Drinking Water from a Well via a Water Treatment Plant: What Must the System and Pump Meet?

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Drinking water from a well through a water pump: what must the system and pump meet?

Supplying a household with drinking water from a well is a common practice in rural areas of Slovakia – it is estimated that a quarter of homes outside the reach of the public water supply draw water using their own means. However, there is a huge difference between when water flows from the well into a bucket and when it flows from the kitchen tap as drinking water. The difference is both technical and hygienic. Many people buy a water pump, connect it to the well and the house, and that is the end of their worries. In practice, it is not that simple – and that is exactly why this article was created.

We will go through everything from the basics of water quality, through the correct choice of pump and its parameters, to the hygienic requirements for the piping, pressure tank, and other system components. If you are here, you are likely dealing with either a new installation or a renovation of an old one – in both cases, you will find answers to what is bothering you.

What does "drinking water" from a well mean – legal and hygienic minimum

The term "drinking" is not just a marketing term. In Slovakia, drinking water is defined by Act No. 355/2007 Coll. on the protection, promotion and development of public health and the subsequent decree of the Ministry of Health of the Slovak Republic No. 247/2017 Coll. This decree sets limit values for dozens of indicators – from nitrates and nitrites, through hardness, pH, manganese and iron content, to microbiological indicators such as E. coli or enterococci.

The key practical consequence: if you have your own well and want to drink from it, you have legal obligations, but no state institution will come after you to check the water. You are responsible for yourself. Regional public health offices only monitor public water supplies serving more than 50 people or supplying more than 10 m³ of water per day.

This does not mean that the legislation does not say anything to you as an individual. It simply means that the control is up to you. And this is precisely the moment when many people fail – the water looks clear, it does not smell, so why deal with the analysis? The problem is that nitrates, bacteria or arsenic cannot be seen with the naked eye.

Minimum what you need to do: have a basic water analysis (biological + chemical) done in an accredited laboratory. The price is from about 60 to 150 €, depending on the scope. It is usually done twice – before starting the system and after the filtration treatment. It is then recommended to repeat it every two years, or after each flood or significant change in quality.

Types of wells and their influence on the choice of system

Not every well is the same and the choice of the correct pump and filtration cannot be made without knowing what kind of source it is. In practice, we encounter these most common types:

Dug well (shaft well)

Diameter usually 80–120 cm, depth from 3 to 15 m. It captures surface water from the first aquifer. It is the most vulnerable type – large surface area, proximity to the surface, risk of contamination from the surroundings (manure, pesticides, runoff). The water is usually softer, but microbiologically risky. For drinking water, a good well construction (cover, head) is essential to prevent surface water from entering during rain or snow melting.

Bored well (borehole)

Diameter typically 3" (76 mm), 4" (101 mm) or 6" (152 mm), depth from 20 to 150+ m. It captures deeper groundwater, which is naturally protected by geological layers. Microbiological quality is usually better, but chemical quality can be problematic – higher manganese and iron content, sometimes also radon or arsenic depending on the geology of the area.

Well with artesian characteristics

The water is under pressure, sometimes it flows out by itself – but that does not mean that a pump is not needed. To supply a household with sufficient pressure (min. 2–3 bar at the appliances), a pump is almost always needed.

For the choice of the correct pump and configuration of the water system, I also refer you to other topics in the knowledge center: Surface vs. submersible water pump: which is better for my water source? and How to choose a home water pump: well, borehole or surface source? – these will help you to orient yourself in the basic selection even before you start dealing with drinking water requirements.

Pump for drinking water: what must it meet and what is not enough

Not every pump is suitable for drinking water. This is a crucial and often underestimated point. A pump that comes into contact with water intended for human consumption must have certification for contact with drinking water. In the European context, this means compliance with the EN 12050 standard or with the relevant hygienic standards for materials in contact with drinking water. Manufacturers must state this in the pump documentation.

In practice, this means that the materials used must not release harmful substances into the water – not even in small amounts over a long period of contact. Pumps intended exclusively for irrigation or drainage do not have this certificate and when used for drinking water, you cannot be sure what they "give" you into your glass.

Concrete examples: home water pump with submersible pump 3 SQIBO 0.55 / 50 l for drinking water into the well is directly marked as suitable for drinking water – this is not just a marketing description, but a reflection of the certification of the materials used. Similarly, home water pump with submersible pump 3Ti-20 / 50 l RTS for drinking water into the well and borehole combines suitability for drinking water and for boreholes – which is an ideal solution if you have a deeper borehole and want drinking water without compromises.

On the other hand, home water pump with submersible pump SCR-0.50 / 50 l into the well for irrigation is a typical example of a product that is not certified for drinking water – it is suitable for garden irrigation, filling tanks, drainage, but not for supplying a household with drinking water from the tap.

