Dr. Bill Mason with the Arkansas Department of Health speaks Thursday at a news conference updating the cleanup of oil in Mayflower. ( Gavin Lesnick

MAYFLOWER — Nearly three weeks after an Exxon Mobil pipeline ruptured in a Mayflower neighborhood, no residents have returned to the 22 homes evacuated in the immediate area, officials said Thursday.

County, state and federal cleanup coordinators along with a representative from the oil company spoke Thursday at a news conference at Mayflower's City Hall, where they said cleanup is progressing well but evacuees still aren't back in the Northwoods subdivision.

Bill Rhotenberry, federal on-scene coordinator with the U.S. Environmental Protection Agency, said air monitoring has continued to show the neighborhood is safe for reentry both outside and in some of the residences where testing has been conducted. But, he said, no residents have returned and it could be a "significant amount of time" before anyone does go back.

Exxon earlier this week unveiled a compensation package for the subdivision residents that included a plan for the company to buy homes for families that wanted to leave, covering closing and cleaning costs.

Karen Tyrone, a vice president with Exxon Mobil Pipeline Co., said negotiations are ongoing and she couldn't divulge whether anyone had agreed to sell their homes, calling the process "private conversations." She said the company would be speaking with others outside the subdivision who were also affected by the spill, though she didn't offer specifics on what kind of compensation they could expect.

"We recognize others in the community have been impacted," she said. "We certainly intend to address the concerns of those who have been impacted by this event."

A 52-foot-long segment of pipeline where the rupture occurred was removed and sent for independent testing Monday. Tyrone said Thursday that it was too early to have any information back from that process or to know when it might reveal what caused the rupture.

"I don't have a firm timeline," she said. "But I can tell you it does take time."

Cleanup in the roughly mile-long stretch from the subdivision to the marsh was progressing, Faulkner County Judge Allen Dodson said. He said the cleanup team is about ready to sign off on the drainage area on Main Street near the subdivision, signifying the free oil has been collected, and a restoration and remediation phase can begin there.

Dodson said extra pumping devices were taken into the marsh area, known as the cove, so officials can maintain water level there even as storms move in Thursday.

Ryan Benefield, deputy director of the Arkansas Department of Environmental Quality, said water samples have showed no chemicals of concern in the main body of Lake Conway or in the cove nearest Arkansas 89. Samples from deeper in the cove are still pending.

"Currently, we believe oil still has not reached the main body of Lake Conway and it's pretty much contained in the marsh area right there before it reaches the open water of the cove," he said. "And we're continuing to monitor that and sample the cove to confirm that."

Dodson said crews would be in the cove "a matter of weeks longer."

The pipeline burst Marcy 29, spilling an estimate 210,000 gallons of oil through the neighborhood and into a drainage system that ran east under Interstate 40 toward and into the cove.