Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Water good idea


Hats off to Yorkshire Water which won the Atkins Environmental Award in this year's British Construction Industry Awards (NCE last week) for its ecological wastewater treatment system at Scrayingham.

It was a brave decision by Yorkshire Water to adopt a natural treatment process, but a decision consistent with the need for civil engineers to put sustainability in the forefront of our thinking. The use of waste stabilisation ponds (WSP) and constructed wetland systems (CWS) for wastewater treatment is at last gaining momentum in the developed world, offering low energy and low whole life costs in comparison to the ubiquitous and electrical energy-thirsty variants of activated sludge, Though the unit cost of the Scrayingham system is very high, I am sure that in the future these natural treatment systems will look increasingly competitive with energyintensive processes as we put more value on amenity and when we take into account the full environmental costs of imported energy.

It is disingenuous however, to think WSP and CWS systems are 'ultra low tech'. The anaerobic, anoxic, aerobic, photosynthetic and plantcentred processes at work in natural treatment systems are complex and there are many challenges ahead for process designers to understand and simulate them in mathematical models and thereby design more efficient systems.

Further, the civil engineering designs for these systems pose novel problems in geotechnics, foundations, hydraulics and the use of vegetation. In fact it brings to mind that oft-quoted definition of the work of civil engineers - 'harnessing the forces of nature for the use of mankind'!

Michael Norton (M) director, Halcrow Group nortonmr@halcrow. com

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.