FAIRHOPE, Ala. — BP’s chief executive officer said Friday that the outcome of the company’s “top kill” operation should be known Sunday morning. Appearing on the CBS “Early Show,” Tony Hayward gave the effort a 60-70 percent chance of success.

Crews on the surface are pumping at high pressure a heavy fluid known as drilling mud, which is being channeled through the failed blowout preventer and into the wellhead in order to stop oil from flowing into the Gulf of Mexico. The plan was implemented Wednesday after two days of pressure testing.

The procedure has been performed with great success in the past, but had never been attempted at this depth. The Gulf bottom is nearly a mile below where the Deepwater Horizon oil platform exploded April 20.

Hayward said once the operation is complete, cement will be pumped through the piping to seal the well. Disputing reports of his company’s lack of urgency in getting the job done, Hayward said he as anxious as coastal residents and Americans in general to stop the oil before it contaminates additional coastline.

But just when it looks as though the tide might be turning in the Gulf, there comes another wrinkle. Researchers aboard the University of South Florida’s remote underwater vehicle Weatherbird II discovered Tuesday afternoon what initial tests indicate is a wide area of the water column containing elevated levels of dissolved hydrocarbons, suggesting that a portion of an undersea oil plume might have spread toward this area.

The location being examined is around 22 miles northeast of the ruptured wellhead, in an area south of Mobile Bay.

Scientists will need to conduct further tests to determine whether the suspected dissolved hydrocarbons were caused by dispersants or the emulsification of oil as it moved through the water away from the leaking well.

When dispersants are used on oil, it breaks up into droplets that hasten its breakdown in the warm waters of the Gulf.

The probable concentration of dissolved hydrocarbons was highest at 400 meters, according to USF researchers, indicating the suspected plume is at its highest concentration in the deeper waters. The discovery is significant because it could mean residue from the Deepwater Horizon is hidden in deep Gulf waters that cannot be seen with the human eye, but could eventually become a threat to marine life and habitats.

The findings of the lab tests were expected to be completed after press time on Friday.

Flow rate nailed down

U.S. Geological Survey Director Dr. Marcia McNutt revealed late this week that the National Incident Command’s Flow Rate Technical Group (FRTG) developed an independent, preliminary estimate of the amount of oil flowing from BP’s leaking oil well.

Based on three separate methodologies, the independent FRTG analysis determined that the overall best initial estimate for the lower and upper boundaries of flow rates of oil is in the range of 12,000 and 19,000 barrels per day.

Based on observations May 17, and accounting for thin oil not sensed by the AVIRIS sensor, the FRTG estimated that between 130,000 and 270,000 barrels of oil are on the surface of the Gulf of Mexico. The agency noted that a similar volume of oil has already been burned, skimmed or dispersed by responders or has evaporated naturally.

McNutt emphasized that since day one, the federal government’s deployment of resources and tactics in response to the spill have been based on a worst-case, catastrophic scenario, and have not been contained by flow rate estimates.

U.S. Coast Guard Mary Landry said that based on those estimations, the well has lost between 18.6 and 29 million gallons of oil so far.

Close to home

In Fairhope, city officials remain in close contact with Unified Command in Mobile. A meeting held Thursday with officials from the USCG, the Alabama Department of Environmental Management and BP at the Ops Center in Mobile. There, the framework for the state’s Strategic Response Plan from this point forward was revealed.

Assistant Public Works Director Ken Eslava said although this plan has not yet been formally adopted, it will likely remain generally the same, but be adjusted as the oil spill hazards change.

This incident has been assigned a color level “Trigger Guide,” according to Eslava, similar to the color levels used by ADEM for ozone levels and Homeland Security for levels of national alert.

The base, or green level, means there are no confirmed tar balls, and remote sensing indicates no oil or sheen within 50 miles of the coast. Guarded (blue) indicates confirmed tar balls on the beach and remote sensing of oil or sheen within 30 miles, or less than five days away. Yellow (elevated) means there are streamers of oil or a sheen observed within three miles of state waters. Red (on shore) is posted, of course, when oil has reached shore.

Eslava said we are currently at the guarded alert — the blue level of trigger status.

The Pier Street Operations Center is still active, he said, with maintenance activities being prepared and executed. He noted state and federal booming strategies along the Eastern Shore have been completed, and Baldwin County, as well as its municipalities, are executing contingency plans and monitoring the path of sheen movement.

Some assets have been shifted to Louisiana, where the need is immediate. But Unified Command in Mobile stressed Thursday that as the situation changes, resources will be reallocated.

Daphne Emergency Management Coordinator Chip Martin said Friday his team continues to monitor developments and met Friday to draft a proposal to the City Council on what additional equipment should be purchased to deal with the oil cleanup.

Meanwhile in Spanish Fort, officials have reported no new activity related to the oil spill.

Fisheries, and a look ahead

There has been a change in Gulf Coast fisheries. NOAA on Friday announced an expansion of the closure of federal waters to commercial and recreational fishing (see press release on www.baldwincountynow.com for details). The closed waters represent about 25 percent of Gulf waters normally open to harvest.

The agency’s 72-hour oil forecast issued Thursday night shifted in the Zone of Uncertainty much closer toward the mouth of Mobile Bay. That could mean that Dauphin Island and part of the Fort Morgan peninsula will be inside the zone when the trajectory map is updated on Sunday. Tar balls are typically found inside that zone.

Officials caution that tar balls should not be handled. Residents and visitors who spot tar balls should call (866) 448-5816. Central Command will send out a SCAT team to remove them and send them to the appropriate lab for testing.

Staff writers Simon Duffy and Kelli M. Dugan contributed to this report.