This report discusses the reliability of environmental indicators obtained from calculations, used by RIVM in the composition of reports on the state of the environment. The considered calculation chain (for the Netherlands) starts at the emission of nitrogen compounds in 1992 and ends with forecasts of the nitrate concentration in untreated water in 2100. To this end the notion of reliability is specified in terms of a reliability factor and a confidence interval. The structure of the chain is depicted with flow diagrams. It is composed of measurement data, registration data, model operations and GIS operations. The primary data with respect to the nitrogen load are obtained from sources outside RIVM. They are based on registrated data, for example agricultural surveys. For the nitrogen emissions a reliability was postulated. The applied RIVM models are respectively OPS (atmospheric transport), DEADM (atmospheric deposition), NLOAD (nitrate leaching from agricultural soils), BOSMODEL (nitrate leaching from forest soils and heathland) and FLOPZ1 (groundwater streamlines and residence times). The measurement data are obtained from the National Monitoring Networks for Air Quality (LML, wind velocities and NOy concentrations) and Groundwater Quality (LMG, nitrate concentration in deep groundwater). Applying uncertainty analyses on models and using statistical techniques, uncertainties in the various indicators are determined, where uncertainties are propagated through the chain. The reliability of the indicators, as reported for 1992, is calculated on the basis of the resulting uncertainties. Most of the calculations are performed on three different scales, 5 x 5 km blocks, Acidification Areas (20 areas in the Netherlands) and on national scale. The reliability of nitrate concentration in untreated water is assessed for two different drinking water stations. Results of the project are presented in the form of tables and graphics, such as histograms and geographical plots of indicators and reliability factors. Table 7.1 on page 73 summarizes the reliability of the investigated indicators. A subsequent goal of this report is to contribute to a (discussion about a) generally applicable method to determine the reliability in the calculation of environmental indicators.

The United Nations Framework Convention on Climate Change (UNFCCC) was ratified by the Netherlands in December 1993. One of the obligations is to provide a National Communication on greenhouse gas emissions, projections and programmes to reduce these emissions. This background report was written at the request of the Dutch Ministry of Housing, Physical Planning and Environment as a background report for the first Dutch National Communication for the Framework Convention on Climate Change. It documents the methodologies, both for estimating greenhouse gas emissions and sinks, and for projections. For the most important greenhouse gases, it gives estimates for 1980, 1985, 1990, 1991 and 1992, and projections of possible future emissions in 2000 and 2010 under two scenarios. The short-term aim of the Convention is stabilization of emissions between 1990 and 2000. Therefore 1990 was chosen as the base year for emission estimation and 2000 as the base year for evaluation. Emissions were estimated using internationally agreed IPCC methodology as well as methodology used in the Netherlands. The differences between the methods are explicitly explained. Carbon dioxide emissions were estimated with and without a temperature correction. The original Dutch policy method estimates emissions including feedstock use. For methane and nitrous oxide emissions, Dutch emission factors were applied instead of IPCC defaults. As more sources were found for nitrous oxide in the Netherlands, the Dutch emission was higher than when strictly applying IPCC methodology.

Within the framework of the Terms of Reference Plan for normalization commission 390011 on materials', the RIVM has developed a set of leaching tests for various organic compounds. In this study the emission of Polycyclic Aromatic Hydrocarbons (PAH) of several materials were determined using the draft column and serial batch test for PAH. On the basis of follow-up studies PAH adsorption was seen to occur on the equipment used for the leaching tests and furthermore this adsorption was shown to be minimalized through several adaptations. When compared with the adapted test method, this method results in lower PAH emissions. Column and serial batch tests were carried out using the following materials: three kinds of soil containing different PAH concentrations, demolition waste, concrete waste, sieve sand, two asphalt samples containing different tar concentrations, municipal incinerator bottom ash, blasting sand, fly-ash (industrial) and dredging sludge. The emissions from the total of 10 PAH from these materials were usually between about 1 and 15 mug/kg. Only the emissions from the heavily contaminated soil and the asphalt with tar emission were higher (165 and 17540 mug/kg respectively). The low molecular PAH are most soluble in water, because of this these PAH emissions were higher than those of the high molecular PAH. The mean PAH concentration in the column test was indicatively compared with limits for water ; from this it appeared that some PAH concentrations in the eluate of the asphalt with tar and of the heavily contaminated soil were higher than the (former) B-value for groundwater. A lower pH and reduction of the particle size to smaller than 125 mum had little influence on the PAH emissions, therefore it was concluded that the current inorganic components for leaching' was not useful in determining the driving force behind PAH leaching. In this study PAH emissions from several materials were determined. For standard-setting research is still needed into the leaching mechanism of PAH and the relation between laboratory experiments and practice.

PROMISE is an acronym for PROgnosis Model of Inputs to Surface water and Emission reductions. It is a co-operation project of RIZA and RIVM and is operational for toxic priority pollutants, like heavy metals and polycycli aromatic hydrocarbons. PROMISE will be used to evaluate Dutch environmental policy (especially in scenario studies like the Water System Analyses and the National Environmental Outlook). Special attention has been paid to the relations of PROMISE with other models like water quality models, soil run-off models and air pollution distribution models. With PROMISE the user generates long-term scenario's of the surface water load. Point and diffuse sources, reduction measures and all important routes to the surface water are taken into account. It shows if and in what year a policy target can be reached. To be able to make a connection between RIM+/PROMISE and Dutch water quality models for the input to surface water the so called PAWN schematisation is used. This schematisation divides the Netherlands in districts (small surface waters) and junctions (main rivers and lakes). RIZA and RIVM have agreed to maintain and update PROMISE together. RIZA is primarily responsible for the data that are related to water emissions and the discharge situation of processes. RIVM is responsible for data related to air emissions and scenarios. By using one model with one central database RIZA and RIVM have taken an important step towards consistent and coherent prognoses of emissions and surface water loadings.

