Nutrient Removal Versus Carbon Footprint Reduction in Wastewater Treatment: An Acceptable Balance?
Ifelebuegu, A., Severn Trent Water Ltd, UK
(free)
Water Companies in the UK are required to meet increasingly stringent consent limits for wastewater
treatment effluent under the Urban Waste Water Treatment Directive (UWWTD) and in the future, Water Framework Directive (WFD). All these are aimed at protecting and improving the water quality in the UK.
Traditionally, Sewage treatment works were designed to meet sanitary consents including BOD, SS and
ammonia. Under the UWWTD, sewage works discharging directly or indirectly to water bodies thought to be sensitive to eutrophication are now required to meet more stringent environmental protection
standards. In pursuit of the overall objectives of environmental protection, the directive requires more
stringent treatment to achieve nutrient removal in so called “sensitive areas”. In addition to this increasing requirement for the water industry to treat for nutrient in sewage, policies in
response to the treat of climate change can be expected increasingly to internalise the external costs
associated with emissions of greenhouse gases, as policy makers use economic instruments and other
means to ensure compliance with the targets of the Kyoto Protocol. Concerns about global warming have
led to the development of the Kyoto Protocol limiting the emission of greenhouse gases. As a signatory,
the UK has been assigned a reduction, relative to 1990 emissions, of 12.5% by 2008-2012.
