Water governance diversity across Europe: Does legacy generate sticking points in implementing multi-level governance?

The Water Framework Directive (WFD) aims to protect and improve water quality across Europe through an integrative and multi-level water governance approach. The goal is to ensure that water quality in Europe meets good ecological status by 2027. Whilst the WFD has been hailed as a cornerstone for governance innovation in water management, most EU member states (MS) still struggle to achieve good ecological status of their waters. The realignment to a multi-level governance structure under the WFD is discretionary, and has generated diversity in WFD multi-level governance implementation approaches and final governance arrangements across MS. This diversity may contribute to low goal achievement and weak compliance. This paper investigates how visual impressions of legislative structure across nine MS can illustrate and contribute to understanding the differences in multi-level implementation of WFD and associated water protection directives. We explore, in-depth, the drivers of visual differences in Portugal, Germany (Lower Saxony) and France. We hypothesise that many of the challenges of WFD implementation, and resulting governance arrangements can be explained in terms of the legacy effects of previous water governance choices. With this conceptual framework of investigating the history and legacy, we found the three in depth studies have had different starting points, paths, and end points in their water governance, with sticking points influencing the decision-making processes and compliance required by the WFD. Sticking points include the complexity of existing water governance structures, lobbying by different sectors, and the mandatory WFD timeline for implementation. Portugal had to resolve its focus on water infrastructure and engineering to enable a re-focus on water quality. France and Portugal experienced 'top down' governance at different points in time, slowing the shift to a multi-level governance system. Lower Saxony, representing just one of 16 federal state systems in Germany, highlighted the complex historic governance structures which cannot easily be restructured, generating a layering effect where new governance systems are fitted to old governance systems. We conclude that there is a need to implement a hybrid approach to water governance and WFD implementation including decentralisation (discretionary) to ensure collaboration and engagement of stakeholders at the local level. This hybrid governance system should run in parallel with a centralised (mandatory) governance and regulatory system to enable national environmental standards to be set and enforced. Such systems may provide the best of both worlds (bottom-up involvement of stakeholders meeting top-down goal achievements) and is worthy of further research.

Restoring groundwater quality at the drinking water catchment scale: A multidisciplinary and participatory approach.

Preserving or restoring the quality of groundwater resources with regard to nitrate is a major challenge. To date, useful and easily applicable tools to identify the best measures to implement at local scale are lacking. An innovative methodology is proposed to identify cost-effective restoration measures at the drinking water catchment scale. The methodology is based on the articulation of two tools: a model simulating nitrate groundwater contamination time series and an economic evaluation, within a participatory approach. It was applied to a representative drinking water catchment in Northwest France that has been affected by nitrate contamination for decades. Five scenarios of measures (changes in fertilization and intercropping practices, or in cropping patterns) were co-constructed with stakeholders, evaluated in terms of cost and impact on groundwater nitrate concentration, and discussed with stakeholders. Overall, two scenarios stand out. Introducing hemp in crop rotations is the only scenario generating an economic benefit, but for a very low impact on nitrate concentration (decrease of 4 mg/l by 2050 for 10% of hemp in crop rotations). Introducing alfalfa in crop rotations is the most effective measure to decrease nitrate concentration (decrease of 23 mg/l by 2050 for 20% of alfalfa in crop rotations), and for a moderate cost compared to the other scenarios (25-51 €/ha/year). Results show that substantial changes in cropping patterns - more important than those imagined initially by stakeholders (e.g. converting 40% of cropland to alfalfa) are needed to restore groundwater quality targets in the medium-long term. Measures deemed promising and achievable by the stakeholders proved to be insufficiently effective. The approach developed has been shown to provide valued and trusted information to stakeholders and to objectify debates. Stakeholders have shown interest in the evaluation of costs and further socio-economic information, in addition to the evaluation of the effectiveness of measures on groundwater quality, validating the multidisciplinary dimension of the approach. The approach has the advantage of being easy to implement, and is therefore applicable to other study sites where needed.

