PULLMAN, Wash. — Washington State University officials are formulating recommendations on how gardeners should handle herbicide-contaminated soils and will make them available on the Web as soon as possible.

WSU announced these plans today after new laboratory tests found traces of the herbicide picloram in Washington State University compost suspected of damaging garden plants in Eastern Washington and Northern Idaho.

Vegetables grown in soil treated with the compost are safe to eat, according to Alan Felsot, a WSU environmental toxicology expert who has reviewed the latest laboratory findings.

WSU announced the possible compost contamination last week, but lab reports at that time were inconclusive. Subsequently, Anatek Labs, Inc., Moscow, Idaho, re-analyzed compost samples to achieve lower detection limits and found picloram in compost and in samples of university-grown grass hay.

James Zuiches, dean of WSU’s College of Agriculture and Home Economics, said WSU’s investigation continues, along with that of the Washington State Department of Agriculture. WSDA has regulatory authority in these matters.

Dan Caldwell, WSU compost manager, said a WSDA inspector has visited WSU three times, collecting samples and pesticide application records. His report is expected around the end of August. WSU is cooperating fully with the investigation.

Meanwhile, Caldwell said WSU officials are examining the university’s practices and policies to ensure that materials that are composted are free of herbicides.

Caldwell is working with Dow Chemical scientists to determine toxicity levels for different garden plants. He also is exploring possible remedial measures that gardeners can take to prevent future problems.

Felsot said picloram levels reported in the latest analyses could be toxic to some plants, but not to people. The human body doesn’t metabolize the chemicals, but simply disposes of them by excretion.

To follow developments, visit http://cahenews.wsu.edu/compost.htm .