Table 4. Effects of implemented policy measures, as estimated using the PCRaster-Extend model suite in terms of load reduction at Hemiksem in 2038 and distance to water quality target as indicated by the mean summer concentration, which can be compared with the EU Water Framework Directive nitrogen standard for good ecological condition of 2.5 mg nitrogen/L for large rivers in Flanders. Investment cost is annualized measured at a 4% interest rate over 20 yr applying 2010 € values. Nitrogen concentration for the business-as-usual scenario is lower than in Fig. 6 because the 2008 values are lower than those for 2006.


Policy measure Proportion remaining of 2008 load (%) Total N in 2038
(mg N/L)
Estimated cost of measure
(million €/yr; idem per percent N load reduction)†
(1) Business as usual 88 4.0 Investment in manure processing plants: 396; 33
(2) 50% cattle stock reduction 74 3.4 Net foregone farmer income: 1686; 65
(3) 50% reduction in fertilizer and manure applications 74 3.4 Net foregone farmer income: 151; 6
(4) 40% improvement in waste-water treatment efficiency 47 2.2‡ Investment in infrastructure§: 233; 4
(5) Implementation of buffer strips 78 3.5 Purchase of land along streams¦: 56; 2
(6) Combination of (2) to (5) 24 1.9‡ N/A
(7) Climate scenario G 88 4.0 N/A
(8) Climate scenario W+ 86 4.3 N/A
†Costs from Broekx and De Kok (2010).
‡The standard of 2.5 mg N/L is reached in 2022 for measure (6) and in 2032 for measure (4).
§At 108–147 € population equivalent−1 yr−1; cost and number of households connected differ between Wallonie, Flanders, and Pas de Calais.
¦At 1485 ha−1 yr−1 and 37,550 ha purchased by 2038.