New:
Gunkel, G. & Michels, U (2019) Das neue Arbeitsblatt W 271 – Herausforderungen und Erfahrungen aus der Praxis. 33. Oldenburger Rohrleitungsforum 2019, 118-127, Vulkan Verlag, ISBN 978-3-8027-2885-3.
Michels, u. & Gunkel, G. (2019) Verminderung von Kleintieren in der Trinkwasserverteilung. 33. Oldenburger Rohrleitungsforum 2019, 128-139, Vulkan Verlag, ISBN 978-3-8027-2885-3.
Gunkel, G., Michels, U. & Scheideler, M. (2018) Erfahrungen und Effizienz der Rohrnetzpflege bei Anwendung des CO2-Spülverfahrens - Vorkommen der Wasserasseln in Trinkwassernetzen. gwf Wasser Abwasser, 12/2018, 77-84.
Gunkel, G., Michels, U. & Scheideler, M. (2018) Kleintiere in der Trinkwasserverteilung – Vorkommen und Anwendung des Arbeitsblatts W 271. Teil 1. Makroinvertebraten. energie wasser praxis 11, 20-27.
German Technical Paper, Working Sheet W 271:
Technische Regeln - Arbeitsblatt W 271
Invertebraten in Wasserversorgungsanlagen: Vorkommen und Empfehlungen zum Umgang. DVGW Verlag, 51 S., 2018
see German short comments >>>Page W 271
Competence team `Biological Drinking water quality´
The competence team `Biological drinking water quality´ is a multi-disciplinary co-operation of specialists in the field of drinking water.
Scientific competences:
Drinking water monitoring – Pipe network maintenance – Determination and evaluation of small invertebrates in drinking water networks – Problem orientated analyses and development of management plans – Training events
Partners of the competence team are:
These services are available
- Sampling, analyses and evaluation of the development of small invertebrates in drinking water networks
- Consultation on drinking water network monitoring and pipe network maintenance
- Consultation on the implementation of W 271 (German Worksheet `Invertebrates in drinking water networks´)
- Implementation of training and continuing education measures concerning occurrence of small invertebrates in drinking water networks and pipe network maintenance.
New: The working sheet W 271 is published
https://shop.wvgw.de/Produkt-Katalog/DVGW-Regelwerk/DVGW-Regelwerk-Wasser/Netze-und-Speicherung/W-271-Arbeitsblatt-04-2018
New: The dissertation of Dr. Ute Michels
Invertebraten in Trinkwasserverteilungssystemen. Lebensraum, Verbreitung, Nahrungsbeziehungen (2018)
Berlin University of Technology, is online available, download >>>.
Small invertebrate (water lice) in the drinking water networks –
Research focus
The research and evaluation of small invertebrates in drinking water networks includes non-visible amoeba and ciliates (micro-invertebrates, < 0.5 mm), nematodes, copepods and water fleas (meiofauna, 0.5 -. 2 mm) and macro-invertebrates that are visible to the naked eye such as water lice, bristle worms (oligochaete) and midge larvae (chironomidae).
Water lice represent an aesthetic problem in the drinking water supply, and hygienic impact can occur by faeces of the animals (the faeces is very stable) and by dead animals.
Increasing water temperatures and a decreasing water use are triggers for an increased development of water lice in pipe lines and require an intensification of the monitoring and the pipe network maintenance.
Monitoring of small invertebrates in drinking water networks by hydrants
The monitoring of the colonization of drinking water networks by small invertebrates can be done using hydrant samples, 1 m3 water with a flow rate of > 0.5 m sec-1 must be abstracted. The animals are gently separated using a low pressure-high flow rate stainless steel filter with a mesh size of 100 µm, and the samples are analysed by a microscopy technique.
The evaluation and classification of the abundance of small invertebrates is done by statistical methods using a data bank of 1039 actual data sets from hydrant sampling.
The development of standardized sampling at hydrants enables a simple monitoring of the development of small invertebrates in drinking water networks with low cost and work. The data bank can serve as the basis for definition of control and intervention values, with
(1) without findings, normal population development
(2) tolerable development (= control range) and
(3) mass development (= intervention range).
