• Agricultural practice and water quality at grassland farms registered for derogation in 2013 : Landbouwpraktijk en waterkwaliteit op landbouwbedrijven aangemeld voor derogatie in 2013

      Lukacs S; de Koeijer TJ; Prins H; Vrijhoef A; Boumans LJM; Daatselaar CHG; Hooijboer AEJ; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2015-07-16)
      Pursuant to the EU Nitrates Directive, the member states are required to limit the use of livestock manure to a maximum of 170 kg of nitrogen per hectare per year. Dutch farms growing grass on at least 70 per cent of their total agricultural area were allowed to deviate from this requirement under certain conditions, and apply up to 250 kg of nitrogen per hectare in the form of livestock manure (this partial exemption is referred to as 'derogation'). The Netherlands are required to monitor agricultural practices and water quality at 300 farms which have been granted derogation, and to submit an annual report of the results to the EU. LEI Wageningen UR and RIVM will compile this annual report. This study examines farms that registered for derogation in 2013 and shows trends between 2006 and 2014. The report concludes that the average nitrate concentration in groundwater on these farms has stabilized or decreased in this period. Agricultural practice This report also shows that, in 2013, derogation farms used on average approximately 4 kg less nitrogen per hectare in the form of livestock manure than the permitted maximum of 250 kg nitrogen per hectare. The quantity of nitrogen that can potentially leach into groundwater as nitrate is partly determined by the nitrogen soil surplus. This surplus is defined as the difference between nitrogen input (e.g. in the form of fertilizers) and output (e.g. via milk). On average, the nitrogen soil surplus has not changed substantially during the period studied. Groundwater quality In 2013, the average nitrate concentration in groundwater on derogation farms in the Sand Region amounted to 37 milligrams per liter (mg/l) and was therefore below the standard of 50 mg/l. On average, farms in the Clay and Peat Regions had even lower nitrate concentrations (11 and 6 mg/l, respectively). Farms in the Loess Region, showing an average nitrate concentration in groundwater of 56 mg/l, however, exceeded the standard. The difference between the regions is mainly caused by a greater share of soils prone to nitrogen leaching in the Sand and Loess Regions. Less denitrification occurs on these soils, and more nitrate can therefore leach into the groundwater.
    • Agricultural practice and waterquality in the Netherlands: status (2012-2014) and trend (1992-2014) : Monitoring results for Nitrates Directive reporting

      Fraters B; Hooijboer AEJ; Vrijhoef A; Claessens J; Kotte MC; Rijs GBJ; Denneman AIM; van Bruggen C; Daatselaar CHG; Begeman HAL; Bosma JN; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2016-09-16)
      Nitrogen and phosphate are essential substances in manure used at farms to improve production. Nevertheless, too much nitrogen or phosphate is harmful. The difference between supply and removal of nitrogen at farms in the Netherlands - the so-called nitrogen surplus - has halved between 1992 and 2014. The phosphate surplus has almost ceased to exist. The nitrate concentration in on-farm groundwater and surface water has diminished, and the quality of the surface waters in the Netherlands has improved. However, compared with the previous monitoring period (2008-2011), the improvement of the water quality is small. According to expectations, nutrient concentrations will further decrease, but the desired quality of groundwater will not be achieved everywhere. In addition, the quality of surface waters will often remain insufficient. Water quality 2012-2014 The improvements in water quality are a result of the measures implemented in the Netherlands pursuant to the European Nitrates Directive. One example is the requirement to apply less manure. In the 2012-2014 period, at most farms the nitrate concentrations in on-farm waters in the Clay and Peat Region were lower than the standard (50 mg/L). In the Sand Region, this was the case for about half of the farms, and in the Loess Region for less than half of the farms. The nitrate concentrations in regional surface waters which are mainly supplied from agricultural areas are almost always lower than the standard. In surface waters designated for the Water Framework Directive (WFD), this standard is not exceeded. Nevertheless, nitrate, other nitrogen substances and phosphate have a negative impact in the majority of surface waters. It turns out that the nitrate standard that is implemented to protect drinking water resources is not sufficient to avert this impact. The nitrogen and phosphorus concentrations in summer, which have a large impact on flora and fauna in surface waters (ecological water quality), have decreased since the beginning of the 1990s.
    • Agricultural practices and water quality on farms registered for derogation in 2012

