LA Outfall Tunnel | USA

LA Outfall Tunnel

This project will protect local waterways by addressing aging infrastructure and involves building a new 7‐mile long, 18‐foot diameter tunnel to convey treated water from the Joint Water Pollution Control Plant in Carson to existing ocean outfalls at Royal Palms Beach in San Pedro, California.

The depths of the tunnels are between 30-450 feet below the surface to the top of the tunnel and are mostly located under roadways.

Sixense’s Services for the LA Outfall Tunnel

Dragados USA, Inc. was awarded the project in 2018. They hired Sixense to provide all the instrumentation and monitoring solutions for the LA Outfall Tunnel, including automatic settlement monitoring with AMTS, sub-surface instrumentation with data acquisition using LoRa ADAS, and ground-borne vibration monitoring.

Monitoring solution key figures:

• 67 MPBXs
• 11 VWPZ
• 8 Inclinometers
• 10 Tiltmeters
• 272 Automatic UMPs
• 14 AMTS (Cyclops)
• 13 Vibration Monitors
• 2 Noise Monitors
• Integrated Data Management Software (IDMS)

All collected data is delivered in near real-time through Sixense’s data management software Geoscope, which integrates the TBM’s position, helping to correlate the instrumentation data with the mining progress.

Project Status

Sixense will continue to provide services until the LA Outfall Tunnel project is complete (expected in 2026). It’s an honor to be a part of such an important project that will ensure a more reliable wastewater system for the Los Angeles County community.