How can wastewater pipes, sewers and manholes be inspected safely, efficiently and in accordance with regulations? Find out what opportunities are offered by automated pressure and leak testing in accordance with standards EN 1610, EN 805, DWA-A 139 and DWA-M 149-6, and how level measurement methods, clearance measurements and digital documentation can be effectively integrated into the workflow.
Before commissioning and during operation, wastewater pipes, sewers and manholes must be checked regularly for leaks. Different test procedures are used depending on the structure. At the same time, before entering any manhole, it must be ensured that there are no gases present that are hazardous to health or explosive. Modern measurement technology helps to carry out tests in accordance with standards, ensure health and safety at work and document results digitally.
When developing our technologies, we always take our customers’ practical needs as our guide. This is also reflected in our case studies. Find out more now!
As part of the maintenance or repair of the water, wastewater and district heating network as well as separator systems, the inspection of manholes is one of the tasks of the specialists. As work on and in manholes (often related to Confined Space Entry, CSE) is associated with various hazards, there are some aspects to consider. Depending on the location of a manhole, the local traffic situation must first be taken into account and, if necessary, measures must be taken to divert traffic.
The most common hazards when working in a manhole are the danger from substances, which include solids, liquids, vapours and gases, each in quantities and concentrations that are hazardous to health, and the danger of falling. As protection against a fall, a tripod with a height safety device including a rescue lift function is usually set up above the manhole. The person working in the manhole is attached to this by means of safety harnesses and ropes. In this article, we want to specifically address the hazard of dangerous gas concentrations and oxygen deficiency and describe the atmospheric testing with our gas detector OLLI.
In accordance with DGUV rules 113-004 and 103-003, atmospheric testing means determining a possible concentration of hazardous substances or the oxygen content before and during work in enclosed spaces with the aim of determining whether the atmosphere in the enclosed space allows safe working. It is thus a measure to protect workers from hazardous substances.
Among the gases in the vicinity of manholes, methane (CH4), carbon dioxide (CO2) and hydrogen sulphide (H2S) are the most common hazardous substances, in addition to oxygen (O2) deficiency. Occasionally, carbon monoxide (CO) is also monitored for, as this can be produced in road traffic during incomplete combustion of fuels.
Before each atmospheric test, the gas detector must be checked to ensure it is functioning correctly. This includes a visual inspection for damage and a quick display test using a suitable test gas. This so-called ‘bump test’ must be carried out every working day in accordance with DGUV Information 213-056 (T 021) and 213-057 (T 023), and simultaneously checks the function of the integrated pump.
On the OLLI, the ‘Bump Test’ function can be started directly from the main menu.
In addition to the daily quick gas test, the gas detector must undergo a functional check at least every four months. As well as a visual inspection, this also includes the calibration and, where necessary, adjustment of the sensors. On the OLLI, this is carried out directly via the “Calibration/Adjustment” menu item.
All functional tests and quick gas tests should be documented. With Esders Connect, these tests can be managed digitally, paperlessly and in compliance with all regulatory requirements.
Atmospheric testing is only carried out after a successful quick gas test and visual inspection – always before entering the manhole.
To do this, select the ‘Confined space entry’ function on the OLLI. The device is switched on in clean ambient air and is ready for use once the sensor initialisation phase is complete. The measurement is then carried out, for example with a float probe connected.
During the measurement, all measured values are shown on the display. If individual measured values exceed the set limit values, the device triggers an optical and acoustic alarm. In this case, the manhole must not be entered. Instead, appropriate measures such as ventilation or the use of personal protective equipment must be taken.
As the atmosphere in the manhole can change at any time, continuous monitoring is required once the atmospheric test has been completed.
The gas detector can either be carried directly by the person working in the manhole or deployed by the designated safety officer outside the manhole using a floating probe. The second option also protects the measurement device from contamination.
Atmospheric testing may only be carried out by competent personnel. This is based on DGUV Guideline 313-002.
The required expertise includes, in particular:
The atmospheric test must also be recorded.
What are the key factors to consider when carrying out the atmospheric test? What data needs to be checked? Our template for the atmospheric testing report for working in confined spaces, manholes and containers can make this task considerably easier for you.
We have drawn up a special protocol for atmospheric testing, which contains useful information on the threshold values of gas detectors for various gases, as well as a handy table to complete when carrying out measurements. Download it now by filling in the form below.
As part of our one-day seminar, we provide participants with the necessary professional knowledge. On request, we can hold the seminar at your premises. We cover both the legal framework and the specific requirements for handling hazardous substances, as well as selecting the appropriate measuring equipment. Our seminars also include practical sessions.
.jpg?width=100)
.jpg?width=100)
.jpg?width=100)
.jpg?width=100)
.jpg?width=100)
The smart memo is a versatile device for carrying out pressure tests. We offer simple, menu-guided test sequences for different test procedures in the gas, water and waste water sectors in accordance with applicable regulations. All test sequences in the device are programmed according to the current version of the
Table of Contents In Germany, more than 95% of the population is connected to the wastewater system, which means that Germany has a very large wastewater network. We have also summarized more information on the wastewater network in Germany for you here. Our wastewater system is also part of the
Table of Contents The wastewater network, just like the gas, electricity, and water networks, is part of the so-called critical infrastructure and is therefore subject to special protection. Due to possible attacks on this network as a result of the currently tense political situation, the maintenance and proper operation of
Leak tests are carried out, amongst other things, on new buildings and during refurbishments, as well as in accordance with the client’s requirements or the relevant regulations.
For newly laid wastewater pipes and manholes, EN 1610 provides the authoritative basis for pressure and leak-tightness tests.
The level measurement method is used in particular for tightness tests on manholes filled with water and enables precise monitoring of changes in the water level.
Before entering a manhole, it is essential to check for a lack of oxygen or the presence of hazardous gases. This measurement, called atmospheric testing, protects staff and forms part of a safe working process. This is where our OLLI (EX/OX/TOX) comes into play.
The most common gases include hydrogen sulphide (H₂S), methane (CH₄) and carbon monoxide (CO), as well as atmospheres with low oxygen content.
