This report provides an overview of fertilisation practices in 2009 and of water quality in 2009 and 2010 on grassland farms that are allowed to use more animal manure than the limit set in the European Nitrates Directive (derogation). Data from this research can be used to study the consequences for the water quality. The water quality values measured in 2009 reflect agricultural practices in 2008, which was the third year in which the derogation was applied. The water quality values measured in 2010 reflect the consequences of agricultural practices in 2009. The European Nitrates Directive obliges Member States to limit the use of animal manure to a specified maximum (the application standard animal manure of 170 kg N/ha). A Member State may request permission from the European Commission to deviate from this obligation under specific conditions. In December 2005, the Commission granted the Netherlands the right to derogate from the obligation from 2006 to 2009. On 5 February 2011, this derogation was extended to 2013. One of the underlying conditions of the derogation is that the Dutch government establishes a monitoring network and reports the results each year to the European Commission. In 2006, the National Institute for Public Health and the Environment (RIVM) and LEI, part of Wageningen University and Research Centre, set up a derogation monitoring network. This measures the effects on agricultural practice and water quality when farmers are allowed to deviate from the European application standard for livestock manure. The derogation monitoring network is part of the Minerals Policy Monitoring Programme (LMM). The agricultural practice was measured on 275 grassland farms and the water quality on 285 grassland farms. The monitoring network covers 300 farms. However, fewer than 300 farms are reported: there were changes to the farms included in the monitoring network and, in retrospect, not all farms applied for derogation or were awarded it.