A watchdog group is accusing the Washington Department of Ecology of suppressing a mercury pollution study.

The group, Washington Public Employees for Environmental Responsibility, also claims the agency’s study was deeply flawed.

“Ecology has been sitting on this report for two years while critical policy decisions about mercury were debated,” said T.J. Johnson, director of PEER.

The 48-page report was posted on the Department of Ecology’s Web site Friday, two years and a month after it was completed. Cullen Stephenson, the agency’s solid waste program manager, said there was no intention to hide the study.

“There were just a bunch of procedural and workload issues,” he said.

The agency spent $50,000 to study mercury pollution in eight state landfills, including Spokane’s North Side landfill. Similar studies in other states have shown that mercury in landfill trash – from batteries, auto parts, fluorescent lights and even thermometers – can escape into the environment, potentially threatening nearby residents and wildlife. The heavy metal is a neurotoxin and can escape by simply leaching out of landfills or combining with methane gas to create methyl mercury.

The report showed levels of mercury emissions much lower than the national average.

PEER criticized the report as sloppy science. The study examined only one sample on one day from each of the eight landfills. Landfill participation was voluntary and came with a confidentiality guarantee, Johnson said. “The study is just so flawed, it doesn’t tell us anything.”

The Department of Ecology disagrees and claims the study was adequate enough to show that mercury pollution from landfills does not appear to be a threat to public health. “There’s no evidence that tells me the emissions of mercury would change significantly over time,” Stephenson said.

The agency initially offered to keep the data confidential, but the offer was retracted later on the advice of state attorneys. Stephenson said results could have been taken involuntarily from any of 20 landfills, but the Department of Ecology chose to ask for volunteers with the offer of keeping the results secret.

“It was purely to protect our good relationship with the landfills,” Stephenson said. “We could get the data either way.”

The report shows that Washington landfill mercury emissions were well below national averages. Seven of the eight landfills sampled had emissions 10 percent below the national average or lower, according to the report. One landfill emitted 220 milligrams per day of mercury, which is 60 percent of the national average and very roughly equal to the weight of a pinch of salt.

Stephenson said landfills are a very small contributor to mercury pollution. Stopping the pollution would take an “incredibly expensive” containment system, and the Department of Ecology would rather devote its efforts to preventing mercury-containing trash from entering landfills in the first place, Stephenson said.

PEER director Johnson said the issue goes beyond the amount of mercury in landfills. He said Department of Ecology feels the agency is becoming too cozy with businesses and other groups that it’s supposed to watch.

“There’s a great fear they cannot give an honest opinion for fear of retribution from top management,” Johnson said.

Earlier this summer, PEER discussed its concerns with top officials at the agency, but the response has been “woefully inadequate,” Johnson said.