Car wash and car valet guidance

This guidance is relevant to you if you clean vehicles. This includes using wheel washes to clean the wheels and undercarriage of vehicles. It is also relevant to you if someone else visits your site to clean vehicles, as it is your responsibility to ensure they do not cause pollution.

If you wash your vehicles at a commercial vehicle wash such as a car wash, this guidance does not apply to you.

You can download GPP 13 which has information on the requirements for vehicle washing sites

GPP 13 Vehicle washing and cleaning (Adobe PDF – 175KB)

What you must do

Control run-off from vehicle cleaning

Surface run-off from washing areas can contain high levels of pollutants such as:

detergents
oil and fuel
suspended solids
grease
antifreeze.

You must not allow run-off to enter surface water drains, surface waters or ground waters. This will cause pollution and you could be prosecuted.

You should only wash vehicles in defined areas where the wash water and any rainfall run-off can be contained.

If possible, direct the surface run-off from your vehicle washing area to an on-site treatment system. You may be able to reuse the water. This will reduce your water use and your impact on the environment. You can also discharge surface run-off directly to a foul sewer or combined sewer. Contact your water and sewerage company or authority to find out if you need authorisation before you discharge run-off to a sewer. You must comply with any conditions of your authorisation.

Trade effluent - managing liquid wastes

Water UK: Water and sewerage operators

Scotland on Tap - water and sewerage providers in Scotland

Alternatively, you can collect your run-off in a sealed unit and send it to an authorised disposal site. Check that anyone who takes your waste away from your site is a registered waste carrier.

Who is allowed to deal with your waste?

You can use sustainable drainage systems (SUDS) to drain run-off from washing areas. SUDS slow and hold back run-off from a site, so that pollutants can be broken down naturally. In Scotland you must use SUDS to drain run-off from all new built-up areas, such as yards.

See our guidance on sustainable drainage systems for more information.

Using water from surface waters or ground waters

If you use (abstract) water from surface water or ground waters for cleaning vehicles, you may need an authorisation or licence from your environmental regulator.

Water use and efficiency

Good practice

Use water efficiently

Use vehicle washing facilities and equipment that filter and reuse water, or set up a wash water recycling system.
Use trigger-operated spray guns. Make sure they have an automatic water supply cut-off.

Treat waste water from vehicle cleaning

Use collection systems to prevent contaminated water entering surface water drains, surface waters or ground waters, or draining onto the land.
Use settlement lagoons or suitable absorbent material such as flocculent to remove suspended solids such as mud and silt. Before using flocculent, contact your water and sewerage company or authority to make sure that you can still discharge to the sewer.
Use catchpots or silt traps on drains, and ensure that they are in place during cleaning. Empty them at regular intervals.

Remove oil, grease, petrol and diesel from wash water by passing it slowly through an appropriately sized oil separator. An oil separator will not work effectively if:

it is too small
the speed of flow is too great
it is poorly maintained.

Ensure that any discharge containing detergent cannot run to the oil separator, as this will stop it working.

If you use detergents, use a recycling system with no discharge or ensure that any run-off containing detergents is collected in a sealed unit. Contact your local water and sewerage company or authority for guidance on how to dispose of any of these materials to the foul sewer.

GPP 3 Use and design of oil separators in surface water drainage systems

Cleaning chemicals

Minimise the amount of cleaning chemicals you use.
If you use detergents, choose biodegradable and phosphate-free products as they are less harmful to the environment.
Only carry out cleaning in a designated impermeable area that is isolated from the surrounding area by a roll-over bund, raised kerb, ramps or stepped access, for example.

Store all cleaning chemicals safely and in an area where you can contain spills. This should be within a secondary containment system (SCS) such as: