Wash water from reusable cup stations at events: which drain, which permission, in England

A reusable cup system has a wash step, and the wash step has an outflow. In our view, the water from that step is easy to overlook when a cup system is planned. This article sets out what two pieces of Environment Agency and Defra guidance say about wash water and drains in England, and what that means for a cup wash station. Neither page mentions cups or events, and the application is our reading. It is general information, not legal advice.

What the guidance counts as pollution

The pollution prevention guidance, last updated on 12 February 2026 and marked as applying to England, says it is not just obviously hazardous substances that can harm people or the environment. Any substance that is not found naturally in an environment could cause pollution, and the examples it gives include detergents, concrete slurry and paper sludge. In our reading, the water that comes off a cup wash is a case of that sentence if the wash uses detergent, which none of our sources says.

Contaminated water and the three routes

The guidance says that if a business produces contaminated water or other polluting liquids, which it calls trade effluent, it must make sure that water does not cause pollution. Its examples of activities that may produce it include vehicle washing, wheelie bin washing, yard cleaning, manufacturing processes, water cooling and cleaning of food production areas or ovens. It does not list the washing of cups.

It suggests assessing whether the process can be redesigned to avoid or minimise contaminated water, for instance with dry systems. If the water is unavoidable, it says to reuse or dispose of it by collecting it in a sealed system for reuse, treatment on site or removal by a registered waste carrier, or by putting it down the foul water or combined drain if the business has permission from its water company.

The right drain

The guidance explains that surface water drains discharge directly to the environment, and that a business must make sure contaminated water from its premises and activities goes into the foul drain or is recycled or removed by a registered waste carrier. Under the heading on using the right drain, it says contaminated water should drain into the foul water drain connected to a foul sewer, with the water company's permission, and that only clean water should drain into the surface water drain or a soakaway. With a combined drainage system, it says the business still needs permission from the water company to use it for contaminated water. It also says not to put fats, oil, grease or solid items down drains.

An event site may have only surface water drains, or none. In our reading, wash water poured onto the ground or into a gully at such a site is the case the guidance warns about, and the options the guidance lists are a sealed collection, a registered carrier, or a connection that the water company has agreed. Our guide to the duty of care that follows a cup off your site sets out the paperwork on waste that leaves a site, and the guide to washing reusable cups between events covers the hygiene side of the same wash.

Permits and the water company

The discharges guidance, last updated on 20 April 2026 and also marked as applying to England, says a business may need an environmental permit if it discharges liquid effluent or waste water into surface waters or into or on the ground, and that waste water includes poisonous, noxious or polluting matter, polluting substances, waste matter and trade or sewage effluent. It says a business is breaking the law if it operates without a permit when it should have one. It says no permit is needed to discharge uncontaminated water such as clean rainwater from roofs. And the pollution guidance adds that a permit or other authorisation may be needed in some cases even when the discharge is to a foul sewer.

For sewered areas, the discharges guidance says to discharge waste water to the public foul sewer where it is reasonable to do so, without an environmental permit, and that the business must check with its sewerage undertaker, usually the local water company, before it makes a new connection to the public sewer or discharges anything other than domestic sewage. The guidance for Scotland, Wales and Northern Ireland is linked from the discharges page and we did not read it, so this article covers England only.

Hiring takes the wash off site

The cup hire page says cups are collected and serviced so that the organiser does not need to wash them on site, and that hire includes collection, washing, drying and storage between uses. It says transport to and from the washing stations is free for orders of 10,000 cups or more. In our reading, that moves the wash to the supplier's washing stations, which are separate from the event site, and we did not read anything about them. An organiser who buys cups and washes them in a tent, for example from the reusable event cups range, keeps the wash water question on its own site. A quote can be for either route.

Where this stands

This was checked on 28 October 2026. The guidance pages are revised from time to time, and the right drain depends on the site, so an organiser with a large wash operation may wish to speak to the water company and the Environment Agency before the event.