About 5,000 barrels of oil spilled from a 22-foot rupture on the Pegasus oil pipeline in Mayflower, Ark., in late March.
Arkansas Attorney General Dustin McDaniel said he was concerned about complaints from residents who reported nausea and other health issues.
"Mayflower residents are rightly concerned about the effects of this oil spill on their property and their well-being," he said in a statement.
The Arkansas Department of Health said there was some risk to people's health in one of the 14 homes tested near the spill. Indoor air quality didn't indicate risks in the others sampled.
Exxon Mobil Pipeline Co. said it would buy outright or otherwise offer compensation for homes affected by the spill. McDaniel said the details of the offer were overly complex, however.
Exxon said the cause of the incident is under investigation. The damaged section of the pipeline was removed and replaced.