Hydraulic Parameters of the Pump for the Household

Certification is a necessary but not sufficient condition. The pump must also have the correct hydraulic parameters – flow rate (l/min or m³/h) and head (m). Without proper calculation, you will either push only a thin stream of water to the kitchen, or on the contrary, you will overpressure the pressure tank and the pump will unnecessarily run at full capacity.

Calculation of Required Flow Rate

The standard calculation is based on the assumed simultaneous consumption. For a typical family house (4 people), an approximate estimate applies: each simultaneously open tap requires about 10–12 l/min. If we consider the simultaneous operation of 2 taps (e.g., shower + sink), we need at least 20–24 l/min, which is about 1.2–1.5 m³/h.

For garden irrigation, the requirements are different – a sprinkler can consume 20–60 l/min depending on the area. However, this is not the primary dimension for drinking water in the household.

Calculation of Required Head

The head must cover three components:

Geodetic height: the difference between the water level in the well and the highest point of consumption in the house. For example, a well 8 m deep, a boiler on the upper floor at 5 m above ground level = 13 m.
Pressure losses in the pipe: depends on the length, diameter, and material of the pipe. Approximately 1–3 m of loss per 10 m of DN 25 pipe.
Required operating pressure: at least 2 bar (= 20 m water column) at the appliance, ideally 2.5–3 bar (25–30 m).

The total required head for a typical house can be 35–55 m. The pump must have sufficient flow rate at this manometric pressure (not only at the peak of the H-Q curve). A more detailed discussion of this topic is covered in the article What pump power do I need for a household water supply? in this knowledge center.

Diagram of the Entire Drinking Water System with a Well

Pipes and Materials: What is Suitable for Drinking Water

The pump is only one part of the system. Equally important is what carries the water from the well to the house and through the house to the taps. Here we encounter a problem that we see very often in older installations: lead or originally galvanized pipes. This is absolutely unsuitable for drinking water.

Approved materials for drinking water distribution today:

Copper (Cu): a classic choice, with bacteriostatic properties, but can corrode in acidic water (pH below 6.5). Incompatible with galvanized steel.
Stainless steel (AISI 304, 316): the most durable, suitable for all types of water, more expensive.
Polypropylene (PP-R): an inexpensive and readily available option for internal distribution. Non-corrosive, easy to process, suitable for drinking water.
Polyethylene (PE, PE-HD): ideal for external piping from the well to the house (frost-resistant when properly buried). Must be labeled as potable water (blue stripe or PE 100 RC marking).
PEX (cross-linked polyethylene): flexible hoses for internal distribution, suitable for drinking water.

Unsuitable materials: PVC (not potable water), iron, zinc, lead, unsuitable rubber seals (nitrile, SBR without certification). Seals, O-rings, and tapes must have certification for contact with drinking water – most commonly EPDM rubber with the appropriate certification.

The connecting hose between the well and the house should be buried in a frost-free depth – in Central Europe, at least 80–100 cm, ideally 120 cm below ground level. At a lesser depth, freezing in winter is a risk, which will not only damage the pipe if it is flexible (PE), but a frozen section will prevent pumping.

Filtration and Water Treatment Before Use

Even if you have a certified pump and correct piping, water from the well may not automatically be potable. This is where filtration comes into play. Design the filtration system based on the results of water analysis – not by eye, not based on what the neighbor sells.

Sediment Filter (Mechanical)

Almost always the first stage. Removes solid particles (sand, silt, rust from pipes). Insert with 20–100 microns. Important: install before the pressure tank and before other filters to prevent clogging. Replace according to contamination – from monthly to every six months.

Carbon Filter

Removes chlorine (if disinfecting), pesticides, organic substances, improves taste and smell. It is not sterilization – it does not catch bacteria, but it can even promote bacterial growth on the carbon if the filter is not changed. Replace every 6–12 months.

UV Sterilizer

One of the most reliable methods for eliminating bacteria, viruses, and other microorganisms without chemicals. UV radiation destroys the DNA of microorganisms, so they cannot reproduce. It does not improve the chemistry of the water (does not remove iron, nitrates), but for microbiological safety, it is almost essential for well water. Always install after the mechanical filter (turbidity reduces UV efficiency). The lamp is replaced once a year regardless of visible condition.

Water Softener, Iron Removal, Denitrification

If the analysis indicates problems with hardness, iron, manganese or nitrates – specific filtration units are required. This is not standard equipment for every water system, but with a poorer chemical quality of the water source, you cannot avoid them. For example, nitrates above 50 mg/l are dangerous for infants and pregnant women – reverse osmosis or ion exchange is necessary in such cases, not a luxury.

