http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch3s3-3-2.html
Many non-climatic drivers affect freshwater resources at the global scale (United Nations, 2003). Water resources, both in quantity and quality, are influenced by land-use change, the construction and management of reservoirs, pollutant emissions, and water and wastewater treatment. Water use is driven by changes in population, food consumption, economic policy (including water pricing), technology, lifestyle, and society’s views of the value of freshwater ecosystems. Vulnerability of freshwater systems to climate change also depends on water management.
Wastewater treatment is an important driver of water quality, and an increase in wastewater treatment in both developed and developing countries could improve water quality in the future. In the EU, for example, more efficient wastewater treatment, as required by the Urban Wastewater Directive and the European Water Framework Directive, should lead to a reduction in point-source nutrient inputs to rivers. However, organic micro-pollutants (e.g., endocrine substances) are expected to occur in increasing concentrations in surface waters and groundwater. This is because the production and consumption of chemicals are likely to increase in the future in both developed and developing countries (Daughton, 2004), and several of these pollutants are not removed by current wastewater treatment technology. In developing countries, increases in point emissions of nutrients, heavy metals, and organic micro-pollutants are expected.
I found a solution to the problem in the book -"Mulder" "Basic principles of membrane technology"
And http://www.sciencedaily.com/releases/2007/11/071129121129.htm
