Water Footprint: A Critical Conceptual and Methodological Revision of the Grey Water Component of the Indicator
Abstract
In 2004, the Czech Republic joined EU and made a commitment to increase the use of sustainable energy resources up to 8 % until 2010. The growing interest in biogas and biofuels has been caused also by the goal to reduce CO2 emissions from energy sector and fossil fuels use.
Since 2007, subsidy schemes for the development of rural areas have included grants for biogas stations. Thus the number of biogas stations increased from 20 in 2008 to 200 in 2011, and to 500 in 2013.
About 60 % of them process maize. Selective pre-emergence herbicides s-triazines are used worldwide for the control of maize cultivation.
The most commonly used is atrazine. After it was identified as an endocrine disruptor and frequently detected at high concentrations in surface and ground water systems, commercial use of atrazine was banned in the European Union (EC, 2004) and another s-triazine - terbuthylazine - has been in use as a direct replacement.
The project presented does not contest the general idea behind the GWF - the project aims at one of the main problems of the Grey Water footprint concept and methodology that is the emphasis on nitrogen (N) and phosphorus (P) only. The complexity of N and P geochemical cycles highly influences the potential impact of fertilizers.
So far the Grey Water footprint based on fertilizer use has not considered the actual level of pollution caused by crop production. The pilot study introduced in the poster therefore critically analyzes nitrogen and phosphorus use in GWF calculation.