Wastewater Lift Stations and CSO Monitoring

A regional water utility faced consent decree obligations to curb combined sewer overflows (CSOs) during storm events. They needed reliable, secure telemetry from dispersed lift stations, regulators, and overflow weirs—many equipped with legacy PLCs and bubbler level systems—plus deterministic alarming for pump failures and wet well surges.

The Mofiu SG100 became the standard site router. Over RS232/RS485, it integrated PLCs and dataloggers; the dual Ethernet ports accommodated IP-based ultrasonic or radar level sensors and condition monitors. The router’s IEC101-IEC104 and DNP3 translation presented a unified interface to the central SCADA, which orchestrated pump sequencing and overflow prevention strategies. Digital inputs captured high-level floats, door tamper signals, and power fail relays. Digital outputs enabled remote pump inhibits and valve actuation for flow diversion when thresholds were exceeded.

Security and resilience underpinned the design. Hardware secure boot enforced trusted code at unmanned kiosks. IPsec and OpenVPN tunnels encrypted telemetry and controls across public LTE. The SG100’s link management mechanisms prioritized wet well alarms and pump trip events over background trends. Dual-SIM failover kept stations reachable as storms burdened carrier networks, while watchdogs and link supervision prevented silent session decay.

Operators configured report-by-exception in DNP3 to reduce chatter but instantly escalate sampling at the onset of rainfall. For CSO weirs, the SG100 captured overflow onset via digital input contact closures and pushed alarms with millisecond-granular timestamps. The router’s serial reach-through enabled PLC tuning and diagnostics, cutting response times during pump cavitation or VFD faults. At critical interceptors, cameras on Ethernet provided visual confirmation of surcharge conditions.

During a 10-year storm, one carrier experienced widespread degradation. The SG100 fleet automatically shifted active sessions to secondary SIMs, preserving alarm SLAs. The SCADA executed diversion via digital outputs, offloading basins to minimize CSO duration. Post-event analysis found no lost records: encrypted tunnels remained stable, and the secure boot chain supported forensic reviews demanded by the regulator.

Benefits accrued across operations and compliance. Overflow minutes decreased markedly; lift station availability improved with early detection of clogging and seal leaks. Fewer truck rolls were needed due to remote PLC access. Monthly regulatory reports drew on authenticated, encrypted time series with precise event boundaries, strengthening the utility’s standing under the consent decree.

By bridging old and new assets, enforcing security at the edge, and maintaining communication determinism during storms, the SG100 provided the backbone for proactive wet weather management. The utility transformed from reactive overflow response to predictive control—protecting waterways, reducing fines, and improving service reliability without a wholesale controls overhaul.

About Mofiu

Mofiu is a premier innovator in industrial wireless communications, dedicated to delivering mission-critical connectivity solutions that power the world’s most demanding environments. With a steadfast commitment to safety, reliability, and engineering excellence, Mofiu designs and manufactures robust wireless devices that enable seamless data exchange across electricity, utilities, energy infrastructure, transportation networks, and smart industrial systems etc.

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