ROSELAND (La. Illuminator) — Federal law enforcement agents served a search warrant at the Smitty’s Supply plant in November, records show, signaling a rare criminal investigation could be underway into last year’s fire and oil spill disaster at a Tangipahoa Parish petroleum products supply plant.

The U.S. Environmental Protection Agency, which appears to be leading the inquiry through its Criminal Investigation Division, has so far said little about the search at Smitty’s Supply Inc. in Roseland and initially refused to confirm or deny it took place. Some details were revealed in EPA progress reports the agency’s emergency response team used to document daily actions that took place at the disaster site in Roseland.

“The CID, with support of the FBI and Louisiana State Police, executed a search warrant for the site,” a progress report entry for Nov. 18 noted.

It’s unclear what federal agents were targeting in their search. Neither Smitty’s Supply nor the public relations firm it hired to handle communications responded to a request for comment.

Some recovery operations at the facility to identify hazardous chemicals and products were paused while agents conducted the search, the report stated. The search continued through the next day with an entry for Nov. 19 noting operations to segregate products behind two warehouses “were still paused today during CID activities.”

After two days of searching, law enforcement agents left the site, allowing the EPA’s response team to continue oversight of the cleanup. On Nov. 20, Smitty’s Supply and its contractors were allowed to resume the work they were doing behind the two warehouses, a report entry stated.

The Environmental Protection Agency filed its progress reports, which are public records, with the Louisiana Department of Environmental Quality. The Illuminator obtained them from the department’s public database during an ongoing review of the Smitty’s Supply file, which includes thousands of records.

Spokeswoman Meagan Molter said the state Department of Environmental Quality is not involved in the investigation and directed questions to the EPA.

EPA spokeswoman Jennah Durant refused to comment on whether a search warrant was executed. The agency refused the Illuminator’s public records request but acknowledged the existence of the warrant in a denial letter from its Office of Criminal Enforcement, Forensics and Training.

“There is an ongoing regulatory investigation, and the records responsive to your request have been compiled for law enforcement purposes,” the letter stated, citing a Freedom of Information Act exemption that applies strictly to law enforcement records that, if disclosed, could interfere with enforcement proceedings.

Environmental laws are generally enforced through civil actions such as lawsuits or administrative fines. The infractions can lead to criminal investigations, but they are exceptionally rare, said Victor Flatt, a professor and associate director of the Burke Center for Environmental Law at Case Western University in Cleveland.

“Criminal charges are much less common — much, much, much less common — than civil,” Flatt said. “For whatever reason, there’s a possibility there were criminal acts here, and that’s what they’re investigating.”

Environmental criminal cases often arise from either an intentionally bad act or gross negligence on the part of the defendant, such as cutting corners or violating regulations in order to save money and increase profits, Flatt said. Other common elements of environmental criminal cases include the concealing of violations or falsification of records, according to the U.S. Department of Justice.

Several environmental statutes allow for criminal prosecution, including the Clean Water Act, Toxic Substances Control Act, Resource Conservation and Recovery Act, Clean Air Act and the Comprehensive Environmental Response, Compensation and Liability Act.

Defendants can include company employees, executives and even the corporations as individual entities.

“You generally only see criminal charges in the really big cases,” Flatt said.

One of the most notable cases was the 2010 Deepwater Horizon offshore rig explosion, which resulted in the largest oil spill in history. BP, the primary operator of the rig that exploded off the Louisiana coast, pleaded guilty to 14 felony charges, including 11 counts of manslaughter, obstruction of Congress and violations of the Clean Water Act and Migratory Bird Treaty Act. The company was ordered to pay $4 billion in criminal fines and placed on probation for five years, which involved enhanced monitoring and a slate of improvements to eliminate the risk of a similar disaster.

Transocean Deepwater Inc., which owned the Deepwater Horizon rig and leased it to BP, pleaded guilty to Clean Water Act crimes. The company was ordered to pay $400 million in fines and also placed on five years probation.

Several BP executives and employees were indicted on related federal charges, but the most serious charges against them were eventually dropped.

The government can be reluctant to prosecute environmental crimes because the burden of proof is much higher than it is for civil offenses, Flatt said. Also, corporations tend to have considerable resources to mount strong defenses, according to a Department of Justice webpage explaining the work of its Environmental Crimes Section.

“Because these cases routinely involve medium to large corporations, sophisticated white collar crime defense counsel are our usual adversaries, which means that our cases must be airtight,” the page states.

The EPA and the Louisiana Department of Environmental Quality are jointly pursuing a civil case against Smitty’s Supply, alleging a long list of violations of the federal Clean Water Act and other federal and state environmental laws for incidents going back nearly five years. The agencies filed their lawsuit Nov. 5 in the federal court for the Eastern District of Louisiana.

It’s possible for the EPA to use a search warrant in connection to a civil case if, for instance, a defendant was preventing access to evidence or a site location. However, Flatt said the search seems more likely to be part of a criminal investigation.

Smitty’s Supply bottled and manufactured a variety of oils, fluids and other chemicals for distribution to automotive and industrial retailers. Its facility was almost completely destroyed in the Aug. 22 disaster. Storage tanks and drums holding millions of gallons of hazardous substances caught fire, with some exploding.

Motor oils comprised most of the plant’s inventory, though the government’s lawsuit also noted the presence of other chemicals such as a concentrated form of hydrogen peroxide, which can be highly volatile under certain conditions.

The fire took two weeks to fully extinguish while oil and chemicals stored at the plant spilled onto both private and public lands and waterways, reaching as far as 47 miles downstream on the Tangipahoa River, according to the EPA. The agency estimates cleanup crews recovered oily waste and petroleum-based materials totaling 11 million gallons, which matches the facility’s storage capacity.

State and federal officials have been unable to determine what started the fire but have discovered numerous violations of laws and environmental regulations they allege could have prevented the disaster or lessened its impact.

If the EPA concludes its investigation and decides to file criminal charges, the case would then be turned over to the U.S. Department of Justice for prosecution, Flatt said. Those proceedings would be separate from the civil case proceedings.