We are at the forefront of using modern sustainability technology in the design of mechanical and electrical systems for our clients.
Our subsidiary Hamson Partnership are consultants for East Sussex County Council (ESCC) under a framework agreement. Recently ESCC asked us to find a solution to a problem being suffered by one of their tenants, the Canoe Centre at Seven Sisters Country Park. One of their septic tank systems had failed, but they were looking for a better long-term solution than regular removal of sludge by road tanker.
We designed a replacement system that first involved installing a Mantair® aerobic digestion unit, which uses compressed air to generate ‘activated sludge’ and causes the pollutants to be broken down to form a ‘liquor’. For the second stage of the process, we chose a reed bed as being the most cost-effective and sustainable solution.
Our engineers designed a horizontal sub-surface flow reed bed, which filters the liquor through the roots of Common Reed (Phragmites australis) plants. The process adds oxygen for secondary decomposition, and the output of the 12m long, 8.5m wide reed bed is clean effluent. It meets Environment Agency standards for discharge straight into the surrounding wetland, so we were able to gain the necessary Consent to Discharge.
The new design was installed and has been a great success. As repeat business, the Canoe Centre have asked us to design a scaled-up version as a replacement sewage system for their visitor centre and offices.