State agency approves Exxon Mobil’s report

Company has 60 days to submit plan

Arkansas’ environmental agency has approved Exxon Mobil’s latest report assessing the extent and severity of oil contamination that remains in drainage ditches and a Lake Conway cove, almost one year after the company’s Pegasus pipeline ruptured in a Mayflower neighborhood.

In a letter dated Wednesday and released Thursday, the Arkansas Department of Environmental Quality notified Exxon Mobil Pipeline Co. of its decision. The letter came after months of communication between the agency and the company on how best to move forward with lingering oil contamination.

Tammie Hynum, chief of the department’s Hazardous Waste Division, told Exxon Mobil that it has 60 days to submit a “Mitigation Action Plan.” That plan and a related study are subject to the department’s approval.

Exxon Mobil has recommended that it reduce oil sheening in the cove by excavating up to 1 foot of affected soil and sediment from a channel of water leading into the cove and by capping sheens in the open-water area with a mixture of sand and an absorbent clay. The channel where excavation would take place runs between Interstate 40 and the cove’s open-water area.

The roughly 850-mile-long pipeline, which runs from Illinois to the Gulf Coast of Texas, cracked open in the Northwoods subdivision last March 29 and spilled an estimated 210,000 gallons of heavy crude oil into the area. The pipeline has been shut down since shortly after the accident.

Authorities have said there is no evidence that oil reached the main portion of the popular fishing lake.

In her letter to Exxon Mobil, Hynum wrote that the company “is responsible for obtaining all state, local, and federal permits necessary to conduct activities in relation to the remediation, as well as complying with all applicable laws and regulations.”

Earlier this month, Exxon Mobil said that while it still planned water cleanup, it didn’t need to do anything more to clean up the soil and sediment in the ditches or cove.

“There are no unacceptable ecological risks in the drainage ways, Dawson Cove, and Lake Conway,” the report added. “Therefore, no action is necessary to mitigate [oil] constituent levels in the soil and sediment in the drainage ways, Dawson Cove, or Lake Conway.”

The Arkansas Game and Fish Commission had said previously that the oil giant’s statements “regarding the presence or absence of adverse effects or risk to ecological receptorsare worded in too definitive a manner.”

Ecological receptors refer to nonhuman, living organisms that environmental contamination can harm. Such receptors include plants and bloodworms.

Hynum’s letter also instructed Exxon Mobil to inspect the cove for sheens weekly and after every quarter-inch rainfall, to sample surface water in the cove and the main portion of the lake weekly for polycyclic aromatic hydrocarbons, and to replace absorbent booms at least every three months and more often if needed until the corrective action begins.

Polycyclic aromatic hydrocarbons are “a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. There are more than 100 different PAHs,” according to the federal Agency for Toxic Substances and Disease Registry’s website.

The federal agency says these hydrocarbons “generally occur as complex mixtures … as part of combustion products such as soot,” for example. They also can be found in substances including coal, coal tar pitch and asphalt used in road construction, it adds.

Exxon Mobil has asked the federal Pipeline and Hazardous Materials Safety Administration to approve a restart plan for a 211-mile Texas section of the pipeline. That request remained pending as of Thursday.

Northwest Arkansas, Pages 9 on 03/21/2014

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