Summary of the technical information from the DVGW with the W 274 fact sheet
Planning, construction and operation as well as self-monitoring of public drinking water wells
· The DVGW regulations are the result of volunteer work. According to case law, there is only one presumption, that the information (fact sheets) prepared is correct in terms of content and subject matter.
· The DVGW regulations are available to everyone and In principle, an obligation may not consist of legislative or administrative provisions.
· By applying the DVGW regulations, no one evades responsibility.
· The DVGW regulations are not the only source of knowledge for professional solutions, but a further source of knowledge.
The leaflet was prepared by the “Drinking Water Fountains” project group in the “Water Quality” Joint Committee.
In the EU Drinking Water Directive, the EU Commission calls on Member States to improve access to water for human consumption for all people and to promote the use of drinking water. This is to be done by installing outdoor and indoor systems in public places.
This fact sheet serves as a basis for the planning, construction and operation of drinking water wells. The leaflet provides the operator with general assistance.
For the monitoring of drinking water wells by health authorities, the federal-state working group (BLAG) developed a guideline “Recommendations for monitoring drinking water wells” for small plants.
The promotion of the use of drinking water is also supported by politicians and scientists for reasons of environmental and climate protection. For example, Directive (EU) 2020/2184 of the European Parliament and of the Council on the quality of water intended for human consumption (EU Drinking Water Directive) requires that more drinking water be made available in public places.
Drinking water fountains provide drinking water to the public. They are therefore subject to the Drinking Water Ordinance (TrinkwV) and therefore to monitoring by the responsible health department.
Scope of application
This leaflet does not apply to
· Drinking water intake points in Inneres of buildings.
· Installation-based water dispensers attached to the drinking water installation in buildings are connected and cool the water to be dispensed and, if necessary, add carbon dioxide
Legal obligations of entrepreneurs or other owners of drinking water wells
Local health authorities are responsible for enforcing the Drinking Water Ordinance
In the case of drinking water wells (“e-systems” in accordance with §3 number 2 letter e TrinkwV), the following events must be notified at least 4 weeks in advance:
· Construction, commissioning and recommissioning
For seasonally operated drinking water wells (“f-systems” in accordance with §3 number 2 letter 5 TrinkwV):
· The construction or commissioning and the expected duration of operation must be reported as early as possible
The report should be made in consultation with the responsible health authority, so that a pragmatic approach is also possible, e.g. collective reports of drinking water wells. A sample form is available in Appendix A.
The materials and materials in contact with drinking water must be suitable for drinking water (§ 17 TrinkwV).
Road safety obligation
Drinking water wells must comply with road safety requirements. The construction of the drinking water well and the outdoor area must be safe (e.g. no tripping hazards). Drinking water wells that are operated all year round may be at risk of frost. Frost combined with escaping water can cause ice formation and thus to a risk of accidents for people.
The use of public space for drinking water wells must be approved by the responsible municipal authorities. Accordingly, the necessary permits must be obtained from the USi. It must also be clarified whether a permit is required for discharge into the sewer or for discharge into a body of water. If a permit is required, it must be obtained from the competent authorities before the drinking water well is installed.
Drinking water from drinking water wells must not cause health problems for consumers (§ 4 paragraph 1 TrinkwV) .Drinking water wells must be planned, built and operated in accordance with generally accepted technical rules (§ 17 TrinkwV).
Drinking water wells must also comply with the principles of drinking water hygiene. These include:
· Avoiding stagnation
· Avoiding stagnation
· regular maintenance
· regular microbiological tests
Materials and products in contact with drinking water
All parts of the plant that come into contact with drinking water as intended must be hygienically perfect and suitable for use in the drinking water sector.
Organic materials and products or materials and products with organic components must meet the requirements of the Federal Environment Agency's assessment basis for plastics and other organic materials in contact with drinking water (KTW-BWGL), meet the requirements of another valid UBA line and the requirements of DVGW worksheet W 270.
Metal materials must meet the requirements of DIN 50930-6 and the Federal Environment Agency's assessment basis for metallic materials in contact with drinking water.
All assembly aids and other auxiliary materials must be selected with regard to their hygienic suitability and used sparingly. Solders and fluxes must comply with DVGW worksheet GW 7, thread cutting materials must comply with DVGW worksheet W 521. Sealants and adhesives must be selected with regard to their hygienic suitability. They must comply with generally accepted technical rules.
