Concern started six years ago when a Sunnyside farmer contacted staff at the Department of Ecology. He thought pesticides leaked from a storage shed on airport property and into the soil. Investigators confirmed his suspicion.
"DDE and DDT," says Sunnyside Public Works Director Shane Fisher.
The pesticides were commonly used by crop dusters until they were banned decades ago. A report from an environmental consulting company last year says it's likely the pesticides were released into the soil in the 1980s or earlier. Fisher says pilots used to wash their crop dusters over the soil and store pesticides improperly.
A storage shed that once stood just off the runway was removed in the mid-1990s. It's now a contamination hot spot.
A local crop duster, who asked not to be identified, says he built a home next to the old storage shed before he knew about the contamination.
Fisher worries about people living nearby.
"It definitely is a concern," he said. "You definitely don't want, you know, people out digging the soil."
He says Sunnyside told neighbors living on airport property about the contamination. However, one woman across the street says she never heard anything.
"They should go door by door and ask the neighbors what they think about this," said Janette Becerra.
She worries how bad the contamination could be.
"It makes me feel nervous because we don't know what's inside of everything."
Now, researchers are doing more testing. They're installing wells to test the groundwater and collect samples.
Only two crop dusting companies still fly out of the airport. Fisher says, as far as he knows, both comply with state and federal requirements by cleaning their planes and storing their chemicals properly.
Sunnyside paid more than $300,000 for the first round of testing with a grant from the Department of Ecology. It will apply for another grant to help pay for any cleanup once the extent of the damage is clear.