American Scene

ALASKA

BP says ice plugs caused rupture

ANCHORAGE — Oil company BP PLC says ice plugs in a pipeline caused a rupture that spilled 46,000 gallons of crude and water in an oil field on Alaska’s North Slope.

BP spokesman Steve Rinehart says the plugs caused pressure to build up in the line on Nov. 29 and then split it. Oil and water sprayed out of a 2-foot lengthwise crack along the bottom of the pipe.

He says the pipeline had been taken out of service several weeks ago because of restricted flow, so it’s not affecting production at Prudhoe Bay.

Mr. Rinehart says ice plugs occasionally form in pipelines and end up causing a rupture.

He says BP is considering several ways of dealing with the plugs, including applying heat or introducing de-icer and warm crude.

CALIFORNIA

City Council delays marijuana vote

LOS ANGELES — The Los Angeles City Council delayed a vote Wednesday on a medical marijuana ordinance that could close hundreds of pot dispensaries across the city.

The council asked planning officials to return next week with zoning maps that show how many pot dispensaries could close if the city bans the shops within 500 feet of homes, schools and public gathering sites.

The council is wrestling with setting that distance at 500 feet or 1,000 feet. Some members feel a 1,000-foot limit would banish pot clinics to industrial areas.

Council members indicated a vote could come in January on the law providing guidelines for pot dispensaries in the nation’s second-largest city.

The city has fumbled previous attempts to adopt a pot law in the past two years.

“Let’s just make a real informed decision,” Councilman Ed Reyes said.

City officials estimate as many as 1,000 dispensaries operate in Los Angeles. Only four were open in 2005, when city officials first began discussing a local medical marijuana law.

Among the proposed provisions is capping the number of dispensaries at 70 — a move that would shutter many shops that don’t comply with the new law.

NEW YORK

Concrete-testing trial set to start

NEW YORK — A major New York concrete-testing firm is going on trial on criminal charges. It’s accused of faking results for projects including ground zero’s signature tower and the new Yankee Stadium.

Opening arguments are scheduled Wednesday in the racketeering case against Testwell Laboratories Inc. and four executives.

Prosecutors say Testwell doctored — and sometimes simply made up — concrete and steel test results for more than 100 projects. The defendants say the disputed results reflect mistakes, minor adjustments or common industry practices.

More than a dozen projects have been retested and declared safe, including the stadium and ground zero’s Freedom Tower. Authorities are awaiting results for dozens more.

The trial is expected to take months.

OREGON

Experiment to test value of killing owls

GRANTS PASS — Federal biologists are designing an experiment to determine whether killing the aggressive barred owl that has invaded old-growth forests of the Northwest would help the survival of the spotted owl, which is protected.

The U.S. Fish and Wildlife Service announced Wednesday that it is doing an environmental analysis laying out the rules for the experiment.

The spotted owl went from a seldom-seen denizen of old-growth forests to the cover of Time magazine in the 1990s as environmentalists forced the federal government to cut back logging on Northwest national forests in order to protect its habitat.

Despite the logging cutbacks, spotted owls continue to decline, most steeply where there are high populations of more aggressive barred owls that are native to eastern North America.

TEXAS

Tank explosion at plant injures 2

PASADENA — An explosion at a chemical plant in the Houston area Wednesday shook nearby homes, generated black smoke seen for miles and injured two workers.

A tank at the American Acryl plant in the Houston suburb of Pasadena exploded just before 9 a.m., Seabrook police Lt. Sean Wright said. The plant is near Seabrook.

TV coverage showed holes in a tank at an industrial complex. Debris could be seen near mangled, blackened equipment.

Officials in Pasadena and Seabrook ordered residents to remain indoors after the explosion because the tank contained toluene, a toxic petroleum byproduct used in paint and gasoline, said Rosie Torres, a spokeswoman for the Harris County Office of Homeland Security and Emergency Management. That order was lifted late Wednesday morning.

Roads around the plant were closed but reopened late in the morning after a fire started by the explosion was brought under control, Ms. Torres said.

Two workers hurt in the blast were taken to an area hospital as a precaution for inhalation injuries, said Kelli Gregory, a spokeswoman for American Acryl. They were treated and released, she said.

The cause of the explosion is still being investigated, Miss Gregory said.

• From wire dispatches and staff reports