00Three large work shafts for TBM launch and retrieval, ranging in depth from 134 feet to 165 feet, were constructed with reinforced concrete diaphragm walls (slurry walls). In addition to the large work shafts, the project includes seven large diameter (10.5- to 13-foot) drilled shafts for maintenance hole construction. All of the work shafts and drilled maintenance holes were constructed in alluvial soils with high groundwater pressures and socketed into bedrock or improved soft ground.

00 The tight project schedule is driven by a Cease and Desist Order (CDO) deadline imposed by the Regional Water Quality Control Board. When complete, the NEIS will convey flows from existing sewers and the future Eagle Rock Interceptor Sewer southward to ECIS and the treatment plant. This is one of the most technically challenging projects the City of Los Angeles has undertaken and it was completed ahead of schedule and exceeded client expectations.

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