Painting Drains


Painting Drains

You may have noticed when visiting distribution sites and warehouse locations that many of the new sites paint their drain covers. More often they are painted either blue or red. What is the reason for this? Why are the drains painted? these are questions which we hope to answer below.

Painting Drains, what do the colours represent?

It really is simple logic that goes into the colour coding of drains. The colour typically denotes the type of drain and where any water or substance entering it will eventually end up.

If you see a blue drain, this type of drain deals with surface water and discharge entering this system will usually be expelled into the environment through a watercourse or soakaway system.


Drains marked up Red in colour denote water discharged to foul drains; this system will generally lead towards a treatment facility managed by the areas local water company.


You may also have drains with other colours, like yellow or green. Although it can vary, yellow often indicates an interceptor and could be accompanied by blue or red paint to indicate whether the interceptor is on the surface or the foul line. Often, green drains are connected to an on-site effluent treatment facility.

Drain painting is now considered best practice

The Environment Agency now recommends that drainage and manhole covers are painted blue for surface water and red for foul water. This is done to give a clear indication as to where to discharge waste and water. The marking of drains is often accompanied by directional arrows too indicating flow direction.

This system of marking and flow direction is extremely useful for site managers and health and safety managers. One great example would be the storage of oils and petroleum-based products. These would not be stored near drains marked up as blue. This is due to contaminants getting into the water system.



Having a painted drain system across your site is especially useful in cases of emergency. If a spillage, or contaminated water enters the drains, responding quickly is paramount in preventing the pollutants from leaving the site and location.

A painted drain system allows spills managers to have a clear understanding of where the pollution is going allowing them to make the most informed spill response decisions.

How can Fastline Services Ltd help?

If you don’t already have one you will need an accurate drainage plan for your site.

This is something that we can help with, our services include the painting and marking of existing drainage systems as well as full site surveys on products and services required for safe practice. Get in touch.

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