DESPITE OUR dependence on the petroleum products that created and continue to fuel our culture, most Americans have never seen a sample of real crude oil, the gooey fluid that's pumped out of the ground and shipped to refineries for distillation into gasoline, diesel, and other hydrocarbon products.

But if you've walked on nearly any beach, you've probably stepped in crude oil in the form of the annoying tar balls that collect on the bottoms of your feet and stain your beach blanket. Tar balls are sticky globules of crude that's been partially distilled by nature; the lighter components have evaporated, and the residue conglomerates into gummy blobs of petroleum that range in size from peas to plates and larger.

A beach littered with tar is an apt symbol of the pollution that's associated with our industrial life. But a significant proportion of the tar balls on American beaches results from naturally occurring seepage from undersea oil reservoirs. Because the seepage occurs under water, estimates of its impact on the environment are imprecise and vary widely, but it could amount to as much as half of all the crude oil that's discharged into the environment.

The other half is "anthropogenic," that is, man-made, and significant discharges occur at every level of production. The fact is, oil is a dirty business. The classic image is James Dean in the movie "Giant," drenched black in greasy crude when his fortune finally blew in. Modern petroleum technology has generally made black-gold gushers a thing of the past, but even under the best conditions tapping into reservoirs of oil under high pressure often results in a certain amount of leakage.

As crude moves from the oil field to the refinery, major events like the grounding of the Exxon Valdez, which discharged 11 million gallons of oil into Alaska's Prince William Sound in 1989, draw considerable attention. But in the course of ordinary transport, through pipelines and pumping stations, additional spillage is inevitable.

More petroleum residue escapes at the refineries. And at the point of use? Well, multiply those few sprinkles of oil beneath the crankcase out in your driveway by about 700 million.

Our leaky petroleum infrastructure came to mind when I read a recent Associated Press account of the damage caused by Hurricane Ike when it swept through the Gulf of Mexico in September.

Even though Ike was a modest storm, 52 offshore oil platforms were destroyed and 32 more were severely damaged. In all, half a million gallons of crude spilled into the Gulf and the bays and bayous of Texas and Louisiana. In some areas an oily sheen still coats the water.

How long does crude oil persist in the environment? The shores of Prince William Sound are still littered with tar balls 20 years after the Exxon Valdez ran aground. But in 1995, the New York Times reported that a group of scientists from the U.S. Geological Survey were surprised to discover that up to two-thirds of the tar balls originated, not from the Exxon spill six years earlier, but from oil imported to Alaska from California in the mid-'60s.

In other words, most of the tar balls polluting the shores of Prince William Sound in 1995 had been around for as long as 30 years.

The energy battle cry of the McCain/Palin ticket is "Drill, Baby, Drill," and Sen. Barack Obama seems to accept more drilling, as well. But for a strategy that can't possibly provide a long-term energy solution, America's ultimate Dirty Job comes, inevitably, with an unpredictable and long-lasting environmental cost.

John M. Crisp (jcrisp@delmar.edu) teaches in the English Department at Del Mar College in Corpus Christi, Texas.

Originally published by John M. Crisp, Syndicated columnist.

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