We tell DTSC’s story to keep the public informed

DTSC Partners with Yolo County on Hazardous Waste Case

Dylan Clark’s “aha” moment in the investigation of a Woodland biomass business came when he discovered that numbers in a laboratory report were higher than those reported by the company.

The power plant in Woodland burned wood and other material to produce electricity, a process that generated ash containing hazardous waste levels of metals. “We knew we had a problem, but didn’t realize the extent until we saw that data,” said Clark, a supervising scientist in the Office of Criminal Investigations (OCI) at the California Department of Toxic Substances Control (DTSC).

Those discrepancies were key discoveries in a joint four-year investigation that resulted in settlements totaling $4.2 million dollars. The May 2017 settlement was between District Attorney Offices in Yolo, Solano and San Joaquin counties and Woodland Biomass Power for illegal management and disposal of hazardous waste at landfills and an agricultural field, as well as false representations of the waste.

In 2013, the Yolo County Environmental Health Department had contacted OCI for help after receiving reports of ash being dumped in a 60-acre field northeast of Davis. OCI assigned two scientists – Clark and Taryn Stokell Buck. They staked out a grid pattern in the 60-acre field and collected surface ash to sample. Some of the ash contained metal chunks and nails, and was two feet deep in places. 

Tests at DTSC’s lab revealed hazardous waste levels of arsenic in one sample, and hazardous waste levels of copper in another. The samples also had elevated levels of dioxins. DTSC Senior Toxicologist Claudio Sorrentino, Ph.D., reviewed the data and expressed concerns over the dioxin levels in the samples. This concern helped prompt the required cleanup of the disposal site.

Wearing a respirator, Clark also collected samples of ash entering the tractor trailers at the Woodland facility. “I had a bucket lined with plastic and would swing it under the ash as it was falling into the truck,” Clark said. He collected 81 samples from 11 truckloads.

Laboratory testing determined that four of the truckloads contained hazardous levels of metals, but there was a problem: the trucking company wasn’t authorized to transport hazardous waste. Clark and Supervising OCI Investigator Enrique Baeza investigated this allegation of illegal transportation of hazardous waste and referred this separate portion to the Yolo County District Attorney’s Office. A $100,000 settlement was reached with the unregistered hauler who illegally transported the hazardous waste in October 2016.

DTSC still wasn’t done. Knowing Woodland Biomass Power had to test their own waste and report it under a prior court judgment, a suspicious Clark and Yolo County District Attorney’s Office subpoenaed four boxes of data from the company’s contract laboratory.

Clark started comparing that data with forms the company submitted to governmental agencies. He reviewed thousands of data points and identified disturbing discrepancies on the lab reports. “I saw the numbers were much higher than what they reported to the city and county,” he said. 

Yolo County District Attorney’s Office summed it up in a press release announcing the May 2017 settlement: “For years, Woodland Biomass Power claimed its ash was non-hazardous. This claim, however, was supported with faulty methods and at times, falsified summaries of the test results for its ash. The company’s own test results have shown that much of its ash had elevated levels of dioxins and…high levels of pH and high concentrations of contaminants like arsenic, lead and copper.”

The District Attorney’s Office said “tens of thousands of tons of ash” – some hazardous waste – was put on properties not authorized to receive it.

DTSC worked with the Yolo County District Attorney’s Office to develop a judgment that required Woodland Biomass to appropriately characterize their waste.

DTSC was an integral part of the settlement negotiations with Woodland Biomass and the DA’s Office. Clark, Baeza and Senior Attorney Vivian Murai met with Woodland Biomass Executives and the prosecutors to ensure the company would comply with California hazardous waste laws. OLC’s Ann Carroll and Jay Cross also provided support at various points of the investigation and negotiations.

The $4.2 million settlement for the Woodland case includes $1.25 million in costs to remove the ash from the fields and to dispose of it at authorized facilities. The District Attorney’s Office said the company has been cooperating in the investigation, re-evaluated plant operations and has improved its ash-management program.                                      

The joint DTSC-County investigation enlisted the support of DTSC’s Office of Legal Counsel (OLC), the Hazardous Waste Management Program’s Waste Classification Unit, Health and Ecological Risk Office (HERO) and the Environmental Chemistry Lab (ECL). 

DTSC first became interested in how biomass power plants manage, test and dispose of ash in 2009 when the Butte County District Attorney’s Office contacted Baeza for assistance on a biomass investigation of the Covanta plant in Oroville.

That investigation grew to encompass all Covanta facilities in California before identifying violations at three plants. Similar to the Woodland Biomass case, DTSC’s investigative, waste classification and legal staff provided critical support for the negotiations and resolution of various issues. Those staff members were Senior Environmental Scientist Kevin Sanchez, and senior attorneys Carroll and Murai.

In December 2014, Covanta paid DTSC costs of about $289,000, settled the case for $825,000 with multiple District Attorneys’ Offices statewide, and agreed to implement a multiyear waste characterization plan.