Anyone who trains regularly on an artificial turf field or 3G sports pitch (or indeed has a son or daughter who does) will recognise the black ant-sized speckles of plastic that follow the player from the field to the car and then into home. The pesky microplastics from artifical turf are notorious for getting flicked into astro turf shoes and being unwittingly transported off the pitch.
Artificial grass sports pitches are compiled of plastic grass fibres and an infill of either sand, rubber crumb or a combination of both. Rubber crumb is made from used tyres, often referred to as end-of-life tyres (ELTs), which are processed and recycled into granules for use as infill.
Infill in artificial sports fields is fundamental to the pitches performance, lifespan and safety. It helps keep the artificial grass upright and the rubber crumb provides a degree of player comfort by absorbing shocks.
The amount of rubber crumb in pitches varies by the manufacturer. A typical 3G pitch, for example, is generally filled to two thirds the pile height with rubber crumb.
Over time, the crumb migrates towards the edges of the pitches and needs to be brushed evenly back towards the centre. Critically, it also has to be topped up, in part to replace the stuff now in your house!!
The Problem – Microplastics from Artificial turf a source of plastic pollution
Artificial sports surface manufacturers recommend that the infill on the pitch is topped up every 1 to 2 years with 3-5 tonnes of infill each time depending on use. Sports Lab suggest that 1 to 3 tonnes is used to top up a field each year.
There are no publically available figures for the amount of rubber infill lost to the environment in Great Britain. However according to the FA, there are 1027 registered 3G pitches in England alone. There are 55 full size 3G pitches in Wales and at least 36 in Scotland. Unless properly managed, the potential amount of rubber infill lost to the environment in the UK could be huge.
So how does rubber infill that needs to be replaced escape, and where does it end up?
Snow clearance from the pitches during colder months can mean that the cleared snow is pushed off the field. When the snow melts the rubber crumbs are outside the playing field. That infill could be reused on the pitch or collected as waste. It is often though just left to the elements.
Microplastics caught up in clothing, sports bags or shoes are likely to be first released from the sports pitch en route to the changing rooms. Rubber crumb deposited around the pitch is carried off with stormwater during heavy rain to the drainage systems or blown by the wind until eventually reaching the drains. In most instances, rainwater (and anything floating in it) flows across the surface and into drains which are connected to a surface water sewer. The surface water sewer takes the water directly to be discharged into rivers and beaches. Unless a filter or other rainwater treatment device is installed within the surface water drainage system, all of the lost rubber crumb will flow (eventually) into the sea.
Any rubber crumb that makes it to the player’s home still in clothing or boots is likely to be either be washed out of the clothes and caught by the water company filters through the foul (wastewater) sewer system* or be vacuumed from carpets and disposed of as household waste.
Along with the rubber crumb infill, the plastic that the artificial grass is made of will break and degrade over time too. This further contributes to plastic pollution in the environment from artificial turf sports pitches.
*unless the home drains have been connected incorrectly or it goes into a combined drain (found in older properties). Combined sewers during intense rainfall often discharge to a Combined Sewer Overflow (CSO). These act as an emergency discharge valve and release the untreated waste water and sewerage into rivers or even directly to the sea. There are 31,000 CSOs in the UK.
The Solution – How to prevent microplastics from artificial turf polluting our oceans
The good news is that there are solutions that clubs can implement to reduce the amount of microplastics and rubber crumb from their artificial sports pitch polluting the wider environment.
There is a lot of advice on the internet about adding physical barriers around the pitch, player “brush down” areas and putting removed snow onto tarpaulins so that the infill pellets can be spread back onto the pitch when the snow has melted. These are all good ideas. However, the only sure fire way of ensuring that rubber crumb from around the pitch does not enter the surface water drainage system is to install or retrofit filters to the drains.
The problem can easily be solved by installing 3P Technik filter systems. 3P systems are easy to retrofit and of course are most easily installed in the drainage systems of new build sports facilities.
With our solution particulate matter with sizes above 50 μm (0.05mm) is no problem as they will be retained by the particle and suspended matter separator – The HydroShark series of Hydrodynamic Separators.
The majority of the finer particles, smaller than <50 μm, as well as the dissolved substances, are retained at the next filter treatment stage – The HydroSystem 1500.
This surface water treatment train allows the rainwater from around artificial sports pitches to be safely discharged into the surface water drainage system, a soakaway, a river or the sea.
Even when retro fitting installations without any head drop, the 3P Technik system is configurable for nearly all existing drainage networks. The existing pipes can be retained during retrofitting and the cleaning unit is simply integrated into the existing pipe network. The system can be deployed with minimal effort and without significant disturbance to the existing infrastructure.
When installed with a height drop across the Hydrosystem, the system solution is particularly ideal for new buildings and then offers maximum performance and optimum operating conditions for the filters.
Maintenance of the 3P system is easy. The pollution collection chamber within the HydroShark is simply emptied with a gulley sucker. The Filters in the HydroSystem can be backwashed and eventually they are exchanged for new ones periodically (depending on pitch use and pollution load).
The 3P Stormwater Treatment System solution is precisely designed to offer maximum flexibility to the planning engineers and the site operators. It also gives confidence to Local Authorities, SABs and other regulators responsible for the UK’s water quality. The system provides a certainty of treatment.
For further information, please contact our team of experienced stormwater management experts.