This evaluation is currently under application to different species.
Actual we are calibrating this evaluation.
|
Group of animals (macroinvertebrates) |
Steadiness of
occurrence |
Mean abundance |
Size range (mm) |
|
Water lice (Asellus aquaticus) |
79,3 |
7,7 |
1 - 20 |
|
Bristle worms (Oligochaeta) |
74,9 |
6,0 |
< 30 |
|
Cave fled cancer (Niphargus aquilex) |
1,4 |
1,9 |
< 5 |
|
Mosquito larvae, snails, and others |
isolated |
|
|
CO2 Flushing of drinking water networks
The newly developed CO2 flushing method is very successful in elimination of water lice from drinking water networks, here CO2 enriched water is injected into a pipe section to sedate the animals and flush them out.
The CO2 enriched water is generated in a CO2 reactor. At the exhausting hydrant a big low pressure-high volume filter with 100 µm mesh ize is operating to separate the macro-invertebrates for control and evaluation of the number of organisms, which had been in the pipe, as well as to prove a sufficient elimination of the water bugs. The flushing with 2 – 3 times of the pipe volume is sufficient to remove nearly all (> 98 %) water lice.
This flushing method has been awarded the Professor Adalbert Seifriz Award (2013) and the Zenit Innovation Award (2015).
The CO2 flushing method is continuously further developed (application to large pipes, reduction of the CO2 consumption, and comparison with other flushing technologies).
CO2-flushing of drinking water pipes: water abstraction by a hydrant, filtering and enrichment with CO2, injection into the flushing sector, and outlet with monitoring at the third hydrant. © Gunkel
Further research projects:
- Impact on biological stability of drinking water,
- Criteria for evaluation of biological drinking water quality,
- Small animals as carrier/host for potential human pathogen microbes,
References
- Michels, Ute, (2018) Invertebraten in Trinkwasserverteilungssystemen. Lebensraum, Verbreitung, Nahrungsbeziehungen. Dissertation Technische Universität Berlin. 111 S. + Anhang. download >>>
- Scheideler, M. & Gunkel, G. (2015) Trinkwasseruntersuchung mit System – Die neue INWERT®-Methode. 3R, 10-11, 69-74.
- Gunkel, G, Michels, U & Scheideler, M. (2015) Invertebrates in Drinking Water Distribution Systems – Filter System for Hydrant Sampling and CO2-Flushing for Elimination of Water Bugs. gwf-Wasser / Abwasser Internat., 156, 52-56,
- Michels, Ute, Gunkel, Günter & Scheideler, Michael (2014) Im Fokus der Wasserversorger – die biologische Trinkwasserqualität. Vom Wasser 112, 3, 93-95.
- Michels, U., Gunkel, G., Scheideler, M. & Ripl, K. (2013) Invertebraten im Trinkwasser - Probenahme, Analytik und Bewertung. Universitätsverlag der Technischen Universität Berlin, ISBN
978-3-7983-2575-3, 98 S.
Download> - Michels, U., Gunkel, G., Scheideler, M. & Ripl. K. (2013) Neues Verfahren zur Probenahme, Analytik und Bewertung von Wirbellosen Tieren in Trinkwasserverteilungssystemen. gwf-Wasser / Abwasser 154, 896-897.
- Gunkel, G. & Titze, D. (2013) Kotpellets als Indikator für die Besiedlung von Trinkwasser-Versorgungssystemen mit Wasserasseln. gwf-Wasser / Abwasser 154, 996-1002.
- Gunkel, G. & Scheideler, M. (2011) Wasserasseln in Trinkwasser-Verteilungssystemen - Eintrag, Vorkommen Bewertung und Bekämpfung der Wasserasseln. gwf–Wasser | Abwasser 308-388.
- Gunkel, G., Michels, U., Scheideler, M. & Ripl, K. (2010) Vorkommen und Bedeutung von Kleintieren in Trinkwasser-Verteilungssystemen – Maßnahmen zu deren Regulierung. 3R, 716-724.