What Are the Most Common Uses for Non-Potable Water?

'Non-potable water' refers to water that does not meet the high standards that drinking water must meet and which has not undergone the treatment required, but which is still safe for use for purposes where direct human contact is limited or controlled. It may contain microorganisms, chemical pollutants, sediment or organic matter, even after treatment, but it remains suitable and legal for use in any of the following applications:

Dust suppression

Non-potable water is routinely used to control airborne dust. When activities such as demolition, excavation, earthmoving and material transport create dust that affects visibility, air quality and health, site managers may have a legal obligation to reduce the spread of this dust. Water applied through sprinklers, bowsers, hoses or misting systems is used to keep dust levels compliant with health and safety standards, and non-potable water is suitable for this provided it does not come into contact with workers.

Through dust control, you ensure you comply with any environmental permits or requirements imposed by local authorities, and reduce the risk of receiving complaints or enforcement action by the relevant regulators. Beyond this, you maintain visibility and air quality for workers, which can improve productivity and offer other benefits.

Washing machines, vehicles and equipment

Non-potable water is typically suitable for washing down construction vehicles, earthmoving machinery and site tools. Using harvested rainwater or recycled water from site operations can help to conserve natural water resources, although it is often best to invest in non-potable water deliveries to meet the high demand of a construction site.

Non-potable water can be used for applications such as:

• Wheel wash stations to prevent track-out of mud and debris.
• Cleaning mixers, excavators and formwork.
• End-of-day maintenance routines.

Almost any equipment used in construction can be cleaned using non-potable water, but it should not be used for showers or to wash human beings, as it may contain contaminants and bacteria - even after undergoing treatment - that may be harmful to health.

Toilet flushing and other site amenities

While non-potable water is not suitable for use in showers or taps, it can be used for flushing toilets where these are installed on construction sites. Where available and permitted, it can also be used for cleaning boots or powering jet washers in welfare cabins. Recycled water from sinks, showers and washing machines can also be used for this purpose to maximise cost-effectiveness and minimise the use of natural resources.

Some temporary facilities are equipped with dual-plumbed systems to separate non-potable water from potable water. If facilities do not have this capacity, the site may need to use potable water for all applications, as there are strict legal requirements to label water correctly and keep supplies separate.

Concrete mixing and curing

Non-potable water may be used in mixing concrete if it meets minimum standards for impurities. Potable water is sometimes preferred for quality control, but certain types of non-potable water (including treated wastewater, greywater and rainwater) can be suitable if they have been tested for contaminants that could affect chemical bonding. If non-potable water is proven to meet standards where regulatory and performance criteria will not be compromised, it may also be used for curing concrete and the hydration of binding materials. Speak to your water supplier for advice on whether or not your non-potable water meets the relevant requirements.

Soil compaction and grading

Non-potable water can be applied to soil to increase moisture content, which is sometimes necessary for proper compaction. Soil that is too dry and fails to compact well can affect ground stability and may lead to settlement or structural defects later, and there is no need to use drinking water for this type of application. Sites may need to compact soil when preparing road bases, backfilling trenches and laying the foundations for pavements or structures, which can lead to significant costs unless non-potable water is used.

Pressure testing and flushing

Non-potable water can be used to test pipelines, tanks or water systems in some civil engineering projects. Systems must be checked for leaks under pressure before they are commissioned and, if the system will not carry drinking water or hygiene is not a concern, non-potable water can be used provided it is free of debris or chemical contaminants.

Similarly, flushing pipes to remove construction debris and silt before they are brought online can sometimes use non-potable water. In all such cases, discharge after testing must be carefully managed, as there may be restrictions on releasing non-potable water into the natural environment, even after it has been treated. The Environment Agency may require sites to obtain licences or consents in circumstances where wastewater is to be discharged into water bodies, but the team at Universal Tankers can advise you on the specifications of treated, non-potable water and the uses for which it is approved.

Non-Potable Water Delivery

If you are looking to maximise the cost-effectiveness of your site and need non-potable water for the applications listed above or any other purposes, it is important to work with a delivery partner that understands the legal requirements and restrictions. For example, any non-potable source must have its own separate system, including independent pipework and storage that is colour-coded where possible, and must be clearly labelled to avoid errors.

The team at Universal Tankers has a wealth of experience in supplying non-potable water for various purposes on construction sites and, thanks to our large fleet of tankers based across England and Scotland, we offer next day delivery to even the hardest-to-reach locations. We can provide details of water quality to help site operators to assess water before using it in processes like concrete production or equipment cooling. We also supply drinking water, and can collect and treat wastewater to support water reuse, which enables us to meet all of a construction site's water needs.