Public comment begins for contamination study of old aluminum byproduct disposal site

This work is part of a legal order between Kaiser and the Washington Department of Ecology (Ecology). The order required Kaiser to conduct what’s called a Remedial Investigation and Feasibility Study at the “Heglar Kronquist” site, 10 miles northeast of downtown Spokane. The public will have until Aug. 5, 2011, to comment.

A public meeting also will take place at 7 p.m., on July 28, 2011, at Mt. Spokane High School, 6015 E. Mt. Spokane Park Dr. in Mead. Ecology and Kaiser will discuss the Remedial Investigation report findings. The feasibility study, which will evaluate cleanup options, will be available by early 2012.

During the meeting, experts will answer questions about drilling new water wells, well-drilling restrictions on properties within 1,000 feet of the property, and more.

The purpose of the investigation was to gather more scientific information to determine if contaminants related to aluminum “black dross” are in groundwater on and near the site. The investigation identified the contaminants, the amount of contamination, and where it is located.

Black dross is a by-product from processing aluminum that contains sodium, potassium, aluminum, chloride, fluoride, ammonia, nitrates, nitrites and metals. These chemicals may be harmful to human health and the environment if they exceed certain levels.

Kaiser evaluated surface water and groundwater to determine risk factors for humans, plants, aquatic and wildlife in the site area. Results of the investigation include: All concentrations of chemicals tested in the air both on the landfill site and at the perimeter met state standards. Drinking water has not been affected by contamination at the site. Areas where levels of nitrates or chlorides are elevated above state standards are not affecting water used for drinking. Kaiser found areas with elevated nitrates and chlorides in groundwater that will decrease more when the landfill site is cleaned up. From 1969 until 1974, Kaiser Aluminum disposed of nearly 55,000 cubic yards of black dross from the Trentwood plant in the Spokane Valley to the disposal site operated by Gemini Management, Inc. Kaiser later bought the property in 1991. The dross disposal stopped in 1974 because high levels of chloride were found in shallow water supply wells and springs down gradient of the site. Air sampling conducted downwind of the site in 1979 showed elevated levels of several organic compounds. Ammonia also was detected at levels higher than accepted by state laws. Kaiser took several steps to address the contamination in 1984, including installing a cover designed to isolate and protect the dross pile. Monitoring during the early 1980s through 2004 indicated decreasing but still elevated chloride and nitrates in springs down gradient of the site.

Ecology has reviewed and approved draft remedial investigation documents, but now it’s the public’s turn. The documents are available at the Ecology office at 4601 Monroe St in Spokane. Call Kari Johnson at 509-329-3415 for an appointment. They also are available at the North Spokane Public Library on Hawthorne Road, at the Spokane Public Library in Hillyard and online.