      Hooijboer AEJ; de Koeijer TJ; van den Ham A; Boumans LJM; Prins H; Daatselaar CHG; Buis E; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMLEI Wageningen UR, 2014-07-08)
      The EU Nitrates Directive obligates member states to limit the use of livestock manure to a maximum of 170 kg of nitrogen per hectare per year. Dutch farms cultivating at least 70 percent of their total area as grassland were in 2012 allowed to deviate from this requirement under certain conditions, and apply up to 250 kg of nitrogen per hectare (this partial exemption is referred to as 'derogation'). The Netherlands is obligated to monitor agricultural practices and water quality at 300 farms to which derogation has been granted, and to submit an annual report on the results to the EU. This study examines farms that registered for derogation in 2012, and concludes that the average nitrate concentration in groundwater on these farms decreased between 2007 and 2013. This report was prepared by the National Institute for Public Health and the Environment (RIVM) in collaboration with LEI Wageningen UR (LEI). Agricultural practices The report also shows that, on average, derogation farms in 2012 used approx. 11 kg less nitrogen in livestock manure than the prescribed maximum of 250 kg of nitrogen per hectare. The quantity of nitrogen that can potentially leach into the groundwater in the form of nitrate is partly determined by the nitrogen soil surplus. This surplus is defined as the difference between nitrogen input (e.g. in the form of fertilisers) and nitrogen output (e.g. via milk). On average, the nitrogen soil surplus has not changed substantially between 2006 and 2012. Groundwater quality In 2012, the average groundwater nitrate concentration on derogation farms in the Sand Region amounted to 36 milligrammes per litre (mg/l) and was therefore below the nitrate standard of 50 mg/l. On average, farms in the Clay and Peat Regions had even lower nitrate concentrations (10 and 4 mg/l, respectively). With an average groundwater nitrate concentration of 55 mg/l, only derogation farms in the Loess Region exceed the standard. The difference between the regions is mainly caused by a higher percentage of soils prone to nitrogen leaching in the Sand and Loess Regions. Less denitrification occurs on these soils, and more nitrate can therefore leach into the groundwater.
    • Agricultural practices and water quality on farms registered for derogation in 2014

      Lukacs S; de Koeijer TJ; Prins H; Vrijhoef A; Boumans LJM; Daatselaar CHG; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMLEI Wageningen UR, 2016-07-05)
      Dutch agriculture is highly productive and efficient. The use of minerals is necessary for efficient production of crops, but also has undesirable (environmental) effects. The Dutch minerals policy seeks to minimise adverse environmental impacts, whereby monitoring is an essential component. This consists with international agreements on the use of minerals and monitoring the impact of policies. Conform the EU Nitrates Directive, the member states are required to limit the use of livestock manure to a maximum of 170 kg of nitrogen per hectare per year. Dutch farms growing grass on at least 80 per cent of their total agricultural area were in 2014 allowed to deviate from this requirement under certain conditions. This exemption from the standard of 170 kg nitrogen is referred to as 'derogation'. LEI Wageningen UR and RIVM monitor agricultural practices and water quality at 300 farms, which have been granted derogation and annually report the results to the EU. This study shows the results in 2014 and trends between 2006 and 2015. The report concludes that the average nitrate concentration in groundwater on these farms has stabilized or decreased in this period. Agricultural practice This report shows that, on average, derogation farms in 2014 applied 237 kg of nitrogen per hectare in the form of livestock manure. The quantity of nitrogen that can potentially leach into groundwater in the form of nitrate is partly determined by the nitrogen soil surplus. This surplus is defined as the difference between nitrogen input (e.g. in the form of fertilisers) and output (e.g. via harvested grass and maize). The average nitrogen soil surplus in the Netherlands has not changed substantially during the period studied, but in 2014 it decreased considerably due to the good growing season for grass and maize. Groundwater quality In 2014, the average nitrate concentration in groundwater on derogation farms in the Sand Region amounted to 40 milligrammes per litre (mg/l), and was therefore below the nitrate standard of 50 mg/l. On average, farms in the Clay Region and Peat Region had lower nitrate concentrations (15 and 9.5 mg/l, respectively). Derogation farms in the Loess Region had an average nitrate concentration in groundwater of 51 mg/l. The differences between the regions are mainly caused by a higher percentage of soils prone to nitrogen leaching in the Sand Region and Loess Region. Less denitrification (microbial decomposition of nitrate) occurs on these soils, and more nitrate can therefore leach into the groundwater.
    • Ammonia workshop 2012 Saint Petersburg : Abating ammonia emission in UNECE and EECCA region

