The Bertha tunnel boring machine has resumed chewing away beneath Seattle after a ‘suspension for cause’ order from WSDOT shut it down in January following two safety incidents. The BTM began tunneling with some conditions in place late in February, and those conditions were lifted when the demonstration period ended on March 7. Bertha has now reached her next scheduled maintenance stop, having tunneled a total of 1,560 feet. [Source: WSDOT Alaskan Way Viaduct Replacement Project Page. Image: WSDOT]
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12 Miles of Tunnels for D.C. Sewer
In Washington D.C., the D.C. Water and Sewer Authority (D.C. WASA) finalized a lont-term plan in 2002 aimed at reducing combined sewer outfalls into the Potomac River and its tributary, the Anacostia River. A major portion of this plan is a $2.2 Billion (US) deep tunnel program to handle excess stormwater flows and prevent the combined sewage from being discharged into the environment. Read on for a map and more info. (Photo of Anacostia River, by D.C. WASA)