Remote Monitoring of Pumping Stations: A Practical Guide and Lessons Learned
Pumping stations—for wastewater lift stations, drinking water supply, irrigation, and industrial drainage—face a common challenge: they are scattered across vast areas, often in hard-to-reach yet critical locations. An undetected pump failure can cause an overflow, an interruption in service, or significant property damage.
Remote monitoring is no longer a luxury for these facilities: it is an operational necessity and, in certain regulated sectors (drinking water, wastewater treatment), a compliance requirement.
1. Specific Challenges Facing Pumping Stations
The Actual Operational Context
An operator managing multiple pumping stations typically oversees between 20 and 200 sites, with a team of a few maintenance technicians covering hundreds of square kilometers. The stations are often:
- Geographically isolated: rural areas, riverbanks, undeveloped land, sometimes difficult to access in bad weather
- Unmanned: no permanent staff on site; scheduled visits 1 to 4 times a month
- Critical to service: a pumping station that goes out of service can cause a sewer overflow or an interruption in the drinking water supply within hours
- Subject to regulatory requirements: water and wastewater operators are subject to the Environmental Code and prefectural decrees, and must submit service reports
Without remote monitoring, the system operates on a reactive basis: a user call, a local alarm (siren, red light), or a periodic patrol signals the problem. Response time is measured in hours, and sometimes in days for the most remote sites.
The Costs of a Reactive Approach
Unnecessary Service Calls: Between 30 and 50% of service calls triggered by alarms are "false alarms"—the technician arrives on site only to find that the problem has resolved itself (automatic pump restart, a temporary power outage) or that the issue does not require immediate attention. A callout costs between €400 and €700 (vehicle, time, and allowances).
Poorly Prepared Service Calls: Without a remote diagnosis, the technician doesn't know what to expect and can't bring the right replacement parts. An extra round trip to pick up a part can double the cost of the service call.
Late Detection of Incidents: A pump that is cavitating (sucking in air), running dry, or whose impeller is beginning to deteriorate can operate for several days in a degraded state before suffering a complete failure. During this time, the pump’s service life is reduced, and the risk of sudden shutdown increases.
Challenges with Regulatory Compliance: Producing annual service quality reports (RPQS for drinking water, operator’s annual report for wastewater treatment) requires a significant amount of manual data consolidation if the data is not automatically archived.
2. Typical Architecture: From Sensor to Dashboard
Architecture Overview
┌──────────────────────────────────────────────────────────────────┐
│ Station de pompage SP-42 │
│ │
│ [Capteurs de mesure] │
│ ├── Niveau bâche : sonde à ultrasons ou pression relative 4-20mA │
│ ├── Débit : débitmètre électromagnétique (impulsions ou 4-20mA) │
│ ├── Courant moteur P1 : transformateur de courant (TA) │
│ ├── Courant moteur P2 : transformateur de courant │
│ └── Présence alimentation : contact sec sur TGBT │
│ ↓ │
│ [Coffret de régulation / Automate] │
│ ├── Siemens LOGO! 8 / S7-1200 │
│ ├── Schneider M221 / M241 │
│ ├── Wago PFC200 │
│ └── Coffret "vrai de vrai" relais + télémesure ancienne │
│ ↓ Modbus TCP ou RTU │
│ [Gateway Eziwan] ← Rail DIN, 24V DC │
│ └── 4G LTE Dual SIM ──────────────────────────────────────────┤
│ │
└──────────────────────────────────────────────────────────────────┘
│ Tunnel OpenVPN
▼
[Cloud Eziwan]
├── Base time-series (données horodatées)
├── Moteur d'alertes
└── Tableau de bord web + app mobile
│
▼
[Salle de conduite — téléopération]
[Application mobile — astreinte]
[Email/SMS — responsable exploitation]
Selecting the Protocol Based on the PLC
| PLC | Protocol | Notes |
|---|---|---|
| Siemens S7-1200 (firmware V4+) | Modbus TCP | MB_SERVER in OB1 |
| Siemens LOGO! 8 (firmware ≥ 1.80) | Modbus TCP | Enable in LOGO! Soft Comfort |
| Schneider M221 / M241 | Modbus TCP | EcoStruxure Machine Expert |
| Schneider M340 | Modbus TCP | EcoStruxure Control Expert |
| Wago PFC100 / PFC200 | Modbus TCP or MQTT | Native MQTT on PFC200 |
| Older PLCs without Ethernet | Modbus RTU (RS-485) | Via the gateway’s RS-485 port |
| Relay cabinets without a PLC | Direct digital inputs | Via the Eziwan expansion module |
Station Management Without a Controller
For the many small lift stations that do not have a programmable logic controller—just a starter panel with contactors and relays—the Eziwan gateway can be connected directly to field signals via a digital I/O expansion module:
[Contact sec "Pompe 1 en marche"] ──→ [Entrée TOR 1 gateway]
[Contact sec "Défaut thermique"] ──→ [Entrée TOR 2 gateway]
[Sonde niveau 4-20mA] ──→ [Entrée analogique gateway]
This approach makes it possible to retrofit existing stations without modifying the wiring or installing a controller.
