The Washington state Department of Ecology is accelerating cleanup of a 2-acre site at Kaiser Aluminum & Chemical Corp.s 512-acre Trentwood rolling mill here.


Kaiser has been investigating soil and ground water contamination at its Trentwood site under an agreement it reached with Ecology in 2005, and has found that the roughly 2-acre portion of land is particularly contaminated, says Jani Gilbert, a spokeswoman for Ecology here. That site, called the west discharge ravine, is at the west end of the Trentwood site, which is located in Spokane Valley west of Sullivan Road and just north of the Spokane River.


We decided we better do something about the west ravine now, because its a more heavily contaminated area, and when it rains in the fall, theres more chance of sending contaminants into the river, Gilbert says.


A spokesman for Foothills Ranch, Calif.-based Kaiser couldnt be reached for comment on the accelerated cleanup.


Without the accelerated schedule, cleanup work on the ravine likely would have started in 2009, when Ecology expects cleanup work on the rest of the Trentwood site to begin, Gilbert says. Kaiser is continuing its investigation into the extent of the contamination of the entire Trentwood site and is having a feasibility study done to identify and evaluate cleanup options. The investigation and study of the Trentwood site, which Ecology is overseeing, are expected to be completed by late 2008, Gilbert says.


Ecology says contaminants at the site include polychlorinated biphenyls (PCBs), petroleum, arsenic, and metals such as iron, manganese, and antimony. Petroleum containing PCBs has been found floating on top of the groundwater in some areas of the site. For the past several years, Kaiser has been removing that petroleum and pumping out groundwater to keep the contamination from spreading, says Teresita Bala, a site manager and environmental engineer at Ecology.


The manufacturing of PCBs has been banned in the U.S. since 1977. PCBs are known to cause cancer in animals, and are a suspected human carcinogen.


Gilbert says that removing PCBs from the Trentwood site is essential to preventing them from spreading to groundwater in other areas of the site, and ultimately to the Spokane River.


The ravine will be cleaned up before the rest of the Trentwood site partly because the contaminated soil is located close to the river, within an area where rainwater could cause the soil to run off into the river, which makes the site particularly vulnerable, Gilbert says.


Trentwood is one of the largest known sources of PCBs in the river, she says. The Spokane River becomes the Long Lake reservoir, located northwest of Spokane, so most pollutants typically wind up there, Gilbert says.


The primary way humans are exposed to PCBs is by eating fish that have been contaminated, since PCBs accumulate in the fatty tissue of fish, she says. A fish advisory currently is in effect for people who eat fish taken from the Spokane River. In some parts of the river, people are only supposed to eat one meal of fish a month. In other parts of the river, fish consumption is advised against totally.


Whats called interim actions, which provide for accelerated cleanup at a site to protect public safety and the environment, are planned for the ravine.


Ecology considered three options there, including taking no action; placing a protective cover over the contamination and limiting site access and excavation; and removing the contamination and hauling it to an off-site disposal facility, backfilling those cleaned areas, and restoring them with natural vegetation.


Ecology chose the third alternative. It has issued a determination of non-significance for the project, which means that the proposed interim actions likely wont harm the environment further.


Documents associated with the cleanup plan are available for public review and comment through June 27. After the comment period, Ecology plans to issue a summary that answers questions or comments the public has submitted.


Unless it modifies its plans in light of those comments, Ecology expects to start cleanup work in the middle of next month and complete the project by mid-September, Gilbert says.


The work will involve hauling an estimated 1,500 cubic yards, or roughly 125 dump trucks, of contaminated materials from the site to a disposal facility, she says.


According to estimates included in state documents related to the project, the cleanup will cost Kaiser $400,000.


The federal government built the Trentwood plant in 1942 to manufacture aluminum for World War II aircraft. Kaiser leased the facility in 1946 and later bought it along with the now-closed Mead smelter. The ravine where the interim cleanup has been proposed was used as a waste-water conveyance from 1942 to about 1973, when waste-water facilities were upgraded, Ecology says.


Since 1979, Kaiser voluntarily has installed more than 100 wells to monitor toxic releases on the property, and, in 2002, it voluntarily installed a $5 million waste-water treatment facility there. In 1995, Ecology named Kaiser as the potentially-liable party responsible for cleaning up the site, and two years ago, the parties reached a legal agreement on an order that would result in cleanup work.


Contact Emily Brandler at (509) 344-1265 or via e-mail at emilyb@spokanejournal.com.