Small Living Wetlands Award winner 2006

The winner of the small Living Wetlands Award 2006 is Scrayingham Ecological Wastewater Treatment system submitted by Yorkshire Water. 

The village of Scrayingham plays host to the first stabilisation pond scheme, designed and built in the UK, that takes combined effluent.   Before the treatment works were built all the effluent from the village discharged to a small stream that drains into the river Derwent. Over time the stream had become eutrophic leading to a loss of biodiversity and odour complaints.  Instead of providing a typical treatment of a small self contained package plant Yorkshire Water awarded the land owner George Winn Darley and Iris Water & Design the contract to design and build an Ecological Wastewater Treatment System. 

The system designed comprises of a series of ponds and rock filters in which all effluent is treated.  Iris Water and Design used applied ecology in their design to create a natural system.  The site chosen benefited from a natural fall ideal for a wetland gravity system and was far enough away from human noise and interference that a wildlife habitat could be created. 

Micro organisms are exploited to enhance the effectiveness of the treatment process.  Algae initially releases oxygen into the air which is utilised by bacteria that breakdown the incoming effluent, nutrients and carbon dioxide is produced as a by product which in turn promotes further algae growth.  This process is continued in the later ponds with lower animals in the food web consuming algal and bacterial biomass which are then in turn consumed by higher animals.
This process is also aided by rock filters.  Effluent flows horizontally through these beds and in the process are filtered biologically reducing suspended solids.

These systems are characterised by their simple construction and operation, robust and reliable performance, low cost of operation and maintenance, high standards of effluent quality and low sludge yields.
As the effluent moves through the various ponds the water quality improves, increasing the diversity of flora and fauna and as a result of these processes the effluent entering the receiving river is of a high quality.