State engineer says shallow cleanup progressing nicely; but decades of monitoring remain
New Mexico Environment Department project manager Steve Jetter said the North Railroad Avenue Superfund site currently has limited restrictions from surface land use activities or redevelopment.
“There are limitations at the source area as they relate to interference with our ongoing remediation efforts,” he said.
Jetter said there are no limitations regarding digging either at the original contamination site or in any of the immediately affected areas.
The Environment Department is currently working with the state Highway Department to install storm drainage near the Plaza de Española.
“The (Highway Department) is designing it to avoid any impact to the plume,” Jetter said.
The plume is the stream of contaminated water that flows west from its point of origin, the old Norge Town Laundromat and Dry Cleaning at 113 N. Railroad Ave. Plans involve routing storm drainage down Los Alamos Highway and along State Highway 84/285 in Española.
However, Jetter said the Highway Department must first submit a redevelopment plan for the storm drainage and that the Environment Department would have to approve such a plan.
“We haven’t seen DOT designs so we can’t respond directly to the specifics,” Jetter said. “However, it is my understanding that the (Highway Department) is designing it to avoid any impact to the plume.”
He said the contamination in the deep zone, which extends west from the old laundromat, toward the historic plaza, is greater than 50 feet, which is considerably deeper than any expected digging plans for installing storm drainage.
Jetter said, in general, that any plans to dig in the contaminated area would likely be approved, so long as the digging doesn’t negatively affect the Environment Department’s cleanup efforts.
“The New Mexico Environment Department and EPA (federal Environmental Protection Agency) never said excavation work couldn’t be done at the Superfund site,” he said, adding that all work would require taking necessary precautions like monitoring worker safety and proper disposal of waste materials.
Jetter said significant progress has been made regarding cleanup of the Superfund site. The cleanup project also includes treatment of 58 acres surrounding the site, referred to as the shallow zone.
Records show that 280 million gallons of ground water had been contaminated and an estimated 275 pounds of tetrachloroethylene (PCE) was found in the area. The Environment Department has significantly reduced the level of contaminated ground water through its treatment system as 95 percent of the original 275 pounds of PCE has been removed.
Jetter said the cleanup effort has progressed ahead of schedule.
“The original time frame was 20 to 30 years,” Jetter said.
Cleanup of the shallow zone, located immediately around the former laundromat and dry cleaning operation, will be done in the next four to five years, he said. However, cleanup of the deep zone, which runs toward the Plaza de Española, will last considerably longer.
“We are looking at doing an engineering evaluation on the deep zone this fall to see how we can get the contamination out more efficiently,” Jetter said. “We also have an issue with secondary water quality standards that we’ll have to meet, primarily with iron and manganese.”
Iron and manganese are two common by-products of the treatment process.
Jetter stressed that Española’s public drinking water supply is safe to consume and use for irrigation purposes.
“The nearest city water supply wells are located a mile or more west of the Superfund site,” he said. “The city performs required testing on the wells and reports back to the New Mexico Environment Department.
“As far as domestic wells, we performed a survey and testing of private wells near the site,” he said, adding that health standards have been met.
Jetter then shared about the treatment system.
“We installed bioremediation treatments in the shallow aquifer, one right in the source zone and another we call the biocurtain at the Stanley Griego (Santa Clara) Bridge,” he said. “The treatment includes injecting soybean oil, a food source for naturally occurring bacteria.”
The soybean oil is injected into contaminated ground water; the bacteria feed on the soybean oil and, in turn, consume the contaminants found in the ground water.
Jetter said he is pleased with the cleanup efforts in general.
“We’ve made significant progress in the shallow zone,” he said. “The shallow zone has been remediated to cleanup standards between the source area and Paseo de Oñate and for all of the contaminants except for vinyl chloride south of the Stanley Griego (Santa Clara) Bridge.” Vinyl chloride, like iron and manganese, is an expected by-product of the treatment system.
Jetter said treatment to ground water in the shallow zone was finished in 2010 as required health standards had been met.
“The ground water is pretty well clean, at least in the shallow zone,” he said.
However, one more treatment to the biocurtain area, near the bridge, is expected later this year.
The Environment Department claims its investigation identified the source and extent of ground water contamination at the site and the potential threat to the public drinking water supply. The Environment Department further states that its remediation plan will protect the city’s drinking water and the Rio Grande from future solvent contamination.