The Common Agriculture Policy also underwent reform in 1992 and later in 2000. The ND was focused on monitoring NVZs and keeping levels of nitrates below 50 mg/L, which is the threshold for drinking-water safety. Although eutrophication risk was one of the criteria for the definition of NVZs, the environment was less of a concern in determining its provisions.30 The ND has constituted one of the basic measures for WFD implementation since 2001.31 During the 2008-2009 period, all Member States formally submitted implementation plans for the first time. A 2010 evaluation showed that action programmes had been effective especially for surface water: it was estimated that nitrate concentrations in surface water remained stable or fell for 70% of monitored sites between 2004 and 2007 (European Commission, 2010(67]).