Application field

Surface Water Analysis

ColiMinder™ is an analyser for monitoring fecal contamination in surface water.
It is able to detect microbiological contamination in 15 minutes.

Surface Water Quality Monitoring

Surface water is an essential source for drinking water, also serving people as bathing and recreational waters. Its microbiological quality is of essence as people get in direct touch, thus a probable faecal or microbiological contamination is affecting directly to people’s health.

To know the bacterial contamination of surface water in almost real time means to protect people’s health and environment:

  • Continuous and long-term monitoring of faecal contamination in both fresh and saline waters
  • Analysis of diurnal fluctuations of faecal contamination
  • Correlation of microbial contamination with environmental events such as CSO (Combined Sewer Overflow) or stormwater events
  • Early warnings in case of contamination events
  • Enabling short-term opening / closing of beaches and other swimming waters
  • Preventing water suppliers from fines and penalties due to exceeding of threshold values
  • Surface water mapping of lakes, rivers, sea, along beaches, shelters, …


How does it work?

The ColiMinder measures the specific metabolic (enzymatic) activity of the target organisms present in the sample.

The measured value provides information about the energy turnover of living organisms in the sample. Living organisms need energy, which they gain through their metabolism, so the metabolic activity reflects the energetic turnover of the existing microorganisms.

The measured activity directly indicates the faecal contamination level of the water.



How do I Use the ColiMinder?

ColiMinder can automatically monitor any type of surface water, bathing and recreational water and raw water, be it fresh or saline water, providing a direct visualization of microbial dynamics of the respective water body.

The timeline displays any change in microbial contamination, providing precise and valuable information that was previously unavailable.

Since the results of the ColiMinder are available in near real time, microbiological water quality is now available as an evidence-based decision parameter. In addition, real-time alerts can be sent when defined bacterial contamination limits are exceeded.

The ColiMinder has proven its ability to specifically measure any type of fecal indicator bacteria or total microbial activity in surface water. It reliably detects any type of contamination, whether it is of fecal or microbial origin.

Different add-on modules are available to ensure stable and reliable sampling and results, even in harsh environmental conditions.

How do I use the results?

The measured enzymatic activity of the sample provides a direct answer to the question: “how high is the faecal contamination of the sample?”.

Depending on the reagent used, the measurement results are specific for the corresponding target organism.

The results not only provide direct quantitative information about the microbial contamination of the product, but shape and course of the measurement timeline also contain valuable information about the dynamics of the microbiological load and thus allow conclusions to be drawn about the causes of changes. Depending on the reagent used, the measurement results are specific for the corresponding target organism.


The analytical capability of ColiMinder in surface water measurements is comparable to that of determinations of HPC or to that of chromogenic coliform agar counts in the case of fecal contamination.

In many different scientific studies the ColiMinder has been used, evaluated or  validated for surface and raw water monitoring, e.g. in the latest publication by Burnet, J.-B (2021). Automated Targeted Sampling of Waterborne Pathogens and Microbial Source Tracking Markers Using
Near-Real Time Monitoring of Microbiological Water Quality. Water, 13, 2069.





The reliability of the ColiMinder has been demonstrated in several installations where the devices have been providing reliable measurement results in continuous operation since 2015.

Thanks to the sophisticated system for fully automatic cleaning and calibration, the maintenance effort is limited to refilling the consumables. Replacement of the silicone hoses is recommended every 2 years, otherwise no maintenance is required.


The ColiMinder instruments measure absolutely stable, no manual calibration is necessary as the instruments calibrate themselves automatically at regular intervals.


The ColiMinder can measure any type of sample without pre-treatment. It has no problem with suspended sediments or turbid samples.

Even fluctuating background fluorescence has no effect on the measurement result due to the measurement approach.

Its robustness towards environmental influences, like temperature, humidity, chemical load etc., is evident in installations like at Stonecutter Island Sewage Treatment Plant in Hong Kong, where it has been monitoring effluent 24/7 since 2017 without any issues.

It has got an IP65 protected housing, and it can measure in the temperature range from 0°C to 40°C





Can I do compliance testing with the ColiMinder?

The ColiMinder provides operational monitoring as recommended by the WHO, the EU Drinking Water Directive, and others.

Real-time measurement of current microbiological quality enables rapid response and correction, so the ColiMinder helps you to meet specified limits at the lowest cost and with the highest level of safety.

A correlation between standard lab results and ColiMinder results can be established and used internally but the system is not intended to replace compliance testing.

Can ColiMinder results be expressed in CFU ?

In contrast to classical culture-based laboratory methods, which are based on the cultivation of bacteria, the enzymatic measurement method of the ColiMinder is based on the direct measurement of the metabolic activity of the target organisms.

There is therefore no direct and generally valid conversion between the two methods.

In general, however, a correlation table can be created through comparative measurements, which can then be used for conversion.


Receive real-time warning

In case of contamination events, to enable qick reaction like closing beaches for swimming

Indentify sources of contamination

by high frequency measurements and 15 minutes time to result

Learn more about the dynamics of contamination levels

The result timelines (microbiological activity, transmission and intrinsic fluoresence of the sample) carry important additional information about the dynamics of your system

Safeguard your water quality

at raw water intakes

Scan your bathing area quickly

to ensure safe bathing and recreational activities

Avoid contamination events

by receiving near real-time warning in case of contamination events



ColiMinder device measuring E. coli levels at Blautopf, famous karstic lake in South of Germany, in cooperation with KIT (Karlsruhe Institute of Technology)


ColiMinder Emergency Response Unit (ERU) Mobile, with all necessary items to run contiuous measurements, can be operated in a car or boat.


ColiMinder monitoring recreational water of Canal de la Vilette in Paris, dedicated for Olympic Games’s swimming competition in 2024. Customer: Eau de Paris


The Coliminder in its portable version, located on a boat, mapping E. coli contamination levels of a lake in US. Project framed by a scientific study.

ColiMinder measurements of bathing water

 the timeline clearly shows the great advantage of near real-time measurement of fecal contamination to ebale tiemly opening and closing beaches for swimming

ColiMinder use cases

proven by customers!

The ColiMinder bacterial analyzer can be installed at any location for real-time surface water quality monitoring.

Beach Water Quality Monitoring

Sea Water Quality Monitoring

Raw Water Quality Monitoring

Well and Groundwater Quality Monitoring

Lake Water Quality Monitoring

Stream Water Quality Monitoring

River Water Quality Monitoring

CSO monitoring

For more information:

Several White Papers can be found here in the download area to provide further information about surface water measurements with the ColiMinder.


The ColiMinder™ had proven its reliability and stability in various drinking water applications world-wide


Austrian municipal drinking water production from groundwater well: the ColiMinder monitoring raw water intake and after activated carbon filtration in alternating mode.

Quick live introduction