In the case of components or devices that are installed as finished products in the drinking water installation, care must be taken that they are not contaminated and can be cleaned and disinfected.
When sealing fittings, care should be taken to avoid using hemp as much as possible. The use of hemp can lead to the multiplication of microorganisms and thus to microbiological complaints.
Construction of drinking water wells
Drinking water wells should be resistant to cases of vandalism, extreme weather and improper use to avoid endangering users and the public.
The drinking water well should be stable and securely fixed. A frost-free foundation (e.g. foundation or frost-free ballast base layer) must be created. The attachment to the foundation should be easy to remove for maintenance or removal/assembly purposes. The mounting elements on the foundation must pose no risk following possible dismantling of the drinking water well. An appropriate cap or other type of cover should be provided (see 9.4).
The body of the drinking water well should be made of sturdy material and be easy to clean. For stability, people climbing the drinking water well, stepping on or starting off by motor vehicles or bicycles and the resulting leverage forces should be taken into account so that the drinking water well does not bend or be damaged.
The surfaces should be able to dry quickly to avoid hygienic abnormalities. Areas that the water hits should be angled or steep so that the water does not stagnate or splash. Direct and targeted drainage of water should be provided; a drip tray at user level should be avoided. This prevents contamination or misuse (animal drinking, waste storage, etc.).
It is important that drinking water wells are structurally barrier-free. The accessibility of drinking water by wheelchair users and small people must be taken into account. The controls on the drinking water well should be placed at a maximum height of 80 cm to 100 cm. The drinking water well should also be accessible from the side with a wheelchair.
Existing systems should be checked to see whether they can be designed barrier-free. New plants must be designed barrier-free.
If the drinking water well is not operated all year round and is not dismantled during the winter months, a closed winter nozzle or a protective cover connected to the drinking water well should be included. It should be clearly visible that the drinking water well is not faulty but out of service, e.g. due to an information sign.
Internal components in contact with drinking water and their flushing
Drinking water wells can be operated with continuous or discontinuous flushing (“interval flushing). With these flushes, stagnation can be avoided and thus drinking water quality can be ensured, even if drinking water wells are not used for a long period of time.
Discontinuously operated drinking water wells must allow drinking water to escape via a device supplied with electricity (such as a button or sensor). The power-supplied unit should only be operated with low-voltage technology or with a battery or rechargeable battery. Even with discontinuous flushing, flushing should preferably be carried out via the removal point (outlet). If there is a concealed flush, please ensure that it must not be connected directly to the sewage system. A free outlet in accordance with DIN EN 1717 must be provided here.
The drinking water-carrying components are located inside the drinking water well. These must be suitable for the drinking water sector and comply with the requirements of the Drinking Water Ordinance Materials and Materials (hygienic requirements).
Components carrying drinking water may include: backflow preventer, shut-off devices to enable dismantling, water meter, magnetic valve, depending on the design of the drinking water well, a valve for pressure regulation and jet width adjustment, emptying option to protect against frost damage.
Connection line, connections and protection of the drinking water supply
Drinking water wells should be installed as close as possible to a flowing drinking water pipe (supply line or house connection pipe/drinking water installation).
If a connection to the distribution network of a water supplier is planned, the appropriate protection of the water supply must be selected, as there is a risk of retrograde contamination of the distribution network.
The connection to a drinking water installation must be made as close as possible to the transfer point of the water supplier to the drinking water installation, i.e. at the house connection, in order to minimize the influence of the drinking water installation on the drinking water well. Regular monitoring of the drinking water installation when a connection is not recommended elsewhere increases safety when dispensing drinking water from the drinking water well. An appropriate safety device in accordance with DIN EN 1717 must be installed, e.g. backflow preventer.
The drinking water well must have an accessible individual shut-off facility in order to be able to carry out dismantling and maintenance. Significant signs are recommended.
With every drinking water well, care must be taken to ensure that unused water can run off and does not pose a risk to users. Particularly in the case of drinking water wells that are also used in winter, care must be taken that escaping water does not endanger users due to freezing.
Drainage must be ensured via infiltration (drainage, green areas or tree drainage) via discharge into a body of water or to the sewage system.
The drain itself must be secured by a grid. When the drain is connected to the sewage system, an odor trap must be provided. Permission for discharge into the sewage system, infiltration or discharge into a body of water must be obtained from the competent authorities before the drinking water well is installed.