      van der Hoek KW; Kozlova NP; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMSZNIIMESH, 2014-06-26)
      Experts from UNECE (United Nations Economic Commission for Europe) and EECCA countries (Eastern Europe, the Caucasus, and Central Asia) exchanged their knowledge and experience on ammonia emissions for the first time in Spring 2012 during a workshop in Saint Petersburg, the Russian Federation. The workshop was a part of the annual meeting of the Task Force on Reactive Nitrogen, which operates under the umbrella of the UNECE CLRTAP (Convention on Long-range Transboundary Air Pollution). In close cooperation with the North-West Research Institute of Agricultural Engineering and Electrification (SZNIIMESH), Saint Petersburg, RIVM put all contributions from the workshop together, both in the English and Russian languages. The contributions of in total 14 countries (ranging from Canada in the West to the Russian Federation and Kazakhstan in the East) deal with the actual emissions of ammonia and the development over time since 1990. The contributions also deal with how countries managed to meet the Gothenburg Protocol targets for emission reduction in 2010; almost all countries were successful in that. The papers also deal with developments foreseen in the near future which may have an impact on the ammonia emissions. For example the number of dairy cows will increase when the EU milk quota system is abandoned in 2015. One of the recommendations of the workshop is to consider ammonia emissions in the context of the whole nitrogen cycle in order to prevent unwanted environmental consequences in the other environmental compartments air, soil and groundwater. For example increasing the grazing time of cattle will reduce the total ammonia emissions but at the same time more nitrate may be leached because ammonia in the soil is readily converted into nitrate. Another recommendation of the workshop is to take care of reliable inventories of ammonia emissions. Nowadays in most countries it is difficult to obtain reliable data to what extent low emission techniques have been implemented. The workshop was concluded with the approval of the Workshop Resolution, which stipulates further cooperation of experts in the UNECE and EECCA regions.
    • Effecten van filtratie op stikstof- en fosforconcentraties in slootwater op landbouwbedrijven in het Landelijk Meetnet effecten Mestbeleid

      Vrijhoef A; Buis E; Fraters B; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2015-08-19)
      High concentrations of nitrogen and phosphorus in surface water can have an adverse impact on vulnerable nature and the quality of bathing water. This RIVM-study shows that the measured concentrations in surface water depend on the way the samples are treated: in filtered samples the concentration of nitrogen and phosphorus is lower than in non-filtered samples. There are two national monitoring networks in which these concentrations are measured. Minerals Policy Monitoring Programme (LMM), which includes measurements in ditch water on farms, and the MNLSO which monitors the quality of agriculturally influenced surface water in which farm emissions predominate such as nearby streams and waterways. Combined results of these monitoring networks can provide a better view on the distribution and sources of nitrogen and phosphorus. The LMM is a monitoring network focussing on groundwater in temporary wells; these samples must be filtered for proper analyses. To be able to compare them to the groundwater samples, the ditch water samples at LMM-farms are filtered as well. The MNLSO surface water samples are not filtered. The Evaluation of the Fertilisers Act 2012 (EMW2012) found that the monitoring networks do not optimally adjoin one another, one of the reasons being the difference in sample treatment. In this RIVM-study the effect of filtering has been researched and it is found that nitrogen concentrations in ditch water are around 5 percent higher in unfiltered samples. Phosphorus concentrations in the unfiltered samples are on average 80 percent higher than in filtered samples. However, the differences between filtered and unfiltered phosphorous concentrations vary greatly, so much so that it was not possible to determine a compensation factor. These results imply that, in order to compare nutrient concentrations between the two monitoring networks, at least the sample treatment must be the same. This means that for either of these two monitoring networks both filtered and unfiltered samples must be available.
    • Evaluation of the Dutch leaching decision tree with the substances bentazone, MCPA and mecoprop

      van der Linden AMA; Beltman WHJ; Boesten JJTI; Pol JW; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2016-09-29)
      The leaching of bentazone, MCPA and mecoprop to groundwater was assessed using the new proposals for evaluating sorption and degradation studies (Boesten et al. 2015). The three substances are weak acids, showing pH-dependent sorption behaviour in soil. The evaluation led to large corrections for the sorption endpoint, KOM, derived for individual studies. Consequently, the curve describing sorption as a function of soil pH changed, indicating lower sorption over the relevant pH range. None of the available Freundlich exponents passed the reliability check. Using the improved interpretation procedures for sorption and degradation experiments revealed that several usages of the substances did not comply with the threshold limit for leaching when assessed at both Tier 1 and Tier 2 of the decision tree on leaching. The assessments did not reveal shortcomings in the decision tree itself. It is recommended that the improved interpretation procedures for sorption and degradation experiments are used for deriving endpoints for future substance leaching evaluations.
    • Hergebruik beeldbuisglasgranulaat : Relatie met REACH en kaderrichtlijn Afval

