Hygiene and Disinfection Guide for Public Outdoor Drinking Fountains

1. Purpose of this Guide

This hygiene and disinfection guide describes how a drinking fountain in a public outdoor area is hygienically and safely installed, commissioned, regularly cleaned, preventively disinfected, and, in case of irregularities, taken out of service and recommissioned.

The aim is to prevent microbiological risks early on, keep water-carrying components hygienically sound, and provide the operator with a clear, documented procedure for installation, annual maintenance, recommissioning, and ongoing operation.

This guide does not replace the requirements of the responsible health authority, the manufacturer's specifications for the drinking fountain, the safety data sheet for the disinfectant, or generally accepted technical standards. It serves as a practice-oriented operator and maintenance instruction.

2. Principle: Hygiene begins before initial commissioning

Increased hygienic attention is required for outdoor drinking fountains. The devices are publicly accessible outdoors, are used by many people, and are exposed to fluctuating temperatures, dust, pollen, splash water, insects, vandalism, stagnation periods, and external contamination.

A microbiological anomaly often does not arise from the newly manufactured device itself, but rather from:

• unhygienic installation,
• contaminated connection lines,
• contaminated couplings, hoses, or transitions,
• stagnant water in supply lines,
• improper storage of components,
• missing initial disinfection,
• excessively long downtime periods,
• insufficient cleaning during operation,
• external contamination by users, animals, dust, or vandalism.

Therefore, it is important to note: The drinking fountain must not be hygienically treated only after contamination has occurred. Disinfection must take place before or during initial commissioning and then be repeated regularly as a preventive measure.

3. Legal Guidance for Operators

For operators of public drinking fountains, the following regulations and principles are particularly relevant:

• § 37 para. 1 Infection Protection Act (IfSG): Water intended for human consumption must be of such a quality that its consumption or use does not cause harm to human health, especially due to pathogens.
• § 5 Drinking Water Ordinance (High Standard German TrinkwV): Drinking water must comply with general requirements, be pure and fit for consumption, and be extracted, treated, distributed, and stored according to the generally accepted rules of technology.
• § 6 Drinking Water Ordinance (TrinkwV): Pathogens and microbiological contaminants must not be present in drinking water in concentrations harmful to health. Microorganisms that can adversely affect drinking water must be kept as low as possible.
• § 10 Drinking Water Ordinance (TrinkwV): The requirements for drinking water quality must be met at the relevant point of compliance.
• § 13 Drinking Water Ordinance (TrinkwV): Water supply systems must be planned, constructed, maintained, and operated according to the generally accepted rules of technology.
• § 14 Drinking Water Ordinance (TrinkwV): Materials in contact with drinking water must be hygienically suitable.
• § 20 Drinking Water Ordinance (TrinkwV): For treatment and disinfection, only approved treatment chemicals and disinfection methods from the UBA list may be used.
• § 39 Drinking Water Ordinance (TrinkwV): Drinking water analyses and sampling according to the TrinkwV may only be carried out by approved testing laboratories.
• §§ 47 and 48 Drinking Water Ordinance (TrinkwV): In case of deviations, exceedances of limit values, or unusual occurrences, there are obligations to report, clarify causes, and take remedial action towards the health authority.

In practice, this means: The operator must not only react when a sample is abnormal. They must already ensure through installation, maintenance, cleaning, flushing, disinfection, documentation, and proper sampling that hygienic risks are prevented from arising in the first place.

4. Recommended disinfectants

For the internal disinfection of water-carrying components, the following active substances are particularly suitable:

4.1 Hydrogen Peroxide

Hydrogen peroxide is suitable for the hygienic treatment of water-carrying components, provided a product approved for drinking water systems is used and applied according to the manufacturer's instructions.

Advantages:

• good material compatibility at appropriate concentrations,
• generally decomposes into water and oxygen,
• low odor,
• well-suited for preventive system disinfections,
• particularly suitable for maintenance, recommissioning, and flushing/disinfection processes outside of regular drinking water operation.

Important: After application, the system must be thoroughly flushed until no relevant residues remain. The disinfectant solution must not be dispensed to consumers.

4.2 Chlorine Dioxide

Chlorine dioxide is a highly effective disinfectant and can also be used for drinking water applications when properly applied.

Advantages:

• high efficacy against many microorganisms,
• effective even against biofilms,
• suitable for more significant hygienic issues,
• effective even in more complex piping systems.

