The 0.74-acre plaza between LOTT’s WET Science Center and the Hands On Children’s Museum on Olympia Avenue is still on schedule to open to the public late this spring, said Eric Hielema, a LOTT senior wastewater engineer.
The total project cost is closing in on $5 million, with the sewer utility contributing about $4 million and the City of Olympia more than $885,000.
The environmental cleanup consisted of excavating contaminated soils, hauling soils to an approved disposal site, placing a geotextile surface over the disturbed areas and backfilling with clean soil.
The original estimate called for removal of about 3,100 cubic yards of soils contaminated with petroleum byproducts and heavy metals. But the volume exceeded 8,000 cubic yards.
The extra dirty dirt – enough to fill 500 dump trucks – was based on expansion of the two, 20-by-20-foot hot spots discovered during the original site investigations. In addition, the state Department of Ecology required excavation to a depth of 6 feet or to contact with groundwater, whichever came first. The original design for the project called for excavation to a depth of 3 feet.
The sewer utility board of directors will be asked to approve a construction change order to cover the environmental cleanup costs when they meet Wednesday night.
The project is quickly taking shape, Hielema noted. A streamlike water feature, which will be fed by reclaimed wastewater from the nearby LOTT treatment plant, is in place. Several of the pathways have been constructed within the open space.
The public plaza will also feature a small wetland, aquatic vegetation, bronze sculptures of wildlife, park benches, a performing arts stage, and interpretive signs and messages inlaid in the pathways describing the role water resources play in the community.
The plaza design by Robert W. Droll & Associates of Lacey is one of 11 pilot projects in a national program for sustainable landscape design.
John Dodge: 360-754-5444
jdodge@theolympian.com
