Brownfield sites are becoming an increasingly popular option for new-build residential and commercial developments. However, as the land can be contaminated from previous industrial use and possible chemical exposure, there are a number of considerations contractors and engineers must address to ensure drainage solutions remain viable. Here, Joana Januseviciute, product manager for clayware at Hepworth Clay, discusses how tried-and-tested clay drainage is an ideal solution.

The latest on brownfield sites


There are currently over 66,000 hectares of possible brownfield sites in England alone, with around a third of these located in Greater London, the South East and the East. With the introduction of Brownfield Land Registers setting out clear, up to date information and cases of planning permission for housing and commercial developments across the UK, it’s predicted that development on brownfield sites will rise considerably over the coming years. This will go some way to alleviating the current housing crisis. Land Remediation Tax Relief, which allows developers to claim relief of 150 per cent for costs incurred cleaning up contaminated land, also serves as an attractive incentive to build on brownfield land.


As brownfield sites are known to be low cost when it comes to purchasing the land, builders and investors are particularly interested in redeveloping these sites. In comparison to greenfield sites, they also typically become available much quicker, making the process from buying to developing much faster. However, they can have potential contamination from their previous use, often from industrial waste and pollution, and in some cases exposure to harsh chemicals. This means residential and commercial repurposing can become a challenge in several areas, particularly when it comes to below-ground drainage.


That’s why it’s important for contractors to thoroughly assess the land in question, which includes surveys on the soil. Once the survey is completed, a course of action can be decided on, as it will then be known if it’s possible to remove all the contaminants from the ground. However, if this is not feasible, an appropriate below-ground pipe system that’s able to withstand the leftover contaminants and chemicals can be specified accordingly. Clay has the ability to cope with most residual contaminants, often making it the ideal choice, although contractors can seek guidance from the manufacturer of the pipe system in regards to suitability for their specific project.


If there is residual contamination, it’s also important that contractors specify the correct coupling, such as the nitrile seals used in Hepworth Clay products. The nitrile sealing ring is capable of resisting contamination involving oil and petrol type (hydrocarbon) contamination, which is a concern found on many brownfield redevelopment sites, especially if the land was previously used for military or industrial purposes. By knowing the seal is just as strong as the pipe, developers can rest assured knowing their pipe systems are water-tight.

Why clay piping?


Due to its inert nature and 100 per cent natural make up, the clay pipes are impervious and resistant to practically all chemicals and compounds that may be found in the ground, with the exception of hydrofluoric acid (HF). Boasting an average lifespan of more than 100 years, it’s also a remarkably reliable and durable solution. This longevity is due to the material characteristics and strength of vitrified clay pipe and fittings, which does not change after the installation process. Clay pipes are also capable of withstanding most structural situations, providing trouble-free performance in the most arduous of conditions.


Additionally, the benefits of clay piping go even further than longevity and can even make ongoing maintenance much easier. The clay material can withstand extremely high pressures when it comes to jet washing, ensuring any blockages can be cleared and regular maintenance carried out without any trouble. This gives contractors working on brownfield sites reassurance that they are investing in a high-quality, sustainable solution that they won’t have to spend further costs on for replacements or extensive repairs in the future.

Sustainable new builds for the future


With the ongoing housing crisis and growing UK population, it’s clear that measures need to be put in place to address housing needs. In England alone, it’s been predicted that three million new homes must be built over the next 20 years to combat the shortage, meaning the pressure is on to find areas where these new homes can be built. Brownfield sites are becoming a more attractive proposition as land becomes available, making it vital that engineers consider ways to ensure these new sites are safe, reliable and attractive places to live.


Choosing a high-quality drainage solution, like clay piping, is a key consideration during the process of developing brownfield sites, whether that be for a residential or commercial project. By choosing the correct below-ground drainage, you can ensure eco-friendliness, low costs and long-term sustainability for a project, all without compromising on quality.