Groundwater report: The good and the bad

The good news is no new groundwater contamination sites were
discovered in San Benito County last year. The bad news is it takes
years of cleanup to remove toxins from a site, which are often
discovered after the damage is done.
That was the assessment from the recently released annual report
by the county’s water district on area groundwater
contamination.
The good news is no new groundwater contamination sites were discovered in San Benito County last year. The bad news is it takes years of cleanup to remove toxins from a site, which are often discovered after the damage is done.

That was the assessment from the recently released annual report by the county’s water district on area groundwater contamination.

However, two known sites of contamination, the John Smith Landfill and the former Whittaker Ordnance Facility – now Quantic Industries – have been undergoing years of remediation. Both facilities have been under close supervision of the state’s Regional Water Quality Control Board with proven results.

Jointly owned by the City of Hollister and San Benito County, the John Smith Landfill has been operating since 1968. At that time, waste was not classified or segregated and no precautions were taken to protect the soil or groundwater supply. Because of this, the landfill was used as a dumping ground for hazardous material.

From 1974-77 hazardous waste was confined to the northern portion of the landfill until the 8.3-acre Class I facility was constructed.

The landfill consists of 65.3 acres with 29 acres designated as a Class III Landfill. The county is the lead agency for the Class III section while the city is the responsible party for the Class I site.

The city operated the Class I site from 1977-83, accepting liquid hazardous waste such as motor oil and pesticides.

“Back then they didn’t use any liners,” said David Athey, water resource control engineer for the Regional Water Quality Control Board. “Government regulations now mandate the use of liners.”

The RWQCB’s latest effort is to target gasoline and other man-made compounds. MTBE is just one contaminant affecting groundwater supplies and there are several toxins being dumped at landfills every day in the form of household products.

In 1989, a plume of volatile organic compounds was found beneath the landfill. Corrective measures were taken to capture the plume and to remediate the groundwater. Two gas extraction pumping wells were constructed on-site and two wells off-site to capture the plume, which is now deemed stationary.

“There is a significant decline in volatile organic compounds at the site,” Athey said. “They continue to pump the groundwater and treat it.”

The treated water is discharged into Hollister’s municipal sewer system by a three-mile pipeline from the landfill to the city’s wastewater treatment plant.

“There is no (wastewater) discharge coming out of the landfill,” Athey said.

Old carpeting, empty food containers and household cleaning containers all contain harmful toxins and gases, with one of the most commonly known being methane gas. Gas probes are used to calculate the effectiveness of the gas extraction system and to track migrating methane gas.

“These extraction systems suck out the gas that’s in the soil,” Athey said. “It measures just how much methane is underneath the landfill.”

John Smith Landfill Plant Manager John Stewart said methane gas does not burn a visible flame like a petroleum plant.

“It burns so clean you can’t see the flame,” he said. “The gas just flares off.”

A timer sets the machine which ignites the flame and in turn burns the methane. Stewart said even though methane gas can be used to run electricity, the landfill does not produce enough methane to run the plant.

“All we can do with it is extract it and treat it,” Stewart said.

A year ago, the city and the county submitted a joint plan to revise and update their waste discharge order for a new 15-acre expansion program. The RWQCB approved the expansion plan, but looking at the county’s growth rate. And Athey said there would not be enough room in 20 years.

“They’re going to have to keep expanding the landfill,” he said.

Since the mid 1990s, the former Whittaker Ordnance has been the subject of ongoing investigations and cleanup abatement orders from the RWQCB to remediate the groundwater contamination.

In 1991, after volatile organic compounds were detected in an on-site water supply well, an environmental assessment of the facility’s activities were mitigated. The report identified trichloroethylene (TCE) and breakdown products such as Freon, vinyl chloride and hexavalent chromium in the soil and groundwater beneath and adjacent to the facility well above water quality standards.

The Whittaker site, located about 2,000 feet from the San Benito River, was an operating dairy farm before 1957. When it was acquired by the Holex Company the property was retrofitted to produce small explosives.

The Holex munitions site reportedly used trichloroethylene until it was discontinued in 1978, two years before Whittaker purchased the property.

“They had discontinued using trichloroethylene awhile back,” said Hector Hernandez, water control engineer for the RWQCB. “But it can takes years before it stops impacting the area.”

It was calculated that TCE traveled at the rate of 26 feet a year.

Whittaker ordnance operated from 1980-93. The company was sold to Quantic Industries then in 2001, Pacific Scientific Energetic Materials (PacSci-Quantic) bought the property and continues to manufacture explosive devices used for car safety products.

“There have been changes in their operations and they no longer are using some of the solvents that they use to use,” Hernandez said. “The company is more conscientious. They’re more knowledgeable about the environment.”

Companies are aware there is a proper way to dispose of their chemicals, but the biggest challenge the RWQCB is facing is receiving funds to clean up contaminated sites, Hernandez said.

“The cost is in the millions,” he said. “With the current economic crisis, these impacts delay the speed of the cleanup.”

Final inspections of the site in 2001 concluded Whittaker effectively outlined the extent of the soil and groundwater impacts in accordance with the Cleanup or Abatement Order. To date a total of 56 groundwater monitoring wells, three soil vapor extraction wells and six piezometers have been installed on-site. Also, eight off-site water supply wells are routinely monitored.

“Progress is being made,” Hernandez said. “The remediation – the technology has all proven to be effective.”

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