Alleged sewage dumper in Rohnert Park is septic tank cleaner with secret pipe, police say

It was a mystery: What was causing backups to a sewer line in a neighborhood outside Rohnert Park?

This was no ordinary plumbing problem. It required the city to repeatedly unclog its underground sewer system, and may have spoiled private wells serving nearby homes.

Investigators now think they know the source of the blockages. A yearlong investigation that included undercover surveillance and round-the-clock video recording of a Rohnert Park home, as well as remote sensors deployed in the city’s network of sewage pipes, finally allowed them to zero in on the suspect.

Police arrested Carlos Velarde Chavez, 63, owner of Carlos’ Petaluma Septic Services, a cleaning company, on suspicion of dumping raw waste into the city’s sewage system through a secret pipe installed in his backyard. In a court filing, investigators said Chavez illegally drained the contents of his 2,800-gallon commercial tanker into the city pipes six days a week, on average, before his Dec. 13 arrest. The illegal dumping amounted to more than 300 separate incidents, a search warrant indicated.

“He was literally caught in the act,” Rohnert Park City Councilwoman Gina Belforte explained during a February council meeting. “They caught the flows going up, and that’s how they figured it out.”

Chavez pleaded not guilty to two dozen charges at a March 13 hearing in Sonoma County Superior Court. Reached at his business Tuesday afternoon, Chavez said, “We’re working on it,” and declined to answer any additional questions.

He said he planned to comment after speaking with his attorney, Roy Miller, but did not respond over the next several days.

Chavez is charged with two felonies - property theft greater than $950 and using an improper contractor’s license number with the intent to defraud. In addition, he is accused of 22 misdemeanor crimes, including nearly a dozen malicious commercial ?discharges, contracting without a license and failure to obtain workers’ compensation insurance for employees, all for alleged activities last year between October and December, according to the legal complaint.

The Santa Rosa Police Department led the investigation because of the impact of the alleged discharges on the Santa Rosa sewage treatment plant, which serves Rohnert Park and three other cities.

Santa Rosa police obtained a search warrant in January to collect evidence from Chavez’s two Sonoma County homes after sensors installed in the sewer lines next to his Rohnert Park house pointed to the property as the cause of blockages dating to December 2015.

That month, raw sewage was detected in wells serving homes in the nearby Canon Manor West neighborhood, located in an unincorporated area south of Rohnert Park. Several residents reported the raw stench of human excrement in their drinking water and the county issued a public health alert after discovering E. coli bacteria in the wells.

The complaint against Chavez does not address the 2015 backups. It remains uncertain if Chavez caused them, according to Santa Rosa Police Detective Brandon Matthies, “but it is probable,” he said.

Three Canon Manor West residents later sued Rohnert Park in 2016, accusing the city of failing to properly maintain its sewer system. The court tossed the lawsuits after the city proved the backup was caused by a buildup of unlawful discharges from grit commonly found in septic tanks.

Rohnert Park City Manager Darrin Jenkins said the presence of E. coli and fecal coliform bacteria in residents’ wells stems from a long history of contaminants from illegal septic systems in Canon Manor West - an assertion backed by officials at the North Coast Regional Water Quality Control Board.

In mid-2016, the same neighborhood sewer line had another septic ?sediment-related blockage downstream from Chavez’s Rohnert Park home.

In January 2017, the city began searching for the culprit, placing sensors in its underground sewer lines that allowed it to detect changes in flows. They identified Chavez’s home as the most likely source of the discharges, according to a search warrant filed in Sonoma County Superior Court.

Video cameras were placed on city light poles just west of the residence in November to watch traffic to and from his driveway. Each time Chavez returned from a job over the next two months and parked his tanker in the back, “the sewer meter would increase substantially indicating a large discharge to the sewer system. There was no indication it came from another property owner,” the search warrant stated.

In response, the City Council urged District Attorney Jill Ravitch to seek the most severe punishment available for Chavez, asserting his “brazenly unlawful business practices … put the city, its residents, the public, and the environment at risk.”

Chavez has two prior misdemeanor convictions in Sonoma County for unlawful dumping of sewage, in 1999 and 2000. In each case he pleaded no contest in exchange for a year of probation. In the second instance, he also paid fines totaling $823.

Metering data from January through December 2017 indicates Chavez made an estimated 326 illegal dumps of sewage into the Rohnert Park sewer system, the search warrant alleges. The criminal complaint alleges Chavez deprived local government of money by failing to use a waste treatment site to dump sewage. He would have paid almost $119,000 to dispose of the waste at Santa Rosa’s plant, based on a rate of $364 per 2,800-gallon sewage tank, according to the search warrant.

Chavez has maintained a county permit to haul septic waste since at least 2011, according to the county Department of Health Services. He does not possess a current discharge permit with the city of Santa Rosa, nor do records suggest he has ever had one, a spokeswoman for the city said. He does have valid waste disposal permits in Novato and Oakland, but his discharges at those facilities “did not correlate to the amount of septic pumping he was doing,” Santa Rosa police said.

An anonymous local sewage hauler told investigators he had never witnessed Chavez or the company discharge waste at a lawful site, according to the search warrant. He said potential clients told him that Chavez charged half the price of other septic haulers.

A preliminary hearing is set for May 8.

You can reach Staff Writer Kevin Fixler at 707-521-5336 or at On Twitter @kfixler.

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