The oil spill shut the shipping channel that runs between the Gulf of Mexico and Lake Charles, where refiners with a combined capacity of more than 700,000 barrels per day, were forced to cut production.

The freeze on shipping vessel traffic also triggered higher oil prices and prompted some refiners to loan crude from the US strategic stockpiles.

"A referral to the enforcement division has been made, and pending action is forthcoming," Eakin said.

The referral will address three to four compliance issues, and the DEQ was currently working on the natural resources damage assessment, Eakin said.

A spokesman for Citgo, a unit of Venezuela's state-owned oil company PDVSA, was unavailable for comment on Monday.

An estimated 47,000 barrels of oil and water spilled on June 21 after torrential rains overflowed a waste-oil-and water tank at a Citgo terminal.

Eakin also said Citgo could face fines of up to US$32,500 a day for notification issues.

This fine will address the time lapse between the oil spill and the notification.

"All compliance concerns and the environment damage assessment will be compiled into one action later this year," Eakin said.