Needs assessment and location selection
A needs assessment should be carried out to select a location. The question to be addressed here is whether the potential location is in an area with a potential need for publicly available drinking water.
· public sports and exercise room (e.g. skate parks, fitness trails)
· heavily frequented green areas and squares (e.g. marketplaces)
· Pedestrian areas and shopping areas
· School centers and universities (educational landscapes)
· outdoor areas of cultural institutions (e.g. in front of museums, theaters)
· Intersections of cycling and hiking trails
· Local and long-distance public transport locations and airports
· touristic locations
Drinking water wells are designed to be operated remotely, so the location must be chosen with care.
For the planning, construction and operation of drinking water wells, the following points should be considered when selecting a location:
• Connections to a drinking water network or drinking water installation must be available.
• Drainage must be possible.
• A suitable surface for safe installation should be available (e.g. tree roots, existing pipes, etc. should be considered).
• The site should be easily accessible for installation, including construction, operation and maintenance.
• It should not be under trees (risk of microbial contamination by bird droppings, aphids or leaves).
• It should be shaded at least partially during the day and therefore not be permanently exposed to the sun (e.g. in the north, west or east next to trees or buildings).
• It should be in a paved area or surrounded by paving to avoid washing out due to splashing water.
• For new buildings, it must be barrier-free and accessible without steps (see also 6.4).
• The location should be safe from damage that may occur through or flowing traffic (e.g. delivery traffic, bicycles), ideally in areas with only foot traffic or protected by furniture such as benches or bollards.
• It makes sense to have a location in the sight of shops or neighbors. Voluntary sponsorships, which report abnormalities at USi, for example, have proven effective.
Construction or installation of drinking water wells
If the drinking water well is to be shut down and dismantled over the winter months, it is also necessary to provide suitable storage space. If a drinking water well is not connected to the public water supply but to a drinking water installation, e.g. from a building, it must be examined for the variable parameters in the drinking water installation (E.coli, coliform bacteria, colony numbers at 22 °C and 36 °C, pseudomonas aeruginosa and lead, copper, nickel). The sampling point closest to the intended connection point of the drinking water well must be selected as the sampling point.
When operating drinking water wells, the principles of drinking water hygiene must be complied with. These include:
• The drinking water wells are outlets in accordance with the Drinking Water Ordinance. Proper operation (including regular removal of water at all outlets) must be ensured.
• Avoiding stagnation and interactions of drinking water with installation materials, which can lead to adverse effects on water quality
• Temperature of cold drinking water not above 25 °C
• regular maintenance
• regular microbiological tests It is recommended to keep an operating manual (start-up, maintenance, assembly and dismantling, shutdown and restart, test findings) (see section 11).
Compliance with intended operation (continuous operation, forced flushing, intervals)
In order to maintain the required normal operation, all drinking water-carrying parts of the drinking water well must be flushed regularly. There are two operating modes with which drinking water quality can be guaranteed, even if the drinking water well is not used for a long period of time. These operating modes are:
• continuous flushing
• discontinuous flushing (“interval flushing”)
Continuous flushing (“continuous operation”) ensures drinking water quality over the long term. The flush can be arranged visibly at the outlet or concealed in the drinking water well. It should preferably be rinsed via the removal point (outlet).
Discontinuous flushing (“interval flushing”) ensures drinking water quality via temporary and repetitive rinse cycles. Flushing should take into account the volume of the connection line up to the outlet. The discontinuous flushing is always connected to a discontinuously operated drinking water well (non-continuous running). This must allow drinking water to escape via a device supplied with electricity (such as a button or sensor). The power-supplied unit should only be operated with low-voltage technology or with a battery or rechargeable battery. Even with discontinuous flushing, flushing should preferably be carried out via the removal point (outlet).
It is recommended to rinse the drinking water well, including its supply line, at least every 24 hours.
The external appearance of the drinking water well must be checked regularly by means of a visual inspection. External damage, changes to the components and the sensory properties of the drinking water must be checked and documented in the operating book.
The drinking water well must be visually inspected at least once a week. For locations that are inconspicuous over a longer period of time, the inspection frequency can also be extended to fortnightly to monthly. A sample protocol is set out in Annex B.
Maintenance and care measures
All external components must be cleaned regularly. For this purpose, cleaning agents suitable for drinking water [see DVGW W 291 (A) and DVGW W 557 (A)] must be used. Depending on the water hardness or contamination, an external cleaning must be carried out. The drinking water well should always be found in an appealing condition by the user. If hygienic abnormalities have been identified during optical inspection or following information provided by citizens, cleaning must be carried out as soon as possible. Depending on the design of the drinking water well, the surface must be cleaned, the drain or drain surface cleaned and possibly spray disinfect the outlet.