      Spijker J; Janssen MJM; Broekman M; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2015-11-16)
      Waste from cathode ray tubes (CRT) from TV sets, computer monitors, et cetera contains lead. Lead is toxic for the reproduction and for the development of children Due to the toxicity of lead, a thorough assessment is needed when lead containing waste is reused in new products. The National Institute for Public Health and the Environment studied the prerequisites for reuse of the material. CRT waste can be processed into glass granulates by grinding the material. These granulates are labelled as hazardous waste due to the high lead content. The presence of lead makes it difficult to reuse the granulates in new safe products. One of the applications of CRT granulates is to use it as aggregates in concrete, replacing natural sand and gravel. This is a safe application because the lead is not released from the concrete. However, there is a problem when this concrete is turned into waste. This waste appears also to be hazardous waste due to presence of lead, as is shown by calculations based on literature data on lead in CRT glass. This means that when CRT glass is reused in concrete elements a larger volume of hazardous waste will be created in the future, with no current recovery options available. It is not allowed to mix lead containing concrete waste with non-hazardous concrete waste. Therefore concrete waste with CRT aggregates must be processed separately from other concrete waste. This research was commissioned by the Ministry of Infrastructure and the Environment, division Rijkswaterstaat, to stimulate sustainable reuse of materials.
    • Jaarverslag Landelijke Werkgroep Grondwater 2011 en 2012

      Sterkenburg A; Claessens JW; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2013-10-10)
      In the National Working Group Groundwater, provinces, ministries, water boards, municipalities and research institutes have been working at the implementation of the Water Framework Directive and the Groundwater Directive concerning groundwater since 2003. In 2011 and 2012 the working group focused on linking different policy fields. In this way knowledge is combined that can be used to establish the next river basin management plans, scheduled for 2015. These plans should guarantee the quality of groundwater and surface water by compiling a program of measures every six years. Between 2011 and 2012, all parties concerned have consulted to fill in, in a consistent way, the factsheets containing information about groundwater bodies in The Netherlands. These documents are the basis of the river basin management plans and contain information about the quality of groundwater bodies, propositions to improve this quality in future and the way this may be attained. In collaboration with the working group, the ministry has also developed a protocol to interpret the current quality of the groundwater, and to evaluate its developments over time. The RIVM manages the working group's secretariat and makes a yearly summary of the proceedings. These summaries may be used as reference for those who have been involved in the working group. These summaries may also be used as information source for those who will be performing the activities arising from the working group.
    • Kwaliteitsstandaarden voor interactie grondwater met terrestrische ecosystemen

      Claessens JW; Verweij W; Lukacs S; de Nijs ACM; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2014-04-03)
      Many natural areas are dependent on groundwater; due to low groundwater levels or contaminated groundwater the quality of these areas can deteriorate. The Water Framework Directive (WFD) therefore prescribes that the influence of groundwater on terrestrial ecosystems should be taken into account when determining criteria for the quality of groundwater. These criteria concern the maximum permissible groundwater substance concentrations and these have been set to achieve those set for drinking water, surface waters and terrestrial ecosystems. The influence of the quality of groundwater on ecosystems on land has not been well-defined until now. The RIVM has therefore determined optimal concentrations for a number of substances (nutrients) to protect terrestrial ecosystems. These concentrations are to be used to when devising the methods and criteria for determining the quality of groundwater. This analysis has been conducted for a number of nutrients: nitrogen, phosphate and chloride. If taking these new insights into account, the criteria for nitrogen and phosphate appear not to have changed when determining the criteria for the quality of groundwater. The optimal concentrations that protect terrestrial ecosystems are considerably lower (a factor 5) than the present values. These are determined by the background levels. As it is difficult to reduce these levels, the policy has been to set the criteria at the level of background values.. This means that the present concentrations of these components in the groundwater are higher than those concentrations that needed to protect natural areas. This study does not investigate the extent to which these effects occur. The values determined in this study for optimal concentrations for terrestrial ecosystems, are applicable for the next generation of 'water basin management plans', to be made in 2021. These plans should ensure a good quality of groundwater and surface water with programmes that measure and monitor water quality. In order to achieve this, the 'so called' status and trend assessment (present concentration of substances) and the characterisation (long term trend for the future) of the groundwater are important. Policy makers can use the newly obtained insights in several ways. The numbers form this report can, for example, be compared to groundwater concentrations recorded in the national Acidification Trend Monitoring Network (TMV).This gives insights into the present quality of shallow groundwater in the surroundings of natural areas, and the possible effects on these natural areas.
    • Landbouwpraktijk en waterkwaliteit in Nederland; toestand (2012-2014) en trend (1992-2014) : Resultaten van de monitoring voor de Nitraatrichtlijn

