Applications
Infiltration
Infiltration systems are designed to provide temporary storage of run off water while natural dispersion into the surrounding soil takes place. Conventional soakaways are the most common example of below ground infiltration. The high void area of Waterloc250 (96%) means that a third of the volume is required compared with a conventional gravel/shingle filled pit. The success of any infiltration installation is wholly dependent on the permeability of the surrounding soil. Waterloc250 cells require a geotextile wrapping (click here for specification) to prevent silts from entering the installation. The images above shows a typical infiltration scheme. The inlet connection can be made via the side inlet plate or via the unique Marley inlet chamber. The advantage of using the inlet chamber is that it provides access to the tank for inspection and cleaning. Inlet chambers can also be used purely as access for inspection. Multiple chambers may be appropriate for larger schemes.
Attenuation
Designed to store stormwater temporarily in a suitable chamber below ground and release it at a pre-determined rate via a flow control device such as the Marley Flowloc or an orifice plate. This limits the peak flow of water, thereby reducing the likelihood of overloading pipelines or watercourses downstream. The sizing of the attenuation tank is critical, to allow sufficient capacity to prevent upstream flooding. The Marley Technical Services team offers a design service to assist with this calculation. Attenuation tanks must be encapsulated within an impermeable membrane and geotextile (click here for specification). Increasingly, as sewer networks approach their limiting capacity, attenuation techniques can offer a cost effective solution for accommodating additional catchment areas without increasing the size of the sewers.
Rainwater harvesting
Rainwater harvesting can form part of a SUDS scheme, providing for the storage and re-use of rainwater from the roof. This can be used for non-potable applications such as garden irrigation or toilet flushing. With the increasing emphasis on reducing the consumption of potable water consumption, rainwater harvesting can be part of the solution. Rainwater harvesting systems cannot be used in isolation to deal with site run off, but can provide additional benefits when combined with infiltration or attenuation schemes. Marley have a range of harvesting systems for both domestic and commercial use. Click here for more information.
