New laboratory test results released Friday showed that most of the tar balls that washed up on Texas shores during the past week were not from the massive Gulf of Mexico oil spill, the Coast Guard said.
Officials had initially said on Monday that the tar balls that were rolling up over the weekend on Galveston and other Texas Gulf shorelines were from the BP-operated Deepwater Horizon rig that blew up April 20, killing 11 people and causing an oil spill that has yet to be controlled. Now, the Coast Guard said only tar balls found Monday were from the rig.
The tar ball sightings in Texas, and the news that it had originated from the BP well, created a stir because it had been the only Gulf state untouched by the oil spill.
From the beginning, officials were perplexed by what they called "the weathering" of the tar balls, saying it was inconsistent with oil that had traveled 400 miles. They speculated the oil had not arrived with the currents or naturally, but may have been carried in by a vessel.
On Tuesday, National Incident Commander Thad Allen said officials were investigating five vessels that may have carried the oil to Texas.
Coast Guard spokesman Petty Officer Richard Brahm said the confusion resulted from a mistake made at a lab in Houma, La.
"It turns out that almost all the tar balls are not BP," Brahm said.
The tar balls that are from the Gulf oil spill were found Monday on McFaddin Beach, a stretch of coast east of Texas' Bolivar Peninsula.
The more accurate test results arrived Friday from a Coast Guard lab in Connecticut, Brahm said.
Texas Land Commissioner Jerry Patterson said he "wouldn't jump too strongly" on the idea that most of the tar balls are not from the Gulf oil spill.
"What we've got here is we have tar balls from the oil spill as well as some not from the oil spill," he said.
All oil has a distinct DNA of chemicals and the government has a database of the different oils in the reservoirs where drilling and production is going on. Further testing should be able to help officials figure out the origin of the tar balls in Texas, Brahm said. If a match is not made, it is likely they are the result of natural seepages from the seabed.
Patterson said reports continue to come in about tar balls and oil, including an oily substance that was found on a Galveston beach Thursday and is still being tested.
"The bottom line is, there are tar balls," Patterson said.