Sewer Blockage and Fatberg Detection
Radar level monitoring in manholes that warns before a blockage becomes a spill
Fats, oils, grease and wet wipes build up into fatbergs that narrow the sewer until it blocks. The first sign is a slowly rising level upstream, long before sewage reaches the street or a watercourse.
The ThingsLog LPMDL-210X hangs under the manhole cover and measures that level with a built-in 60 GHz radar, with nothing in the flow. It runs for years on its battery and reports over LTE-M or NB-IoT.
For manholes classified as hazardous areas, the Ex variant is designed for ATEX Zone 0.
Key Features and Capabilities
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1. Built-in 60 GHz Radar
- The radar inside the logger measures up to 6 m through the enclosure
- Narrow 8° beam keeps manhole walls, ladders and pipes out of the measurement
- Range up to 6 m; sensor accuracy from 2.7 mm at short range to 5.1 mm at long range (typical standard deviation, A121 datasheet)
- Advanced detection of objects at different levels
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2. Early Blockage Warning
- Level alarms on thresholds and on deviation from the normal daily profile
- Uploads become more frequent after an alarm, so the event is followed as it develops
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3. Designed for ATEX Zone 0
- The Ex variant of the LPMDL-2106 is designed to intrinsic safety requirements, target marking II 1G Ex ia IIB T4 Ga
- ATEX certification is in progress; contact us for the current status
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4. Years on One Battery
- Two D-size lithium cells inside the IP68 enclosure, with no mains power and no solar panel
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5. Coverage Below Ground
- LTE Cat M1 and NB-IoT reach into chambers and manholes where other signals fade
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6. Chamber Climate
- Temperature and humidity are measured on every unit as extra context for each alarm
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7. Fast Installation
- One unit under the manhole cover: no external sensor, no cable and no cabinet
- Configured from the ThingsLog mobile app and the platform
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8. Open Data
- Dashboards, alarms and reports in the ThingsLog platform
- Data can be sent to SCADA, GIS and asset systems through the API
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9. Contactless Level Measurement
- Nothing touches the sewage, so there is no probe to foul or clean
- The logger hangs under the manhole cover, above the flow
Key Benefits
Fewer Spills
Crews are sent to a rising level, not to a flooded street.
Targeted Jetting
Clean the sewers that are actually silting up, instead of working to a fixed calendar.
Fewer Manhole Entries
After installation the data comes to the office; nobody has to lift covers to check levels.
Designed for Sewer Gas
The Ex variant is designed for Zone 0, where methane and hydrogen sulphide can be present.
Evidence for Reporting
Time-stamped level records document every event and the response to it.
Scales by the Manhole
Start with known hot spots and add points as the network demands.
Use Cases
Wastewater utilities and municipalities place level monitors at the points where blockages repeat: downstream of restaurants and food plants, at flat sections and siphons, upstream of pumping stations and at overflow chambers.
Fatberg Hot Spots
✔️ Follows the level trend where fat, oil and grease accumulate
✔️ Shows whether cleaning restored the full cross-section
Blockage Detection in Gravity Sewers
✔️ Detects the rise upstream of roots, debris and collapsed pipes
✔️ Compares neighbouring manholes to locate the affected section
CSO and Overflow Chambers
✔️ Records the start, duration and frequency of overflow events
✔️ Gives time-stamped evidence for spill reporting
Wet Wells and Pumping Stations
✔️ Independent level reading as a backup to the station control
✔️ High-level alarm when pumps fail or the inflow exceeds capacity
How It Works
1. Install Under the Cover
• The logger is suspended in the manhole and the radar looks down at the flow • No power, no cabling and no parts in the sewage
2. Learn the Normal Profile
• The level follows a daily pattern of dry-weather flow and rain events • Data arrives in the ThingsLog platform over LTE-M or NB-IoT
3. Detect the Deviation
• A level that rises and stays high points to a restriction downstream • The platform raises an alarm and the logger reports more often
4. Clear and Verify
• The crew jets the section before it surcharges • The level returning to its profile confirms the result
Fatberg and Blockage Detection for Wastewater Utilities
Many sewer floods start with a blockage that grew unnoticed. Continuous level monitoring turns that slow process into a visible trend and an alarm. The ThingsLog LPMDL-210X makes monitoring practical at scale: the radar sensor is built into the logger, the battery lasts for years, and the Ex variant is designed for ATEX Zone 0, so the same device family can be used in manholes where sewer gas is expected.
Explore the Product
LPMDL-210X Data Logger with Built-in Radar Level and Pressure
One IP68 unit with radar level, pressure, temperature and humidity inside, LTE-M / NB-IoT or 4G, and an Ex variant designed for ATEX Zone 0.
Sewer Blockage and Fatberg Detection: FAQs
Answers about installation, hazardous areas, battery life and data.
How does level monitoring detect a fatberg?
A fatberg narrows the pipe, so the level upstream rises and stays higher than the normal daily profile. The platform compares each reading with thresholds and with the usual pattern and raises an alarm when the deviation persists.
Does the sensor touch the sewage?
No. The radar is inside the logger and measures the distance to the surface from above, through the enclosure wall.
Can it be installed in a manhole classified as an ATEX zone?
The Ex variant of the LPMDL-2106 is designed for Zone 0 with target marking II 1G Ex ia IIB T4 Ga. Certification is in progress; contact us for the current status before installing in a hazardous area.
How deep can the manhole be?
The radar measures up to 6 m from the logger to the liquid surface.
How is the data used?
Levels, alarms and reports are available in the ThingsLog platform and mobile app, and can be forwarded to SCADA or other systems through the API.
Still have questions? Contact us to discuss your wastewater metering needs or visit our Help Center.