Pesticides in groundwater at a national scale (France): Impact of regulations, molecular properties, uses, hydrogeology and climatic conditions.

Contaminants in groundwater are a major issue worldwide. Temporal trends of such occurrences in French groundwaters were evaluated for several active substances of pesticides belonging to different chemical classes, to identify key factors explaining groundwater contamination. Our study relied on exploitation of a French national database (ADES, created in the mid-1990s and remarkable for the available data, including over 88 million analyses). Temporal changes in the frequency of exceeding a reference value of 0.1 µg/L for several substances were determined at yearly and monthly scales. Such trends were examined by distinguishing different periods according to changes in regulations (new approval, withdrawal, or dose reduction), and were combined with data on effective rainfall as a proxy for groundwater recharge, on aquifer lithology, and on sales of active substances as a proxy for actual applications. A review of monthly data shows that a rapid transfer of pesticides with contrasting physico-chemical properties can occur after application in many aquifers, regardless of their lithology. For substances such as metolachlor, showing a sharp increase in sales, a clear relationship exists between quantities sold and frequency of exceeding the reference value. For other active substances, such as isoproturon or chlortoluron, frequencies of exceedance are governed by both sales and effective rainfall. Finally, the occurrence of active substances in groundwater several years after their withdrawal from the market is explained by at least three major mechanisms: the transfer time from soil into groundwater, processes of remobilization from soil and/or unsaturated zone, and no or low degradation in the saturated zone. While these processes are well documented for atrazine and different types of aquifers, they can be virtually unknown for other active substances.

Multi-bioindicators to assess soil microbial activity in the context of an artificial groundwater recharge with treated wastewater: a large-scale pilot experiment.

In the context of artificial groundwater recharge, a reactive soil column at pilot-scale (4.5 m depth and 3 m in diameter) fed by treated wastewater was designed to evaluate soil filtration ability. Here, as a part of this project, the impact of treated wastewater filtration on soil bacterial communities and the soil's biological ability for wastewater treatment as well as the relevance of the use of multi-bioindicators were studied as a function of depth and time. Biomass; bacterial 16S rRNA gene diversity fingerprints; potential nitrifying, denitrifying, and sulfate-reducing activities; and functional gene (amo, nir, nar, and dsr) detection were analyzed to highlight the real and potential microbial activity and diversity within the soil column. These bioindicators show that topsoil (0 to 20 cm depth) was the more active and the more impacted by treated wastewater filtration. Nitrification was the main activity in the pilot. No sulfate-reducing activity or dsr genes were detected during the first 6 months of wastewater application. Denitrification was also absent, but genes of denitrifying bacteria were detected, suggesting that the denitrifying process may occur rapidly if adequate chemical conditions are favored within the soil column. Results also underline that a dry period (20 days without any wastewater supply) significantly impacted soil bacterial diversity, leading to a decrease of enzyme activities and biomass. Finally, our work shows that treated wastewater filtration leads to a modification of the bacterial genetic and functional structures in topsoil.

Comparison of methods for the detection and extrapolation of trends in groundwater quality.

Land use changes and the intensification of agriculture since the 1950s have resulted in a deterioration of groundwater quality in many European countries. For the protection of groundwater quality, it is necessary to (1) assess the current groundwater quality status, (2) detect changes or trends in groundwater quality, (3) assess the threat of deterioration and (4) predict future changes in groundwater quality. A variety of approaches and tools can be used to detect and extrapolate trends in groundwater quality, ranging from simple linear statistics to distributed 3D groundwater contaminant transport models. In this paper we report on a comparison of four methods for the detection and extrapolation of trends in groundwater quality: (1) statistical methods, (2) groundwater dating, (3) transfer functions, and (4) deterministic modeling. Our work shows that the selection of the method should firstly be made on the basis of the specific goals of the study (only trend detection or also extrapolation), the system under study, and the available resources. For trend detection in groundwater quality in relation to diffuse agricultural contamination, a very important aspect is whether the nature of the monitoring network and groundwater body allows the collection of samples with a distinct age or produces samples with a mixture of young and old groundwater. We conclude that there is no single optimal method to detect trends in groundwater quality across widely differing catchments.

