A former wastewater plant operator for Union Pacific Railroad who allowed more than a thousand gallons of oil to seep from an overflowing tank into the Willamette River in January 2018 was sentenced Monday to two years of probation and ordered to pay a $2,500 fine.

Robert LaRue Webb II, 58, negligently discharged oil from a storage tank at Union Pacific’s Albina Yard in North Portland into the river after he was distracted by a cellphone call, according to court records.

Webb pleaded guilty in August to violating the Clean Water Act with the discharge, a misdemeanor.

About 1,800 gallons of oil were estimated to have gone into the river, according to an engineering firm hired by Union Pacific. That estimate did not include additional oil that spilled but was captured by a containment boom, according to court records.

Emergency response and cleanup cost Union Pacific more than $500,000. After the oil spill, Union Pacific installed an overflow alarm system, a concrete barrier and an overfill protection system at a cost of more than $80,000.

“I’m appalled that this happened on my watch,’’ Webb, 58, told U.S. District Judge Michael W. Mosman. “I sincerely apologize to the court and to the citizens of Oregon.’’

Webb was working for Mott MacDonald, a company contracted by Union Pacific to manage the treatment plant at 1525 N. River St.

On Jan. 22, 2018, Webb operated an oil-water separator and then used a manually activated electric pump to transfer the oil to a nearby 10,000-gallon oil tank.

About 12:20 p.m., Webb started the pump but the tank was near capacity. Webb then walked away and left the pump unattended for about an hour, according to Assistant U.S. Attorney Ryan Bounds.

Webb was distracted by a phone call and then attended to other work until he received a call at 1:22 p.m. alerting him to the overflowing tank and oil spilling out of the yard, onto the street and into a drain, Bounds wrote in a sentencing memo.

The tank overflowed, but the pump continued running. By the time the pump was shut off, several thousands of gallons of oil had escaped, according to the prosecutor.

Employees of the U.S. Environmental Protection Agency happened to be nearby removing other hazardous substances from another facility. They placed absorbent materials down to contain the oil. They had already placed a containment device called a “hard boom’’ in the river near where the oil seeped from the storm drain’s pipe and believed that trapped a significant amount of the oil.

Prosecutors urged the judge to place Webb on probation for five years, partly to deter others from such negligence.

Webb’s lawyer, Todd Maybrown, argued that two years would be sufficient, noting this was an isolated incident and his client has no prior criminal convictions.

Webb was fired from his job. Webb held a few similar jobs after leaving Mott MacDonald, although he has been out of work since September. He’s now looking for a job in a sales or retail, according to his lawyer.

-- Maxine Bernstein

Email at mbernstein@oregonian.com

Follow on Twitter @maxoregonian

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