Exploration no. 146509 is a Geotechnical (depth 26.5 feet) named: B-106 described in subsurface document no. 64159. The document, a report titled Geotechnical Data Report Madison Valley Long Term Solution Northwest Diversion and Washington Park Storage Seattle, Washington was prepared by City of Seattle, Public Utilities, Geotechnical Engineering on 04-01-2010 for a Utility project.