Apsu Environmental Limited, a recently formed waste water processing company based in Midlothian, Scotland has teamed up with the University of Edinburgh to design and develop pioneering surface water filtration systems which offer large reductions in the land needed for a traditional Sustainable Urban Drainage System (SUDS) installation by up to 80% and achieves pond reduction by 70%.

The technology – Advanced Treatment Station (ATS-SUDS) - was developed for use in sustainable urban drainage, but also addresses the significant challenge faced by road engineers and highways departments in handling road gully and road sweepings wet waste, through a proprietary technology ATS-TARP – a means of recycling road gully & sweepings waste in a Treatment and Recycling Plant (TARP).

This allows the recycled water to wash and refill the gully trucks preventing the use of previously used drinking standard water.

The dewatered solids mainly Inorganic matter – sand, for example - can be passed through a grit recovery system for reuse as a road fill material whilst smaller organic materials such as leaf mould and twigs, can be composted. The remainder 2% consisting of plastics etc is the only element landfilled.


Within the ATS-SUDS, water is received from the surface water drainage system into a primary chamber where the majority of solids and associated contaminants are removed. Depending upon the water flow conditions, the system will naturally select its own exit from the system through integral high and low level filtration and infiltration chambers.

The results are impressive, with removal of up to 76% of total suspended solids, 99% of hydrocarbons from oils/fuels and approximately 80% of dissolved and heavy metals.

Apsu’s ATS-SUDS can handle can water flow rates from 1 – 1000 lps, with the high performance ATS-SUDS system unit providing both capital and whole of life savings against conventional ‘above ground’ treatment and attenuation processes.

As Iain Robinson, managing director of Apsu Environmental explains, the entire concept was borne out of a need to find a collaborative academic partner to refine the water decontamination technology.

"We approached University of Edinburgh to find a suitable academic partner to develop our technology which could then be commercialised. We formed a collaborative partnership with Dr Colin Cunningham, who is now our technical director.

This now gives us the platform to innovate and create the most robust Advanced Treatment Station applications for use in road engineering, highway construction and a number of areas where land reduction measures for SUDS and waste water recycling are critically important considerations to the construction planning strategy."

Dr Cunningham was previously employed as the Research Co-ordinator of the Contaminated Land Assessment & Remediation Centre (CLARRC) at The University of Edinburgh. In addition to his role with Apsu Environmental, he leads the Scottish Environmental Technology Network, which now supports around 150 companies in the Scottish environmental and clean technology sector.

Apsu Environmental was formed in 2010 with private equity funding.

(GK)