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