As many as two dozen FBI agents descended on the offices of Diamond Environmental Services in San Marcos and San Diego early Wednesday morning, apparently searching for proof that the company skirted clean-air rules.

The early morning raids came just seven days after owner Arie Eric De John was sentenced to five months in federal prison for illegally dumping waste from the company’s portable toilets into city sewer systems across southern California.

De Jong, who must report to federal prison on or before July 6, could not be reached for comment. Knut Johnson, De Jong’s criminal defense attorney, said the FBI was executing a search warrant issued in an unrelated air-pollution investigation.

“In this case, they’re just starting an investigation,” Johnson said. “We don’t know what all the facts are but I do believe within the last few weeks (Diamond) had their trucks inspected by an independent inspector and I think they are all in compliance.”


Chief Operating Officer Warren Van Dam, who pleaded guilty and received five years probation in the earlier federal case, declined to discuss the FBI when reached by telephone.

“I have no comment,” he said before ending the call.

According to witnesses, FBI agents turned up at the East Mission Avenue headquarters of Diamond Environmental Services as early as 6:30 a.m. and began their search. Officers from the California Highway Patrol contributed to the effort.

They carted off boxes of paperwork, computers and other electronic goods. They also interviewed employees, especially truck drivers, about company practices that may violate U.S. Environmental Protection Agency standards.


“They interviewed all of the drivers, then they sent us home,” said one employee, who did not want to be named due to fear he might lose his job.

The employee said investigators were especially interested in whether trucks had been mechanically altered. “They said they were working with the EPA,” the employee said. “They asked me what it was like working for them, if I had seen anything and what I knew about the DPFs.”

DPFs, or diesel particulate filters, are devices that are designed to remove soot from the exhaust gases emitted from diesel engines. Under state and federal clean-air rules, trucks are supposed to be equipped with the devices to reduce air pollution.

FBI spokeswoman Davene Butler said she could not provide much detail on the activity, though she did say in an email that more than one site was involved.


“We can only confirm court authorized law enforcement activity took place at the Diamond Environmental facilities in San Marcos and San Diego facilities this morning,” she wrote in a statement.

The FBI raids came just seven days after De Jong and Van Dam faced criminal sentencing in U.S. District Court on an unrelated case that accused them of illegally dumping portable-toilet waste into municipal sewer systems across southern California.

According to federal prosecutors overseeing the recent criminal case, De Jong and Van Dam conspired to avoid discharge permit fees and save travel time to and from plants that treat the waste by pumping the sludge into city sewer systems illegally.

The scheme went on for at least four years, and saved the company at least $2 million, prosecutors and court documents said.


Both De Jong and Van Dam pleaded guilty last year. A third executive was convicted of perjury for lying to a grand jury about the company disposal practices. The company agreed to pay $6 million or more in fines, restitution and illegal profits.

In addition to the prison and probation terms, the company and its senior executives agreed to pay millions of dollars in fines, restitution and forfeited profits.

Johnson said his clients works hard to meet all environmental regulations.

“They are extremely concerned about the environment,” the criminal defense attorney said of his clients. “Diamond Environmental Services does a fantastic job in a very dirty business in keeping the environment clean.”


It is not clear how the new criminal investigation might affect the sentences handed down last week. One condition of the probation sentences received by De Jong and Van Dam was for the defendants to obey all laws.


Watchdog Videos On Now Sexual misconduct accusers worry deputy is being protected 6:16 On Now City funded $2-million waterfront bathroom 1:26 On Now Public water district charges customer for legal work, response to records request On Now Video: Tiny homes won't be reused amid housing, homeless crisis On Now Attorney General seeks documentation for Miss Middle East On Now Rep. Hunter probe covers possible fraud On Now Video: SDG&E delaying solar credit for some low-income housing tenants On Now Video: Former San Diego Junior Theatre teacher sentenced for sex with teen girl 0:24 On Now Video: Shelter volunteers believe they were fired for finding a dog a home 0:49 On Now McKamey Manor is leaving San Diego 3:35

jeff.mcdonald@sduniontribune.com (619) 293-1708 @sdutMcDonald