Important: Chlorine dioxide must only be used by qualified personnel and strictly according to manufacturer's instructions. Particular attention must be paid to dosage, contact time, residual levels, neutralization, flushing, and potential reaction products such as chlorite and chlorate.

4.3 General Requirements for Disinfectants

Only products suitable for the specific application in drinking water systems may be used. Before use, the following must always be checked:

• Product Data Sheet,
• Safety Data Sheet,
• Manufacturer's specifications,
• Permitted scope of application,
• Concentration,
• Contact time,
• Neutralization,
• Rinsing instructions,
• Material compatibility,
• Disposal instructions.

Never mix disinfectants. In particular, chlorine-containing products, acids, hydrogen peroxide, and chlorine dioxide must not be combined uncontrollably.

5. Disinfection Timings

Disinfection is recommended:

1. before initial commissioning, immediately during installation;
2. after work on water-carrying parts, for example, after replacing hoses, valves, couplings, or connections;
3. after a prolonged period of inactivity, especially after winter shutdown;
4. at least once a year preventively, preferably before the start of the season in spring;
5. before recommissioning after decommissioning, especially after a frost period;
6. in case of microbiological abnormalities, e.g., if E. coli, enterococci, coliform bacteria, unusual colony counts, or Pseudomonas aeruginosa are detected;
7. after vandalism, contamination, or backflow incidents;
8. in case of unusual odor, taste, turbidity, or visible contamination;
9. following an official order or recommendation from the health authority.

6. Hygienic Installation before Initial Commissioning

The installation significantly determines whether the drinking water fountain can be operated hygienically and stably later on.

6.1 Preparation

Before starting the installation, the following should be prepared:

• clean protective gloves,
• safety glasses,
• protective mask, if necessary,
• clean tools,
• suitable disinfectant solution,
• clean cloths,
• rinsing facility,
• laboratory sampling bottles, if an initial sample is required,
• documentation sheet for installation and disinfection.

All water-carrying connections, couplings, and hoses must be stored cleanly and protected until installation. Components must not be placed on the floor. Open pipe ends must be protected from dirt, splashing water, and contact.

6.2 Flushing the connection line

Before connecting the drinking water fountain, the on-site supply line must be thoroughly flushed with drinking water. The aim is to remove stagnant water, particles, installation residues, and potential contaminants from the line.

Flushing must be carried out until:

• clear water emerges and no more particles are visible,
• there are no abnormalities in odor or turbidity,
• a stable water temperature is reached.

6.3 Hygienic Connection

When connecting the drinking water fountain, ensure that:

• only materials suitable for drinking water are used,
• couplings and connections are disinfected before being connected,
• no contaminated sealants are used,
• no open pipe ends come into contact with dirt, hands, or tool rests,
• backflow and back-siphonage are technically prevented,
• the installation complies with generally accepted engineering practices.

Upon completion of assembly, the device must undergo internal disinfection.

7. Internal Disinfection of the Drinking Water Fountain

7.1 Decommissioning and Securing

Before starting disinfection, the drinking water fountain must be taken out of service. Access to the water dispenser must be blocked or clearly marked.

Recommended Notice:

"Drinking water fountain temporarily out of service – Disinfection/Maintenance. Do not use."

7.2 Personal Protective Equipment

Before handling disinfectants, at least the following must be worn:

• Protective gloves and safety glasses or appropriate workwear,
• Protective mask, if required by the safety data sheet.

7.3 Remove Filter

If a filter or other insert is installed in the device, it must be removed before disinfection, unless otherwise specified by the manufacturer. Filters can bind disinfectants, reduce their effectiveness, or be contaminated themselves.

7.4 Introduce Disinfectant Solution

The disinfectant solution is introduced into the device via the main inlet or the main hose. 

Procedure:

1. Shut off water supply.
2. Insert disinfection cartridge or dosing system into the main inlet.
3. Dose disinfectant according to manufacturer's instructions.
4. Slowly open water supply.
5. Activate all dispensing points, buttons, valves, and lines sequentially.
6. Ensure that the disinfectant solution reaches all water-carrying areas.
7. Start the contact time as soon as the disinfectant solution has reached all dispensing points.

The concentration and contact time are determined solely by the manufacturer's instructions for the product used.

7.5 Contact Time

During the contact time, the drinking water fountain remains out of service. No water may be dispensed to users.