      Fraters B; Hooijboer AEJ; Vrijhoef A; Claessens J; Kotte MC; Rijs GBJ; Denneman AIM; van Bruggen C; Daatselaar CHG; Begeman HAL; Bosma JN; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMRijkswaterstaat Water Verkeer en LeefomgevingCentraal Bureau voor de Statistiek (CBS)LEI Wageningen URRijksdienst voor Ondernemend Nederland, 2016-07-06)
      Nitrogen and phosphate are essential substances in manure used at farms to improve production. However, too much nitrogen or phosphate are harmful. The difference between supply and removal of nitrogen at farms in the Netherlands, the so-called nitrogen surplus, has halved between 1992 and 2014. The phosphate surplus has almost ceased to exist. The nitrate concentration in on-farm ground- and surface waters has diminished and the quality of the surface waters in the Netherlands has improved. However, compared with the previous monitoring period (2008-2011), the improvement of the water quality is small. According to expectations, nutrient concentrations will further decrease, but the desired quality of groundwater will not be achieved everywhere. In addition, the quality of surface waters will often remain insufficient. Water quality 2012-2014 The improvements in water quality are a consequence of the measures implemented in the Netherlands due to the European Nitrates Directive. An example is the requirement to apply less manure. In the 2012-2014 period, the nitrate concentrations in on-farm waters in the Clay and Peat region are lower than the standard (50 mg/L) at most farms. In the Sand region this is the case for about half of the farms and in the Loess region for less than half of the farms. The nitrate concentrations in regional surface waters that are mainly draining agricultural areas are almost always lower than the standard. In surface waters designated for the Water Framework Directive, this standard is not exceeded. Nevertheless, nitrate, other nitrogen substances and phosphate has a negative impact in the majority of surface waters. It turns out that the nitrate standard, that is implemented to protect drinking water resources, is not sufficient to avert this impact. The nitrogen and phosphorus concentrations in summer, that have a large impact on flora and fauna in surface waters (ecological water quality), have decreased since the beginning of the 1990s.
    • Landbouwpraktijk en waterkwaliteit op landbouwbedrijven aangemeld voor derogatie in 2012 : Resultaten meetjaar 2012 in het derogatiemeetnet

      Hooijboer AEJ; de Koeijer TJ; van den Ham A; Boumans LJM; Prins H; Daatselaar CHG; Buis E; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMLEI Wageningen UR, 2014-07-08)
      The Nitrates Directive obliges Member States to limit the use of animal manure to 170 kg of nitrogen per hectare. Farms in the Netherlands with at least 70 per cent grassland were under certain conditions allowed to deviate from of this standard in 2012 and use 250 kg per hectare (derogation). The Netherlands are required to measure the agricultural practice and water quality on 300 farms that use derogation and to report these results annually to the EU. The outcome of this study of farms that are registered for derogation in 2012, which is composed by RIVM and LEI Wageningen UR, is that the average nitrate concentration in groundwater on these farms decreased between 2007 and 2013. Agricultural practice This report also shows that the use of nitrogen from animal manure on the derogation farms is on the average circa 11 kilograms less than the maximum allowable 250 kg nitrogen per hectare in 2012. The amount of nitrogen that can potentially leach into groundwater as nitrate is partly determined by the nitrogen soil surplus. This is the difference between nitrogen input (such as fertilizers) and output (including through milk). On the average, nitrogen soil surplus has not changed substantially between 2006 and 2012. Groundwater quality In 2012, the nitrate concentration in groundwater on derogation farms in the Sand region, with on average 36 milligrams per liter (mg/l), was lower than the nitrate standard of 50 mg/l. Farms in the Clay- and Peat region on average have a lower nitrate concentration (10 and 4 mg/l). The derogation farms in the Loess region, with an average of 55 mg/l, are above the standard. The difference between the regions is mainly caused by a higher percentage of soils prone to nitrogen leaching in the Sand and Loess region. On these soils less denitrification occurs and therefore more nitrate may leach into the groundwater.
    • Landbouwpraktijk en waterkwaliteit op landbouwbedrijven aangemeld voor derogatie in 2013 : Agricultural practices and water quality at grassland farms registered for derogation in 2013

