Runoff From Industrial Estates

Polluted runoff from roads, industrial estates and large car parks damages every river in London, but it is unregulated and uncontrolled. Contaminants build up during dry weather and are then washed down drains that lead to rivers. 

It is illegal for a property to discharge polluted water to a river without a permit. A permit would require operators of these sites to install separators which clean the water. While it would be difficult to build separators into existing roads, due to a lack of space, this is not the case at industrial estates and large car parks. Enforcing the law here would see a significant reduction in this preventable source of pollution.

In December 2024 we asked the Environment Agency if they are enforcing the Environmental Permitting Regulations 2016 at industrial estates and large car parks, using an Information Request. They replied that they are not, but their position is a mess of contradictions. We plan to challenge this failure to meet their statutory duty by formally complaining to the Office for Environmental Protection, which can take legal action against the Environment Agency.

Runoff polluting a river in London

The Environment Agency “acknowledges the environmental concerns associated with urban diffuse pollution from large-paved areas (such as those on industrial estates or large car parks)”.

Despite this in, its reply to London Waterkeeper it said “The Environment Agency does not currently issue individual permits specifically for urban diffuse runoff from paved areas like industrial estates or large car parks in London, given that these typically fall under our position on managing uncontaminated surface water runoff.” But by definition these sites are not discharging uncontaminated surface water runoff. On the Government website it says “Typically a separator is needed for any site with a risk of oil contamination, such as: car parks larger than 800m2 or for 50 or more parking spaces”. It also says site operators must “Make sure only clean water drains into the surface water drain”.

The website also says that companies do not need a permit “to discharge uncontaminated water, such as clean rainwater from roofs or from small areas of hardstanding to surface water”. By definition a large car park is not a small area, and the runoff from the paved areas of industrial estates is not clean rainwater from roofs. 

The Environment Agency’s circular, contradictory position will be challenged by London Waterkeeper.

Our position is that the law is clear, but the Environment Agency is refusing to enforce it. This means there is no incentive for companies to install separators, instead it encourages them to allow chemicals, heavy metals, oil and micro-plastics to leave their site and damage the local river. Rather than advocating for the polluter pays principle the Environment Agency is doing nothing.

This is a failure to fulfil their statutory duties. We are doing the work of the regulator by contacting the operators of industrial estates and retail parks and encouraging them to clean their runoff.

We are pressing the Environment Agency and Defra to tackle this problem using the Environmental Permitting Regulations 2016. If they do not we will complain to their regulator, the Office for Environmental Protection. We would seek a ruling from them that the EA should use the law to tackle this source of pollution.