The following must be documented:

• disinfectant used,
• active ingredient,
• concentration,
• batch number,
• quantity prepared,
• start time of contact,
• end of contact,
• responsible person.

7.6 Neutralization and Rinsing

After the contact time, the disinfectant solution must be properly neutralized or rinsed out according to the manufacturer's instructions.

Afterwards, the drinking water fountain is thoroughly rinsed with clear drinking water. All dispensing points, buttons, and valves must be activated multiple times.

The rinsing process is only finished when:

• no disinfectant residues are detectable,
• no unusual odors are present,
• no turbidity is visible,
• the water is taste-neutral,
• all pipework has been flushed with fresh water.

For hydrogen peroxide, the residual peroxide value must be checked if the product specifies this. For chlorine dioxide, residual levels and relevant by-products must be observed in accordance with manufacturer and regulatory requirements.

7.7 Waiting Period and Release

After disinfection, the drinking water fountain remains out of service for at least one hour or until it is cleared by the operator, the laboratory, or the health authority.

A drinking water sample is recommended before release in cases of initial commissioning, prolonged shutdown, contamination, or upon official request.

8. Microbiological Testing

Water testing is recommended:

• after initial installation,
• after annual disinfection,
• after winter shutdown,
• after prolonged shutdown,
• after repairs to water-carrying components,
• after disinfection due to microbiological abnormalities,
• after vandalism or suspected external contamination,
• if required by the health authority.

Testing should be carried out by an accredited testing body. Depending on regulatory requirements and risk assessment, the following parameters, among others, may be relevant:

• Escherichia coli,
• intestinal enterococci,
• coliform bacteria,
• Colony count at 22 °C,
• Colony count at 36 °C,
• Pseudomonas aeruginosa,
• Turbidity,
• Odor,
• Taste,
• Water temperature.

Sampling should be carried out at the actual water outlet of the drinking water fountain, as this is where the water quality is critical for the user. Sampling must be performed according to laboratory specifications.

9. Annual preventive disinfection

Preventive disinfection of the drinking water fountain is recommended at least once a year. The ideal time is immediately before recommissioning in spring.

Recommended procedure:

1. Visual inspection of the device.
2. Check for frost damage, leaks, loose components, and vandalism.
3. Cleaning of surfaces.
4. Flushing of the supply line.
5. Internal disinfection of all water-bearing parts.
6. Adherence to the contact time.
7. Neutralization and thorough rinsing.
8. Functional check of all buttons, valves, and drains.
9. Microbiological control sample.
10. Documented clearance.

Without documented disinfection and hygienic clearance, a drinking water fountain should not be made available to the public after a prolonged period of inactivity.

10. Winterization before the frost period

Many outdoor drinking water fountains are shut down in autumn, often in October, to prevent frost damage.

Prior to shutdown, it is recommended:

• Thoroughly clean the exterior of the unit,
• Flush the lines,
• Shut off the water supply,
• Drain water from the unit / empty the unit,
• Activate frost protection measures,
• Clean and protect the dispensing point,
• Remove visible dirt and limescale,
• Document the shutdown.

If the unit is completely taken out of service, ensure that no stagnant residual water remains in critical areas. Stagnant water promotes biofilm formation and can complicate recommissioning.

11. Ongoing Operation: Cleaning and Maintenance

11.1 Regular Visual Inspection

The drinking water fountain should be inspected regularly. In high-traffic areas, a daily or several-times-weekly visual inspection is recommended.

Points to check include:

• visible contamination,
• Damage,
• Vandalism,
• Foreign objects in the water dispenser nozzle,
• Blockages in the drain,
• unusual odor,
• unusual turbidity,
• Water dispensing function,
• sufficient water pressure,
• hygienic condition of the outlet.

11.2 Surface Cleaning

The surface must be cleaned regularly.

Recommendation:

• Clean stainless steel surfaces with a suitable stainless steel cleaner,
• Carefully clean the water outlet,
• Do not use aggressive or highly concentrated agents,
• Do not use abrasive or material-damaging cleaners.

For limescale deposits, citric acid in combination with baking soda or vinegar in combination with baking soda can be used. Afterwards, rinse thoroughly with clear water.

11.3 Hygienic Flushing During Operation

Stagnation is one of the most significant risk factors for hygienic irregularities. Therefore, a drinking water fountain should be flushed regularly, especially:

• after weekends,
• after holidays,
• after hot days,
• after extended periods of non-use,
• with low frequency,
• after maintenance work,
• in the morning before starting operations, if no automatic flushing is installed.