3. Essential Monitoring Variables
Standard Supervision Plan for a Pumping Station
For a station with two pump sets (the most common configuration), here are the minimum variables to monitor:
Status variables (Boolean values):
%MW300 bits :
bit 0 : Pompe 1 en marche
bit 1 : Pompe 2 en marche
bit 2 : Défaut thermique pompe 1 (disjoncteur déclenché)
bit 3 : Défaut thermique pompe 2
bit 4 : Défaut disjoncteur général
bit 5 : Alimentation électrique présente
bit 6 : Niveau haut bâche atteint (pré-alarme)
bit 7 : Niveau très haut bâche (alarme)
bit 8 : Niveau bas bâche (risque fonctionnement à sec)
bit 9 : Mode manuel activé (maintenancier sur place)
bit 10 : Défaut sonde niveau (valeur hors plage ou absence signal)
Analog variables (16- or 32-bit registers):
%MW100 : Niveau bâche (% × 10 → ex. 752 = 75.2%)
%MW101 : Débit instantané (L/min)
%MW102-103 : Volume journalier pompé (m³ × 1000, int32 sur 2 registres)
%MW104 : Courant moteur pompe 1 (A × 10 → ex. 142 = 14.2 A)
%MW105 : Courant moteur pompe 2 (A × 10)
%MW106 : Nombre de démarrages pompe 1 (compteur)
%MW107 : Nombre de démarrages pompe 2 (compteur)
%MW108-109 : Durée de marche cumulée P1 (minutes, int32)
%MW110-111 : Durée de marche cumulée P2 (minutes, int32)
%MW112 : Tension secteur (V × 10)
%MW113 : Code défaut détaillé (bitfield constructeur)
Why Monitor Motor Current
Monitoring motor current is the most informative indicator for preventive maintenance of pumps:
Cavitation Detection: A pump that is drawing in air has a lower-than-normal motor current (the fluid is less dense). This is an early indicator of a level or suction problem.
Dry-run detection: The current drops sharply below the rated no-load current. There is a risk that the mechanical seal could be damaged within a few minutes.
Rotor Deterioration: A worn or fouled rotor consumes more current for the same flow rate. A gradual increase in current at a constant flow rate indicates that maintenance is needed.
Power Supply Issue: An unbalanced current between phases (on a three-phase pump) may indicate a faulty cable or a problem with the site's electrical system.
Set up an alert in Eziwan for motor current: trigger an alert if the current exceeds 115% of the reference value (overload) or falls below 60% (cavitation/dry running). These two thresholds help detect the most common problems before a failure occurs.
4. Configuring Multi-Level Alerts
Alert Hierarchy
An effective alarm system for a pumping station must be calibrated to prevent alarm fatigue (too many alarms → operators ignore them) while ensuring that critical incidents are reported immediately.
Level 1 — Information (team leadership email):
Démarrage pompe 2 alors que pompe 1 est déjà en marche
→ Information uniquement (situation normale en pointe)
Niveau bâche > 75% alors que les deux pompes sont en marche
→ Vérification débit entrant inhabituellement élevé
Level 2 — Pre-alarm (email + mobile app notification):
Niveau bâche > 85%
→ Situation anormale, surveiller l'évolution
Courant moteur > 110% de la valeur de référence pendant > 2 minutes
→ Surcharge légère, vérifier à la prochaine ronde
Aucune mise en marche des pompes depuis > 24h alors que niveau > 30%
→ Pompes peut-être en défaut silencieux
Level 3 — Alarm (SMS + email + on-call webhook):
Niveau bâche > 95%
→ Risque de débordement, intervention urgente
Défaut thermique pompe 1 ET pompe 2 simultanément
→ Station hors service, intervention immédiate
Courant moteur < 40% de la valeur nominale pendant > 30 secondes
→ Fonctionnement à sec probable, arrêt automatique conseillé
Perte d'alimentation électrique
→ Toutes les pompes s'arrêtent, vérifier groupe électrogène si disponible
Perte de connectivité gateway > 15 minutes
→ Impossible de savoir l'état de la station
Configuring Time Slots and Escalation
Alerts can be configured with time ranges and escalation rules:
Défaut thermique pompe :
Heure ouvrée (8h-18h) → SMS technicien de service
Nuit / week-end → SMS astreinte + email responsable
Si pas d'acquittement en 30 minutes :
→ Appel téléphonique (webhook vers système de téléphonie)
→ SMS responsable de service
5. History, Compliance, and Regulatory Reporting
The Value of Historical Data
A pumping station's historical data is a valuable operational asset that accumulates over time:
Long-Term Trend Analysis: Compare the motor current curves for Pump 1 in January 2024 and January 2025. An 8% increase indicates that the rotor is wearing out—schedule preventive maintenance before a failure occurs, during the winter shutdown.
