EPA to recommend Moses Lake contamination cleanup

EPA to present final record of decision on contamination of Moses Lake site on Sep. 30

MOSES LAKE — After meeting with the Environmental Protection Agency Feb. 9, regarding Trichloroethylene contamination near the former Larson Air Force Base, the Grant County Board of Health will most likely wait until the EPA concludes its report in September before making any further decisions.

At the meeting, EPA representatives presented three options for how the county might go about cleaning up land contaminated with TCE, an industrial solvent commonly used for de-greasing metal parts.

Those options include leaving the contamination, using technical equipment to remove the contamination or applying institutional controls which can include zoning, paving over soil contaminated with TCE or putting up fences to limit access where TCE is present.

The EPA suggested to the Board of Health that they and the rest of the county consider institutional controls at this time.

"No matter how aggressively we try to treat the TCE there are going to be areas where we didn't know about it and even in areas where we know where it is it can take quite awhile," said Marcia Knadle, a hydrogeologist with the EPA in a recent phone interview. "Institutional controls are how to be protective of people who may come into contact with contaminants by hindering that contact so that we can rapidly respond to it," she said.

During the meeting, Wallace Reid, remedial project manager with the EPA, told the Board of Health that he believed most of the contamination is no more than five parts per billion, which is the Maximum Contaminant Level set by the EPA.

"We know in most places south of the airport we have found TCE," Reid said at the meeting in early February, adding that the contamination starts south of the Grant County International Airport and heads southwest in the direction of the water flow. "What we don't know is over the course of 20 to 30 years, if what was at the surface has migrated farther."

Knadle later said that TCE contamination could extend as far as a half mile south of the former LAFB and in some places as deep as 300 feet into the ground.

At the Feb. 9 meeting, Lee Blackwell, chairman of the Board of Health, asked about the possibility of TCE migrating down farther in the ground. Reid said it was possible.

"Theoretically its a possibility for TCE oils to continue migrating deeper, but I think it's probably as deep as it's going to get as (the TCE) was released a long time ago," Knadle said.

As far as building residential wells near the contaminated area in the future and the potential risk to those living in former base housing, Reid said he does not believe that to be a problem as the concentrations of TCE in most places below five parts per billion.

"A person living there is not impacted by it," Reid said as they are not on a land fill, or in close proximity to where TCE was used. "The land fills tend to be a mile away from those houses … kids trespassing on the land is an issue," he said.

Cleaning up the TCE, which was first detected in Moses Lake in 1988, is a task the EPA says will most likely take several decades with no way of pinpointing exactly what parties are responsible and how much they each contributed to the overall contamination.

"At this point there is a list of potential responsible parties and it is a fairly long list," Knadle said, mentioning the United States government and Boeing as significant contributors to the contamination.

According to the EPA, TCE contamination near land where the former LAFB existed, most likely began as early as the 1950s and 1960s, but was not detected in Moses Lake until the late 1980s.

"Nobody knew too much that it was bad," Knadle said of TCE dumping, emphasizing that prior to legislation in the late 1970s and 1980s, government contracts did not stipulate how TCE was disposed of. "Government contractors had provisions in contracts that held them harmless and research into the way contracts were structured at the time (is currently being done)," she said.

At present, the EPA does not believe TCE is currently being used at the former LAFB. "I'm not sure its ever been made illegal, but it is highly regulated," Knadle said. "If you get caught dumping, that is highly illegal."

Bill Maddox, water division supervisor with the city of Moses Lake, said soon after the city was aware of the TCE contamination in the late 1980s, a number of wells were replaced, getting rid of some of the TCE.

Other well replacements have included the one the EPA installed in 2003 in the Skyline community just south of Highway 17, a project also overseen by the Army Corps of Engineers.

That well, Reid said, serves approximately 100 homes in the Skyline community. "The other wells we've tested in the test area that are residential drinking wells are either non-detect for TCE or below five parts per billion, except for a few and those houses have filters," Reid said.

Health effects of long-term exposure to TCE can cause liver problems and result in an increased risk of developing cancer.

Until the EPA finishes its record of decision, which is scheduled to be completed by Sep. 30 of this year and will present what the EPA believes is the best solution to cleaning up the TCE, the health district says it is reluctant to make any further decisions.

"It's really a dilemma for the health district because in one sense we're responsible … we're supposed to make sure people can get an appropriate source of water and if we know this is in an area it seems we should be responsible for testing in that area," said Jerry Campbell, environmental health director with the Grant County Health District.

However, Campbell said testing is extremely expensive and would require the health district to partner with a lab or train health district staff to carry out the tests. In the meantime, Campbell said he wants to wait and see what the EPA presents in September. "We want to see what happens then and then talk with all the parties involved," he said.