Generally, the more frequent the water exchange, the lower the risk of stagnation, temperature increase, and biofilm formation.

12. Actions in Case of Microbiological Abnormality

If contamination or an unusual microbiological finding is detected, immediate structured action must be taken.

12.1 Immediate Measures

1. Take drinking water fountain out of service.
2. Stop water dispensing.
3. Clearly label device: “Out of Service – Use Prohibited”.
4. Inform responsible authority.
5. Secure and document findings.
6. Inform health department according to regulations.
7. No release without cause clarification and control examination.

12.2 Cause Clarification

Possible causes must be systematically investigated:

• building-side supply line,
• Connection couplings,
• Hoses,
• Valves,
• Dispensing point,
• Stagnation periods,
• Water temperature,
• Backflow/back-siphonage,
• Improper installation,
• Vandalism,
• External contamination,
• Inadequate cleaning,
• Insufficient flushing.

It is advisable to take a comparative sample before the device and at the outlet of the drinking water fountain. This makes it easier to determine whether the cause originates from the supply line, the device, or the immediate outlet area.

12.3 Remedy

Depending on the findings, the following may be considered:

• Intensive flushing,
• Internal disinfection,
• Replacement of contaminated hoses,
• Cleaning and disinfection of the outlet,
• Checking the backflow prevention device,
• Adjustment of flushing intervals (if possible),
• technical repair,
• re-sampling.

Recommissioning only occurs after a satisfactory control sample and documented approval.

13. Documentation in the Operating Logbook

Every hygiene-relevant measure must be documented. The operating logbook should contain at least:

• Location of the drinking water fountain,
• Device type and serial number,
• Date of installation,
• Name of the installer,
• Date of each cleaning,
• Date of each flush,
• Date of each disinfection,
• Disinfectant used,
• Active ingredient,
• Concentration,
• Contact time,
• Flushing duration,
• Result of the residue check,
• Name of the person performing the work,
• Lab results,
• official correspondence,
• Malfunctions,
• Repairs,
• Shutdown,
• Recommissioning,
• Release approval.

Thorough documentation protects operators, facilitates cooperation with the health authority, and demonstrates that the drinking water fountain is operated according to a clear hygiene concept.

14. Quick Checklist for Operators

Before initial commissioning

• Supply line flushed
• water-bearing components hygienically installed
• connections and couplings kept clean
• filter removed before disinfection
• unit disinfected internally
• disinfectant completely rinsed out
• control sample initiated
• approval documented

During operation

• regular visual inspection
• regular surface cleaning
• regular flushing
• remove limescale
• keep outlet clean
• document vandalism
• report irregularities immediately

Before winter shutdown

• clean unit
• shut off water supply
• drain unit or activate frost protection
• protect outlet
• document decommissioning

Before recommissioning

• visual inspection
• rule out frost damage
• flush supply line
• internally disinfect unit
• rinse thoroughly
• have sample taken
• document release

15. Concluding Remarks

A public drinking water fountain can be operated hygienically and safely in the long term if installation, disinfection, cleaning, flushing, maintenance, and documentation are consistently implemented. Crucial is not only the quality of the device, but above all, hygienically clean installation and regular preventive operation.

The most important rule is:

First, install hygienically, then disinfect, flush regularly, disinfect preventively annually, and document every step.

Note on myBach Hygiene Monitoring

A large portion of the aforementioned control, documentation, and reporting tasks can be digitally supported by the myBach Hygiene Monitoring system. The system monitors hygiene-relevant key figures in real-time, identifies critical developments early, and helps operators prevent potential contamination. For information and offers, please contact: service@aquadona.com

Legal Notice and Disclaimer

This hygiene and disinfection guide has been prepared to the best of our knowledge and belief, based on publicly available information, technical experience, and generally available manufacturer and application instructions. It does not constitute legally binding advice, official approval, or a conclusive technical or hygienic assessment in individual cases.

The application of the described measures is the sole responsibility of the operator, installer, or the executing specialist. Always decisive are the currently valid legal regulations, the requirements of the competent health authority, the generally accepted rules of technology, and the product, safety, and application instructions for the disinfectants used.

No guarantee is given for the accuracy, completeness, topicality, and applicability of the information contained herein. Any liability and legal claims against the author for direct or indirect damages arising from the use of this guide are – to the extent legally permissible – excluded.