      Lukacs S; de Koeijer TJ; Prins H; Vrijhoef A; Boumans LJM; Daatselaar CHG; Hooijboer AEJ; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2015-07-16)
      Pursuant to the EU Nitrates Directive, the member states are required to limit the use of livestock manure to a maximum of 170 kg of nitrogen per hectare per year. Dutch farms growing grass on at least 70 per cent of their total agricultural area were allowed to deviate from this requirement under certain conditions, and apply up to 250 kg of nitrogen per hectare in the form of livestock manure (this partial exemption is referred to as 'derogation'). The Netherlands are required to monitor agricultural practices and water quality at 300 farms which have been granted derogation, and to submit an annual report of the results to the EU. LEI Wageningen UR and RIVM will compile this annual report. This study examines farms that registered for derogation in 2013 and shows trends between 2006 and 2014. The report concludes that the average nitrate concentration in groundwater on these farms has stabilized or decreased in this period. Agricultural practice This report also shows that, in 2013, derogation farms used on average approximately 4 kg less nitrogen per hectare in the form of livestock manure than the permitted maximum of 250 kg nitrogen per hectare. The quantity of nitrogen that can potentially leach into groundwater as nitrate is partly determined by the nitrogen soil surplus. This surplus is defined as the difference between nitrogen input (e.g. in the form of fertilizers) and output (e.g. via milk). On average, the nitrogen soil surplus has not changed substantially during the period studied. Groundwater quality In 2013, the average nitrate concentration in groundwater on derogation farms in the Sand Region amounted to 37 milligrams per liter (mg/l) and was therefore below the standard of 50 mg/l. On average, farms in the Clay and Peat Regions had even lower nitrate concentrations (11 and 6 mg/l, respectively). Farms in the Loess Region, showing an average nitrate concentration in groundwater of 56 mg/l, however, exceeded the standard. The difference between the regions is mainly caused by a greater share of soils prone to nitrogen leaching in the Sand and Loess Regions. Less denitrification occurs on these soils, and more nitrate can therefore leach into the groundwater
    • Landbouwpraktijk en waterkwaliteit op landbouwbedrijven aangemeld voor derogatie in 2014

      Lukacs S; de Koeijer TJ; Prins H; Vrijhoef A; Boumans LJM; Daatselaar CHG; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMLEI Wageningen UR, 2016-07-05)
      Dutch agriculture is highly productive and efficient. The use of minerals is necessary for efficient production of crops, but also has undesirable (environmental) effects. The Dutch minerals policy seeks to minimise adverse environmental impacts, whereby monitoring is an essential component. This consists with international agreements on the use of minerals and monitoring the impact of policies. Conform the EU Nitrates Directive, the member states are required to limit the use of livestock manure to a maximum of 170 kg of nitrogen per hectare per year. Dutch farms growing grass on at least 80 per cent of their total agricultural area were in 2014 allowed to deviate from this requirement under certain conditions. This exemption from the standard of 170 kg nitrogen is referred to as 'derogation'. LEI Wageningen UR and RIVM monitor agricultural practices and water quality at 300 farms, which have been granted derogation and annually report the results to the EU. This study shows the results in 2014 and trends between 2006 and 2015. The report concludes that the average nitrate concentration in groundwater on these farms has stabilized or decreased in this period. Agricultural practice This report also shows that in 2014 derogation farms used on average 237 kilogram nitrogen in the form of livestock manure per hectare per year. The quantity of nitrogen that can potentially leach into groundwater as nitrate is partly determined by the nitrogen soil surplus. This surplus is defined as the difference between nitrogen input (e.g. in the form of fertilizers) and output (e.g. via harvested grass). On average, the nitrogen soil surplus has not changed substantially since the start of the monitoring in 2006, but in 2014 it decreased considerably due to the good growth season. Groundwater quality In 2014, the average nitrate concentration in groundwater on derogation farms in the Sand Region amounted to 40 milligrams per liter (mg/l) and was therefore below the standard of 50 mg/l. On average, farms in the Clay and Peat Regions had lower nitrate concentrations (15 and 9,5 mg/l, respectively). Farms in the Loess Region showed an average nitrate concentration in groundwater of 51 mg/l. The difference between the regions is mainly caused by a greater share of soils prone to nitrogen leaching in the Sand and Loess Regions. Less denitrification (microbial decomposition of nitrate) occurs on these soils, and more nitrate can therefore leach into the groundwater.
    • Landbouwpraktijk en waterkwaliteit op landbouwbedrijven aangemeld voor derogatie. : Resultaten meetjaar 2011 in het derogatiemeetnet

