Sinclair, and refinery managers Kapura and Connell, previously admitted to knowingly manipulating the refinery processes, wastewater flows, and wastewater discharges to result in unrepresentative wastewater samplings during mandatory testing required under the National Pollutant Discharge Elimination System (NPDES) permit program. The manipulated samplings were intended to influence analytical testing results reported to the Oklahoma Department of Environmental Quality (ODEQ) and the Environmental Protection Agency (EPA).

"Companies and their employees have a legal obligation to abide by the laws that protect our rivers and waterways from the harmful effects of pollution," said Matthew J. McKeown, Acting Assistant Attorney General for the Justice Department's Environment and Natural Resources Division. "The Justice Department will continue to prosecute companies who fail to comply with the laws that protect our environment from illegal pollution."

"Accurate information is essential for EPA to assure compliance with environmental regulations," said Granta Nakayama, EPA's Assistant Administrator for Enforcement and Compliance Assurance. "By falsifying wastewater sampling results, Sinclair undermined our efforts to protect the public and the environment."

"The investigation and prosecution of Sinclair Tulsa Refining Company should make it clear that corporations and their employees must play by the rules," Oklahoma Attorney General Drew Edmondson said. "Today's sentences protect Oklahoma from future pollution, and it provides money for the Tulsa River Parks Authority. My hope is that the money will be used so we can enjoy this precious natural resource for generations to come."

According to the criminal information and plea agreement filed on December 13, 2006, between January 2000 and March 2004, the Sinclair refinery discharged an average of 1.1 million gallons of treated wastewater per day into the Arkansas River. Under the CWA, Sinclair was permitted to discharge treated wastewater into the Arkansas River, pursuant to certain limitations and conditions, which include scheduled monitoring and required sampling during weekdays. According to the information, on numerous occasions in 2002 and 2003, Sinclair directed employees to limit wastewater discharges in order to manipulate the result of required bio-testing. During monitoring periods, Sinclair, by way of its employees, reduced flow rates of wastewater discharges to the river, and diverted more heavily contaminated wastewater to holding impoundments, among other means of ensuring that they had passed the tests.

Sinclair Oil Corporation is a privately owned oil refinery located in Tulsa, Okla. Although the refinery is headquartered in Salt Lake City, it is incorporated in the state of Wyoming. Sinclair has owned and operated the Tulsa refinery since 1983.

The case was investigated by the U.S. Environmental Protection Agency Criminal Investigation Division and the Oklahoma Attorney General's Environmental Protection Unit. The case was prosecuted by the Environmental Crimes Section of the Justice Department's Environmental and Natural Resources Division and the Northern District of Oklahoma United States Attorney's Office.