City plans to remove tainted soil from park
May 10, 2011
By Warren Kagarise
The city has agreed to spend up to $26,000 to clean up contaminated soil at Squak Valley Park North — open space along Issaquah-Hobart Road Southeast about a mile south of downtown Issaquah.
Planners estimate about 56 tons of soil need to be removed due to contamination from a leaky heating oil tank, although the actual amount remains uncertain until additional testing confirms the extent of the tainted soil.
City Council members approved the expenditure May 2.
The city purchased the land and a farmhouse at the former Erickson farm 24 years ago for use as open space and to restore the natural habitat.
Crews breached a Great Depression-era levee at the site last summer, and then Mountains to Sound Greenway volunteers planted more than 2,000 trees and shrubs at the site in October. The city relied on grants to cover about 75 percent of the $1.4 million cost.
Crews discovered a leak in a heating oil tank during the farmhouse demolition. The demolition team removed the tank, and the city hired a consultant to assess the soil contamination.
The consultant’s report identified heating oil in high concentrations between 10 and 15 feet beneath the site, although groundwater had not been contaminated.
The soil cleanup could not be completed as part of the restoration, but such a project is ineligible for funding under the grants used.
The city had leased the house for more than 20 years.
The state uses soil-cleanup guidelines to determine the amount of soil to be removed. The cost estimate includes excavation, disposal of contaminated soils at a state-approved facility, consultant oversight, additional soil testing, reporting and a reserve fund.