      Hooijboer AEJ; van den Ham A; Boumans LJM; Daatselaar CHG; Doornewaard GJ; Buis E; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMLEI Wageningen UR, 2013-09-26)
      The Nitrates Directive obliges Member States to limit the use of animal manure to 170 kg of nitrogen per hectare. Farms in the Netherlands with at least 70 per cent grassland may under certain conditions deviate from of this standard and use 250 kg per hectare (derogation). The Netherlands are required to measure the agricultural practice and water quality on 300 farms that use derogation and to report these results annually to the EU. The outcome of this study is that the average nitrate concentration in groundwater on these farms decreased between 2007 and 2012. The report is composed by RIVM and LEI Wageningen UR and commissioned by the Ministry of Economic Affairs. Agricultural practices The report also shows that the use of nitrogen from animal manure on the derogation farms is on the average a few kilograms less than 250 kg nitrogen per hectare in 2011. The amount of nitrogen that can potentially leach into groundwater as nitrate is partly determined by the nitrogen soil surplus. This is the difference between nitrogen input (such as fertilizers) and output (including through milk). On average, nitrogen soil surplus decreased significantly throughout the country between 2006 and 2011. Groundwater quality In 2011, the nitrate concentration in groundwater on derogation farms in the Sand region, with on average 41 milligrams per liter (mg/l), was lower than the nitrate standard of 50 mg/l. Farms in the Clay- and Peat region on average have a lower nitrate concentration (14 and 7 mg/l). The derogation farms in the Loess region, with an average of 55 mg/l, are above the standard. The difference between the regions is mainly caused by a higher percentage of soils prone to nitrogen leaching in the Sand and Loess region. On these soils less denitrification occurs and therefore more nitrate may leach into the groundwater.
    • Leaching of inorganic contaminants towards groundwater : Impact assessment of the Dutch Soil Quality Decree on groundwater

      Spijker J; Groenenberg BJ; Comans R; Dijkstra JJ; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMAlterraUniversiteit WageningenECN, 2014-03-27)
      Since the industrial revolution, Dutch soils have gradually been diffusely contaminated by human activities like industry, agriculture and road traffic. Nevertheless, most soils comply with the threshold levels of the Dutch Soil Quality Decree. However, in the long term (several hundreds of years) underneath (diffusely) contaminated soils the increasing concentrations of heavy metals in groundwater may become a risk. These substances can leach from the upper soil and gradually contaminate the groundwater. The National Institute for Public Health and the Environment recommends that for sustainable groundwater management these long-term effects are taken into account. Special attention is needed for the concentrations of cadmium, nickel and zinc. It is unrealistic to undo the impact of human activities on soils. However, it is important for spatial planning to reckon with the effects of soil contamination on groundwater - for example, when diffusely contaminated soils are being reused. For sustainable groundwater management the groundwater function (ecosystemservice) should not deteriorate as a result of these effects - for example, when groundwater is used for drinking water production or when groundwater feeds a sensitive surface water ecosystem. At locations with residential or industrial activities, higher metal soil concentrations are allowed in accordance with use. For the model calculations the worst case scenarios from the Dutch Soil Quality Decree are simulated. In these scenarios soils have the maximum concentrations allowed (the so-called Maximum Values). The National Institute for Public Health and the Environment recommends refining the model scenarios to gain insight into the specific situations in which these increased concentrations in groundwater can occur. It is also recommended that the model be improved so that it can be used to address general questions concerning the relationship between heavy metal impact on soils and groundwater quality - for example, in the case of sustainable spatial planning and the re-use of contaminated soils and waste products.
    • A method to rank the relative environmental hazard of coolants leaking directly into groundwater

      van Beelen P; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2013-03-29)
      Some coolants are hazardous when leaking into groundwater This report ranks the relative environmental hazards of coolants from Borehole Thermal Energy Storage (BTES) systems, if these liquids were to leak into groundwater. Some coolants contain persistent and toxic chemicals which can pollute groundwater for many decades. The use of coolants with unknown, probably hazardous, constituents can form a risk for groundwater quality. Most coolants contain unknown chemicals Only a few producers were willing to inform the RIVM about the constituents of their coolants. The relative environmental hazard of coolants can be calculated from the maximum allowable concentration in the groundwater and their concentration in the coolants. 1 liter of coolant can pollute several cubic meters of groundwater, depending on the composition of the coolant. Environmentally friendly coolants can only pollute a few cubic meters groundwater per liter leaked coolant and will be degraded in the long run. Only a few environmentally friendly coolants are already identified Tap water, a potassium carbonate solution or monopropylene glycol can be suitable coolants and are tested as the top three coolants in a ranking of environmental effects. In peat areas the anaerobic and acid conditions in groundwater will strongly inhibit biodegradation of organic substances like monopropylene glycol. Potassium carbonate is therefore a better choice for peat areas. There are huge differences in the environmental hazards of coolants. More environmentally friendly coolants will probably be identified when sufficient information from the producers will become available.
    • Onderzoek naar vervangend rekenmodel om weersinvloeden op nitraatconcentraties te berekenen : Vergelijking van de modellen ONZAT, HYDRUS-1D en SWAP

