Why Corrosion-Resistant 3-in-1 Radar Flow Meters Are Becoming Critical for Sewer Overflow Monitoring

The reason is practical.

The revised EU Urban Wastewater Treatment Directive (EU) 2024/3019 places greater emphasis on monitoring storm-water overflows and developing integrated urban wastewater management plans.

Importantly, the Directive does not simply require every CSO above 10,000 population equivalent to install a specific radar flow meter. Instead, it requires representative monitoring of storm-water overflows in relevant agglomerations and requires integrated wastewater management planning where storm-water overflows create environmental or public-health risks.

This is where non-contact radar becomes increasingly attractive.

A typical overflow chamber can experience very different hydraulic conditions within the same day.

For a submerged flow meter, these conditions can translate into fouling, mechanical damage, cleaning requirements and difficult maintenance access.

Hydrogen sulfide is particularly important. European wastewater research has documented how H₂S generated in sewer systems can contribute to corrosion and create difficult measurement conditions.

The Honde RD-600S-02 combines three important measurements in one installation:

Instead of installing a submerged electromagnetic or mechanical flow sensor directly into the wastewater stream, the radar sensor can be mounted above the channel.

RD-600S-02 Key Specifications

For sewer applications, the most important feature is not simply the measurement range.

It is the combination of:

Standard outdoor radar equipment is not necessarily optimized for sewer environments.

A wastewater overflow chamber can expose equipment to:

Honde’s RD-600S-02 uses a hardened black industrial anti-corrosion coating designed to improve the protection of the external sensor structure in aggressive environments.

This makes the configuration particularly relevant to:

The strongest demand opportunity is not necessarily the country with the largest number of rivers.

It is the market where three conditions overlap:

1. Large or aging wastewater infrastructure
2. Increasing regulatory pressure for overflow monitoring
3. Investment in digital water and remote monitoring

Based on regulatory activity, existing monitoring programs, wastewater infrastructure and publicly documented smart-sewer projects, we assess the following markets as high-potential targets.

International Market Opportunity Assessment

Note: This is an engineering-market opportunity score based on publicly available regulatory and infrastructure signals, not a published national sales-volume ranking.

The UK provides one of the clearest examples of how sewer overflow monitoring is evolving.

According to the UK government’s 2025 storm-overflow guidance, all storm overflows in England are now fitted with Event Duration Monitors (EDMs). The installation program was completed in December 2023. Since January 2025, water companies have also been required to publish storm-overflow information in near real time.

This creates a much more mature monitoring market than simply installing a level sensor.

Utilities need to know:

• When an overflow starts
• When it stops
• How frequently it occurs
• Where it occurs
• How the system behaves during rainfall
• Whether additional hydraulic intervention is required

The UK also has formal MCERTS requirements for flow monitoring. The Environment Agency specifies performance and management requirements for flow measurement installations, including monitoring of sewage and trade-effluent flows.

One important commercial point is that RD-600S-02 should not be marketed as MCERTS-certified unless the exact product/system has the required certification. MCERTS certification concerns the monitoring installation and applicable equipment requirements, not simply the fact that a sensor uses radar.

Denmark provides another useful real-world example.

In March 2026, the Danish Environmental Protection Agency published results from the OVERLØB – Data-Driven Solutions for Reducing Environmental Effects of Overflows project.

• Water level
• Water flow
• Temperature
• Substance concentrations

The objective was to obtain better data on the hydraulic and pollutant effects of wastewater-system overflows and use that information to target environmental improvements more accurately.

That is exactly the type of application in which a 3-in-1 radar system can add value.

The United States has a different regulatory framework, but the engineering problem is similar.

The U.S. EPA estimates that approximately 700 communities have combined sewer systems experiencing CSO discharges, concentrated particularly in the Northeast and Great Lakes regions.

EPA also promotes smart sewer systems, real-time monitoring and data infrastructure for CSO management.

For example, EPA documents smart-sewer deployments using distributed sensors, real-time controls and decision-support systems to reduce overflow volumes and improve system management.

This makes the U.S. market particularly interesting for:

The strongest applications are not limited to CSO chambers.

Application Map

A radar sensor alone is only the first layer.

For a utility, the real value comes from turning field measurements into usable operational data.

Honde’s solution can be configured around three layers.

France is one of the most relevant European markets because the revised EU wastewater framework is increasing attention on storm-water overflows and integrated urban wastewater management.

A practical deployment could look like this:

Proposed Configuration

The objective is not merely to produce a sensor reading.

It is to create a continuous chain:

The traditional measurement question is often:

For wastewater applications, another question is equally important:

A non-contact radar configuration can reduce exposure to:

This can be particularly valuable at remote overflow structures where maintenance access is expensive or where confined-space entry creates additional safety requirements.

The UK MCERTS EDM guidance explicitly emphasizes that monitoring equipment should be accessible for safe maintenance, inspection and verification, and that the monitoring point should not interfere with cleaning and maintenance of the overflow structure.

Based on the terminology used by regulators, utilities and the wastewater-monitoring industry, the most commercially useful keywords should focus on application + measurement + technology, rather than simply repeating “water flow sensor.”

Core High-Intent Keywords

High-Value Long-Tail Keywords

Based on the regulatory environment, existing overflow-monitoring programs, smart-water investment and the need for remote measurement, the current market opportunity can be visualized as follows:

Index = Honde engineering-market opportunity assessment, not official market-size data.

The UK currently stands out because storm-overflow monitoring is already highly developed: all storm overflows in England have EDM systems, and near-real-time publication requirements have been in place since January 2025.

France is particularly interesting for new European infrastructure investment, while Denmark demonstrates how dense sensor networks and data-driven overflow management are being used to improve understanding of environmental impacts.

The United States represents a different but substantial opportunity because of its large installed base of combined sewer systems and established CSO monitoring and smart-sewer programs.

The next generation of wastewater monitoring will not be defined by one sensor technology.

It will be defined by how effectively field instruments generate reliable data for utility operators.

A modern system can therefore be structured as:

This architecture can be adapted from a single remote monitoring point to a distributed network covering dozens or hundreds of locations.

For wastewater utilities, the value of an anti-corrosion radar flow meter can be summarized in five areas:

Honde Technology — Smart Monitoring for Water Infrastructure

Honde Technology Co., Ltd.

Product: RD-600S-02 Anti-Corrosion 3-in-1 Radar Flow Meter