The Oregon Transportation Commission is scheduled to hear and decide on the engineers’ recommendation at a meeting in Silverton in late October.
Ancient Lake, Modern Ramifications
Project managers ordered routine soil tests of the project area before construction of the Wickiup Junction overpass began, but the tests failed to detect rare diatoms in the subsurface of the soil, said Della Mosier, an engineer and interim area manager for ODOT projects in Central Oregon.
The diatoms are silica-based skeletons of algae that lived in an ancient lake in the area and sank, forming a thick bed on the bottom thousands of years ago. The lake had been identified in geological maps, but initial tests gave no indication the soil differed from other parts of Central Oregon, where ODOT has successfully built other bridges, Mosier said.
Read the whole story at Pamplin Media.