      Janssen GMCM; Fraters B; Boumans LJM; Vrijhoef A; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMDeltares, 2013-12-18)
      The Minerals Policy Monitoring Programme (LMM) has measured the nitrate concentrations in the upper groundwater since 1992 in order to show the effects of the national minerals policies on concentrations. However, these nitrate concentrations are also subject to weather influences, especially the precipitation excess in previous years. After a couple of years with high precipitation excess the measured nitrate concentration usually is lower than normal due to dilution. RIVM accounts for these weather influences on measurement so that policy effects on trends in water quality become more distinct. This is done by using a hydrological process model. SWAP model more suitable for index concentration RIVM still uses the ONZAT model, developed by RIVM, for the calculations of the index concentration. However, ONZAT, a model to calculate transport of substances through the soil towards and through groundwater, is no longer updated or maintained. Therefore, RIVM considered it desirable to select and use another, more generally applied process model for the computation of index concentrations. The model comparisons showed that SWAP (Soil, Water, Atmosphere and Plant) was the most suitable successor for ONZAT to calculate index concentrations. The migration of the ONZAT model to SWAP does not have a significant effect on the weather corrections of the nitrate measurements, notwithstanding the differences between these models.
    • Scenarios for exposure of aquatic organisms to plant protection products in the Netherlands : Soilless cultivations in greenhouses

      van der Linden AMA; van Os EA; Wipfler EL; Cornelese AA; Ludeking DJW; Vermeulen T; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2016-09-30)
      New methodologies for the assessment of the exposure of aquatic organisms to plant protection products (PPP) after their use in substrate cultivations in greenhouses were developed. The relevant protection goal is the aquatic ecosystem. In contrast with the current methodology, which was not specifically developed for substrate cultivations, the new methodology accounts for two major potential emission routes: the discharge of recirculation water and the discharge of filter cleaning water into surface water. The Dutch Ministry of Economic Affairs and the Ministry of Infrastructure and the Environment initiated this research to develop an exposure assessment methodology suitable for substrate cultivations in greenhouses. The new methodology assigns substrate cultivations to four different crop groups according to their water requirement and sodium tolerance. For each of the groups an assessment scenario was developed, taking into account nutrient emission limits. A representative discharge-receiving ditch was selected and parameterised. For each scenario and PPP application method, the Greenhouse Emission Model calculates water flows and PPP behaviour in the growing system, emissions of water and PPP to surface water and the fate of the PPP in the surface water. The resulting concentrations in surface water can be used to decide on the authorisation of PPPs.
    • Scouting Vollegrondsgroenten op zand (2007-2010), een verkennend onderzoek

      Hooijboer AEJ; van der Meer RW; Fraters B; van Leeuwen TC; IBW; M&V (Rijksinstituut voor Volksgezondheid en Milieu RIVMLEI Wageningen UR, 2014-04-03)
      The exploratory research Scouting Open field vegetables on sandy soils (SVs) confirms the existing image that nitrate concentrations in groundwater at open field vegetable farms on sandy soil are higher than the standard. This study was conducted by the RIVM and LEI Wageningen UR, commissioned by the Ministry of Infrastructure and Environment and the Ministry of Economic Affairs. Given the small scale of the study these findings apply only to the surveyed SVscompanies and they cannot be translated to the entire field vegetables sector on sandy soil. In the Minerals Policy Monitoring Programme, no vegetable production companies are incorporated because of the limited proportion (about 1%) in the total agricultural area in the Netherlands. Therefore these open field vegetable farms are relatively unexplored in terms of fertilizer use and nitrate leaching. In the past, however, high nitrate concentrations were measured in the upper groundwater of these types of farms. This study was performed to create a current view on the nitrate problem of field vegetables on sand. The study includes twelve farms that grow asparagus, strawberries, leeks or leafy vegetables (such as lettuce), mainly located in the sandy areas of Limburg and North Brabant (Sand South). All farms have high (more than 80 milligrams per liter) nitrate concentrations in their upper groundwater. The high nitrate concentration is partly explained by the dry sandy soil in which the plants are grown. In this type of soil very little nitrate is reduced and a relatively large part leaches to groundwater. The type of farm may affect the nitrate concentration in groundwater as well. Arable farms located in the same region on comparable soils, use about the same amount of manure and fertilizer but have much lower nitrate concentrations. This difference can be explained by the inefficient use of nutrients by the vegetables. In comparison with arable farms, a larger portion of the fertilizer is not used by the plant and remains in the soil. The soil nitrogen surplus (the difference between input and output of nitrogen in the soil) is therefore on open field vegetable farms two times higher than on arable farms. This surplus can leach into groundwater as nitrate.