A decade after BP failed a series of oil spill cleanup drills off Alaska's northern coast, uncertainty -- heightened by BP's disaster in the Gulf of Mexico -- remains about whether industry is prepared for an arctic oil spill.

In 2000, state environmental regulators found BP had problems responding to a mock oil spill at its Northstar field, a manmade island six miles northwest of Prudhoe Bay in the Beaufort Sea. It was the last time the state required BP or any other company to test at similar scale its employees and equipment in a mock, open-water oil spill on the North Slope, home to the nation's largest oil fields.

Ten years later, regulators say BP and other companies are as prepared as the law requires.

"No matter where -- onshore or offshore -- there is never zero risk," said Betty Schorr, an industry preparedness program manager for the Alaska Department of Environmental Conservation, which helped oversee the Northstar drills in 2000. "So we always have to be vigilant and keep a healthy oversight of industry."

Whether the guidelines for oversight are stringent enough is another matter.

Just as industry's response capabilities are tested periodically, state laws and requirements for industry practices are also under a microscope -- scrutiny that was set in motion by then-Gov. Sarah Palin three years ago. Palin called for a review of oversight on the North Slope in the wake of BP's 2006 oil spills at Prudhoe Bay, the result of corroded pipelines.

The review is analyzing potential gaps in state and federal oversight and the risks of industry's activities and infrastructure. Final reports are scheduled to be completed this summer at around the same time BP and Royal Dutch Shell plan to drill for offshore oil and gas in the Arctic. DEC is specifically looking at how to reduce the number and severity of spills on the North Slope, but the inquiry does not review whether laws should be tightened.

Alaska has long faced criticism over its conflicted relationship with the oil industry. On the one hand, oil funds more than 85 percent of the state's general budget. It spawned the program that pays residents an annual dividend. And it is one of the state's leading employers. But oil has also sparked safety and environmental problems over the years, from the North Slope oil fields to the trans-Alaska pipeline to the Valdez tanker port.

After the Exxon spill in 1989, oversight was greatly increased and numerous changes were made in how oil is shipped through Prince Williams Sound. Still in the past decade, watchdogs have questioned whether the state is up to the task of regulating aging oil fields operated by BP and other companies on the North Slope, along with proposed offshore oil exploration along the coast.

Icy waters

BP is the same company that operated the Deepwater Horizon rig in the Gulf of Mexico that exploded April 20, killed 11 workers, and now is causing thousands of barrels of crude to wash up on the Louisiana coast. The accident and BP's response to the Gulf spill are now being questioned as President Barack Obama calls a temporary halt to new offshore oil drilling.

For Alaskans, the Gulf oil disaster resonates on several levels. The scenes bring back memories of the Exxon Valdez spill. BP -- which operates Prudhoe Bay, the nation's largest oil field -- has had problems in Alaska over the past decade that have resulted in fines and federal probation, including the largest spill ever on the North Slope in 2006.

The Gulf spill, too, raises questions about whether oil companies -- and regulators -- are up to responding to spills along the Arctic coast or farther out in the Chukchi and Beaufort seas.