More than a year after a pipeline cracked open and spilled an estimated 210,000 gallons of heavy crude oil into a Mayflower neighborhood, Exxon Mobil is preparing for other phases of cleanup and restoration, now focused in a cove of Lake Conway.
The oil giant's task has shifted from the Northwoods subdivision -- where the pipeline ruptured between two houses March 29, 2013 -- to the cove, separated from the main portion of the popular fishing lake by Arkansas 89. Authorities have said oil reached the cove but not the main portion of the lake.
Work ahead includes sheen remediation and wetlands restoration. But Exxon Mobil hasn't yet submitted the restoration plan.
"Exxon will restore the habitat," said Katherine Benenati, a spokesman for the Arkansas Department of Environmental Quality, also called ADEQ. "Exxon is in the process of writing that plan" to meet requirements of the U.S. Army Corps of Engineers.
After removing and replacing oil-contaminated dirt, grass and plants in the subdivision, the company moved its attention to the cove and drainage ditches that lead to it.
Now, after months of sheen monitoring, Exxon Mobil has proposed a "mitigation action plan" to get rid of oil sheens "to the extent technologically feasible."
The state's environmental agency must approve the mitigation plan submitted May 19, which is divided into four parts and totals hundreds of pages.
That plan "is currently under review by several agencies," Benenati said last week. "This is the proposed plan which would cover all remediation warranted.
"We are targeting completing our review [in] the next several weeks," she added.
The mitigation plan calls for a contractor to begin work on sheen correction this summer or fall. Months of labor would follow.
"We will continue to work with the ADEQ throughout implementation and any subsequent monitoring period," Exxon Mobil spokesman Aaron Stryk said in an email Friday.
The mitigation plan would include excavation and off-site disposal of about 480 cubic yards of sheen-bearing sediment in the cove's inlet channel. Exxon Mobil also has proposed installation of a reactive cap over about 4.5 acres of sediment where sheens have been spotted in the cove's open water area.
Further, organoclay would be placed at targeted locations in up to 2 acres of the cove's heavily vegetated area. Organoclay, which comes from a clay mineral, can remove oil from water. Getting this clay in those areas will be "a challenge," so some sheens may remain after the first application, the report says.
"After approximately 3 months (and after the leaves fall from the vegetation), an additional application of [organoclay] may be conducted in targeted locations," the report adds. "The extent of the mitigation area within the Heavily Vegetated Area and the approach for this area were selected with a goal of preserving the habitat and ecological function of this buffer area."
The company could take additional action in this area if warranted, the report says.
Other measures proposed include monitoring of naturally occurring ways to reduce contamination, rather than more active human intervention, at inaccessible locations within the heavily vegetated area. These areas, the report says, "were left in place during the emergency response due to the habitat value and light degree of oiling."
Since the Good Friday 2013 spill, Exxon Mobil has demolished three houses that had oil beneath their foundations and bought about two dozen more homes from residents who did not want to move back into the subdivision.
The 648-mile, northernmost section of the Pegasus pipeline, which was built in 1947-48 and which runs from Patoka, Ill., to Corsicana, Texas, remains idle.
More than two months after Exxon Mobil submitted a remedial work plan for that portion of the line, the proposal is still under review by the federal Pipeline and Hazardous Materials Safety Administration, also called PHMSA.
Central Arkansas Water spokesman John Tynan said Friday that he understood Exxon Mobil was "in negotiations with PHMSA about what the approved work plan will look like."
Central Arkansas Water oversees Lake Maumelle, which provides drinking water to about 400,000 residents, and has had discussions with Exxon Mobil about the pipeline, which runs through part of the lake's watershed.
In September, Central Arkansas Water notified Exxon Mobil and the safety administration that the utility would sue them unless the agency worked diligently to address what the utility said were several federal safety violations.
The notification letter said the utility would file "a citizens suit" seeking to prevent Exxon Mobil from operating the pipeline until it corrected any violations within the watershed. The utility said it also would ask that the pipeline be relocated outside the watershed.
Asked Friday about the possibility of such a lawsuit after so much time, Tynan said, "We haven't withdrawn the notice of intent that we sent. At this point, we have all our options on the table."
In November, the safety administration notified Exxon Mobil of nine "probable" violations of safety regulations and proposed fines totaling more than $2.6 million as a result of the Mayflower accident. Exxon Mobil has challenged those allegations, the proposed fines and a proposed compliance order.
The safety administration is scheduled to hold a hearing on the issues Wednesday in Houston. The hearing will not be open to the public.
A section on 06/09/2014