Tarmac's porous asphalt system, TarmacDry, has become the first product of its kind to be awarded BBA (British Board of Agrément) accreditation.

Designed for lightly-trafficked areas, TarmacDry can be used as part of Sustainable Drainage Systems (SuDS) to capture rain and surface water before storing it for recycling, performing a controlled discharge into the primary drainage system, or gradually releasing it into the sub-grade.

The BBA accreditation assessed the system's mechanical resistance, hydraulic performance and durability at two trial locations in Bristol and Bolton.

James Freeman, national special products manager for Tarmac, said the accreditation would give architects, engineers and contractors added assurance that TarmacDry is an effective water-management system, either on its own or as part of a wider SuDS system.

'The likely introduction of the Draft Floods and Water Bill later this year will have far-reaching implications for how surface water is controlled,' he commented. 'It is vital, therefore, that the construction industry can draw upon a proven pavement technology to help mitigate flood risk by designing porous surfacing into all developments.'

TarmacDry is supplied and installed throughout the country by Tarmac National Contracting.

Download our BBA certificate.

TarmacDry, which was launched in September 2008, fought off two finalists to grab the top spot. More than 1,000 attendees were at the event which is described as 'the building industry's version of the Bafta's'.

Commenting on Friday's success, Andy Jones, business manager - TarmacDry said: "Winning the award is an excellent result for it shows Tarmac as an innovator providing products and systems of real value to the Building industry and is testament to the environmental and sustainability benefits of the system."

Launched in September 2008, the patented product is supplied and installed throughout the country by Tarmac's National Contracting team and is a fast-growing hit with customers. It is an innovative pavement technology that actually holds, purifies and recycles water from torrential downpours.

WMCCE Constructing Excellence Awards judges said: "...applications for the award (were) particularly challenging to assess with a wide variety of innovative ideas put forward."

Pictured above (Left to Right): Andy Smith - HBL Associates, Neil Thomas, asphalt product development manager, Andy Jones, business manager - TarmacDry, Colin Poxon, general manager, Tarmac's BDP Surfacing and Kiren Sidhu, special products manager

You can set your watch by it.  The floods arrive and there are the inevitable cries that our pleasant green land has been paved over by too much impermeable concrete and asphalt. This blame culture misses the point. The fact remains that increased rainfall patterns are set to continue and our antiquated drainage systems cannot cope. What really matters is that central government, the construction industry and local authorities learn quickly from mistakes and fully grasp the need to embrace Sustainable Drainage Systems (SuDS). Both government and the construction industry have been talking about this for too long now with no action. The construction industry has failed to call for legislation that would change the way we manage and alleviate the pressures that unpredictable rainfall patterns place on our traditional drainage systems. Sustainable Drainage Systems (SuDS) have at times fallen by the wayside in authorities’ plans – perhaps a result of cost-cutting exercises, lack of forward planning, lack of understanding of what the systems can offer or because contractors are not always being equipped to install them. Responsibility for provision, operation and maintenance of SuDS has clearly not been set out by central government. This is set to change as we now stand on the cusp of new legislation which will change the way local authorities manage flood risk.  The Pitt Report and Defra’s announcement in July which outlined a broad proposal for the Floods and Water Bill will, if implemented in 2009, have far reaching implications.  Thankfully, the Floods and Water Bill will address a need for responsibility for drainage. Local authorities will have a clear responsibility to tackle surface water flooding in the communities they serve. They will be supported by the Environment Agency, who in the future will have a new strategic role to oversee this work.   Phil Woolas, Environment Minister, has indicated that government would give local authorities new powers to ensure that organisations and landowners fulfil their obligations such as the maintenance of drains. Ultimately, the draft Flood and Water Bill could pave the way for more specific legislation on SuDS. While this legislation is not in place yet, I believe that the construction industry now has a clear responsibility to develop, specify and ensure that contractors understand how to install SuDS systems. With the pressures that our permanent drainage systems now face, SuDS will be a vital ingredient in the overall strategy of local authorities for water management and flood mitigation.  Critically, SuDS need to be given priority over traditional permanent drainage designs at the early stages of projects as a specific planning condition - this would provide a more robust framework for implementation.  The technology is already available. Pervious pavement technologies can work as part of a wider SuDS programme to manage excess surface water, reduce flood risk, minimise damage to properties and maximise the area available for development. They enhance public safety and protect the aquatic environment by filtering pollutants from surface water before it is released back into watercourses. They also offer huge potential to capture rainwater for reuse elsewhere.  Permeable pavements and SuDS have been used in France, the USA and Sweden for over 20 years with proven success. Yet they have not, up until now, been used as widely in the UK. I am hopeful that the Floods and Water Bill will help to transform this.At Tarmac, we have been at the forefront of porous asphalt pavement technologies for more than ten years and have recently developed TarmacDry, a unique, patented permeable pavement system that we design, build and maintain. It looks and performs in the same way as normal asphalt but can hold up to 30 - 40 percent of its volume with water. Used alone or as part of a wider SuDS system, TarmacDry™ can capture, clean and release rainwater slowly into the sub soil or alternatively collect it in a reservoir layer for harvesting as grey water. Increasing pressures from development and more intense rainfall patterns dictate that we must take SuDS seriously. Ahead of the implementation of the Floods and Water Bill in 2009, now is the time for the construction industry to ensure that it has water management right at the top of its agenda.