This analysis was based on a review of published measurements of nitrous oxide (N2O) emission from fertilized fields. From the literature data selections were made to analyze the importance of factors that regulate N2O production, including soil conditions, type of crop, nitrogen (N) fertilizer type and soil and crop management. Reported N2O losses from anhydrous ammonia and organic forms of N fertilizers or combinations of organic and synthetic N fertilizers are higher than those for other types of N fertilizer. However, the management and environmental conditions represented by the set of measurement data is too limited to be used for estimating emission factors for each fertilizer type individually. The literature data are appropriate for estimating the order of magnitude of emissions. The fertilizer-induced N2O emission is higher for measurements covering longer periods than for measurements which represent short periods. Therefore, a simple method to estimate the total annual direct N2O emission from fertilized fields was based on those measurements covering periods of one year, resulting in the following equation: N2O emission (kg N ha-1.yr-1) = 1 + 1.25 +/- 1% of the N application (kg N ha-1.yr-1). The relation is independent of the type of fertilizer. Although the above regression equation includes considerable uncertainty , it may be appropriate for global analyses.

Within the framework of the study to dredging and processing technics for sanitation of polluted water bottoms, the leachability of organic compounds and metals has been investigated from sludge. The CEN-test, somewhat altered, was carried out in a laboratory for the determination of the leachability. First the results are used to work out the alteration of leaching behaviour as a result from dredging and second as a result from processing the sludge.

The current investigation represented an initial survey on the presence of organic contaminants in Bio-waste compost (garden, fruit and vegetable wast). This report provides an indicative comparison between the pollution levels in compost and the target value for soil (H=20%). Partly based on this research, however, standards for organic contaminants will be developed. It was found that all compost samples contained organic contaminants. The PAH levels in the compost samples were shown to be relatively high when compared to the target value for soil. It was found that for most PAH no relation between the levels in the compost and the compost production plant existed. The amount of HCB and phthalates was also found to be higher than the target values. In some samples, the content of chlorinated phenols, PCB, endrin and/or mineral oil turned out to be higher than the target value. All compost samples were shown to contain amounts of dioxins far below the provisional value for soil in urban areas. With reference to the results of this investigation it is recommended to set up extensive research into organic contaminants in compost to get a representative picture of the contaminant levels in compost.

This model study assessed the environmental effects of several technical measures for the reduction of energy and water use and the use of materials in existing and new dwellings, projected over the 1995-2020 period. The model assesses the effects by a physical causal represention of the dwellings. The measurements taken alter the energy, water and materials efficiency in the dwellings, leading to a reduction in the use of each of the three resources. Taking place under the policy of sustainable building the above measures are instrumented by regulation (energy efficiency in newly built dwellings), information transfer and covenants with the public and private partners in the decisionmaking chain of the building industry. Each of the measures has been equiped with an penetration scenario for the autonomous developement and the stimulus for this given by the sustainable building policy. The set of relevant policy instruments imposed by the sustainable building policy will be either certainly or probably employed up to 2005. The instruments are assumed to persist after this period, thus leading to a continued penetration of the measures.

This report describes: 1. The mathematical, statistical argumentation of the testing of batches for the enforcement check, 2. an estimation of the total variance of the batch as a result of the specific variance of the batch (heterogeneousness) and the measurement error, 3. Calculation of the rejection value, 4. The effect of the choices on the acceptance chance and on the height of the rejection value, 5. The effect of the testing method on: - the protection of the soil - the re-usability of construction materials - the costs of the testing 6. Proposal for a testing procedure.

This report was written at the request of the Dutch Ministry of Housing, Physical Planning and Environment to comply with the European Unions Greenhouse Gas Monitoring Mechanism (Council Decision 93/389/EEC). The member states of the European Community have adopted the objective of stabilising CO2 emissions in the Community as a whole by 2000 at 1990 levels. The monitoring mechanism provides a means whereby the Commission can monitor progress towards this target on the basis of annual emission inventories supplied by the member states and national programmes which set out emission trajectories and policy measures to limit CO2 or to increase sinks. It also requires member states to report inventories of other greenhouse gases. Under the monitoring mechanism each member state reports its greenhouse gas emissions by the 31st of July each year. By each reporting deadline member states should supply inventories based on provisional data for the previous year and final data for the year previous to that. The first submission of provisional inventories in 1995 should also include data for the base year 1990. A review will be carried out under the responsibility of the European Commission. This report is also written to comply with the obligations under the United Nations Framework Convention on Climate Change. The inventory is compatible with the reporting requirements under the United Nations Framework Convention on Climate Change. It contains a greenhouse gas emissions inventory for the years 1993 and 1994, together with a short description of how the internationally adopted IPCC Guidelines have been applied in the Netherlands. Temperature corrected carbon dioxide emissions in 1993 and emissions of methane and nitrous oxide were slightly higher than 1990. A dip in the economic development especially in the chemical industry sector prevented a further growth in emissions. Provisional data for 1994 suggest a significant increase in carbon dioxide emissions due to the prosperous economic developments. Energy efficiency improvements prevented an even further growth in emissions.