Pesticides containing lead and arsenic commonly used throughout Central Washington were phased out about 70 years ago, but their environmental impacts may still remain.
They stay in the environment for long periods of time and take many years to degrade, according to the National Pesticide Information Center.
Legacy pesticides were commonly used from about 1900 to 1950 in orchards across some 115,000 acres in Central Washington.
The most affected areas are in Yakima, Chelan, Douglas and Okanogan counties, as well as parts of Benton County, according to the state Department of Ecology.
Many of these historic orchards have been replaced by residential development, shopping centers and offices. More development is occurring where these orchards once stood.
“All you have to do is drive around town. There’s a lot of new construction, a lot of new houses going up,” said Valerie Bound, Ecology’s section manager for toxic cleanup.
Farmers used lead arsenate as a pesticide on crops from 1905 to 1947 to combat infestations. One target was the codling moth, whose larvae burrow into fruits, causing major crop rot.
Lead and arsenic pose human health risks. Long-term exposure to lead has been linked to behavioral problems, hyperactivity and learning disabilities in children, and arsenic has been linked to cancer, adverse pregnancy outcomes and infant mortality, according to the World Health Organization.
There could be a risk in disturbing contaminated soil. But there’s a plan in place to help address potential impacts.
A work group spent the past year identifying historic orchards and devising a series of recommendations to help developers, landowners and the community address such contamination on historic orchard lands.
The work group is composed of more than 30 members representing banking, health, real estate, local government and home builders.
In January the group issued its final report, which provides information and resources on lead arsenate and a series of cleanup recommendations for developers and residents. A public comment period on the report ends Monday, June 7.
The group set up an online ”Dirt Alert” map showing areas of historic orchards with possible contamination. Landowners can enter their address to see if their property is within the footprint of an historic orchard.
If so, they can request a free soil sampling online.
“So that’s pretty cool — I’ve gotten good response about that,” Bound said.
Most of the responses are from the Wenatchee area, she said.
Now there’s an effort to get more inquiries from Yakima County, where historic orchard areas cover much of the city of Yakima and West Valley, the Naches Valley and a swath of the Lower Valley, much of it on the east side of the Yakima River from Parker to south of Zillah.
The group is meeting with municipalities, businesses and housing officials in effort to get the message out ahead of new construction, Bounds said.
“We just decided we needed to have these properties cleaned up before people move into them,” she said.