Sustainable Drainage Systems (SuDS) are already a well-established concept, and we are used to the idea of roads discharging water in an effective and responsible manner – an issue whose importance was brought home by last year’s floods.

Flood Risk

“Flood risk assessments are a major part of planning approval now,” points out Neil Thomas, Tarmac’s Product Development Manager for Asphalt. “New construction sites are restricted in the amount of water they are allowed to discharge. Developments must handle their own water.”

“Tarmac recognised the need for porous paving in the mid-90s, when there were concerns about impending climate change and flood-risk,” says Howard Robinson, Head of Product Development. “People think of it as a recent development but the government and Defra have been talking about SuDS for over 10 years and we started developing the technology for permeable surfaces back then. We have three patents granted, and TarmacDry is due to be launched in June. It’s the only patented asphalt and concrete SuDS system.’

TarmacDry holds, purifies and recycles water from torrential downpours, helping to combat the effects of both flash flooding and droughts. The surface material can absorb water up to a third of its own volume. It helps take the pressure off existing drainage systems by complementing the way in which they work. It then removes impurities like oil and sand before the water either commences its natural journey into existing ground or is diverted for household use and the watering of landscapes reducing the use of high-quality drinking water.
“It’s a system comprising a porous surface course, which could be asphalt or concrete,” explains Robinson. “From the experience of America and Europe, we know that if these systems are properly designed and installed, they will last at least 20 years.”

The future is black

Robinson is understandably optimistic about the potential of asphalt technology. “The future is black not grey,” he declares. “Asphalt has many advantages over blocks: it can be laid more quickly, it offers considerable cost savings, and unlike blocks it can be designed to provide surface characteristics such as skid-resistance. The Environment Agency and Defra want to see car parks and light traffic areas go porous, so it will become more mandatory. You’ll be seeing it on everything from big supermarket developments to households.”

Aggregate Industries (AI) aims to reduce flood risk by controlling the rate and volume of surface water run off from developments, in addition to managing the quantity of surface water more effectively. SuDS improve water quality by mirroring nature in providing filtration and allowing for natural bio-degradation of hydrocarbons and the dilution of other contaminants as water passes through the system.

SuDS are a good example of how the industry now looks at the bigger picture. “It forces us to bring different elements of our work together,” argues Bob Allen, Research Manager at AI. He describes the future as “exciting”, and thinks that there is potential for further innovation.

“Pavements used to be a safe hard area where you parked, drove or walked safely,” he says. ‘What we’ll see over the next 20 years is pavements becoming systems, and themselves part of bigger systems, and you can see that happening in SuDS.  A car park becomes part of the management, cleaning and re-use of water and the re-use of energy within the system.’

Article from Asphalt Now issue 22 

Sustainable Drainage Systems (SuDS) have at times fallen by the wayside in authorities’ plans – perhaps a result of cost-cutting exercises, lack of forward planning, lack of understanding of what the systems can offer or because of contractors not always being equipped to install them. The responsibility for provision, operation and maintenance of SuDS has also not clearly been set out.

This is set to change as we now stand on the cusp of new legislation which will change the way local authorities manage flood risk. The announcement from government outlining a broad proposal for the Floods and Water Bill will, if implemented in 2009, have far reaching implications.

Local authorities would have a clear responsibility to tackle surface water flooding in the communities they serve. They will be supported by the Environment Agency, who in the future will have a new strategic role to oversee this work.  

In a speech this week, Phil Woolas, Environment Minister, indicated that government would give local authorities new powers to ensure that organisations and landowners fulfil their obligations such as the maintenance of drains. Ultimately, the draft Flood and Water Bill could pave the way for more specific legislation on SuDS.

While this legislation is not in place yet, I believe that the construction industry now has a clear responsibility to develop, specify and ensure that contractors understand how to install SuDS systems. With the pressures that our permanent drainage systems now face, SuDS will be a vital ingredient in the overall strategy of local authorities for water management and flood mitigation

Critically, SuDS need to be implemented at the early stages of projects as a specific planning condition - this would provide a more robust framework for implementation.

The technology is already available. Porous pavement technologies can work as part of a wider SuDS system to manage excess water, reduce flood risk, minimise damage to properties and maximise the area available for development, as well as enhancing public safety and protecting the aquatic environment by filtering pollutants from surface water before it is released back into watercourses. They also offer huge potential to capture rainwater for reuse elsewhere. Porous pavements and SuDS have been used in France, the USA and Sweden for over 20 years with proven success, yet they have not, up until now, been used as widely in the UK. I am hopeful that the Floods and Water Bill will help to transform this.

At Tarmac, we have been at the forefront of porous pavement technologies for more than ten years, and have recently developed TarmacDry, a unique, patented porous pavement system that we design, build and maintain. It looks and performs in the same way as normal asphalt but can hold up to 30 percent of its volume with water. Used alone or as part of a wider SuDS system, TarmacDry can capture, clean and release rainwater slowly into the sub soil or alternatively collect it in a reservoir for harvesting as grey water.

Increasing pressures from development and more intense rainfall patterns dictate that we must take SuDS seriously. Ahead of the implementation of the Floods and Water Bill in 2009, now is the time for the construction industry to ensure that it has water management right at the top of its agenda.