Safety.

And now, it's Hobson's Choice:

A United States official in Baghdad, speaking anonymously according to official procedure, said earlier this month that Baiji was still turning out about 90,000 barrels a day of refined products, which would yield about 36,000 barrels a day of black oil.

Iraq's refineries will grind to a halt if the black oil does not go somewhere. "Unless we find a way of dealing with the fuel oil, our factories will not work," said Shamkhi H. Faraj, director of economics and marketing at the Iraqi Oil Ministry.

Mussab H. al-Dujayli, a technical expert at the State Oil Marketing Organization, said the large-scale dumping defied sound engineering practice. "The consequences of it are dreadful," he said. "God forbid."