A San Joaquin County jury has convicted 52-year-old David Sump on multiple felony and misdemeanor counts after what prosecutors say was a deliberate industrial oil dump into Stockton’s Smith Canal last fall. Officials said the spill coated the canal embankment and sent pollution moving toward the San Joaquin River. Sump is scheduled to return to court for sentencing on March 3, wrapping up a multiagency investigation and cleanup that shut down parts of the waterway and temporarily restricted fishing last year.
According to a press release from the San Joaquin County District Attorney's Office, Sump drove to the Smith Canal levee on Shimizu Drive on Sept. 27, 2024, towing a trailer loaded with an industrial “lube cube” that held more than 200 gallons of used motor oil, lubricants, and filters. Prosecutors say he tethered the container to a pole and repeatedly hit the gas until the tank was yanked onto the levee and ruptured, then tried to cover his tracks by spray-painting the trailer. A jury convicted him of felony water-code and hazardous-waste violations, along with vandalism and related misdemeanors. The DA’s office says responding agencies ultimately recovered about 225 gallons of oil and kept the spill from reaching the San Joaquin River.
“This was a calculated and hazardous act of environmental destruction,” District Attorney Ron Freitas wrote in a post about the verdict. The office credited neighbor security cameras, doorbell footage and a prosecution led by Deputy District Attorney Cameron Graber for securing the convictions, according to a post on Facebook. That post also notes Sump was remanded into custody and faces a potential six-year state prison sentence.
What Agencies Found and How the Cleanup Unfolded
State and federal responders described arriving last September to find an industrial oil tank dumped at the waterway and a spreading mess that demanded a coordinated response. The operation pulled in CDFW’s Office of Spill Prevention and Response, the U.S. Coast Guard and the U.S. Environmental Protection Agency. The EPA’s site profile for the incident reports that the dumped oil burner had a capacity of about 280 gallons and that EPA and the Coast Guard coordinated shoreline and soil cleanup. The Coast Guard later said it finished on-water recovery work and then formally handed off remaining duties to the EPA as the response shifted into remediation and monitoring.
Investigation, Evidence and Earlier Charges
The criminal investigation that led to this week’s verdict began after the California Department of Fish and Wildlife and local police responded to reports of petroleum in Smith Canal and gathered tips from the public, CDFW said when charges were first filed last year. At the time, local reports and state agency notices described recovered oil and removal of contaminated soil along a stretch of canal between American Legion Park and the San Joaquin River. Investigators used that physical evidence, along with witness video, to build the case ultimately prosecuted by the San Joaquin County District Attorney’s Office.
Legal Stakes and What Comes Next
Sump was convicted on felony counts that include knowingly discharging a pollutant into state waters and illegally disposing of hazardous waste, along with related misdemeanors. According to the DA’s office, he faces up to six years behind bars at sentencing. He is due back in San Joaquin County Superior Court on March 3, when the judge will weigh prison time, any sentencing enhancements and financial consequences. County prosecutors say they plan to seek restitution and penalties connected to the environmental damage.
Neighbors and officials say the incident drove home how vulnerable Smith Canal, a narrow residential waterway that feeds into the larger San Joaquin River, is to pollution and to the upheaval that follows a hazardous-materials response. Agencies involved in the 2024 cleanup continue to monitor the site, and state investigators have urged anyone with additional information to contact CDFW’s tip line or local law enforcement.