Pressure tank: its role in the drinking water system

The pressure tank is not an optional accessory – it is a basic component of every home water system. Its function is to dampen pressure surges, reduce the frequency of pump switching and maintain pressure in the network even when the pump is not running.

The same principle applies to drinking water systems as to the pump: the membrane and the inner side of the tank must be made of materials suitable for drinking water. Most current galvanized or enameled tanks with a food-grade butyl rubber membrane (or EPDM with certification) meet this requirement – check the documentation to confirm.

Tank size: for a typical household, tanks of 24–80 l are used. All water systems available at atria.sk (e.g. home water system with submersible pump IBO 3 SDM24 / 50 l RTS or home water system with submersible pump 3 SQIBO 0,75 / 50 l for well and borehole water) are delivered with 50-liter tanks, which is a well-dimensioned volume for a four-person household – the pump does not switch on with every tap use and has sufficient storage for short-term consumption.

The pre-set air pressure in the tank (via the air valve) should be approximately 0.2–0.5 bar below the pressure switch setting (pump activation). For example, if the pump activates at 2.0 bar, the air pressure in the tank should be 1.5–1.8 bar. More details in the article Pressure tank in a home water system: what it is for and how to set it up?

Hygienic protection of the well and its surroundings

A technically perfect water system will fail if the well itself is in poor hygienic condition. This is often underestimated in practice. We have seen wells where:

the well cover (wellhead) was not waterproof and surface water entered after every rain
the pump cable was passed through the side wall without sealing and insects and water entered from there
septic tanks, manure pits or compost bins were located in the immediate vicinity of the well
ordinary building concrete instead of waterproof concrete was used for the sealing concrete around the well

Minimum hygienic requirements for a dug well for drinking water:

Distance from potential sources of contamination (septic tank, septic pit, barn, dump) at least 10–15 m, ideally more
Surface around the well is paved and drained away from the well (so that rainwater runs away, not towards the well)
Wellhead at least 50 cm above ground level and waterproofly covered
All openings (cable, pipe) sealed with vulcanized bushings or hydraulic sealant
Inner side of concrete rings without cracks or defects

Disinfection of the well and system before starting up

A new well, a restored well, a pump after service or the entire system after a break in operation – all of these should be disinfected with chlorine before starting up. Procedure:

Calculate the volume of water in the well (circular well: π × r² × water column height)
Add a sodium hypochlorite solution (5% bleach) in an amount of approximately 200 ml per 1000 l of water – the resulting concentration should be around 50–100 mg/l of chlorine
Let it act for 12–24 hours, during which also flush the pipes in the house (open taps until you smell chlorine)
After the time has passed, pump the water out (to the garden, not to the sewer – it is not suitable), until the chlorine smell disappears
Before first use for drinking water, perform a water analysis (at least microbiological)

Disinfection is a one-time procedure when starting up or after contamination. Regular disinfection is not standard practice – instead, continuous UV sterilization is used.

Electrical installation and system protection

A home water system with a submersible pump is an electrical device operating in a wet environment. The electrical installation must meet the requirements of the standard STN 33 2000-7-702 (outdoor environment) and the relevant regulations.

Key requirements:

Socket or distribution board for the pump must be protected by a residual current device (RCD) with sensitivity 30 mA
Cable to the well must be suitable for wet environments (H07RN-F or equivalent), without underground joints
Control box / pressure switch must be in a dry environment (not directly at the well, ideally in a home boiler room or technical room)
For larger pumps (over 1 kW) we recommend dry-run protection (probe or float in the well)

Dry running is one of the most common causes of submersible pump failure. If the well dries up or the water level drops below the pump's suction, the pump runs without cooling (it is cooled by water) and overheats. Prolonged dry running will damage the motor winding. Quality water supply systems (e.g., set with 3Ti-20 / 50 l RTS pump) have dry-run protection built directly into the control unit – check this when choosing your system.

Water flow in the well: yield and its impact on the system

This is a point many customers are not aware of. A pump may have a capacity of 60 l/min, but if the well only delivers 15 l/min, the pump will drain the well in 20–30 minutes and then pump air. The well yield (water inflow) must be equal to or greater than the maximum pump draw.

Yield is determined by a test pumping: pumping at maximum capacity, monitoring the drop in water level and the time it takes for the level to stabilize (inflow = outflow). In practice, this is done by a hydrogeologist, or you can estimate it yourself using a simple method – measure the drop in water level at a certain pump flow rate over a certain period of time.

If the yield is low (under 5 l/min), the solution is a larger storage tank (500–2000 l) installed in the house, into which the pump slowly and continuously pumps, and from this tank a second (hydrofor) pump then draws water according to current demand. This is a different system topology, but for some locations the only solution.

