Transforming Safety Management in Large Underground Sewage

 Treatment Facilities with UWB + Wi-Fi Hybrid Positioning 

Background

As cities advance their ecological governance and carbon-reduction goals, underground sewage treatment plants are increasingly adopted to minimize land occupation and eliminate the traditional“NIMBY” effect.
In Jiangsu, a major Phase III expansion project—now the province's largest and highest-standard underground sewage treatment facility—processes 100,000 m³/day across a 5.6-hectare footprint, serving 116 km² of surrounding area.

However, the fully buried structure introduces significant safety challenges. With 90,000+ m² of enclosed underground space, limited ventilation, and the presence of toxic gases such as hydrogen sulfide and ammonia, workers face multiple risks: poisoning, suffocation, explosion, electric shock, and falls.

The plant required a high-precision, reliable, and intelligent personnel safety management system capable of addressing these unique risks.

Challenges

1. Blind spots in underground safety
Two underground levels, scattered work areas, and complex operational tasks make personnel supervision difficult.

2. Unauthorized access to hazardous zones
Contractors and non-operational personnel may enter restricted areas accidentally, increasing risk.

3. Slow emergency response
Without precise location data, rescue teams lose valuable time during emergencies.

4. Weak patrol traceability
Manual inspections are prone to omissions and lack verifiable records.

Solution: UWB + Wi-Fi Hybrid Precision Positioning System

To build a safety framework that“sees clearly, manages proactively, and responds rapidly,” the project deployed Woxu's UWB high-precision positioning system, combined with Huawei industrial Wi-Fi APs through an innovative dual-network fusion architecture.

Deployment Highlights

• Full underground coverage of B1 (49,400 m²) and B2 (41,970 m²)

• 100+ UWB anchors, industrial Wi-Fi APs, and personnel positioning tags

• LS-1000 location engine for real-time data processing

• Shared wireless channel: UWB data transmitted via Wi-Fi network to reduce IoT deployment cost
  

Core Safety Capabilities

1.Dual-function badge (Positioning + Access Control)
UWB tags integrate RFID to support both location tracking and role-based access control, streamlining operations.

2. Restricted-area authorization
Unauthorized entry triggers instant alerts and automatic security notifications, eliminating “blind intrusion” risk.

3. Intelligent personnel management
Real-time 2D/3D location visualization
Historical trajectory playback
Automatic detection of boundary crossing, idle time, clustering, and post abandonment
Video linkage for dual confirmation during alarms

4. Closed-loop patrol management
Pre-patrol: configurable tasks and routes
In-patrol: progress tracking and coverage monitoring
Post-patrol: structured reports and video-backed validation

5. Accelerated emergency response
One-click SOS with instant pop-up and video linkage
One-click evacuation with mass vibration/beeper alerts
Automated muster counting via geofencing
Last-known-location rescue routing

Results

• After implementation, the system achieved:

• Emergency response time reduced to under 10 seconds

• Rescue efficiency improved by more than 60%

• Patrol compliance rate exceeded 98%

• Significant reduction in equipment-related incidents

• A full shift from manual, reactive safety management to digital, intelligent, and proactive control

Conclusion

Woxu's UWB High-Precision Positioning System provides centimeter-level accuracy, millisecond-level alerts, and multi-system integration—ideal for complex industrial environments such as underground facilities.

The solution has now been deployed in water treatment plants, smart construction sites, chemical facilities, power utilities, and tunnel corridors, supporting enterprises in building a more proactive and data-driven safety management framework.