Correlation Between Rainfall and Inflow: For wastewater pumping stations, the correlation between rainfall events and inflow helps determine storage capacity and identify instances of extraneous water entering the system.
Optimizing Control Parameters: Analyze start/stop cycles: A pump that starts more than 15 times per hour indicates a sizing issue (pump too powerful, tank too small) or a control issue.
Regulatory Reports for Water and Sanitation
For operators under a public service delegation (DSP) or a lease agreement, several reporting requirements apply:
RPQS — Report on Price and Service Quality: Required annually by the General Code of Local Authorities (CGCT) for drinking water and wastewater services. Must include performance indicators: water quality compliance rate, service interruption rate, volume produced/distributed, and network efficiency.
The Eziwan dashboard automatically generates the raw data for these metrics (pumped volumes, downtime, number of incidents).
Required Monitoring Reports: Certain water intake or discharge facilities require periodic reports to be submitted to the DREAL (Regional Directorate for the Environment, Planning, and Housing). Historical data from Eziwan can be exported as CSV files to populate these reports.
Data Retention: For drinking water, monitoring data must be retained for at least 5 years. Eziwan allows you to configure data retention for up to several years, depending on your subscription plan.
6. Real-world example: Reducing field trips
Background
An intermunicipal wastewater management authority in the Pays de la Loire region oversees 65 pumping stations spread across an area of 1,500 km². Before the Eziwan deployment:
- 3 maintenance technicians covering the entire area
- Approximately 180 service calls per year (2.8 per site)
- Estimated budget for travel and on-call duties: €85,000 per year
After 12 months of using Eziwan
Field visits avoided thanks to remote diagnostics:
- 45% of alarms resolved remotely without a field visit (remote reset, confirmed non-emergency diagnosis)
- 20% of service calls prepared in advance thanks to the pre-alarm feature (technician leaves with the correct part)
Measured results:
- Trips: from 180 to 105 per year (-42%)
- Average response time: from 3 hours to 1 hour and 45 minutes (improved preparation)
- Incidents detected before failure: 8 cases over the year (pumps with current drift)
- Estimated savings: €38,000/year in maintenance costs
Our customers who operate pumping stations see an average reduction of 35 to 55 percent in travel within the first 12 months after deployment.
For secure remote access configuration on pumping station PLCs, see Industrial VPN vs. TeamViewer and How to Connect to an S7 Remotely.
FAQ — Remote Monitoring of Pumping Stations
Does the gateway work with older lift control panels that don't have a programmable logic controller?
Yes. Using the digital I/O expansion module, the gateway can directly read the dry contacts on electromechanical starter cabinets: pump status, thermal fault, and power supply presence. For 4–20 mA analog level sensors, a direct analog input is available. This approach eliminates the need to install a PLC at existing stations.
How many variables can be monitored on a small station (LOGO! 8 or M221)?
The Siemens LOGO! 8 supports up to 64 configurable Modbus blocks, and the Schneider M221 supports up to 100 %MW words in Modbus TCP. For a standard station with two pumps, the monitoring plan described in this article (approximately 20 variables) is well within the limits of these PLCs. The Eziwan gateway itself has no practical limit on the number of variables it can collect.
Are the pumped volume data accurate enough for RPQS reports?
This depends on the accuracy of the installed flow meter (typically ±0.5% to ±2% for an electromagnetic flow meter). The gateway collects and time-stamps the pulses or the analog value from the flow meter with a configurable resolution (every second if necessary). The Eziwan history can be exported to CSV with all raw measurements for the integrated volume calculations required by the RPQS.
How can we deal with frequent power micro-outages at certain rural sites?
The Eziwan gateway boots up in less than 30 seconds after a power outage and automatically reestablishes the VPN tunnel. Data collected before the outage is already transmitted to the cloud. If the outage lasts longer than 30 seconds, the gateway buffers the data as soon as it restarts and retransmits it. For sites with very frequent outages (several times a day), a small-capacity 24 V DC UPS (with a few minutes of runtime) is sufficient to handle micro-outages.
Is it possible to send remote commands to the pumps (reset, start)?
Yes, by writing to Modbus registers (FC=06 or FC=16). This feature must be explicitly enabled in the Eziwan configuration and protected by restrictive access rights (only certain accounts are allowed to write). Full traceability is ensured: each register write is logged with the operator’s ID and a timestamp.
Do you operate scattered pumping stations and want to set up centralized monitoring?
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Overview of the architecture, features designed for water and energy operators, and subscription plans tailored to fleets of 10 to 500 sites.