Maintenance of the drinking water system

A drinking water system is not "set and forget". To remain safe and reliable, it must be regularly checked and serviced. Overview of tasks and intervals:

Every 1–3 months: check sediment filter (depending on dirt), visual inspection of connection tightness, check air pressure in the pressure tank (when the system is depressurized)
Every 6 months: replace sediment filter insert, replace activated carbon filter (if installed)
Once a year: replace UV lamp (even if it is still lighting, after 9000 hours of operation it can lose up to 40% efficiency), full inspection of electrical wiring, check condition and air filling of the pressure tank
Every 2 years: water analysis (biological + chemical), check condition of the pump (flow, power consumption), visual inspection of the well and its surroundings

For more on the topic of maintenance, see the article Maintenance and service of a home water supply system: what and how often to check?

Most common installation errors of a drinking water system from a well

From real customer experience: these are things that many people do and then wonder why the water smells, why the pump burned out, or why the water analysis failed:

They bought a cheap pump without certification for drinking water. They saved 80 €, but potentially harmful substances from plastics are getting into the water.
They left the pump cable freely run through the concrete wall of the well. Instead of a leak, it is a path for surface water and microorganisms directly into the well.
They did not install a check valve on the discharge pipe. Water drains back after each pump stop, and the pump runs dry for several seconds each time it starts.
They forgot to disinfect after installation. New pump, new piping, installer with unclean hands – and without disinfection, bacteria get into the system.
They installed the UV lamp before the mechanical filter. Water turbidity reduces the efficiency of UV radiation – the order of filters must be mechanical filter → UV.
They set the pressure switch too tightly (e.g., on at 3 bar, off at 3.2 bar). The pump switches on every 30 seconds, rapid wear, quick end of the pump's life.

Frequently asked questions (FAQ)

Do I have to test the water from the well every year, even if nothing has changed?

The law does not monitor you as a private owner, but common health sense does. We recommend testing every 2 years and after each significant event (flood, neighbor's construction nearby, change in taste or color of water). Water can change subtly – new fertilizer nearby, neighbor's septic tank failure, new industrial activity. The cost of testing is negligible compared to the risk.

Can I use a garden pump for drinking water supply in an emergency?

Short-term and occasionally – yes, but not as a permanent solution. Garden pumps are not certified for contact with drinking water and have different sealing and plastic materials. Long-term operation poses a hygiene risk that does not appear immediately, but accumulates over time.

What is the minimum well depth to ensure microbiologically acceptable water?

There is no fixed limit, it depends on geology and surroundings. In general, deeper wells (20+ m) with water from a closed aquifer are microbiologically safer than shallow dug wells. But even a deep well does not guarantee microbiological purity without testing – the well casing can be damaged and surface water can get into the depth. UV sterilization is a good insurance for any type of source.

The pump in the well provides enough pressure – do I still need a pressure tank?

Yes, a pressure tank is always part of the system. Without it, the pump will switch on every time you open a tap – even for a small draw, e.g., when you are washing your hands. This means dozens to hundreds of switches per day, rapid pump wear and pressure surges in the piping. A pressure tank extends the life of the entire system and improves comfort of use.

Can I connect a home water supply system in parallel with public water supply?

Technically yes, but it is a sensitive topic. Connecting your own source (well) with public water supply is allowed in Slovakia only with written consent from the public water supply operator and under the condition that the system is properly connected with a check valve and physical separation (air gap), to ensure that well water can never flow back into the public network. Without this, contamination of the public network is possible – and the fine for this is not small.

How long will a submersible pump in the well last without service?

A quality submersible pump with proper sizing, clean water and dry-run protection can last 7–15 years. The key is: correct flow selection (the pump must not be oversized or undersized), clean water without sand (sediment protection), dry-run protection and regular inspection of the electrical installation. Pumps in oversized systems that switch on every minute will last significantly less.

Conclusion: a drinking water system is a whole, not just one device

If you take one thing from this article, let it be this: a drinking water system from a well is not just a pump in a well. It is an entire system that must be properly designed, properly installed, regularly maintained and regularly checked. Every link in this chain – the well, the pump, the check valve, the piping, the filtration, the pressure tank, the electrical installation – must meet hygiene and technical requirements.

Investing in a quality system with certified components (such as water supply systems from atria.sk with pumps certified for drinking water) pays off in terms of reliability, safety and peace of mind. It is a much smarter path than saving on every component and in a few years dealing with contaminated water, a burned-out pump or illness in the family.

For further specific steps we recommend the articles Installation of a home water supply system with a submersible pump step by step, What diameter of borehole or well do I need for a 3" submersible pump? and Home water supply system not pumping or losing pressure: causes and solutions – these will help you with specific installation and diagnostic questions.

Do you have a question on this topic?

Having trouble making a decision or dealing with a specific situation in your home? Write to us – we are happy to help.