In accordance with DIN EN 806-5, the proper functioning of all safety devices must be checked at least twice a year.
Commissioning and decommissioning measures (e.g. for the winter season)
Newly installed or seasonally operated drinking water wells are cleaned both inside and outside when the season starts for the first time and at the start of the season. All components carrying drinking water must be checked for perfect functionality and replaced if necessary. When the supply line is started up, the supply line and the drinking water well must be flushed with a sufficient volume of drinking water and a sufficient flushing rate (2 m/s).
Drinking water wells must be put into operation immediately after cleaning and inspection. At the end of the season, the seasonally operated drinking water well will be shut down. In addition, the drinking water well remains
• either stand, is emptied and gets an occluded winter gland
• stops, is emptied and is protected (by hood, etc.) or
• It is completely dismantled.
If the system has not been designed to be frost-proof, all drinking water-carrying components of the drinking water well and the parts of the plant at risk of frost are completely emptied.
The drinking water well must be secured in such a way that no damage can occur due to contamination or vandalism during the winter season. All removed components must be stored in such a way that they cannot be damaged, soiled or made unusable. Particular care must be taken to dry all components as far as possible before storage in order to avoid contamination by microorganisms and possible biofilm formation.
Dealing with limit values being exceeded
If the requirements of the Drinking Water Ordinance are not met, this must be reported in writing to the responsible health authority (in accordance with Section 16 paragraph 1 TrinkwV). The further procedure must be coordinated with the responsible health department.
Following the determination of non-compliance with the TrinkwV, the supply of drinking water from the drinking water well to consumers must be suspended until the cause has been eliminated. A complete shutdown of the drinking water well should be avoided (stagnation). Labeling as non-drinking water alone is not sufficient. The drinking water well must be secured against use by unauthorised persons. The safety of the drinking water well must be checked regularly until the drinking water well is put back into operation as intended.
It must be determined whether the cause of the non-compliance with the drinking water supply is due to the drinking water well or whether the source lies in the upstream pipeline network or the dispensing drinking water installation. All causes caused by the drinking water well must be eliminated by the operator of the drinking water well.
Supervision by the responsible health department
As part of the monitoring, the responsible health authority determines the tests that the operator is required to carry out for drinking water wells (Section 18 paragraph 1 sentence 1 TrinkwV).
The health department can follow the recommendations of the Federal-Länder Working Group (BLAG) small plants. The recommendations for monitoring drinking water wells were developed and published by BLAG as guidelines for health authorities. They are intended to support health authorities in enforcing the Drinking Water Ordinance with regard to public drinking water wells.
Investigations of drinking water from drinking water wells
Drinking water wells must be connected to monitored drinking water distribution systems (see Installation Site section). Therefore, and due to the low pipe volume and the short contact time of the water with the materials used, it is generally possible to dispense with the examination of chemical and physical parameters.
The tests, including sampling, must be carried out by testing bodies approved for drinking water.
Investigations during start-up
Drinking water must be examined when the drinking water well is started for the first time and in the case of seasonally operated drinking water wells at the start of the season. The scope of the investigation must include at least the following parameters:
• Colony count at 22 °C and 36 °C
• coliform bacteria
• Escherichia coli
• Pseudomonas aeruginosa
Investigations during operation
During operation, the drinking water of the drinking water well can be examined at regular intervals. These tests must be carried out at least once a month. If, within three years, all test results were below the limits and requirements of the Drinking Water Ordinance, the test interval can be extended.
The scope of the control tests must include at least the following parameters:
• Colony count at 22 °C and 36 °C
• coliform bacteria
• Escherichia coli
Taking water samples
Sampling from drinking water wells for microbiological testing must be carried out in accordance with DIN EN ISO 19458 purpose c. Extraction in accordance with purpose c means that the water is removed in the same way as it is also removed by the consumer.
Investigations in case of non-compliance with the TrinkwV
If the requirements and limits of the TrinkwV are not met, the scope and frequency of the examination will be determined by the responsible health authority.
As of January 2022
The copyright of the original text is held by the DVGW
Thank you very much for preparing these helpful recommendations for action, which make it easier for many craftsmen, health authorities and planners to operate a drinking water well.