A refined lack-of-fit statistic to calibrate pesticide fate models for responsive systems.

BACKGROUND: Calibration by inverse modelling was performed with the MACRO transport and fate model using long-term (>10 years) drainflow and isoproturon (IPU) data from western France. Two lack-of-fit (LOF) indices were used to control the inverse modelling: sum of squares (SS) and an alternative statistic called the vertical-horizontal distance integrator (VHDI), which is designed to account for offsets in observed and predicted arrival times of peak IPU concentration. With these data, SS was artificially inflated because it is limited to comparison of predicted and observed IPU concentrations that are concurrent in time. The LOFs were used along with the index of agreement (d) and the correlation coefficient (r) to ascertain the fit of the calibrated models. RESULTS: Predicted arrival times of peak IPU concentration differed somewhat from observed times. All four indices indicated better model fit for the second of two validation periods when inverse modelling was controlled by VHDI rather than SS (SS = 26.4, d = 0.660, r = 0.606 and VHDI = 1.25). The VHDI statistic was markedly lower compared with the uncalibrated model (38.0) and SS calibration results (24.5). The final maximum predicted IPU concentration (44.5 microg L(-1)) for the calibration period was very similar to the observed value (44 microg L(-1)). CONCLUSION: VHDI is seen as an effective alternative to SS for calibration and validation of pesticide fate models applied to responsive systems. VHDI provided a more realistic assessment of model performance for the transient flows and short-lived concentrations observed here, and also effectively substituted for the objective function in inverse modelling.

Identification of key climatic factors regulating the transport of pesticides in leaching and to tile drains.

BACKGROUND: Key climatic factors influencing the transport of pesticides to drains and to depth were identified. Climatic characteristics such as the timing of rainfall in relation to pesticide application may be more critical than average annual temperature and rainfall. The fate of three pesticides was simulated in nine contrasting soil types for two seasons, five application dates and six synthetic weather data series using the MACRO model, and predicted cumulative pesticide loads were analysed using statistical methods. RESULTS: Classification trees and Pearson correlations indicated that simulated losses in excess of 75th percentile values (0.046 mg m(-2) for leaching, 0.042 mg m(-2) for drainage) generally occurred with large rainfall events following autumn application on clay soils, for both leaching and drainage scenarios. The amount and timing of winter rainfall were important factors, whatever the application period, and these interacted strongly with soil texture and pesticide mobility and persistence. Winter rainfall primarily influenced losses of less mobile and more persistent compounds, while short-term rainfall and temperature controlled leaching of the more mobile pesticides. CONCLUSIONS: Numerous climatic characteristics influenced pesticide loss, including the amount of precipitation as well as the timing of rainfall and extreme events in relation to application date. Information regarding the relative influence of the climatic characteristics evaluated here can support the development of a climatic zonation for European-scale risk assessment for pesticide fate.

Effects of asparagine, fructose, and baking conditions on acrylamide content in yeast-leavened wheat bread.

A repeatable procedure for studying the effects of internal and external factors on acrylamide content in yeast-leavened wheat bread has been developed. The dough contained wheat endosperm flour with a low content of precursors for acrylamide formation (asparagine and reducing sugars), dry yeast, salt, and water. The effects of asparagine and fructose, added to the dough, were studied in an experiment with a full factorial design. More than 99% of the acrylamide was found in the crust. Added asparagine dramatically increased the content of acrylamide in crusts dry matter (from about 80 microg/kg to between 600 and 6000 microg/kg) while added fructose did not influence the content. The effects of temperature and time of baking were studied in another experiment using a circumscribed central composite design. Mainly temperature (above 200 degrees C) but also time increased the acrylamide content in crust dry matter (from below 10 to 1900 microg/kg), and a significant interaction was found between these two factors. When baked at different conditions with the same ingredients, a highly significant relationship (P < 0.001) between color and acrylamide content in crust was found. Added asparagine, however, did not increase color, showing that mainly other amino compounds are involved in the browning reactions.