Private Water Supplies



Private water supplies are any water system that isn’t fed from the mains water network that is provided by Scottish Water. This may include domestic or commercial properties in rural locations where there is no access to mains water supplies and the only source of water is from a private supply. According to the Drinking Water Quality Regulator (DWQR) for Scotland, approximately 3% of the Scottish population drink from a private water supply (that’s roughly 160,000 people). Private water supplies are typically from springs, streams, boreholes and lochs. The water quality can vary drastically between sources and there’s no “one size fits all” system that can treat every supply. It’s essential that suitable water treatment be installed to remove all contaminants and disinfect the water before use.

Commercial Property

If you operate a commercial property on a private water supply you will be regulated by your local council. This will include a private water supply risk assessment to assess what equipment you have installed and any recommendations for improvement. Your local council will also take annual water samples to test for various bacteria and chemical contaminants to ensure that your water quality is satisfactory for drinking purposes. As a commercial property, you are also required to complete a Legionella risk assessment. Legionella is naturally found in water courses and can proliferate in your system, particularly with private water supplies as the water is untreated. For this reason, it’s vital that the correct water treatment equipment is installed.

Domestic Property 

Domestic properties on private water supplies are classed as exempt and aren’t normally regulated by your local council. However, if you are selling your property you will be required to prove that the supply is safe to use before the property can switch to the new owner. This can cause delays and financial burden during the sale process and consideration should be given to ensure the system is sampled and any remedial work is completed before putting the house on the market.

Landlords have a duty to provide suitable and sufficient water to their tenants and should also have completed a private water supply risk assessment. If you are a tenant, you have the right to see this.


Where We Come In

We can help you with your private water supply whether it be a new installation, a system upgrade or servicing of existing water treatment systems.

We can install water tanks, pumps, water filters and disinfection equipment such as UV sterilisers and chlorine dosing units. We can also provide water tank cleaning services to remove sediment and other fouling that can be detrimental to the quality of water. 

We always ensure the installation of appropriate, cost effective and reliable equipment to remove all contamination from your incoming water supply.

Our engineers can do on site testing for pH, temperature, Chlorine, conductivity and dissolved solids. Any other water sampling requirements can be taken by us and sent to an independent UKAS accredited lab for analysis. We then study the results and recommend the best course of action.


The most common type of filtration is sediment filters. These come in various shapes and sizes and remove suspended solids from the water. It’s essential that sediment be removed down to 5 micron before water passes a UV sterilser as the sediment can block the UV light, allowing bacteria to pass through the UV sterilisation equipment and into your drinking water system. Although a 5 micron filter is suitable in most circumstances, sometimes the water can still be cloudy or hazy, this is known as turbidity. Turbidity in the water will also negatively effect the UV steriliser as the UV light doesn’t penetrate the water fully allowing bacteria to enter your system. This requires an upgrade to the filtration, most commonly activated carbon.

Another common issue is Iron and Manganese. This causes the dark orange to black staining that you see on water tank internals and plumbing fittings. This can be removed in many ways although the most common is an Iron and Manganese removal system that filters the water as it passes. These systems have an automatic backwash to flush the removed iron and manganese to drain.


The most common type of disinfection is UV light. It’s popular for private water supplies as it’s simple to use with minimal maintenance and consumables. UV light has no by-products and uses no chemicals. UV sterilisers should be at “point of entry” providing disinfection for all the properties water, not just the kitchen tap. The downside of UV disinfection is that there is no residual disinfectant in the water so it doesn’t fight any bacteria that is already within the system.

Another type of disinfection is chemical dosing such as Sodium Hypochlorite (Chlorine), Hydrogen Peroxide or electrolysed water. This may be suitable for larger scale private water supplies where UV sterilisation may not adequately control the risk from bacteria. These systems operate proportionally meaning that the chemical dosing pump doses the correct amount of disinfectant relative to the incoming flow.

pH Correction

Whatever water supply you are using it’s essential that the pH is between 6.5 – 9.5. If the pH is too low it’s acidic. This low pH can damage copper pipe / fittings and release harmful metals into your water supply. pH correction systems work by water passing through media which dissolves in the water, neutralising the water. This media needs replenished periodically.



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